Effects of fermented brown rice on the intestinal environments in healthy adult.

The aim of this study is to investigate the prebiotic effects of brown rice fermented by Aspergillus oryzae (FBRA) on the intestinal environment in vitro and in healthy adults. Fresh fecal slurries from six healthy adults were incubated with FBRA to confirm prebiotic potentials of FBRA. Another thirty-six healthy adults were randomly allocated to 2 groups for the clinical study. Subjects consumed 21.0 g/day of either FBRA or control food for 2 weeks, followed by a 12-week intermission and then 2-week ingestion vice versa. Main outcome measures were bifidobacterial numbers and organic acid concentration in feces. Sub outcome measures were fecal microbiota, fecal environments and bowel function. Incubation of fecal slurries with FBRA in vitro resulted in increased organic acids with individual-specific patterns. Bifidobacterial numbers were increased during incubation. In the clinical study, all participants safely completed this study. FBRA had little effect on fecal number of bifidobacteria, concentrations of organic acids or putrefactive metabolites, fecal pH, or fecal microbiota. FBRA has the potentials as a prebiotic, however, we could not detect its effects on the intestinal environment in vivo. The results in a clinical study indicated that FBRA could be safely used for healthy adults.