Exploring drug metabolism by the gut microbiota: modes of metabolism and experimental approaches

Increasing evidence uncovers the involvement of gut microbiota in the metabolism of numerous pharmaceutical drugs. The human gut microbiome harbours 10-100 trillion symbiotic gut microbial bacteria that utilize drugs as substrates for enzymatic processes to alter host metabolism. Thus, microbiota-mediated drug metabolism can change the conventional drug action course and cause inter-individual differences in efficacy and toxicity, making it vital for drug discovery and development. This review focuses on drug biotransformation pathways and discusses different models for evaluating gut microbiota role in drug metabolism. Significance Statement This review emphasizes the importance of gut microbiota and different modes of drug metabolism mediated by them. It provides information on in vivo, in vitro, ex vivo, in silico and multi-omics approaches for identifying the role of gut microbiota in the metabolism. Further, it highlights the significance of gut microbiota mediated metabolism in the process of new drug discovery and development as a rationale for safe and efficacious drug therapy.