Improvement of bowel movements among people with a sedentary lifestyle after prebiotic snack supply – preliminary study

INTRODUCTION: Dietary fiber is one of the most important components of food. Fulfilling regulatory and nutritional functions for the intestinal microbiota, it appears to be an essential ingredient for people with a sedentary lifestyle. AIM: We hypothesized that regular intake of a snack containing high amounts of soluble fibre in parallel to a regular diet may rapidly improve bowel habits with simultaneous elevation of synthesis of short-chain fatty acids (SCFA). MATERIAL AND METHODS: A total of 20 healthy volunteers, with a stool frequency of less than 3 spontaneous bowel movements per week, completed a 14-day double-blind, parallel-arm, randomized clinical trial with the intervention comprising daily intake of 2 doses (9.99% per 100 g or 13.91% per 100 g) of fibre. Food consumption was evaluated via 72-hour recall diaries at baseline and after 14 days of intervention. Gastrointestinal symptoms (abdominal comfort, distension, bloating, flatulence, stomach rumbling, number of bowel movements) were monitored via the IBS/VAS scale every day. RESULTS: We found that the elevated fibre intake improved bowel habits significantly (defecation frequency increased from 0.28 to 0.87 times/day; p = 0.0002) in both study arms. After 14 days of the trial, an increase in SCFA concentration (for whole study group: acetic p < 0.036, propionic p < 0.019, and butyric acid p < 0.0012 compared to baseline parameters) with no adverse gastrointestinal symptoms was reported. CONCLUSIONS: Short-term, regular intake of a snack containing soluble fibre improves the SCFA synthesis and bowel habits in healthy people living a sedentary lifestyle. The exact mechanism behind this observation requires further investigation.