Your gut microbiome does far more than digest food — it's actively managing your oestrogen through a community of bacteria called the estrobolome. In perimenopause, declining hormones disrupt this microbial ecosystem, which then worsens hormone signalling in return. The result? A vicious cycle that may be driving your bloating, brain fog, hot flashes, mood crashes and weight gain harder than you realise. Here's the science — and what the evidence says actually helps.