Fermentation Characterization of Chinese Yam Polysaccharide and Its Effects on the Gut Microbiota of Rats
This study was conducted with the rat model to characterize 4 fractions of the Chinese Yam polysaccharide (CYP 1, CYP 2, CYP 3, and CYP 4) in vitro and in vivo. In Exp. 1, cecal digesta was collected from SD rats fed the normal diet and used as the control inoculum, and the four CYPs were used as the substrates during 48-h fermentation in an anaerobic in vitro system. The fermentation kinetic parameters, pH value, NH3 content, production and composition of short-chain fatty acids (SCFA), and bacterial community diversity in the fermentation broth were determined. The maximum volume and rate of gas production in the CYP 3- supplemented group were higher (P < 0.05) compared with the other CYP-supplemented groups and the control group, while the pH values and NH3 contents in CYP 2-, CYP 3-, and CYP 4-supplemented groups were lower (P < 0.05) than the control group. Contents of acetate, propionate, and butyrate were increased (P < 0.05) by CYP 3 or CYP 4 supplementation compared to the other groups except for the glucose-supplemented group. Contents of isobutyrate for the 4 CYPs groups were decreased (P < 0.05) in comparison with the control group. Denaturing gradient gel electrophoresis (DGGE) analysis showed that CYP 3 enhanced the density of the beneficial gut microbiota with the same migration distance with Lactobacillus amylovorus, and Ruminococcus forques, but suppressed bacterial pathogens co-migrating with Staphylococcus aureus, Salmonella typhimurium and Clostridium lituseburense. Therefore, CYP 3 was chosen for an in vivo study. In Exp. 2, forty SD rats were randomly assigned into 1 of 4 treatment groups,representing supplement of 0, 0.25, 0.5 or 1.0 g/kg of CYP 3 to maize- and soybean meal-based diets (n = 10). Cecal digesta of 4 rats per group were collected on days 7 and 21 to determine the above parameters in cecal digesta except for the fermentation kinetic parameters. On day 7, contents of acetate and butyrate in cecal digesta of rats fed 0.25 or 0.5 g CYP 3 per kg diet were higher (P < 0.05) than the other 2 groups, and propionate in the 0.25 g/kg of CYP 3 group was greater (P < 0.05) than the other groups. The pH values in rats fed 0.25 or 0.5 g/kg of CYP 3 were lower (P < 0.05) than the 1.0 g/kg CYP 3 group. The contents of acetate in 0.25 or 0.5 g/kg of CYP 3 group were greater (P < 0.05) than the other 2 groups on day 21. The profiles of DGGE indicated that the gut microflora in the CYP 3-supplemented rats had more diversity than the none-supplemented rats. Consistently, CYP 3 enriched the density of beneficial gut microbiota with the same migration distance with Lactobacillus amylovorus and Bacillus subtilis, but suppressed bacterial pathogens co-migrating with Salmonella typhimurium in rat cecum. Collectively, these findings suggested that CYP 3, as a phytochemical dietary additive, is a good source of carbon and energy, and may improve bacterial community diversity and modulate SCFA production in hindgut of rats.
fermentation Chinese Yam polysaccharides gut bacteria
X.F.Kong T.J.Li Y.Z.Zhang X.Wu Y.L.Yin Z.L.Tan F.Yang F.Y.Yan M.J.Bo R.L.Huang
Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of SubtropicalAgricult Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agricul Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of SubtropicalAgricult
国际会议
4th International Symposium on Animal Nutrition,Health and Feed Additive(第四届动物营养、保健与饲料添加剂国际学术研讨会)
广州
英文
290-309
2009-07-04（万方平台首次上网日期，不代表论文的发表时间）