Probiotic Lactobacillus johnsonii RS-7 Alleviates Intestinal Inflammation Via the TLR4/MyD88/NF-κB Signaling Pathway.

Developing novel probiotics can help in preventing livestock diarrhea and associated intestinal diseases. Lactic acid bacteria (LAB) are symbiotic intestinal bacteria, which contribute to gastrointestinal tract health. An LAB strain, designated L. johnsonii RS-7, was isolated from the feces of healthy adult pigs and was resistant to acidic conditions and bile salts. In vitro evaluation showed significant antioxidant and anti-inflammatory properties, suggesting its potential application in alleviating intestinal inflammation. An artificially induced colitis model was established in mice to investigate the efficacy of L. johnsonii RS-7. Results indicated that mice administered water containing 3% DSS developed pronounced colitis symptoms, characterized by weight loss, elevated disease activity index, shortened colon length, microvilli shedding, tight junction disruption, reduced goblet cell counts, suppression of anti-inflammatory cytokines, activation of pro-inflammatory cytokines and the TLR4/MyD88/NF-κB signaling pathway, and impaired gut microbiota diversity. These suggest that oral administration of L. johnsonii RS-7 significantly alleviated colitis symptoms. In summary, L. johnsonii RS-7 acted as a probiotic by inhibiting activation of the TLR4/MyD88/NF-κB pathway.