Lactobacillus plantarum CLP-0611 ameliorates colitis in mice by polarizing M1 to M2-like macrophages

The TNF-α expression-inhibitory effect of lactic acid bacteria (LAB) isolated from kimchi were measured in lipopolysaccharide (LPS)-stimulated peritoneal macrophages. Among the LAB evaluated, Lactobacillus plantarum CLP-0611 inhibited the IL-1β and IL-6 expression, as well as the NF-κB and AP1 activation in LPS-stimulated peritoneal macrophages. Therefore, we investigated its inhibitory effect on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. TNBS significantly induced colon shortening, as well as myeloperoxidase activity and macroscopic score. Oral administration of CLP-0611 significantly reduced TNBS-induced body weight loss, colon shortening, myeloperoxidase activity, IRAK-1 phosphorylation, NF-κB and MAP kinase (p38, ERK, JNK) activation, and iNOS and COX-2 expression. CLP-0611 also inhibited TNBS-induced expression of TNF-α, IL-1β, and IL-6. However, IL-10 expression was induced. CLP-0611 also induced the production of M2 macrophage markers (IL-10, arginase I and CD206). Based on these findings, CLP-0611 inhibits TLR-4-linked NF-κB and MAPK signaling pathways and polarizes M1 to M2-like macrophages, thus ameliorating colitis.