Dietary supplementation with a novel wild-type Pediococcus acidilactici strain suppresses inflammation and modulates the gut microbiome in a mouse model of colitis

Background Ulcerative Colitis is an inflammatory disorder characterized by significant gut microbial alterations. In this context, probiotics emerge as a promising means for modulating the microbiome and addressing this chronic, relapsing inflammatory disorder which lacks effective treatment options. We investigated the anti-inflammatory effect of Pediococcus acidilactici SK2, a novel wild-type potential probiotic strain isolated from the human gastrointestinal tract in the DSS-induced murine model of ulcerative colitis. Methods and results Mice received dietary supplementation containing P. acidilactici SK2 cells at a daily dose of 10 9 CFU and were subjected to DSS administration. The anti-inflammatory effect of P. acidilactici SK2 was confirmed by reduced mRNA and protein levels of pro-inflammatory cytokines and chemokines. Expression of mucus and tight junction genes was enhanced, suggesting the beneficial role of P. acidilactici SK2 on epithelial barrier integrity. Additionally, 16S rRNA analysis revealed beneficial changes in gut microbial composition. Conclusion P. acidilactici SK2 arises as a promising dietary supplement with targeted anti-inflammatory and barrier-protective properties against a murine DSS-induced colitis model, necessitating further preclinical and clinical evaluation of its mechanisms of action and its potential against ulcerative colitis.