Purpose : 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. Methods : 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. Results : 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.
Conclusion : 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