How Gut Bacteria Help Keep Estrogen in Circulation After Menopause

This review sets out the mechanics of how gut bacteria interact with oestrogen after the ovaries scale back production. Certain microbes produce β-glucuronidase, an enzyme that "reactivates" oestrogen so it can re-enter circulation rather than being excreted — meaning gut microbial diversity has a genuine hand in a woman's postmenopausal oestrogen status. The authors summarise research showing that postmenopausal women tend to have lower gut diversity than premenopausal women, and that this is associated with disrupted lipid metabolism, cognitive changes and greater osteoporosis risk. They position prebiotics and probiotics as a promising, if still underexplored, way to support this system. As a narrative review rather than original data, it synthesises existing evidence rather than testing anything new, and the authors are upfront that clinical application is still emerging. It's a helpful, plain-language account of why "gut health" and "hormonal health" aren't really separate conversations in midlife — they're two views of the same regulatory system.