EFFECT OF DIETARY CHITOSAN ON FECAL MICROBIOTA AND FECAL METABOLITES OF HUMANS

The effects of chitosan (CS) intake on faecal microbiota and faecal me tabolites were studied in eight healthy volunteers who consumed a mixe d free choice diet (control diet) for 2 wks before and after CS intake (CN-1 and CN-2 period, respectively), and the same diet with an addit ional 3 g CS/day for 1 wk (CS-1 period) and 6 g CS/day for 1 wk (CS-2 period). During CS intake, there was no detectable change in the conce ntrations of the microorganisms examined throughout the experimental p eriods. However, the frequency of occurrence of lecithinase-negative c lostridia decreased significantly (P<0.05). Faecal concentrations of a mmonia, phenol, p-cresol and indole were significantly reduced (P<0.05 ). The values of total volatile fatty acid showed a significant increa se (P<0.01) from 14.3 +/- 3.2 mg/g to 20.3 +/- 2.4 mg/g on day 14 of t he intake, with a significant increase of acetic (P<0.05) and propioni c (P<0.01) acids, and a decrease of iso-valeric acid (P<0.05) during t he intake. The moisture and weight of the faeces were slightly increas ed during the intake, while the pH values were slightly decreased.