Dietary Bacillus velezensis 411 improves intestinal health and antioxidant capacity via regulating the gut microbiota and the expression of MPEG1

Bacillus velezensis (B. velezensis) has recently received increasing attention as a biological fungicide and a potential probiotic agent because of its broad spectrum of antibacterial and antifungal activities. Here, a newly isolated B. velezensis strain 411 were characterized by comprehensive bioinformatics and comparative genomic analyses, and the beneficial traits of it were evaluated using in vitro and in vivo experimental approaches. Whole genome sequencing and assembly results showed that the genome of B. velezensis 411 consists of a circular chromosome, which encodes proteins involved in important biological processes such as sporulation, quorum sensing, and antibiotic synthesis. Additionally, dietary B. velezensis 411 did not affect the body weight, whereas significantly relieved weaning diarrhea in piglets, and improved intestinal antioxidant capacity. The addition of B. velezensis 411 significantly increased the abundance of Akkermansia in mice, and significantly decreased the abundance of pathogenic bacteria such as pathogenic Escherichia coli, Staphylococcus aureus, etc in piglets. The transcriptomic results suggest that B. velezensis 411 addition may affect the composition of intestinal microorganisms by regulating the expression of MPEG1 gene. Taken together, dietary B. velezensis can improve intestinal health via regulating the gut microbiota and the expression of MPEG1.