Human-derived probiotic Lactobacillus reuteri demonstrate antimicrobial activities targeting diverse enteric bacterial pathogens

Abstract

Lactobacillus reuteri is a commensal-derived anaerobic probiotic that resides in the human gastrointestinal tract. L. reuteri converts glycerol into a potent broad-spectrum antimicrobial compound, reuterin, which inhibits the growth of gram-positive and gram-negative bacteria. In this study, we compared four human-derived L. reuteri isolates (ATCC 55730, ATCC PTA 6475, ATCC PTA 4659 and ATCC PTA 5289) in their ability to produce reuterin and to inhibit the growth of different enteric pathogens in vitro. Reuterin was produced by each of the four L. reuteri strains and assessed for biological activity. The minimum inhibitory concentration (MIC) of reuterin derived from each strain was determined for the following enteric pathogens: enterohemorrhagic Escherichia coli, enterotoxigenic E. coli, Salmonella enterica, Shigella sonnei and Vibrio cholerae. We also analyzed the relative abilities of L. reuteri to inhibit enteric pathogens in a pathogen overlay assay. The magnitude of reuterin production did not directly correlate with the relative ability of L. reuteri to suppress the proliferation of enteric pathogens. Additional antimicrobial factors may be produced by L. reuteri, and multiple factors may act synergistically with reuterin to inhibit enteric pathogens.

Lactobacillus reuteri in management of Helicobacter pylori infection in dyspeptic patients: a double-blind placebo-controlled randomized clinical trial

“…Third, probiotics could secrete antibacterial substances. It has been suggested that the antibacterial activity of the L. reuteri is related to an antimicrobial substance called reuterin which has bactericidal and bacteriostatic activities against a number of gram positive and negative bacteria and even some fungi [Hamilton-Miller, 2003;Spinler et al 2008]. Fourth, some strains of probiotics are known to have anti-inflammatory activity (e.g.…”

Lactobacillus reuteri DSM 17938 differentially modulates effector memory T cells and Foxp3+ regulatory T cells in a mouse model of necrotizing enterocolitis

“…These findings further support adhesion mechanisms in the probiotichost interaction. In addition, L. reuteri strains inhibit enteropathogenic E. coli by direct antimicrobial activity attributable to secreted reuterin (54) or to the repression of genes expressed by pathogenic E. coli (21).…”

Host-microbial symbiosis in the vertebrate gastrointestinal tract and the Lactobacillus reuteri paradigm

“…The mechanisms that underlie this protection have not been clearly identified, but might include an increase in competitive exclusion. Various L. reuteri strains produce an array of antimicrobial compounds that inhibit pathogens in vitro (76,77). The best characterized of those, reuterin, is a mixture of different forms of beta-hydroxypropionaldehyde (3-HPA) that have bactericidal and bacteriostatic activity against a wide range of bacterial pathogens (77).…”