Jørgen Valeur

• Martinsen, Tilde; Jensen, Caroline; Hatlebakk, Jan Gunnar; Valeur, Jørgen; Nygård, Ottar Kjell & Lied, Gülen Arslan (2026). Gastrointestinal symptoms, faecal short-chain fatty acids and dietary intake in older adults: the Hordaland Health Study 3. European Journal of Nutrition. ISSN 1436-6207. 65(6). doi: 10.1007/s00394-026-04077-6. Full text in Research Archive Show summary

  Purpose: Ageing is associated with a decline in gastrointestinal (GI) functions, but data on GI symptoms in older adults remain limited. This study assessed the prevalence of GI symptoms, irritable bowel syndrome (IBS), and faecal short-chain fatty acids (SCFAs) in older adults, and associations between GI symptoms and faecal SCFAs, dietary intake, and BMI. Methods: 907 older adults (66–69 years, 50.7% females) from the community-based Hordaland Health Study 3 − Microbiota study were included. GI symptoms and IBS status were assessed by validated questionnaires (Gastrointestinal Symptom Rating Scale, Rome IV-criteria, IBS-Severity Scoring System), dietary intake by a 279-item food frequency questionnaire, and the concentration of SCFAs were measured from faecal samples. Results: 33.9% experienced at least one GI symptom, 16.4% reported IBS-like symptoms, and 5.0% had IBS according to Rome IV-criteria. Indigestion was the most common GI symptom (24.2%). Females had a higher total mean score of GI symptoms (p = 0.021), with higher frequencies of constipation (p = 0.006) and abdominal pain (p = 0.031), compared to males. Males had higher concentration of total faecal SCFAs (p = 0.004) and all major SCFAs compared to females. Total faecal SCFAs were negatively associated with constipation, independently of dietary fibre intake, total energy intake, sex and BMI (B =  − 0.006, 95% CI [− 0.009, − 0.004], p < 0.001). We observed a positive correlation between total faecal SCFA concentrations and diarrhoea (r = 0.072, p = 0.039) and looser stool consistency (r = 0.185, p < 0.001); however, these associations did not persist in the regression analyses. All GI symptoms positively correlated with increasing BMI. Conclusion: GI symptoms are common in older adults, and IBS is at least as prevalent as observed in the general adult population. Improving dietary habits and preventing overweight and obesity may reduce the risk of GI symptoms and improve gut health in older adults.

• Villmones, Heidi Cecilie & Valeur, Jørgen (2026). Persistent small intestinal microbial colonisation: a potentially pathological rather than physiological state. Medical Hypotheses. ISSN 0306-9877. 214. doi: 10.1016/j.mehy.2026.112079. Full text in Research Archive
• Hansen, Simen Hyll; Bhattacharjee, Niharika; Hu, Chang; Maseng, Maria Gjerstad; Grannö, Olle & Bang, Corinna [Show all 20 contributors for this article] (2026). Bacterial clusters are associated with the risk of severe disease progression in inflammatory bowel disease irrespective of conventional disease categories. Microbiome Research Reports. 5(1). doi: 10.20517/mrr.2025.96. Full text in Research Archive Show summary

  Background: Inflammatory bowel diseases (IBDs) are complex conditions marked by chronic inflammation in the gastrointestinal tract. Traditional classification separates IBD into Crohn’s disease and ulcerative colitis, but this division may not fully capture disease heterogeneity. Here, we examine whether microbiome-driven subtyping can describe novel clinical IBD phenotypes. To achieve this, we applied unsupervised clustering to fecal microbiota profiles from the population-based Inflammatory Bowel Disease in South-Eastern Norway III (IBSEN III) cohort. Methods: A Gaussian Mixture Model (GMM) was used to cluster participants with IBD based on microbiome composition and examine associations between clusters and clinical outcomes, including inflammatory markers and disease severity during the first year after inclusion. Results: Three microbiome-based clusters were identified: CLO (dominated by Clostridia UCG-014), ALF (Agathobacter, Lachnoclostridium, and Faecalibacterium), and RUM (Ruminococcus gnavus). Participants in the RUM cluster had a higher risk of future severe disease than those in the CLO cluster, even among participants with remission-to-mild disease at inclusion (21% vs. 6%, P < 0.00001). This association could not be explained by antibiotic use or baseline disease severity. Cluster membership alone performed comparably to fecal calprotectin in distinguishing severe disease, and a combined model significantly improved accuracy (P < 0.0001). Conclusion: Our findings demonstrate a connection between microbiome composition and the risk of severe disease development, which is partly independent of inflammation levels at the time of sampling. Microbiome-informed subgrouping could lead to more personalized treatment strategies. Further validation is needed to determine the clinical utility of these clusters.

• Maseng, Maria Gjerstad; Hansen, Simen Hyll; Grännö, Olle; Bang, Corinna; Lund, Charlotte & Huppertz-Hauss, Gert [Show all 22 contributors for this article] (2026). Disentangling the gut microbiome and inflammation in inflammatory bowel diseases: longitudinal observations from the IBSEN III study. Inflammatory Bowel Diseases. ISSN 1078-0998. doi: 10.1093/ibd/izag051. Full text in Research Archive Show summary

  Background and Aim Despite the well-established involvement of the gut microbiome in inflammatory bowel disease (IBD), less is known about how the gut microbiome changes over time and how it varies with clinical disease activity and fecal calprotectin (f-calprotectin). To address this gap, we utilized samples from the population-based inception cohort of the Inflammatory Bowel Disease in South-Eastern Norway III (IBSEN III) study. Methods Data and stool samples from study participants with IBD and symptomatic controls were collected at diagnosis and after 3, 6, and 12 months. Microbiome profiling of stool samples was performed targeting the V3-V4 region of the 16S rRNA gene, and a consensus-based approach of mixed models was employed for the longitudinal microbiome analysis. Results We included 1251 samples from 744 patients with ulcerative colitis, 618 samples from 356 patients with Crohn’ s disease and 266 samples from 164 symptomatic non-IBD controls. In the IBD population, we observed that levels of f-calprotectin decreased over time, as did the patient-reported disease activity (P < .001). Distinct changes in the gut microbiome of IBD patients were observed throughout the first year, such as increased alpha diversity (P < .001) and significant taxonomic changes. Notably, there was no covariation between the changes in alpha diversity and f-calprotectin or symptom score. Conclusion The gut microbiome during the first year after IBD diagnosis showed changes that paralleled inflammation and clinical disease activity, albeit without covariation, suggesting that there may be a disease-driving impact of gut microbiome independent of inflammation and inflammation-driven symptoms.

• Dale, Hanna Fjeldheim; Kolby, Marit & Valeur, Jørgen (2025). Ultra-Processed Food Consumption and Irritable Bowel Syndrome: Current Evidence and Clinical Implications. Nutrients. 17(22), p. 3567–3567. doi: https:/www.mdpi.com/2072-6643/17/22/3567. Full text in Research Archive Show summary

  Irritable bowel syndrome (IBS) is a prevalent disorder of gut–brain interaction (DGBI) with an adverse impact on quality of life. The global consumption of ultra-processed foods (UPF) is rapidly increasing, and UPF intake has recently been linked to a wide range of metabolic and chronic diseases. The potential role of UPF consumption in the onset and symptom generation of IBS is emerging but remains unclear. This narrative review synthesizes epidemiological evidence on the association between UPF consumption and IBS, integrates mechanistic insights from experimental and clinical studies and suggests clinical implications based on the current state of knowledge. Observational studies suggest that higher UPF intake may be associated with increased risk of IBS, although the evidence base is limited and subject to methodological challenges. Mechanistic studies indicate that additives including emulsifiers and non-nutritive sweeteners can alter pathways relevant to IBS symptom generation, such as gut microbiota composition, impair intestinal barrier function and trigger low-grade inflammation. Current evidence supports a possible link between UPF consumption and IBS. Increasing overall dietary quality and reducing UPF intake are promising complementary strategies to established dietary interventions. Future intervention trials may provide insights into relevant biological mechanisms, particularly if such changes co-occur with symptom improvement.

• Seferowicz, Maria; Lerdal, Anners; Edvardsen, Hilde Marie Erøy; Skråstad, Ragnhild Bergene; Valeur, Jørgen & Jørgenrud, Benedicte Marie [Show all 8 contributors for this article] (2025). Unveiling stages of change among medical inpatients with an increased-risk alcohol consumption—a cross-sectional study. Alcohol and Alcoholism. ISSN 0735-0414. 61(1). doi: 10.1093/alcalc/agaf067. Full text in Research Archive Show summary

  Abstract Aims Alcohol-related harm occurs at lower levels than previously recognized, warranting a need to identify mediators to reduce alcohol-associated risk in increased-risk drinkers. Stages of change (SOC) have been used to assess motivation for health behaviour alteration. The primary aim was to explore distribution on SOC among medical inpatients when comparing low-risk, increased-risk, and high-risk consumers as defined by Alcohol Use Disorder Identification Test-Consumption (AUDIT-C). Our secondary aim was to assess the distribution of SOC when consumption was stratified with a biomarker of alcohol use—phospatidylethanol 16:0/18:1. Methods Cross-sectional study with three participating hospitals. Recruiting consecutive medical inpatients ≥18 years with regular alcohol consumption as screened by score ≥2 on the first question in AUDIT-C (N = 888). AUDIT-C score and SOC were assessed by questionnaires, and phospatidylethanol concentration in a blood sample. Odds ratios and the 95% confidence intervals were calculated through a univariate logistic regression analysis for each variable, and multivariable logistic regression models were then fit to calculate the adjusted odds ratio and 95% confidence interval. Results Distributions of SOC differed between the three risk-groups. Distribution of SOC was comparable whether assessed by phospatidylethanol or AUDIT-C. Conclusions Increased-risk consumers constitute the majority of those in action—the only stage associated with consecutive reduction in drinking. Potentially, these results can aid in reducing perceived barriers among health care professionals in screening and offering health advice to those with increased-risk consumption and inform further research on mediators in this subgroup.

• Bekkelund, Mattis; Steinsvik, Elisabeth Kjelsvik; Valeur, Jørgen; Søfteland, Eirik; Dimcevski, Georg & Sangnes, Dag André (2025). Key variables associated with gastroparesis in diabetes patients with gastroparesis-like symptoms. Scandinavian Journal of Gastroenterology. ISSN 0036-5521. 60(9), p. 865–873. doi: 10.1080/00365521.2025.2531038. Full text in Research Archive Show summary

  Background/aims Gastroparesis is a late complication of diabetes mellitus characterized by delayed gastric emptying and upper gastrointestinal symptoms. The disorder substantially impacts the quality of life, glycemic stability, nutrition and absorption of orally administered drugs. Since symptom severity is a poor predictor of gastric emptying status, the clinician has little to aid them in whom to refer for gastric emptying testing. In this study, we aim to identify clinical characteristics associated with delayed gastric emptying in diabetes patients with gastroparesis-like symptoms. Materials and methods Diabetes patients consecutively referred to Haukeland University Hospital for assessment of gastroparesis-like symptoms underwent gastric emptying scintigraphy, blood samples and questionnaires for assessing gastrointestinal symptoms (Gastrointestinal Symptom Rating Scale), neuroticism (Eysenck Personality Questionnaire-Short Form), and symptoms of anxiety and depression (Hospital Anxiety & Depression Scale). Results: Seventy-one patients were included in the study, of which 28 displayed delayed gastric emptying. Delayed gastric emptying was characterized by having type 1 diabetes, younger age, lower BMI, presence of other late complications including distal symmetric polyneuropathy and retinopathy, higher Hb1Ac levels and lower albumin and hemoglobin levels. Symptoms were not related to gastric emptying status. Conclusion We identified several clinical variables associated with delayed gastric emptying in diabetes patients with gastroparesis-like symptoms. These variables are commonly assessed during a medical consultation and may be used to aid the clinician in choosing who to refer for gastric emptying testing.

• El-Salhy, Magdhy; Valeur, Jørgen; Brønstad, Ingeborg; Gilja, Odd Helge & Hatlebakk, Jan Gunnar (2025). Possible Role of Butyric Acid in Long-Term Symptom Relief in Irritable Bowel Syndrome Patients Following Fecal Microbiota Transplantation. Neurogastroenterology and Motility. ISSN 1350-1925. 37(12). doi: 10.1111/nmo.70115. Full text in Research Archive Show summary

  Background: We previously found that the fecal levels of short-chain fatty acids (SCFAs) changed in irritable bowel syndrome (IBS) patients at 1 month and 1 year after fecal microbiota transplantation (FMT). This study analyzed SCFAs at 2 and 3 years after FMT in the same IBS patients included in those previous studies. Methods: This study randomized 113 IBS patients into placebo, 30-g, and 60-g groups, who received FMT with 30 g of their own feces and with 30 g and 60 g of the donor's feces, respectively. The patients completed four questionnaires to assess IBS symptoms, fatigue, and quality of life, and supplied fecal samples at the baseline and at 2 and 3 years after FMT. The fecal SCFA levels were measured using gas chromatography. Results: The butyric acid level was significantly increased at 2 and 3 years after FMT in the 30-g and 60-g groups, and was significantly higher than that in the placebo group. The total SCFA and acetic acid levels decreased significantly in the 30-g and 60-g groups at 2 and 3 years after FMT, while the propionic acid level decreased in the 60-g group at both time points. The butyric acid level was inversely correlated with IBS symptoms and fatigue. Conclusion and Inferences: The increased butyric acid levels in IBS patients at 2 and 3 years after FMT and their inverse correlation with both IBS symptoms and fatigue suggest that butyric acid contributes to the long-term improvement seen after FMT (www.clinicaltrials.gov: NCT03822299).

• Olsen, Bjørn Christian Elias Grova; Opheim, Randi; Kristensen, Vendel Ailin; Høivik, Marte Lie; Lund, Charlotte & Aabrekk, Tone Bergene [Show all 22 contributors for this article] (2025). Prevalence of Irritable Bowel Syndrome Based on Rome IV Criteria in Patients in Biochemical and Endoscopic Remission From Newly Diagnosed Inflammatory Bowel Disease: One- and Three-Year Results (the IBSEN III Cohort). Inflammatory Bowel Diseases. ISSN 1078-0998. 31(10), p. 2704–2713. doi: 10.1093/ibd/izaf047. Full text in Research Archive Show summary

  Background: Distinguishing irritable bowel syndrome (IBS) from inflammatory bowel disease (IBD) flare-ups is challenging. This study used objective remission markers to accurately determine IBS prevalence in a population-based cohort of patients with IBD. Methods: Adults with ulcerative colitis and Crohn’s disease were recruited from the IBD in South-Eastern Norway III cohort study. Irritable bowel-like symptoms were assessed using the Rome IV criteria for patients in remission from IBD at 1- and 3-year follow-ups. Remission was defined objectively using the biochemical marker fecal calprotectin (FC) ≤ 250 μg/g, and comparisons to remission based on endoscopic indices were made at 1-year follow-up. Results: Among patients with FC ≤ 250 μg/g, IBS prevalences were 21.9% (n = 62/283) and 16.1% (n = 49/304) at the 1- and 3-year follow-ups, respectively, which were higher than that in the Norwegian population (9.5%; P < .005). Of patients in endoscopic remission at 1-year follow-up, 19.2% (n = 43/224) reported IBS-like symptoms, which was not significantly different from IBS prevalence for patients with FC ≤ 250 μg/g. Irritable bowel syndrome was independently associated with substantial fatigue (odds ratio: 3.05 [95% CI, 1.48-6.27]) and female sex (odds ratio: 2.67 [95% CI, 1.34-5.32]) at the 1-year follow-up. Patients with IBS reported significantly reduced health-related quality of life (HRQoL) scores. Conclusions: The prevalence of IBS among patients in remission from IBD was approximately twice as common as that in the Norwegian population. Irritable bowel syndrome was independently associated with substantial fatigue, female sex, and reduced HRQoL.

• Zerouga, Insaf; Valeur, Jørgen; Sommer, Christine; Carlsen, Monica Hauger; Hagen, Milada & Høivik, Marte Lie [Show all 22 contributors for this article] (2025). Habitual Intake of Macronutrients and Fermentable Oligo-, Di-, Monosaccharides and Polyols is not associated with Irritable Bowel Syndrome-like Symptoms in Inflammatory Bowel Disease. Clinical Nutrition ESPEN. ISSN 2405-4577. 67, p. 105–113. doi: 10.1016/j.clnesp.2025.03.005. Full text in Research Archive
• Strande, Vibeke; Hagen, Milada; Lund, Charlotte; Asak, Øivind Wessel; Bengtson, May-Bente & Cetinkaya, Raziye Boyar [Show all 26 contributors for this article] (2025). Predicting severe inflammatory bowel disease: a risk matrix model based on the IBSEN III inception cohort. Scandinavian Journal of Gastroenterology. ISSN 0036-5521. 60(7), p. 716–727. doi: 10.1080/00365521.2025.2512591. Full text in Research Archive Show summary

  Background and aims: Identifying patients at risk of developing severe inflammatory bowel disease (IBD) can aid treatment decisions. However, predicting disease course remains challenging. We aimed to identify predictive factors associated with severe disease course in the first year after IBD diagnosis. Methods: Newly diagnosed adult (≥18 years) patients with IBD were recruited from a population-based inception cohort (IBSEN III study). Preselected baseline factors were tested for associations with severe disease course, defined as IBD-related hospitalisation, surgery, treatment with ≥2 steroid courses, >2 biologics and/or new event of complication (stricture, fistula, abscess only applicable Crohn's disease (CD)). From a best fitted multivariable logistic regression model stratified by diagnosis and age (18-40/>40 years), probability of severe disease for given combinations of predictive factors was summarised in prediction matrices. Results: At one-year follow-up, 90/559 (16%) patients with ulcerative colitis (UC) and 74/312 (24%) with CD had severe disease. Treatment with systemic steroids, vitamin D deficiency, Simple Clinical Colitis Activity Index >2, and hypoalbuminemia at diagnosis were all significantly associated with severe disease in UC patients. CD patients with stricturing or penetrating disease behaviour, systemic steroids and hypoalbuminemia at diagnosis were associated with severe disease course. The least favourable combination of these factors increased the probability of severe disease from 3% (95%CI[0-5%]) to 72% (95%CI[66-79%]) for UC and from 8% (95%CI[3-13%]) to 88% (95%CI[84-93%]) for CD. Conclusions: Our study identified predictive factors associated with severe disease the first year after diagnosis. The probability of severe disease summarised in matrices enables easy risk stratification.

• Lorentsen, Jing Lisa Li; Brunborg, Cathrine; Aasebø, Anders Theodor Michaelsen; Valeur, Jørgen; Haavardsholm, Espen A. & Molberg, Øyvind [Show all 8 contributors for this article] (2025). Incidence and prevalence of Behçet's disease in Oslo, Norway: a two-decade population-based analysis. Rheumatology. ISSN 1462-0324. 64(8), p. 4703–4712. doi: 10.1093/rheumatology/keaf224. Full text in Research Archive
• Hansen, Simen Hyll; Maseng, Maria Gjerstad; Grännö, Olle; Vestergaard, Marie V; Bang, Corinna & Olsen, Bjørn Christian Elias Grova [Show all 33 contributors for this article] (2025). Fecal Microbiome Reflects Disease State and Prognosis in Inflammatory Bowel Disease in an Adult Population-Based Inception Cohort. Inflammatory Bowel Diseases. ISSN 1078-0998. 31(8), p. 2066–2080. doi: 10.1093/ibd/izaf060. Full text in Research Archive
• Juul, Frederik Emil; Bretthauer, Michael; Johnsen, Peter Holger; Samy, Faye; Tonby, Kristian & Berdal, Jan-Erik [Show all 29 contributors for this article] (2025). Fecal Microbiota Transplantation Versus Vancomycin for Primary Clostridioides difficile Infection : A Randomized Controlled Trial. Annals of Internal Medicine. ISSN 0003-4819. 178(7), p. 940–947. doi: 10.7326/ANNALS-24-03285. Full text in Research Archive
• Asledottir, Tora; Comi, Irene; Devold, Tove Gulbrandsen; Røseth, Arne; Valeur, Jørgen & Vegarud, Gerd (2024). Ex Vivo Digestion with Human Gastrointestinal Juices. In Ferranti, Pasquale (Eds.), Proteomics applied to foods. Springer. ISSN 9781071640746. p. 149–173. doi: 10.1007/978-1-0716-4075-3_10. Full text in Research Archive
• Valeur, Jørgen (2024). Web Exclusive. Annals Graphic Medicine - Remnants of Breaking Bad News. Annals of Internal Medicine. ISSN 0003-4819. 177(2). doi: 10.7326/G23-0006. Full text in Research Archive
• Dale, Hanna Fjeldheim; Hagen, Milada; Malmstrøm, Gunn Helen; Fiennes, Jennifer Twisleton; Høivik, Marte Lie & Kristensen, Vendel Ailin [Show all 7 contributors for this article] (2024). Assessing hard and loose “endpoints”: comparison of patient and expert Bristol Stool Scale scoring of 2280 fecal samples. F1000 Research. 13. doi: 10.12688/f1000research.152496.2. Full text in Research Archive Show summary

  Background Stool consistency is an important outcome measure to evaluate in the investigation of several gastrointestinal diseases. The Bristol Stool Scale (BSS) is one of the most commonly used tools for evaluation of stool consistency. BSS ranges from 1-7 and each score is assigned to a given consistency of the feces. Self-reported characterizations can differ from an expert evaluation, and the reliability of BSS is unclear. We aimed to evaluate the reliability of BSS by comparing patient scores with expert scores. Methods Patients with inflammatory bowel disease collected stool samples throughout a 3-year follow-up. The stool´s consistency was evaluated with BSS by the patients and matched with an expert score. Agreement between patient and expert scores was assessed using Cohen’s kappa. Results BSS scores from 2280 fecal samples collected from 992 patients at up to five time points were included. When all samples were compared, there was good to substantial agreement between patient and expert scores (Cohen’s weighted kappa: 0.66-0.72). When the BSS scores were simplified and categorized as 1 (scores 1-2), 2 (scores 3-5) or 3 (scores 6-7), the agreement improved slightly (Cohen’s weighted kappa: 0.73-0.77). When the scores from the first sample per patient were compared, the experts were more likely to assign higher scores compared to the patient. The proportion of the lowest assigned scores (1-2) was 12.1% for patients and 8.1% for experts. Conclusions The agreement between patient and expert BSS scores is good to substantial, especially when the BSS scores are simplified into three categories.

• Dale, Hanna Fjeldheim; Småstuen, Milada Cvancarova; Deb, Chirajyoti; Skar, Viggo Øystein & Valeur, Jørgen (2024). Diagnosing sucrase-isomaltase deficiency: a comparison of a ¹³C-sucrose breath test and a duodenal enzyme assay. Scandinavian Journal of Clinical and Laboratory Investigation. ISSN 0036-5513. 84(4), p. 268–272. doi: 10.1080/00365513.2024.2377960. Full text in Research Archive Show summary

  Background Reduced activity of the sucrase-isomaltase (SI) enzyme can cause gastrointestinal symptoms. Biochemical measurement of SI activity in small intestinal biopsies is presently considered the gold standard for the diagnosis of SI deficiency, but this invasive test is not suitable as a routine diagnostic tool. Aim To evaluate a 13C-sucrose-breath test (13CSBT) as a diagnostic tool for SI deficiency in an adult population. Methods 13CSBT results were compared to sucrase activity measured in duodenal biopsies. Results Forty patients with gastrointestinal symptoms were included in the study, 4 of whom had celiac disease and the rest (n = 36) had normal histological findings. Nine patients (22.5%) had low sucrase activity measured using duodenal biopsies. No correlation was observed between enzymatic sucrase activity and the 13CSBT results. The 13CSBT-curves for the celiac patients versus patients with normal duodenal histology demonstrated that the patients with celiac disease were within the lower range of the distribution. Conclusion We observed a mismatch between the 13CSBT results and the biochemically measured sucrase activity, suggesting that SI activity is not uniformly distributed throughout the small intestines. This methodological discrepancy should be acknowledged when diagnosing SI deficiency.

• Holm, Ida Marie; Lorentzen, Sissi C. Stove; Carlsen, Monica Hauger; Valeur, Jørgen; Mellin-Olsen, Tonje & Dale, Hanna Fjeldheim (2024). Evaluation of dietary quality in patients with functional gastrointestinal symptoms: a Norwegian single centre study. Food & Nutrition Research (FNR). ISSN 1654-6628. 68. doi: 10.29219/fnr.v68.10692. Full text in Research Archive Show summary

  Background: Poor dietary quality has been described as a contributor to symptoms in subjects with functional gastrointestinal (GI) symptoms. Hitherto, the focus in dietary evaluation and treatment in this patient group has mainly been on avoiding individual nutrient deficiencies, and less attention has been given to the dietary pattern and the overall food quality. Hence, we aim to describe and evaluate the dietary quality in patients with functional GI symptoms. Methods: Patients with GI symptoms and a diagnosis of irritable bowel syndrome or inflammatory bowel disease in remission, consecutively referred to a clinical dietitian for nutritional guidance, were included. All participants completed a 7-day weighed food record. The intake of foods, energy, macro- and micronutrients was computed. Dietary quality was evaluated by intake frequencies based on a predefined food index, combined with assessing achievement of nutrient intake recommendations. Results: A total of 35 patients were included. Intake frequencies of red meat, cheese and sweets were high, whereas intake frequencies of green leafy vegetables, berries, nuts, whole grain and legumes were low. The total intake of vegetables, fruit, berries, fish and nuts was lower than current recommendations, and the intake corresponded to intake below recommendations for several micronutrients, including vitamins D, C and A; iodine; folate; potassium; and selenium. Conclusion: The group of patients with GI symptoms had overall inadequate dietary quality. Low intake of nutrient-dense food groups considered as beneficial for health corresponded with insufficient intake of several micronutrients. We recommend that dietary evaluation should focus on the intake of food groups, rather than nutrients, in the treatment of patients with functional GI symptoms, to ensure a better evaluation of dietary quality.

• Teige, Erica Sande; Hillestad, Eline Margrethe Randulff; Steinsvik, Elisabeth Kjelsvik; Brønstad, Ingeborg; Lundervold, Arvid & Lundervold, Astri J. [Show all 10 contributors for this article] (2024). Fecal bacteria and short-chain fatty acids in irritable bowel syndrome: relations to subtype. Neurogastroenterology and Motility. ISSN 1350-1925. 36(9). doi: 10.1111/nmo.14854. Full text in Research Archive Show summary

  Background: The relationship between gut microbiota and irritable bowel syndrome (IBS) subtype is unclear. We aimed to explore whether differences in fecal bacteria composition and short-chain fatty acid (SCFA) levels were associated with subtypes and symptoms of IBS. Methods: All participants delivered fecal samples and self-reports on IBS Symptom Severity Score (IBS-SSS), Bristol Stool Scale (BSS), and Gastrointestinal Symptom Rating Scale (GSRS). Fecal bacteria composition was assessed by the GA-map® Dysbiosis Test based on 16S rRNA sequences of bacterial species/groups. SCFAs were analyzed by vacuum distillation followed by gas chromatography. Key Results: Sixty patients with IBS were included (mean age 38 years, 46 [77%] females): Twenty-one patients were classified as IBS-D (diarrhea), 31 IBS-M (mixed diarrhea and constipation), and eight IBS-C (constipation). Forty-two healthy controls (HCs) (mean age 35 years, 27 [64%] females) were included. Patients had a significantly higher relative frequency of dysbiosis, lower levels of Actinobacteria, and higher levels of Bacilli than HCs. Eight bacterial markers were significantly different across IBS subgroups and HCs, and 13 bacterial markers were weakly correlated with IBS symptoms. Clostridia and Veillonella spp. had a weak negative correlation with constipation scores (GSRS) and a weak positive correlation with loose stools (BSS). Diarrhea scores (GSRS) and looser stool (BSS) were weakly correlated with levels of total SCFAs, acetic and butyric acid. Levels of total SCFAs and acetic acid were weakly correlated with symptom severity (IBS-SSS). Conclusions & Inferences: Patients with IBS had a different fecal bacteria composition compared to HCs, and alterations of SCFAs may contribute to the subtype.

• Jensen, Caroline; Sommersten, Cathrine Horn; Laupsa-Borge, Johnny; Storås, Inghild; Valeur, Jørgen & Mellgren, Gunnar [Show all 9 contributors for this article] (2024). Quality and quantity of carbohydrates, faecal short-chain fatty acids and gastrointestinal symptoms– results from a randomised, controlled trial (CARBFUNC). Clinical Nutrition. ISSN 0261-5614. 44, p. 54–64. doi: 10.1016/j.clnu.2024.11.041. Full text in Research Archive Show summary

  Background & aims: Diet is a key determinant of gastrointestinal (GI) health, in part in association with microbiota-derived short-chain fatty acids (SCFAs). However, we need more knowledge of the relative impact of dietary carbohydrate amount and quality on GI symptoms, GI-associated quality of life (QoL) and faecal SCFAs. Methods: 193 males and females with obesity were randomly allocated to follow one of three isocaloric, iso-proteinic dietary patterns (2000 kcal/day for females, 2500 kcal/day for males): a higher-carbohydrate lower-fat diet with refined carbohydrate sources (acellular diet, A-HCLF, comparator arm), a higher-carbohydrate lower-fat diet with minimally refined carbohydrate sources (intact cellular structures, cellular diet, C-HCLF), or a low-carbohydrate high-fat diet (LCHF), all low in added sugars. Secondary outcomes of this randomised controlled trial (CARBFUNC) were assessed, i.e., changes in abdominal symptoms (irritable bowel syndrome severity scoring system (IBS-SSS)), reflux symptoms (gastro-oesophageal reflux disease questionnaire (GerdQ)), GI-related QoL (Short-Form Nepean Dyspepsia Index (SF-NDI)) and fatigue (Fatigue Impact Scale), and faecal SCFAs concentrations after following the diets for 3 and 12 months. Group differences were analysed by constrained linear mixed effect modelling (cLMM). Results: 118 and 57 participants completed 3 and 12 months of the dietary intervention, respectively, with no significant group differences in weight loss at 12 months (5–7%). At 12 months, the mean daily fibre intake was 34 ± 7 g/day, 41 ± 14.3 g/day, and 18.5 ± 6 g/day on the A-HCLF, C-HCLF and LCHF diet, respectively, compared to 21 ± 7, 21 ± 7 and 20 ± 6 g/day at baseline. We observed no significant between-group difference in IBS-SSS sum score after 3 and 12 months. We found significant improvement in GerdQ score (change score [95 % CI]: −0.62 [−1.18, −0.048], p = 0.034), and SF-NDI sum score (−1.88 [−3.22, −0.52], p = 0.007) after 3 months on the LCHF diet compared to the A-HCLF diet, and GerdQ remained significant at 12 months (−1.03 [−1.88, −0.19], p = 0.017). Compared to the A-HCLF diet, the concentration of faecal butyric acid increased significantly more after 3 months on the C-HCLF diet (4.97 [1.71, 8.23] p = 0.003) and faecal acetic acid decreased more (−6.41 [−12.8, −0.047]. p = 0.048) on the LCHF diet. At 12 months the greater reduction in faecal acetic acid on the LCHF diet remained significant (−9.82 [−19.0, −0.67], p = 0.036), along with significantly greater reductions also in total SCFAs (−21.3 [−38.0, −4.56], p = 0.013), propionic (−4.42 [−7.79, −1.05], p = 0.010), and butyric acid (−5.05 [−9.60, −0.51], p = 0.030). Conclusion: In this sample of adults with obesity and mild GI symptoms at baseline, modest improvements were observed only for the LCHF diet in QoL (at 3 months) and reflux symptoms (at 3 and 12 months), which was significantly different from the acellular carbohydrate diet, and independent of total fibre intake. Concomitantly, compared to the acellular carbohydrate diet, the cellular diet significantly increased the faecal concentration of butyric acid, whereas the LCHF diet lowered acetic acid after 3 months and all the major SCFAs after 12 months.

• Herfindal, Anne Mari; Nilsen, Morten; Aspholm, Trude Elise; Schultz, Gry Irene Granli; Valeur, Jørgen & Rudi, Knut [Show all 10 contributors for this article] (2024). Effects of fructan and gluten on gut microbiota in individuals with self-reported non-celiac gluten/wheat sensitivity—a randomised controlled crossover trial. BMC Medicine. 22:358(1), p. 1–19. doi: 10.1186/s12916-024-03562-1. Full text in Research Archive Show summary

  Background Individuals with non-celiac gluten/wheat sensitivity (NCGWS) experience improvement in gastrointestinal symptoms following a gluten-free diet. Although previous results have indicated that fructo-oligosaccharides (FOS), a type of short-chain fructans, were more likely to induce symptoms than gluten in self-reported NCGWS patients, the underlying mechanisms are unresolved. Methods Our main objective was therefore to investigate whether FOS-fructans and gluten affect the composition and diversity of the faecal microbiota (16S rRNA gene sequencing), faecal metabolites of microbial fermentation (short-chain fatty acids [SCFA]; gas chromatography with flame ionization detector), and a faecal biomarker of gut inflammation (neutrophil gelatinase-associated lipocalin, also known as lipocalin 2, NGAL/LCN2; ELISA). In the randomised double-blind placebo-controlled crossover study, 59 participants with self-reported NCGWS underwent three different 7-day diet challenges with gluten (5.7 g/day), FOS-fructans (2.1 g/day), and placebo separately (three periods, six challenge sequences). Results The relative abundances of certain bacterial taxa were affected differently by the diet challenges. After the FOS-fructan challenge, Fusicatenibacter increased, while Eubacterium (E.) coprostanoligenes group, Anaerotruncus, and unknown Ruminococcaceae genera decreased. The gluten challenge was primarily characterized by increased abundance of Eubacterium xylanophilum group. However, no differences were found for bacterial diversity (α-diversity), overall bacterial community structure (β-diversity), faecal metabolites (SCFA), or NGAL/LCN2. Furthermore, gastrointestinal symptoms in response to FOS-fructans were generally not linked to substantial shifts in the gut bacterial community. However, the reduction in E. coprostanoligenes group following the FOS-fructan challenge was associated with increased gastrointestinal pain. Finally, correlation analysis revealed that changes in gastrointestinal symptoms following the FOS-fructan and gluten challenges were linked to varying bacterial abundances at baseline. Conclusions In conclusion, while FOS-fructans induced more gastrointestinal symptoms than gluten in the NCGWS patients, we did not find that substantial shifts in the composition nor function of the faecal microbiota could explain these differences in the current study. However, our results indicate that individual variations in baseline bacterial composition/function may influence the gastrointestinal symptom response to both FOS-fructans and gluten. Additionally, the change in E. coprostanoligenes group, which was associated with increased symptoms, implies that attention should be given to these bacteria in future trials investigating the impact of dietary treatments on gastrointestinal symptoms. Trial registration Clinicaltrials.gov as NCT02464150.

• Dale, Hanna Fjeldheim; Hagen, Milada; Bekkelund, Mattis; Deb, Chirajyoti & Valeur, Jørgen (2024). Disaccharidase deficiencies and gastrointestinal symptoms in patients referred to gastroscopic examination: a single center study from Norway. Scandinavian Journal of Gastroenterology. ISSN 0036-5521. 59(10), p. 1166–1171. doi: 10.1080/00365521.2024.2395848. Full text in Research Archive Show summary

  Objective Gastrointestinal illnesses have been reported in relation to low disaccharidase activity, yet both the prevalence of disaccharidase deficiency and its association with gastrointestinal symptoms and irritable bowel syndrome (IBS) are largely unknown. We aimed to determine the association between low activity of disaccharidase enzymes on gastrointestinal symptoms and presence of IBS. Methods Patients referred for gastroscopic examination due to gastrointestinal complaints were consecutively included. A pinch biopsy was taken from the distal part of duodenum, and disaccharidase activity was measured using the Dahlqvist method. Gastrointestinal symptom severity was measured using IBS-Symptom Severity Score (IBS-SSS). Results A total of 40 patients were included. Disaccharidase deficiency was detected in 24 patients (60%). Half of the patients (n = 21) had IBS according to Rome IV criteria. A majority (75%) of all patients reported moderate to severe gastrointestinal symptoms. Moderate to severe gastrointestinal symptoms were reported by 16 patients (67%) with disaccharidase deficiency and in 14 patients (88%) with normal disaccharidase activity. Lactase deficiency was detected in 22 patients (55%), maltase deficiency in 11 patients (28%), sucrase deficiency in 9 patients (23%), isomaltase deficiency in 13 patients (33%) and glucoamylase deficiency in 12 patients (30%). The activity of all enzymes was reduced in 8 patients (20%). Degree of disaccharidase deficiency was not associated with either the severity of gastrointestinal symptoms or the diagnosis of IBS. Enzymes levels were not associated with gastrointestinal symptom scores. Conclusion Our findings did not reveal any association between biochemically measured disaccharidase deficiency and gastrointestinal symptoms or the presence of IBS.

• Zerouga, Insaf; Valeur, Jørgen; Sommer, Christine; Småstuen, Milada Cvancarova; Medhus, Asle Wilhelm & Lund, Charlotte [Show all 22 contributors for this article] (2024). Dietary intake and nutritional status in patients with newly diagnosed inflammatory bowel disease: insights from the IBSEN III study. Scandinavian Journal of Gastroenterology. ISSN 0036-5521. 59(6), p. 1–9. doi: 10.1080/00365521.2024.2313056. Full text in Research Archive Show summary

  Background: Dietary recommendations in inflammatory bowel disease (IBD) are inconclusive, and patients may follow restrictive diets with increased risk of malnutrition. The aim of this study was to compare dietary intakes and nutritional status in men and women with newly diagnosed IBD with a general population sample, and to investigate whether intakes were in line with the Nordic Nutrition Recommendations. Methods: This was a cross-sectional study including adults≥ 40 years with IBD from the Inflammatory Bowel Disease in South-Eastern Norway (IBSEN) III cohort study. A validated food frequency questionnaire (FFQ) was used in dietary data collection, and a sample from the seventh survey of the Tromsø Study was included as a comparison group. Results: A total of 227 men and women with IBD were included. IBD patients had higher intake of grain products, sweetened beverages, energy, fat and polyunsaturated fat (PUFA), but lower intake of dairy products, alcohol and iodine compared to adults from the comparison sample (p < 0.01). Intakes of saturated fat and carbohydrates in both genders, and vitamin D in women were not within recommended levels. Anemia and hypoalbuminemia were more prevalent in IBD patients than in the comparison sample. Conclusions: Dietary intakes in newly diagnosed IBD patients were mostly in line with Nordic Nutrition Recommendations. Higher proportion of IBD patients exceeded recommended allowances of fat and added sugar than the comparison sample. Insufficient micronutrient intake, anemia and hypoalbuminemia are present challenges in IBD patients that require monitoring.

• Birkeland, Eline; Gharagozlian, Sedeghe; Valeur, Jørgen & Aas, Anne-Marie (2023). Short-chain fatty acids as a link between diet and cardiometabolic risk: a narrative review. Lipids in Health and Disease. 22(1). doi: 10.1186/s12944-023-01803-5. Full text in Research Archive Show summary

  Aim Diet has a profound impact on cardiometabolic health outcomes such as obesity, blood glucose, blood lipids and blood pressure. In recent years, the gut microbiota has emerged as one of several potential key players explaining dietary effects on these outcomes. In this review we aim to summarise current knowledge of interaction between diet and gut microbiota focusing on the gut-derived microbial metabolites short-chain fatty acids and their role in modulating cardiometabolic risk. Findings Many observational and interventional studies in humans have found that diets rich in fibre or supplemented with prebiotic fibres have a favourable effect on the gut microbiota composition, with increased diversity accompanied by enhancement in short-chain fatty acids and bacteria producing them. High-fat diets, particularly diets high in saturated fatty acids, have shown the opposite effect. Several recent studies indicate that the gut microbiota modulates metabolic responses to diet in, e.g., postprandial blood glucose and blood lipid levels. However, the metabolic responses to dietary interventions, seem to vary depending on individual traits such as age, sex, ethnicity, and existing gut microbiota, as well as genetics. Studies mainly in animal models and cell lines have shown possible pathways through which short-chain fatty acids may mediate these dietary effects on metabolic regulation. Human intervention studies appear to support the favourable effect of short-chain fatty acid in animal studies, but the effects may be modest and vary depending on which cofactors were taken into consideration. Conclusion This is an expanding and active field of research that in the near future is likely to broaden our understanding of the role of the gut microbiota and short-chain fatty acids in modulating metabolic responses to diet. Nevertheless, the findings so far seem to support current dietary guidelines encouraging the intake of fibre rich plant–based foods and discouraging the intake of animal foods rich in saturated fatty acids.

• Dale, Hanna Fjeldheim; Lorentzen, Sissi C. Stove; Mellin-Olsen, Tonje & Valeur, Jørgen (2023). Diet-microbiota interaction in irritable bowel syndrome: looking beyond the low-FODMAP approach. Scandinavian Journal of Gastroenterology. ISSN 0036-5521. doi: 10.1080/00365521.2023.2228955. Full text in Research Archive
• Stø, Kristine; Skagen, Karolina Ryeng; Valeur, Jørgen; Yang, Kuan; Bjerkeli, Vigdis & Aukrust, Pål [Show all 8 contributors for this article] (2023). Increased plasma levels of non-sugar sweeteners in patients with symptomatic carotid atherosclerosis. Scandinavian Cardiovascular Journal. ISSN 1401-7431. 57(1). doi: 10.1080/14017431.2023.2205068. Full text in Research Archive Show summary

  Purpose. The non-sugar sweeteners acesulfame K and saccharin are considered safe, but there is conflicting evidence on their effects on cardiovascular health. Materials and methods. In this explorative pilot study, we measured plasma levels of acesulfame K and saccharin in 15 patients with symptomatic carotid atherosclerosis, 18 asymptomatic patients and 15 control subjects. Fecal microbiota and short-chain fatty acids were analyzed. Dietary and medical history was assessed. Results. Symptomatic patients had higher levels of acesulfame K and saccharin compared to controls. Acesulfame K was associated with increased leukocyte count. Saccharin was associated with more severe carotid stenosis, as well as lower fecal butyric acid.

• Herfindal, Anne Mari; Megen, Frida van; Gilde, Mari Kristine Overvik; Valeur, Jørgen; Rudi, Knut & Skodje, Gry [Show all 9 contributors for this article] (2023). Effects of a low FODMAP diet on gut microbiota in individuals with treated celiac disease having persistent gastrointestinal symptoms-a randomized controlled trial. British Journal of Nutrition. ISSN 0007-1145. 130(12), p. 2061–2075. doi: 10.1017/S0007114523001253. Full text in Research Archive Show summary

  Abstract Individuals with coeliac disease (CeD) often experience gastrointestinal symptoms despite adherence to a gluten-free diet (GFD). While we recently showed that a diet low in fermentable oligo-, di-, monosaccharides and polyols (FODMAP) successfully provided symptom relief in GFD-treated CeD patients, there have been concerns that the low FODMAP diet (LFD) could adversely affect the gut microbiota. Our main objective was therefore to investigate whether the LFD affects the faecal microbiota and related variables of gut health. In a randomised controlled trial GFD-treated CeD adults, having persistent gastrointestinal symptoms, were randomised to either consume a combined LFD and GFD ( n 39) for 4 weeks or continue with GFD (controls, n 36). Compared with the control group, the LFD group displayed greater changes in the overall faecal microbiota profile (16S rRNA gene sequencing) from baseline to follow-up (within-subject β -diversity, P &lt; 0·001), characterised by lower and higher follow-up abundances (%) of genus Anaerostipes ( P group &lt; 0·001) and class Erysipelotrichia ( P group = 0·02), respectively. Compared with the control group, the LFD led to lower follow-up concentrations of faecal propionic and valeric acid (GC-FID) in participants with high concentrations at baseline ( P interaction ≤ 0·009). No differences were found in faecal bacterial α -diversity ( P group ≥ 0·20) or in faecal neutrophil gelatinase-associated lipocalin (ELISA), a biomarker of gut integrity and inflammation ( P group = 0·74), between the groups at follow-up. The modest effects of the LFD on the gut microbiota and related variables in the CeD patients of the present study are encouraging given the beneficial effects of the LFD strategy to treat functional GI symptoms (Registered at clinicaltrials.gov as NCT03678935).

• Stø, Kristine; Valeur, Jørgen; Ueland, Thor; Malmstrøm, Gunn Helen; Bjerkeli, Vigdis & Trøseid, Marius [Show all 12 contributors for this article] (2022). Fecal level of butyric acid, a microbiome-derived metabolite, is increased in patients with severe carotid atherosclerosis. Scientific Reports. 12(1), p. 1–9. doi: 10.1038/s41598-022-26759-x. Full text in Research Archive Show summary

  Abstract The short-chain fatty acid (SCFA) butyric acid maintains a healthy gut barrier and vascular endothelium. We aimed to investigate the association between fecal butyric acid, carotid atherosclerosis and risk factors for ischemic stroke. Patients with severe carotid atherosclerosis (i.e. ≥ 50% stenosis) (n = 43) were compared with healthy controls (n = 38). We analyzed fecal SCFAs by gas chromatography, microbiota composition by 16S rRNA sequencing, markers of gut barrier damage and inflammasome activation by immunoassay, and plasma SCFAs by ultra-high performance liquid chromatography-tandem mass spectroscopy. Patients had higher fecal butyric acid level ( p  = 0.024), along with increased functional potential of microbial butyric acid production ( p  = 0.031), compared with controls. Dietary fiber intake was comparable. Patients had higher levels of gut barrier damage markers CCL25 and IFABP, and the inflammasome activation marker IL-18, whereas plasma level of butyric was similar. Increased fecal butyric acid was associated with higher BMI, waist-hip ratio, HbA1c, CRP and leukocyte count. Contrary to our hypothesis, patients with severe carotid atherosclerosis had higher fecal butyric acid level, and increased microbial production, compared with controls. Gut barrier damage in patients might indicate decreased absorption of butyric acid and hence contribute to the higher fecal level.

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• Valeur, Jørgen & Haug, Camilla Spersrud (2025). Ventrikkelslimhinne i rektum. doi: 10.4045/tidsskr.25.0492. Full text in Research Archive
• Valeur, Jørgen (2025). Ny vin i gammel flaske? Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. Full text in Research Archive
• Bu, Fanny; Valeur, Jørgen; Johnson, Katerina & Brummer, Robert J (2025). Mener kosttilskudd kan gi bedre humør – på bare to uker. [Internet]. Tv2.no. Full text in Research Archive
• Hanes, Emma & Valeur, Jørgen (2025). Nyt kaffen med god samvittighet. [Internet]. www.klikk.no. Full text in Research Archive
• Maseng, Maria Gjerstad; Hansen, S Hyll; Bang, Corina; Valeur, Jørgen; Huppertz-Hauss, Gert & Opheim, Randi [Show all 18 contributors for this article] (2025). Longitudinal Changes in Gut Microbiota During the First Year following diagnosis of Inflammatory Bowel Disease – the IBSEN III study. Journal of Crohn's and Colitis. ISSN 1873-9946. 19, p. i2387–i2387. doi: 10.1093/ecco-jcc/jjae190.1498. Full text in Research Archive
• Bekkelund, Mattis; Juul, Frederik Emil; Sandstad, Olav & Valeur, Jørgen (2025). Bakteriell overdiagnostikk i tynntarm. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 145. doi: 10.4045/tidsskr.24.0655. Full text in Research Archive
• El-Salhy, Magdy; Valeur, Jørgen; Brønstad, Ingeborg; Gilja, Odd Helge & Hatlebakk, Jan Gunnar (2025). The possible role of butyric acid in long-term symptom relief in irritable bowel syndrome patients following fecal microbiota transplantation. Full text in Research Archive
• Solberg, Trine & Valeur, Jørgen (2025). Kjempestudie om tarmbakterier: Dette bør du spise. [Internet]. Nettavisen. Full text in Research Archive
• Maseng, Maria Gjerstad; Hansen, Simen Hyll; Bang, Corina; Valeur, Jørgen; Huppertz-Hauss, Gert & Opheim, Randi [Show all 18 contributors for this article] (2025). Longitudinal Changes in Gut Microbiota During the First Year following diagnosis of Inflammatory Bowel Disease – the IBSEN III study. Full text in Research Archive
• Bekkelund, Mattis; Steinsvik, Elisabeth Kjelsvik; Valeur, Jørgen; Dale, Hanna Fjeldheim & Jacobsen, Birgitte Berentsen (2025). Effekt av en lav-FODMAP-diett på visceral hypersensitivitet ved irritabel tarm-syndrom. Full text in Research Archive
• Bekkelund, Mattis; Sangnes, Dag André; Steinsvik, Elisabeth Kjelsvik; Søfteland, Eirik; Dimcevski, Georg & Valeur, Jørgen (2025). Autonom nevropati hos pasienter med diabetes og symptomer på gastroenteropati. Full text in Research Archive
• Bekkelund, Mattis; Steinsvik, Elisabeth Kjelsvik; Valeur, Jørgen; Søfteland, Eirik; Dimcevski, Georg & Sangnes, Dag André (2025). Kliniske karakteristika ved diabetisk gastroparese. Full text in Research Archive
• Valeur, Jørgen (2025). «Tarmkultur» - magetarmsystemets betydning i mytologi, historie, kultur og kunst. Full text in Research Archive
• Valeur, Jørgen (2025). «Tarmkultur» - magetarmsystemets betydning i mytologi, historie, kultur og kunst. Full text in Research Archive
• Valeur, Jørgen & Hem, Erlend (2025). Larmen fra tarmen. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 145. doi: 10.4045/tidsskr.25.0069. Full text in Research Archive
• Valeur, Jørgen (2025). Dinosaurmagefest. NGF-nytt. ISSN 0809-6570. 32(1), p. 48–48. Full text in Research Archive
• Bekkelund, Mattis; Sangnes, Dag André; Steinsvik, Elisabeth Kjelsvik; Søfteland, Eirik; Dimcevski, Georg & Valeur, Jørgen (2025). Autonom nevropati hos pasienter med diabetes og symptomer på gastroenteropati. NGF-nytt. ISSN 0809-6570. 32, p. 24–25. Full text in Research Archive
• Valeur, Jørgen (2025). Avføring som terapi - historisk overblikk. Full text in Research Archive
• Sollund, Adrian; Røssberg, Jan Ivar & Valeur, Jørgen (2025). Antidepressiva: Nye sjokkfunn. [Internet]. Dagbladet.no. Full text in Research Archive
• Valeur, Jørgen (2025). Tarmfloratilpasset medisin. Full text in Research Archive
• Klevstul, Miriam; Olsen, Peder Sandvold; Norin, Elisabeth; Valeur, Jørgen; Røseth, Arne & Johansson, Mads (2025). Tilbyder av fekal transplantasjon stoppet av statlig instans: - Dette er David mot Goliat. [Journal]. Fordøyelsen. Full text in Research Archive
• El-Salhy, Magdy; Valeur, Jørgen; Brønstad, Ingeborg; Gilja, Odd Helge & Hatlebakk, Jan Gunnar (2025). Kortkjedede fettsyrer etter FMT. Full text in Research Archive
• Halsne, Ruth & Valeur, Jørgen (2024). Nanomateriale med karbon brytes ned av bakterier i tarmen. [Journal]. Tidsskrift for Den norske legeforening (Tidsskriftet). doi: 10.4045/tidsskr.23.0841. Full text in Research Archive
• Valeur, Jørgen & MIkalsen, Knut-Erik (2024). Frykter du ubehag på flyturen? Dette er løsningen. [Internet]. Flysmart24.no. Full text in Research Archive
• Hem, Erlend; Roos, Merethe & Valeur, Jørgen (2024). Rolv Gjessing - den tvetydige pioneren. 21(4), p. 473–481. doi: 10.56175/michael.11938. Full text in Research Archive
• Hem, Erlend; Roos, Merethe & Valeur, Jørgen (2024). Rolv Gjessing - et hundreårsminne. Michael. ISSN 1893-9651. 21(4), p. 385–386. doi: 10.56175/michael.11931. Full text in Research Archive
• Valeur, Jørgen (2024). Kryp i magen. NGF-nytt. ISSN 0809-6570. 31(4), p. 36–36. Full text in Research Archive
• Valeur, Jørgen (2024). Forsideillustrasjon til NGF-nytt nr. 4 2024. Full text in Research Archive
• Valeur, Jørgen (2024). Irritabel tarm-syndrom (IBS): Symptomer, patofysiologi og behandling. Full text in Research Archive
• Valeur, Jørgen (2024). Noe å tygge på. NGF-nytt. ISSN 0809-6570. 31(2), p. 34–34. Full text in Research Archive
• Jensen, Caroline; Martinsen, Tilde Kristine; Valeur, Jørgen; Nygård, Ottar Kjell & Lied, Gülen Arslan (2024). Gastrointestinal symptoms and associations with faecal SCFAs and dietary intake in older adults - results from the Hordaland Health Studie 3. Full text in Research Archive
• Rosman, Mari; Lundin, Knut & Valeur, Jørgen (2024). Tarmen din lekker. [Journal]. Fordøyelsen. Full text in Research Archive
• Valeur, Jørgen; Tveito, Kari; Røseth, Arne; Strøm, Finn; Kristensen, Vendel Ailin & Sandstad, Olav [Show all 9 contributors for this article] (2024). Minneord: Viggo Øystein Skar (1945-2024). Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 144(14), p. 1155–1155. Full text in Research Archive
• Tovan, Anders Ihle; Valeur, Jørgen & Johansson, Mads J. (2024). Nye IBS-funn: Kan gi stor symptomlindring. [Internet]. VG. Full text in Research Archive
• Valeur, Jørgen (2024). Pytonslangens prandiale pekuliaritet. NGF-nytt. ISSN 0809-6570. 31(1), p. 44–44. Full text in Research Archive
• Hollekim, Thea Elisabeth; Thorud, Oda Myrvold & Valeur, Jørgen (2024). Funksjonelle mage- og tarmlidelser (IBS). [Internet]. Tarmlyd (podcast). Full text in Research Archive
• Ingebrigtsen, Julia Renate; Valeur, Jørgen; Zinöcker, Marit; Spurkland, Anne & Østvik, Ann Elisabeth (2024). Eksperter: Dette kan du gjøre for å unngå kronisk inflammasjon. [Journal]. VG. Full text in Research Archive
• Valeur, Jørgen (2024). «Tarmkultur» - magetarmsystemets betydning i mytologi, historie, kultur og kunst. Full text in Research Archive
• Maseng, Maria Gjerstad; Hansen, Simen Hyll; Bang, Corina; Detlie, Trond Espen; Huppertz-Hauss, Gert & Kristensen, Vendel Ailin [Show all 18 contributors for this article] (2024). Longitudinal Changes in Gut Microbiota During the First Year following diagnosis of Inflammatory Bowel Disease– the IBSEN III study. Full text in Research Archive
• El-Salhy, Magdy; Valeur, Jørgen; Brønstad, Ingeborg; Gilja, Odd Helge & Hatlebakk, Jan Gunnar (2024). Faecal butyric acid levels are increased at 2 and 3 years after faecal microbiota transplantation (FMT) in patients with irritable bowel syndrome (IBS). Full text in Research Archive
• Strømland, Stine Sofie; Aspholm, Trude; Fjørtoft, Jenny; Brønner, Charlotte Utheim; Stolt, Emma & Snipen, Lars-Gustav [Show all 12 contributors for this article] (2024). Effects of sulfur amino acid restriction on gut microbiota and inflammation in people with overweight and obesity: an 8-week randomized controlled dietary intervention study. Full text in Research Archive
• Juul, Frederik Emil; Bretthauer, Michael; Tonby, Kristian; Berdal, Jan-Erik; Hoff, Dag Arne Lihaug & Ofstad, Eirik Hugaas [Show all 27 contributors for this article] (2024). Fecal microbiota transplant versus Vancomycin for primary Clostridioides difficile infection - a randomized non-inferiority trial. Full text in Research Archive
• Valeur, Jørgen & Rickers, Andreas Lykke (2024). Trang vinkel mellom a. mesenterica superior og aorta. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 144(2). doi: 10.4045/tidsskr.23.0756. Full text in Research Archive
• Lindseth, Inge Andreas; Villmones, Heidi Cecilie & Valeur, Jørgen (2024). Tarmflora med feil adresse? [Journal]. Sunnhetsbladet. Full text in Research Archive
• Valeur, Jørgen (2024). Stjernemage. NGF-nytt. ISSN 0809-6570. 31(3), p. 42–42. Full text in Research Archive
• Sollund, Adrian & Valeur, Jørgen (2024). Omstridt IBS-diett hjalp Cecilie. [Journal]. Dagbladet. Full text in Research Archive
• Sollund, Adrian; Zinöcker, Marit & Valeur, Jørgen (2024). Formelen: Kvitt IBS-plagene. [Internet]. Dagbladet. Full text in Research Archive
• El-Salhy, Magdy; Valeur, Jørgen; Brønstad, Ingeborg; Gilja, Odd Helge & Hatlebakk, Jan Gunnar (2024). Faecal butyric acid levels are increased at 2 and 3 years after faecal microbiota transplantation (FMT) in patients with irritable bowel syndrome (IBS). Neurogastroenterology and Motility. ISSN 1350-1925. 36, p. 144–144. Full text in Research Archive
• Valeur, Jørgen (2023). Å puste med magen. NGF-nytt. ISSN 0809-6570. 30(2), p. 36–36. Full text in Research Archive
• Valeur, Jørgen (2023). Strutsens stålmage. NGF-nytt. ISSN 0809-6570. 30(1), p. 54–54. Full text in Research Archive
• Valeur, Jørgen (2023). Funksjonelle lidelser i øvre GI-traktus. Full text in Research Archive
• Valeur, Jørgen (2023). Forsideillustrasjon til NGF-nytt nr. 4 2023. Full text in Research Archive
• Valeur, Jørgen (2023). Kulemage. NGF-nytt. ISSN 0809-6570. 30(4), p. 40–40. Full text in Research Archive
• Sangnes, Dag André; Engjom, Trond; Løvaas, Kristian; Berentsen, Birgitte; Softeland, Eirik & Dimcevski, Georg Gjorgji [Show all 19 contributors for this article] (2023). Epidemiologi og patofysiologi ved diabetisk diaré (DIAREPA). Full text in Research Archive
• Hansen, Simen Hyll; Maseng, M Gjerstad; Bjørkqvist, O; Halfvarsson, J; Bang, C & Detlie, Trond Espen [Show all 23 contributors for this article] (2023). Gut microbiota at diagnosis is associated with clinical features and future disease course in Inflammatory Bowel Disease: Data from IBSEN III, a new large Norwegian population-based inception cohort. Journal of Crohn's and Colitis. ISSN 1873-9946. 17, p. i1028–I2029. doi: 10.1093/ecco-jcc/jjac190.1050. Full text in Research Archive
• Bergseth, Wilma; Garnås, Eirik; Hatlebakk, Jan Gunnar & Valeur, Jørgen (2023). Expert: Så kan viss kost minska IBS-symtom. [Internet]. Aftonbladet. Full text in Research Archive
• Bergseth, Wilma; Garnås, Eirik; Hatlebakk, Jan Gunnar & Valeur, Jørgen (2023). IBS-funn: − Kan gi betydelig symptomreduksjon. [Internet]. VG. Full text in Research Archive
• Strøm, Anne-Karine & Valeur, Jørgen (2023). Derfor er tarmen så viktig for helsen. [Journal]. Vi over 60. Full text in Research Archive
• Juul, Frederik Emil; Hov, Johannes Espolin Roksund; Trøseid, Marius; Johnsen, Peter Holger & Valeur, Jørgen (2023). Tarmflora og tarmsykdom - en edruelig formaning. 143(10), p. 849–850. doi: 10.4045/tidsskr.23.0121. Full text in Research Archive
• Valeur, Jørgen (2023). Illustrasjoner til boken Steinsvik EK, Larsen CH, Hausken T. Skitt la gå. Løst og fast om plager, sykdom og resten av tarmens forunderlige liv. Full text in Research Archive
• Zerouga, Insaf; Sommer, Christine; Carlsen, Monica Hauger; Valeur, Jørgen; Kristensen, Vendel Ailin & Høivik, Marte Lie [Show all 8 contributors for this article] (2023). Kosthold og ernæringsstatus ved nydiagostisert IBD: resultater fra IBSEN III. Full text in Research Archive
• Årdal, Ingrid G.; Jakobsen, Celina; Zinöcker, Marit; Valeur, Jørgen & Villmones, Heidi Cecilie (2023). Celina (27) har hatt laus mage i ni år – så endra ho kosthaldet. [Internet]. nrk.no. Full text in Research Archive
• Valeur, Jørgen (2023). Vampyrmage. NGF-nytt. ISSN 0809-6570. 30(3), p. 34–35. Full text in Research Archive
• Bekkelund, Mattis; Sangnes, Dag André; Valeur, Jørgen & Hatlebakk, Jan Gunnar (2023). Nausea associated to subsegmental intestinal hypomotility in diabetic gastroenteropathy. Full text in Research Archive
• Teige, Erica Sande; Hillestad, Eline Margrete Randulff; Steinsvik, Elisabeth Kjelsvik; Brønstad, Ingeborg; Bjørkevoll, M & Straume, Mariell Gaassand [Show all 14 contributors for this article] (2022). Bergen Braingut Study: Relations between fecal microbiota profile and its metabolites (short-chain fatty acids) and symptoms in irritable bowel syndrome. United European Gastroenterology Journal (UEG Journal). ISSN 2050-6406. 10, p. 412–412. Full text in Research Archive
• Teige, Erica Sande; Hillestad, EM; Steinsvik, Elisabeth Kjelsvik; Brønstad, Ingeborg; Bjørkevoll, M & Straume, Mariell Gaassand [Show all 14 contributors for this article] (2022). Bergen Braingut Study: Relations between fecal microbiota profile and its metabolites (short-chain fatty acids) and symptoms in irritable bowel syndrome. Full text in Research Archive
• Roos, Merethe; Lillestøl, Kristine & Valeur, Jørgen (2022). Dr. Sopp: Markant mykolog - og mye mer. Michael. ISSN 1893-9651. 19(4), p. 333–335. Full text in Research Archive
• Valeur, Jørgen (2022). Soppenes planet. Michael. ISSN 1893-9651. 19(4), p. 409–410. Full text in Research Archive
• Valeur, Jørgen (2022). Engastrasjon. NGF-nytt. ISSN 0809-6570. 29(3), p. 38–38. Full text in Research Archive
• Valeur, Jørgen (2022). Urtarmdyret. NGF-nytt. ISSN 0809-6570. 29(2), p. 42–42. Full text in Research Archive
• Soares, Jelena Zugic; Bogdanovic, Nenad; Pettersen, Renate Regine; Selbæk, Geir & Valeur, Jørgen (2023). Vitamin D in cognitive impairment and Alzheimer´s disease. Universitetet i Oslo. Full text in Research Archive Show summary

  Background Dementia, especially due to Alzheimer`s disease (AD), is a major and increasing health problem in the elderly population worldwide. To date there is no curative treatment. It is therefore crucial to examine all possibly modifiable factors for disease development; vitamin D deficiency is one of them. There are conflicting results regarding vitamin D and cognitive function in the literature, and little is known about the presence and impact of vitamin D in the human brain. Aim The aim of this study was to explore the possible significance of both serum and intrathecal Vitamin D for cognitive health in older persons. To achieve this, we investigated the following: 1. Vitamin D in serum in persons t 65 years and associations with cognitive performance (paper I). 2. The association between vitamin D levels in serum and volumetric MRI measurements of key brain regions in persons with cognitive impairment (paper II). 3. Serum/cerebrospinal fluid (CSF) ratios of vitamin D in people with good and poor cognitive health (paper III). 4. VDR gene polymorphisms in association with cognitive performance and vitamin D status (paper III). 5. The association between vitamin D levels in CSF and levels of biomarkers of Alzheimer's disease, β-amyloid, total tau protein and phosphorylated tau protein in CSF (paper IV). 6. The association between vitamin D levels in CSF and cytokine levels in CSF (paper IV). Methods Patient data were collected from the Norwegian register for persons assessed for cognitive symptoms. A control group was included in papers III and IV. Results In paper I, we found that lower levels of vitamin D in serum were associated with worse performance on cognitive tests of executive function. In paper II, the results showed an association between lower levels of vitamin D in serum and lower volumes of cortical grey matter. In paper III, we found that the relationship between vitamin D in serum and CSF was not linear. Further, we found that patients with a clinical diagnosis of AD had lower levels of vitamin D in CSF compared to the control group, despite normal serum vitamin D levels. In paper IV, the main finding was that lower levels of vitamin D in CSF were associated with pathological levels of tau protein and phosphorylated tau protein, but not with β-amyloid in CSF. We did not find a consistent association between polymorphisms of vitamin D receptor with vitamin D levels or cognition, nor an association between vitamin D levels in CSF and selected cytokines in CSF. Interpretation and conclusion The results of this study support the hypothesis that vitamin D can be an important part of brain health and raise the question of whether vitamin D in the brain can have a metabolism that is partly independent of its metabolism in blood.

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