2.4. Bowel Habits and Analyses of Fecal Samples
All participants were directed to record daily defecation frequency, stool volume, and stool form. Stool volume was compared with a ball-shaped model 40 mm in diameter. The stool form was evaluated according to the Bristol Stool Scale (BSS) [Fecal samples were collected per participant at the start and end of the intervention. The samples were frozen in the freezers after collection and brought to the study site during the visits. These samples were analyzed for metabolite composition and microbiota composition. Analyses using CE-TOFMS were performed using the Agilent CE-TOFMS system (Agilent Technologies, Waldbronn, Germany) with procedures developed by Soga et al. [DNA isolation from fecal samples was performed by beads beating previously described [