Abstract
The effects of alginate consumption on the faecal microbiota and faecal metabolic activity were studied in eight healthy male volunteers who consumed a mixed free choice diet (control diet) for 1 wk before and after alginate consumption, and the diet with additional 10 g alginate once a day for 2 wks. During alginate consumption, the levels of bifidobacteria increased significantly (P < 0.05), while the levels of Enterobacteriaceae and the frequency of occurrence of lecithinase-negative clostridia showed tendencies to decrease. No detectable change occurred in the levels or the incidence of other microorganisms throughout the experimental period. Faecal sulphide, phenol, p-cresol, and indole were significantly decreased (P < 0.05) during alginate consumption. After 2 wks of alginate consumption, faecal concentrations of ammonia and skatole were significantly reduced (P < 0.05), whereas the values of acetic and propionic acids were significantly increased (P < 0.05). The water content and weight of the faeces were slightly increased to some extent during the consumption. The odour of the faeces decreased markedly during alginate consumption.