Bacteriocin production: a probiotic trait?

Abstract

Bacteriocins are an abundant and diverse group of ribosomally synthesized antimicrobial peptides produced by bacteria and archaea. Traditionally, bacteriocin production has been considered an important trait in the selection of probiotic strains, but until recently, few studies have definitively demonstrated the impact of bacteriocin production on the ability of a strain to compete within complex microbial communities and/or positively influence the health of the host. Although research in this area is still in its infancy, there is intriguing evidence to suggest that bacteriocins may function in a number of ways within the gastrointestinal tract. Bacteriocins may facilitate the introduction of a producer into an established niche, directly inhibit the invasion of competing strains or pathogens, or modulate the composition of the microbiota and influence the host immune system. Here we review the role of bacteriocin production in complex microbial communities and their potential to enhance human health.

Fig 1

Mechanisms via which bacteriocin production could contribute to probiotic functionality. Bacteriocins may act as colonizing peptides, facilitating the competition of a probiotic with the resident microbiota (23); they may function as killing peptides, directly eliminating pathogens (9); or they may serve as signaling peptides, signaling other bacteria or the immune system (32, 40, 56).

Fig 2

Bacteriocin-mediated anti-infective activity of L. salivarius UCC118. Survival of luminescent L. monocytogenes EGDe in the livers of mice administered a placebo (no bacterium; black bar) or 10⁹ CFU L. salivarius UCC118 (gray bar) for 6 days prior to Listeria infection.