Reduced diversity and imbalance of fecal microbiota in patients with ulcerative colitis.

BACKGROUND: Clinical observations and experimental colitis models have indicated the importance of intestinal bacteria in the etiology of ulcerative colitis (UC), but a causative bacterial agent has not been identified. AIM: To determine how intestinal bacteria are associated with UC, fecal microbiota and other components were compared for UC patients and healthy adults. METHODS: Fresh feces were collected from 48 UC patients. Fecal microbiota were analyzed by use of terminal-restriction fragment length polymorphism (T-RFLP), real-time PCR, and culture. The concentrations of organic acids, indole, and ammonia, and pH and moisture, which are indicators of the intestinal environment, were measured and compared with healthy control data. RESULTS: T-RFLP data divided the UC patients into four clusters; one cluster was obtained for healthy subjects. The diversity of fecal microbiota was significantly lower in UC patients. There were significantly fewer Bacteroides and Clostridium subcluster XIVab, and the amount of Enterococcus was higher in UC patients than in healthy subjects. The fecal concentration of organic acids was significantly lower in UC patients who were in remission. CONCLUSION: UC patients have imbalances in the intestinal environment-less diversity of fecal microbiota, lower levels of major anaerobic bacteria (Bacteroides and Clostridium subcluster XIVab), and a lower concentration of organic acids.

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

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.