Presence of spores and vegetative cells in rat intestine and feces and their physiological effects.

This study was aimed to investigate the presence of vegetative cells in the intestine and fecal samples in rats fed spores as well as to estimate the ratios of spores and vegetative cells in these samples. A two-step process has been developed to enumerate in different mixed bacterial samples, specifically (1) observation of yellow ring formation on modified GYEA medium upon incubation at 55°C, (2) microscopic examination of spore formation after 7 d of incubation. Our results have demonstrated the presence of vegetative cells in the intestinal and fecal samples in rats fed spores. The ratios of spores and vegetative cells in cecal fluid, colonic content, and feces were approximately 2:8, 2:8, and 4:6, respectively. The existence of vegetative cells improved the intestinal milieu through an elevated short-chain fatty acid concentrations, higher fecal moisture, and lower fecal pH.