Effect Of Yeast Polypeptide Combined With Probiotic Lactobacillus Casei Zhang On Fecal Microbiota And Immunity Of Rats

As a bioactive polypeptide,yeast polypeptide can regulate the physiological function of body.Lactobacillus casei Zhang(LCZ)was isolated from traditional koumiss,which has many probiotic properties.At present,there are relatively few researches on the probiotic function of yeast polypeptide combined with probiotics.Dietary intervention was administered to 72 rats for 10 weeks by using yeast polypeptide(YP),soybean polypeptide(SP),probiotics(LCZ,4×109 CFU/d),yeast polypeptide combined with LCZ(YPZ)and soybean polypeptide combined with LCZ(SPZ),and the effects of yeast polypeptide combined with probiotics on fecal microbiota and immunity were explored with immune factors,serum metabolites and fecal microbiota.The results are as follows:(1)The results of the immune factors:level of the inflammatory factors IL-1?,RANTES,MIP-1? and MIP-2 were significantly reduced in YPZ group(P?0.05).The level of inflammatory factors MCP-1 and MIP-2 were significantly reduced(P?0.05)but the inflammatory factor GRO-? was significantly enhanced in SPZ group(P?0.05).There was no significant change in the other 4 groups(P?0.05).In addition,the levels of inflammatory factors in YPZ group were lower than those in SPZ group.(2)Results of serum differential metabolites:the content of anti-inflammatory metabolite N-methyl arachidonic amine in serum of rats in YPZ group and SPZ group was increased significantly(P?0.05).(3)Results of correlation between serum differential metabolites and differential immune factors:level of RANTES,MIP-1?,MIP-2 and MCP-1 were negatively correlated with the level of anti-inflammatory metabolite N-methyl arachidonic amine in YPZ group and SPZ group.(4)Results of fecal differential bacteria:the average relative contents of beneficial bacteria Roseburia and Bacteroides dorei of YPZ group were significantly increased(P<0.05),and the average relative contents of beneficial bacteria Ruminococcus flavefaciens and lachnospiraceae bacillium 1 1 57FAA of SPZ group were significantly increased as well(P?0.05).(5)Results of correlation between inflammatory factors and fecal bacteria:the beneficial bacteria Roseburia and Bacteroides dorei were increased significantly in YPZ group,which were negatively correlated with the level of MIP-1? and MIP-2.The beneficial bacteria Ruminococcus flavefaciens and Lachnospiraceae bacterium 1 1 57FAA were increased significantly in SPZ group,which were negatively correlated with the level of MIP-2 as well.Yeast polypeptide combined with LCZ can regulate the levels of inflammatory factor MIP-2 by enhancing beneficial bacteria Roseburia and Bacteroides dorei or regulate the levels of inflammatory factors RANTES,MIP-1?,MIP-2 and MCP-1 by enhancing the content of anti-inflammatory metabolite N-methyl arachidonic amine,thus enhancing host immunity,and the effect is better than soybean polypeptide combined with probiotic LCZ.This research can not only further broaden the research field of the fecal microbiota and human health,but also promote industrial application of yeast polypeptide and probiotics.