The testobolome in microbial testosterone metabolism and human health

This review proposes the "testobolome" — the collection of gut microbial genes and pathways that metabolize testosterone — as the androgen counterpart of the estrobolome. It traces testosterone from endogenous and exogenous sources through hepatic phase I/II metabolism to bile, then describes how luminal microbes deconjugate and structurally modify conjugated hormones, reactivating bioactive steroids that are reabsorbed into enterohepatic recirculation. The authors argue that only liver and intestine meaningfully contribute to testosterone reabsorption and map how microbial processes can raise or lower systemic sex-steroid levels.