Summary: Background: Grains are high in FODMAPs (Fermentable Oligo‐, Di‐, Monosaccharides And Polyols) and often considered as triggers of IBS symptoms.Aim: To evaluate if rye bread low in FODMAPs would be better tolerated than regular rye bread in subjects with IBS.Methods: The study was conducted as a randomised double blind controlled cross‐over study (n = 87). Participants were supplied with both regular rye bread and low‐FODMAP rye bread for 4 weeks. Symptoms were measured with a symptom severity scoring system (IBS‐SSS) and visual analogue scale (VAS) assessments of individual symptoms. Quality of life was monitored. Colonic fermentation was measured by the breath hydrogen test and dietary intake by food diaries.Results: Dietary fibre intake increased during both study periods compared to baseline. Many signs of IBS i.e. flatulence, abdominal pain, cramps and stomach rumbling were milder on the low‐FODMAP rye bread (P‐values: 0.04; 0.049; 0.01 and 0.001). The mean of VAS measurements was favourable towards LF bread [−3 (95% CI): −6 to −1, P = 0.02] but no differences were detected in IBS‐SSS or quality of life. The AUC of breath hydrogen values was significantly lower during the low‐FODMAP bread period (median 52.9 vs. 72.6; P = 0.01).Conclusions: Low‐FODMAP rye bread helps IBS patients to control their symptoms and reduces gastrointestinal gas accumulation. However, replacing regular rye bread by low‐FODMAP bread without concomitant broader dietary changes does not improve quality of life or IBS‐SSS. Nonetheless, inclusion of low‐FODMAP rye bread in diet might be one way that IBS patients could increase their fibre intake.

Many patients suspect wheat as being a major trigger of their irritable bowel syndrome (IBS) symptoms. Our aim was to evaluate whether sourdough wheat bread baked without baking improvers and using a long dough fermentation time (>12 h), would result in lower quantities of alpha-amylase/trypsin inhibitors (ATIs) and Fermentable, Oligo-, Di-, Mono-saccharides and Polyols (FODMAPs), and would be better tolerated than yeast-fermented wheat bread for subjects with IBS who have a poor subjective tolerance to wheat. The study was conducted as a randomised double-blind controlled 7-day study (n = 26). Tetrameric ATI structures were unravelled in both breads vs. baking flour, but the overall reduction in ATIs to their monomeric form was higher in the sourdough bread group. Sourdough bread was also lower in FODMAPs. However, no significant differences in gastrointestinal symptoms and markers of low-grade inflammation were found between the study breads. There were significantly more feelings of tiredness, joint symptoms, and decreased alertness when the participants ate the sourdough bread (p ≤ 0.03), but these results should be interpreted with caution. Our novel finding was that sourdough baking reduces the quantities of both ATIs and FODMAPs found in wheat. Nonetheless, the sourdough bread was not tolerated better than the yeast-fermented bread.

A low intake of Fermentable, Oligo-, Di-, Mono-saccharides and Polyols (FODMAPs) is effective in the symptom control of irritable bowel syndrome (IBS) patients but may exert negative effects on the intestinal microbiota. The microbial effects of increasing regular or non-FODMAP fibre sources are largely unknown. Furthermore, it is not known if the baseline microbiota composition is associated with individual symptom control during the consumption of different rye products in IBS patients. Our objective was to evaluate whether increased consumption of low-FODMAP rye bread or regular rye bread for 4 weeks would alter the intestinal microbiota composition of IBS patients following their habitual diet, and whether these changes associate to symptoms and/or the baseline microbiota. The study was conducted as a randomized double blind controlled cross-over study (n = 50). Microbiota was analysed by 16S rRNA gene sequencing and associated with gastrointestinal symptoms. Both microbial changes and their associations to symptoms were secondary outcomes. The consumption of the test breads did not alter microbiota diversity. Compared to baseline, consumption of the low FODMAP rye bread decreased the abundance of Bacteroides, Flavonifractor, Holdemania, Parasutterella and Klebsiella and showed a trend towards increased bifidobacteria, whereas the regular rye bread decreased the abundance of Flavonifractor. When comparing between the two test breads, Klebsiella was decreased after low-FODMAP rye bread intake. Patients whose symptoms decreased during the low-FODMAP rye bread displayed more Blautia and less Barnesiella at baseline. Consumption of low-FODMAP rye bread had modest, potentially beneficial effects on patients’ microbiota while increasing their intake of fibre substantially. The baseline microbiota composition was associated with the variable degrees of symptom relief experienced by the patients. Consumption of a low-FODMAP rye bread might be one way to increase dietary fibre intake and improve the mild dysbiosis often observed among patients with IBS. ClinicalTrials.gov: NCT02161120 . Retrospectively registered 11 June 2014.

Unspecific gastrointestinal symptoms associated with milk consumption are common. In addition to lactose, also other components of milk may be involved. We studied whether the partial hydrolysation of milk proteins would affect gastrointestinal symptoms in subjects with functional gastrointestinal disorders. In a randomised, placebo-controlled crossover intervention, subjects (n = 41) were given ordinary or hydrolysed high-protein, lactose-free milkshakes (500 mL, 50 g protein) to be consumed daily for ten days. After a washout period of ten days, the other product was consumed for another ten days. Gastrointestinal symptoms were recorded daily during the study periods, and a validated irritable bowel syndrome-symptom severity scale (IBS-SSS) questionnaire was completed at the beginning of the study and at the end of both study periods. Blood and urine samples were analysed for markers of inflammation, intestinal permeability and immune activation. Both the IBS-SSS score (p = 0.001) and total symptom score reported daily (p = 0.002) were significantly reduced when participants consumed the hydrolysed product. Less bloating was reported during both study periods when compared with the baseline (p < 0.01 for both groups). Flatulence (p = 0.01) and heartburn (p = 0.03) decreased when consuming the hydrolysed product but not when drinking the control product. No significant differences in the levels of inflammatory markers (tumor necrosis factor alpha, TNF-α and interleukin 6, IL-6), intestinal permeability (fatty acid binding protein 2, FABP2) or immune activation (1-methylhistamine) were detected between the treatment periods. The results suggest that the partial hydrolysation of milk proteins (mainly casein) reduces subjective symptoms to some extent in subjects with functional gastrointestinal disorders. The mechanism remains to be resolved.

Background: Animal models have provided some evidence of the pro-inflammatory effects of the commonly used emulsifier carrageenan. However, the effects of food-grade carrageenan among people with ulcerative colitis (UC) are largely unknown. Methods: A randomized, placebo-controlled cross-over study comparing high molecular carrageenan and oat-based beta-glucan preparation (placebo) among patients (n = 7) with quiescent UC was performed. Primary endpoint was Simple Clinical Colitis Activity Index (SCCAI) at the end of the treatment (7th day). Secondary analyses included biochemical biomarkers of inflammation, intestinal permeability, detoxification of intestinal lipopolysaccharide (LPS), and gastrointestinal symptoms measured by visual analog scale. Results: There were no statistically significant differences in SCCAI or any biochemical markers between carrageenan and placebo periods, nor were there any significant differences when comparing either period to baseline. Gastrointestinal symptoms were higher during the placebo period; the sum of all symptoms and borborygmi was statistically significantly higher at the end of the placebo period than at the end of the carrageenan period (20.8 ± 18.6 vs. 13.3 ± 16.4; P = 0.031, and 29.7 ± 28.6 vs. 17.9 ± 23.6; P = 0.016). Conclusions: Our study suggests that at least short-term usage of food-grade carrageenan is safe among people with UC, but given the limitations of the current study, robust human studies are still urgently needed.

Chemotherapy-induced mucosal injury of the small intestine may interfere with the enzymes and transporters responsible for the hydrolysis and absorption of dietary carbohydrates causing diarrhoea, abdominal discomfort and pain. The aim of this study was to investigate the association between the consumption of foods rich in FODMAPs (fermentable oligo-, di- and monosaccharides and polyols) and gastrointestinal symptoms in patients receiving adjuvant therapy for colorectal cancer. The patients (n = 52) filled in a 4-day food diary at baseline and during therapy and kept a symptom diary. The intakes of FODMAP-rich foods were calculated as portions and the intakes were divided into two consumption categories. Patients with high consumption of FODMAP-rich foods had diarrhoea more frequently than those with low consumption (for lactose-rich foods the odds ratio (OR) was 2.63, P = 0.03; and for other FODMAP-rich foods 1.82, P = 0.20). Patients with high consumption of both lactose-rich and other FODMAP-rich foods had an over 4-fold risk of developing diarrhoea as compared to those with low consumption of both (OR, 4.18; P = 0.02). These results were confirmed in multivariate models. Conclusion: Consumption of lactose-rich foods results in an increased risk of diarrhoea during adjuvant therapy for colorectal cancer, especially when the consumption of other FODMAP-rich foods is also high.