Abstract
The effects of chitosan (CS) intake on faecal microbiota and faecal metabolites were studied in eight healthy volunteers who consumed a mixed 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 additional 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 concentrations of the microorganisms examined throughout the experimental periods. However, the frequency of occurrence of lecithinase-negative clostridia decreased significantly (P<0.05). Faecal concentrations of ammonia, phenol, p-cresol and indole were significantly reduced (P<0.05). The values of total volatile fatty acid showed a significant increase (P<0.01) from 14.3 ± 3.2 mg/g to 20.3 ± 2.4 mg/g on day 14 of the intake, with a significant increase of acetic (P<0.05) and propionic (P<0.01) acids, and a decrease of iso-valeric acid (P<0.05) during the intake. The moisture and weight of the faeces were slightly increased during the intake, while the pH values were slightly decreased.