Affiliation:
1. National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University
2. College of Veterinary Medicine, Huazhong Agricultural University
3. Key Laboratory of Preventive Veterinary Medicine in Hubei Province, the Cooperative Innovation Center for Sustainable Pig Production
Abstract
Bacillus velezensis
is a species of
Bacillus
that has been widely investigated because of its broad-spectrum antimicrobial activity. However, most studies on
Bacillus velezensis
have focused on the biocontrol of plant diseases, with few reports on antagonizing
Salmonella
Typhimurium infections. In this investigation, it was discovered that
Bacillus velezensis
HBXN2020, which was isolated from healthy black pigs, possessed strong anti-stress and broad-spectrum antibacterial activity. Importantly,
Bacillus velezensis
HBXN2020 did not cause any adverse side effects in mice when administered at various doses (1 × 10
7
, 1 × 10
8
, and 1 × 10
9
CFU) for 14 d. Supplementing
Bacillus velezensis
HBXN2020 spores, either as a curative or preventive measure, dramatically reduced the levels of
Salmonella
Typhimurium ATCC14028 in the mice’s feces, ileum, cecum, and colon, as well as the disease activity index (DAI), in a model of colitis caused by this pathogen in mice. Additionally, supplementing
Bacillus velezensis
HBXN2020 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. Most importantly, adding
Bacillus velezensis
HBXN2020 spores to the colonic microbiota improved its homeostasis and increased the amount of beneficial bacteria (
Lactobacillus
and
Akkermansia
). All together,
Bacillus velezensis
HBXN2020 can improve intestinal microbiota homeostasis and gut barrier integrity and reduce inflammation to help treat bacterial colitis.
Publisher
eLife Sciences Publications, Ltd