Manipulation of the Quorum Sensing Signal AI-2 Affects the Antibiotic-Treated Gut Microbiota

Abstract

The mammalian gut microbiota harbors a diverse ecosystem where hundreds of bacterial species interact with each other and their host. Given that bacteria use signals to communicate and regulate group behaviors (quorum sensing), we asked whether such communication between different commensal species can influence the interactions occurring in this environment. We engineered the enteric bacterium, Escherichia coli, to manipulate the levels of the interspecies quorum sensing signal, autoinducer-2 (AI-2), in the mouse intestine and investigated the effect upon antibiotic-induced gut microbiota dysbiosis. E. coli that increased intestinal AI-2 levels altered the composition of the antibiotic-treated gut microbiota, favoring the expansion of the Firmicutes phylum. This significantly increased the Firmicutes/Bacteroidetes ratio, to oppose the strong effect of the antibiotic, which had almost cleared the Firmicutes. This demonstrates that AI-2 levels influence the abundance of the major phyla of the gut microbiota, the balance of which is known to influence human health.

Microbiome engineering: Current applications and its future

“…Additionally, E. coli has been engineered to interrupt signalling between microbes as a means to alter microbiota composition. For instance, E. coli created to overproduce AI-2 signalling molecules rebalanced the Firmicutes/Bacteroidetes ratio caused by streptomycin-induced dysbiosis in mouse intestine [49]. Furthermore, vaccination against Vibrio cholerae infection in the gut has been achieved with E. coli overexpressing both AI-2 and the genus specific autoinducer-1 (CAI-1) [50][51][52].…”

“…Particularly, the dynamics of microbiome and interactions between microbes that determine the microbial composition are still not wellunderstood. Recently, E. coli has been engineered to output readable signals in response to quorum sensing molecules used for cell-to-cell communication within the microbiota [49,61], essentially allowing us to "eavesdrop" on the microbes. This strategy can potentially be used to complement existing omics techniques for high-throughput profiling of signalling within and changes to the microbial population over time, hence furthering our understanding of microbiome to accelerate progress in microbiome engineering.…”

“…Humans Administration of SCFAs, LED209, tempol, AI-2, CAI-1 [18,19,26,[49][50][51][52][53]61] Treat or prevent disorders and diseases e.g. metabolic syndrome, obesity and cholera…”

“…Humans Engineered microbes that overexpress quorum sensing molecules [49][50][51][52] Treat bacterial infection and dysbiosis…”

Borderline Products between Bio-fertilizers/ Bio-effectors and Plant Protectants: The Role of Microbial Consortia

“…Furthermore, the balance among the different components of a MC, in quantitative terms, will ultimately consist of a continuous shift between actively growing (i.e., viable and culturable) cells and non-dividing (i.e., viable but non-culturable) cells of the various components of the total population. It is known that different microbial populations in a given environment "talk" to each other (e.g., through the "quorum sensing" mechanism) by exchanging precise chemical signals [26]. Natural MC holds many appealing properties also in a bioprocessing context, such as stability, functional robustness and the ability to perform complex tasks.…”