Dietary supplementation of Bacillus sp. DU106 activates innate immunity and regulates intestinal microbiota in mice

Abstract

• Bacillus sp. DU106 is a newly isolated member of the Bacillus cereus group. • Dietary supplementation of Bacillus sp. DU106 enhances body immune organ indexes and lymphocyte transformation rate in vitro . • Bacillus sp. DU106 supplementation increases the level of sIgA and sIgG in vitro . • Bacillus sp. DU106 modulates gut microbiome structure and composition. Probiotic dietary supplementation plays a crucial role in shaping gut microbiota and enhance gut health. In this study, we explored the mechanism of Bacillus sp. DU106, a new member of Bacillus cereus by which analyzed the immune cytokines, immunoglobulins, gut microbial community structure, and compared with three different strains of probiotics affected innate immunity. The result revealed that the thymus index, T lymphocyte transformation rate, sIgA and sIgG were increased remarkably (p < 0.05) in DU106 group. 16S rRNA sequencing analyzed revealed that the community structure of gut microbiota was altered, the genus of Akkermansia, Bifidobacterium and Faecalibaculum, the family of Lactobacillaceae and the phylum of Verrucomicrobia, showed obvious increased in DU106 group, while the species of Actinobacteria, Streptococcus, and Bacteroidesfragilis, were detected to be downregulated in all supplement groups, and reduced significantly in DU106 group. These findings suggest that Bacillus sp. DU106 could be a potential probiotic for activating innate immunity.