Professor Siobhain O’Mahony, neurobiological scientist and microbiome researcher, joins us to discuss how your microbes talk to your hormones and your brain. She explains the gut microbiome, why most serotonin is made in the gut, and how the estrobolome can influence estrogen levels, touching endometriosis, perimenopause, and menopause. Professor O’Mahony also talks about “leaky gut,” stress, and practical ways fiber, prebiotics, and probiotics can support our mood.