Prebiotics and probiotics: Impact on gut microbial populations, nutrient digestibilities, fecal protein catabolite concentrations, and immune function of humans and dogs.

摘要

Prebiotics and probiotics are dietary constituents used to beneficially alter microbial populations in the gut and improve host health. Although the supplementation of these functional ingredients has demonstrated beneficial effects in several species, very little has been studied in humans and dogs. Therefore, the overall objective of this research was to evaluate the effects of supplemental prebiotics and (or) probiotics on indices associated with gut health in humans and dogs.; The first experiment tested the effects of a prebiotic [fructooligosaccharides (FOS)] and (or) a probiotic [Lactobacillus acidophilus (LAC)] on bowel function and fermentative end-product concentrations in adult humans. Prebiotic and probiotic supplementation resulted in minor effects on bowel function. Fructooligosaccharides decreased fecal isovalerate and ammonia concentrations, while LAC increased several fecal putrefactive compounds.; The second experiment tested the effects of a prebiotic (FOS) and (or) probiotic (LAC) on gut microbial populations, fermentative end-product concentrations, and nutrient digestibility by healthy dogs. Fructooligosaccharide supplementation improved gut microbial ecology, increased fecal butyrate and lactate concentrations, and decreased fecal putrefactive compound concentrations. Probiotic supplementation tended to improve gut microbial ecology and total tract nutrient digestibility. However, LAC supplementation increased several fecal putrefactive compounds.; The third experiment tested the effects of two prebiotics [FOS and mannanoligosaccharides (MOS)] on gut microbial populations, fermentative end-product concentrations, immune function, and nutrient digestibility by ileal-cannulated dogs. Fructooligosaccharides decreased concentrations of fecal putrefactive compounds, while MOS tended to increase fecal lactobacilli populations and improve immune capacity.; The fourth experiment tested the effects of FOS and MOS on ileal and fecal microbial populations and immune function in ileal-cannulated dogs. Fructooligosaccharide and MOS supplementation increased concentrations of fecal bifidobacteria, fecal lactobacilli, and ileal lactobacilli. A shift in blood immune cells also was observed.; These experiments demonstrated that prebiotic and (or) probiotic supplementation seems to improve indices associated with gut health of humans and dogs. However, caution should be taken, as LAC supplementation did result in some negative effects (e.g., increased fecal putrefactive compounds). Prebiotic and probiotic supplementation may be most beneficial to dogs with abnormal gut ecology or dogs under high stress conditions.