eLife assessment
This study presents a valuable finding on the impact of metformin-induced shifts in gut microbial community structure and metabolite levels for drug efficacy in a mouse model of liver injury. The current evidence supporting the claims of the authors is incomplete, although inclusion of additional controls and a revision to clarify the reviewer's methodological concerns could strengthen the study. With revision, this paper could be of broad interest to researchers across multiple disciplines, including the microbiome, liver disease, and pharmacology.