The aim of this study is to investigate the effects of enzymatic treatment to reduce GOS (galactooligosaccharides) in legume-based crackers in IBS (irritable bowel syndrome) persons. The crackers are pea-based: the control crackers contain high amounts of GOS, while the enzymatically treated crackers contain a minimal amount of GOS. The participants will eat each type of cracker for three days (daily dose of 12 crackers) and report their gut symptoms (e.g. flatulence, stomach pain, bloating) by using a mobile app. There is a washout period of four days between the different crackers. In addition, the participants will keep food records on the cracker eating days as well as collect five fecal samples during the study. The participants will also report their physical activity and the number of defecations on each day. The study is carried out in a double-blinded crossover setting.

A human intervention study with volunteers suffering from either irritable bowel syndrome (IBS) or functional bloating (FB) will be carried out to investigate the effects of enzymatic treatment of pea-based product on gastrointestinal symptoms and gut microbiota composition as well as hydrogen production due to carbohydrate fermentation. Enzyme-treated product will be compared to a control product.

The aim of the study is to investigate, whether enzyme-treated cracker, compared to a control product, will reduce gastrointestinaI symptoms, or have an impact on fecal microbiome or carbohydrate fermentation measured by breath hydrogen concentration. The effects of eating enzyme-treated crackers on food intake, exercise and stool frequency will also be investigated.

The study is carried out in a randomized, double-blinded, placebo-controlled crossover design. The study includes two 1-week treatment periods with 1-week run-in period before the intervention. Participants (N=35 at the maximum) are adult males and females who meet Rome IV criteria for IBS or FB.

Exclusion criteria will be as follows:

• coeliac disease
• inflammatory bowel disease
• pregnancy or breastfeeding
• antibiotics within the last 3 months
• colonoscopy and preparations for it within 4 weeks

During both treatment weeks each participant will receive three-day portion of either α-galactosidase-treated or control pea-based crackers. The participants will be advised to avoid foods that trigger their gastrointestinaI symptoms and otherwise follow their habitual diets for the whole 3-week study period. They will be asked to report severity of nine gastrointestinaI symptoms, keep food record, collect fecal samples, measure breath hydrogen and report their physical activity as well as stool frequency.

The participants will report their gastrointestinal symptoms throughout the study weeks (twice a day on cracker eating days, once on washout days). Physical activity and stool frequency will also be reported daily. Fecal samples will be collected during the run-in period (at baseline) and on third and seventh day of each treatment week. Breath hydrogen will be measured on second day of both treatment weeks. Nutrient intake and food consumption will be analyzed from 3-day food records during the run-in week and each treatment week (total 9 days). Nutrient intake will be calculated using a new Finnish 'Aromi Diet' software.

Inclusion Criteria:

• IBS (Rome IV criteria) or functional bloating
• over 18 years old

Exclusion Criteria:

• IBD (inflammatory bowel disease)
• coeliac disease
• pregnancy or breastfeeding
• antibiotics within the last 3 months
• colonoscopy and preparations for it within 4 weeks

Data cannot be shared

The study is double-masked - neither the researchers or the participants know which cracker they are eating.