Lactobacilli Mitigate Gut Inflammation by Modulating T-Helper/T-Regulatory Cells and Suppressing Signaling Pathways...

Intestinal inflammation disrupts epithelial integrity, fuels antibiotic resistance, and underlies disorders such as inflammatory bowel disease. Lactobacillus species, established inhabitants of traditional and contemporary fermented foods, are increasingly viewed as bioactive cultures that shape host immunity and support formulation of next-generation functional foods. This review integrates multidisciplinary evidence from in vitro studies, animal models, human observations, and multi omics datasets to clarify how dietary or probiotic Lactobacillus strains alleviate gut inflammation. Particular attention is given to strain specific effects on T-helper/T-regulatory cell balance, suppression of TLR4-MyD88, NF-κB, MAPK, and NLRP3 signaling cascades, and the influence of food matrices, microencapsulation, dosage, and processing parameters on bacterial viability and efficacy, which are the factors central to food industry application. Across models, Lactobacillus consistently down regulates pro-inflammatory Th1/Th17 responses, while expanding forkhead box protein 3 (Foxp3⁺) T reg, leading to reduced TNF-α, IL-1β, and IL-6 and elevated IL-10 and TGF-β. Short chain fatty acids (SCFAs) and indole metabolites derived from fermentation further dampen NF-κB activity and reinforce epithelial barrier function. Food matrix studies show that dairy and cereal formulations enhance probiotic survival, whereas acidic beverages often require micro encapsulation; a daily intake of ~ 10¹⁰ CFU appears both effective and safe. Taken together, these insights position Lactobacillus as a scientifically robust, industry ready tool for developing anti-inflammatory foods, prioritizing future work for well-designed human feeding trials that couple multi-omics read outs and optimizing strain matrix combinations.