GC-MS based metabolomic profiling of synbiotic action of probiotic lactobacilli with aqueous garlic extract against Salmonella spp.

Abstract

Probiotics and garlic extracts have shown promise as alternative treatments for Salmonella infections. This study aimed to explore the metabolomic interactions between probiotic lactobacilli and garlic extract in their action against Salmonella Typhi and Salmonella Typhimurium. Probiotic lactobacilli were isolated from fecal samples of Indian and Nigerian human subjects and screened for their probiotic and anti-Salmonella properties. Aqueous garlic extract (GE) was tested for its selective effects on both probiotic lactobacilli and Salmonella in broth cultures at varying concentrations. Standard plating techniques assessed the viability of the organisms. Coculture experiments involved Salmonella and Lactobacillus spp. in the presence of 125 mg/mL GE, identified as the minimum bactericidal concentration. Metabolomic profiling was performed using GC-MS, followed by statistical analyses, including hierarchical clustering, correlation analysis, and partial least squares discriminant analysis (PLS-DA), using MetaboAnalyst. At 125 mg/mL GE, a significant reduction in Salmonella populations was observed during synbiotic treatment, indicating a synergistic interaction between Lactobacillus and garlic extract. GC-MS analysis identified the up-regulation of key antimicrobial metabolites, including malic acid, pentanoic acid, pyrrolo[1,2-a]pyrazine-1,4-dione, and thymol-beta-D-glucopyranoside, in the garlic-Lactobacillus combination. The combination of probiotic lactobacilli and aqueous garlic extract exhibits a synergistic anti­ microbial effect against Salmonella, evidenced by reduced bacterial populations and enhanced production of bioactive metabolites. These findings highlight the potential of this synbiotic approach in developing alternative therapeutic strategies for Salmonella infections.