Lactobacillus Johnsonii Glj001 Prevents Dss-Induced Colitis in Mice by Inhibiting M1 Macrophage Polarization Via Gut Microbiota-Scfas Axis

Abstract

Inflammatory Bowel Disease (IBD) is increasing worldwide and has become a global emergent disease. Probiotics have been reported to be effective in relieving colitis. Previous studies found Lactobacillus johnsonii GLJ001, isolated from feces of ripened Pu-erh tea (RPT)-administrated mice, might be responsible for RPT preventing DSS-induced colitis in mice. However, its role in alleviation of DSS-induced colitis in mice needs to be validated. Upon finding L. johnsonii GLJ001 attenuated symptoms of DSS-induced colitis in mice, based on indexes (weight change, disease activity index, colon length, colon tissue damage, mRNA expression of inflammatory cytokines and intestinal barrier function), the enhanced abundance of short-chain fatty acids (SCFAs)-producing bacteria (i.e. Clostridium cluster IV and XIVa, Lachnospiracea_incertae_sedis and Ruminococcus) was disclosed, accompanying by increase of SCFAs production, which might be associated with macrophage polarization. By comparing the effect of SCFAs on M1 macrophage polarization, it was found that SCFAs inhibited mRNA expression of M1 macrophage markers (Inos and CD86), inflammatory cytokines (Tnf-α and Il-1β) and SCFAs receptors (Gpr41 and Gpr43) induced by lipopolysaccharide (LPS) and interferon-γ (IFN-γ) in THP-1 cell line. Collectively, L. johnsonii GLJ001 prevented DSS-induced colitis in mice by inhibiting M1 macrophage polarization via gut microbiota-SCFAs axis, and should be expected to be a supplement for prevention of colitis.

Note:
Funding declaration: This work was supported by the National Natural Science Foundation of China (grant no. 82360114).

Conflict of Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethical Approval: Animal experiments were approved by the Animal Ethics Committee of Nanchang University (No. 0064257).

Keywords: colitis, Lactobacillus johnsonii, gut microbiota, SCFAs, macrophages