The capacity of a microbial synbiotic to rescue the in vitro metabolic activity of the gut microbiome following perturbation with alcohol or antibiotics. in vitro batch human gut microbiota

The human gut microbiome contributes crucial bioactive metabolites that support human health, and is sensitive to perturbations from the ingestion of alcohol and antibiotics. We interrogated the response and recovery of human gut microbes after acute alcohol or broad-spectrum antibiotic administration in a gut model simulating the luminal and mucosal colonic environment with an inoculated human microbiome. Both alcohol and antibiotic treatments reduced the production of major short-chain fatty acids (acetate, propionate, and butyrate), which are established modulators of human health. Treatment with a microbial synbiotic restored and enhanced gut function. Butyrate and acetate production increased by up to 29.7% and 18.6% relative to untreated, dysbiotic samples. In parallel, treatment led to an increase in the relative abundances of beneficial commensal organisms not found in the synbiotic (e.g. Faecalibacterium prausnitzii and the urolithin producing Gordonibacter pamelae), as well as species present in the synbiotic (e.g. Bifidobacterium infantis), suggesting synergistic interactions between supplemented and native microorganisms. These results lead us to conclude that functional shifts in the microbiome -- evaluated by both metabolite production and specific taxonomic compositional changes -- are an appropriate metric to assess microbiome "recovery" following a dysbiosis-inducing disruption. Overall, these findings support the execution of randomized clinical studies to determine whether a microbial synbiotic can help restore microbiome function after disruption.