Effect Of Lactobacillus Acidophilus On Fecal Microbiota In ?-Lg Allergy Mice

Cow's milk allergy(CMA)is one of the earliest and most prevalent food allergies and?-lactoglobulin(?-Lg)is the major allergen.Studies have shown that CMA can destroy the intestinal microecological balance and intestinal immune tolerance.Furthermore,probiotics can promote the metabolism of the body by regulating the intestinal microflora,maintain the stability of the internal environment,and induce immune regulation or immune tolerance in patients with allergic diseases.However,so far there have been few studies on the relationship between probiotics regulating the host intestinal environment and alleviating the allergic inflammation of milk.Our previous study reported that oral administration of Lactobacillus acidophilus KLDS1.0738 was able to reduce?-Lg-induced hypersensitivity.This study aimed to further investigate the effect of L.acidophilus KLDS 1.0738 on the microbiome diversity and structure of allergic mice.1.L.acidophilus alleviates allergy symptoms in?-Lg allergy miceIn this study,?-Lg allergic mice model,which was randomly divided into blank group,?-Lg allergy group,commercial probiotic group,and different concentrations of L.acidophilus group(10~8 cfu/mL,10~9 cfu/mL),was used to evaluate the anti-allergy capacity of Lactobacilli.The results showed that the levels of total IgE and eosinophils were increased and the colon length was shorter in?-Lg allergy group.However,oral administration of L.acidophilus KLDS 1.0738 or commercial probiotics could relieve?-Lg-induced inflammatory.2.Effect of L.acidophilus on fecal microbiota of?-Lg allergic miceThen this study analyzed the effect of L.acidophilus on fecal microbiota diversity and structure in mice with?-Lg allergy by high-throughput sequencing.The results indicated that there were significant differences in the structural composition of the intestinal microbiota among the five groups.After L.acidophilus-treated,the overall structure of the fecal microbiota and the composition at different taxonomic levels were significantly different.First,the results of the alpha diversity index showed that the commercial probiotics and L.acidophilus increased the diversity and richness of fecal microbiota in?-Lg allergic mice compared with allergy group.At the phylum level,the dominant bacteria in the normal group were Firmicutes,followed by Bacteroidetes and Proteobacteria.Compared with the normal group,the number of the Firmicutes was significantly decreased(49.21%vs 32.37%,P<0.05),and the number of Proteobacteria(2.58%vs 18.47%,P<0.05)was significantly increased in allergic group.Commercial probiotics and L.acidophilus could significantly reduce the abundance of Proteobacteria(P<0.05).However,the change about the abundance of Firmicutes and Bacteroidetes was completely opposite in the commercial probiotics group and L.acidophilus group.At the family level,compared with the normal group,the proportion of Rikenellaceae,Bacteroidaceae and Helicobacteraceae in the allergic group was significantly increased(P<0.05),and the abundance of Ruminococcaceae and Lachnospiraceae were significantly decreased(P<0.05).Both commercial probiotics and L.acidophilus could reduce the levels of Rikenellaceae and Bacteroidaceae.However,compared with the allergy group,L.acidophilus could significantly increase the abundance of Ruminococcaceae and Lachnospiraceae,commercial probiotics could significantly reduce the abundance of them.At the genus level,the dominant bacteria in the normal group were Bacteroides(6.81%),Lachnospiraceae_NK4A136_group(30.16%),Alloprevotell(2.76%),Helicobacter(1.93%)and Rikenellaceae_RC9_gut_group(1.55%).The abundance of Helicobacter in the allergy group was significantly increased compared with normal group(P<0.05).After the intervention of L.acidophilus,the abundance of Helicobacter,Bacteroides and Rikenellaceae_RC9_gut_group was significantly decreased(P<0.05).Finally,this study has explored the specific flora that responds to allergy in the form of Heatmap.It was found that Alloprevotella,Bacteroides and Helicobacter were the dominant flora of the allergy group.After L.acidophilus-treat,the abundance of Bacteroidales_S24-7 and Lachnospiraceae-NK4A136 were significantly increased compared with the allergic group,while the abundance of Alloprevotella was significantly reduced(P<0.05).This study shows that?-Lg allergy could cause disorders in the intestinal flora of mice,and intervention with L.acidophilus could regulate the fecal microbiota of?-Lg allergy mice,which may be responsible for relieving allergic respond.