Bacillus velezensisHBXN2020 alleviatesSalmonellaTyphimurium-induced colitis by improving intestinal barrier integrity and reducing inflammation

Abstract

AbstractBacillus velezensisis a novel species of Bacillus that has been widely investigated because of its broad-spectrum antimicrobial activity. However, most studies onBacillus velezensishave focused on biocontrol of plant diseases, with few reports on antagonizingSalmonellaTyphimurium infections. In this study,Bacillus velezensisHBXN2020 was isolated from healthy black piglets and was found to exhibit broad-spectrum antibacterial activity and robust anti-stress capabilities. Importantly,Bacillus velezensisHBXN2020 did not cause any adverse side effects in mice when administered at various doses (1 × 107, 1 × 108, and 1 × 109CFU) for 14 days. In aSalmonellaTyphimurium ATCC14028-induced mice colitis model, either curative or prophylactic, supplementingBacillus velezensisHBXN2020 spores significantly lowered the levels ofSalmonellaTyphimurium ATCC14028 in their feces, ileum, cecum, and colon, and the disease activity index (DAI). Importantly, supplementingBacillus velezensisHBXN2020 spores significantly regulated cytokine levels (TNF-α, IL-1β, IL-6, and IL-10) and maintained the expression of tight junction proteins and mucin protein. More importantly, supplementingBacillus velezensisHBXN2020 spores also significantly enhanced the homeostasis of colonic microbiota and the abundance of beneficial bacteria. Collectively,Bacillus velezensisHBXN2020 can alleviate bacterial colitis by enhancing intestinal homeostasis and gut barrier integrity and reducing inflammation.