Lactobacillus johnsonii promotes polarization of M2-like macrophages through JAK-STAT pathway to relieve colitis

Ulcerative colitis (UC) is a chronic non-specific inflammatory disease of the intestinal tract. Due to the characteristics of limited treatment methods and easy recurrence, finding safer and more effective treatment strategies has become an urgent problem to be solved. Here, we hope to explore the mitigation effect of Lactobacillus johnsonii on UC and explore its relationship with the host immune system. We found that Lactobacillus johnsonii colonization was reduced in two mouse colitis models. Gavage Lactobacillus johnsonii could alleviate DSS-induced acute and chronic colitis models, and this effect is mediated by macrophages. We further found that Lactobacillus johnsonii can promote the polarization of M2-like macrophages through the JAK-STAT signaling pathway in vivo and in vitro, and can promote the secretion of anti-inflammatory factor Il-10. In addition, we tested the correlation between Lactobacillus johnsonii and M2-like macrophages, IL-10 in UC clinical samples. Taken together, we have discovered a new type of Lactobacillus, which as a probiotic can inhibit colitis and its anti-inflammatory effect may provide a new strategy for the treatment of UC.