The microbiome - the trillions of bacteria, viruses, and fungi in your gut - aren’t invaders but symbiotic partners. They break down carbs into short-chain fatty acids (SCFAs), synthesise essential vitamins, and even influence epigenetic processes throughout the body. One of the most profound roles of the microbiome is its impact on mood and brain health via the “gut–brain axis.” Changes in gut composition can ripple outward, altering neurotransmitter levels and behaviour. In a rat study, one month of finasteride treatment triggered a significant shift in gut microbiome composition that paralleled increased depressive‐like behaviour. Human studies echo this: patients on finasteride often show reduced microbial diversity, notably a drop in the Ruminococcaceae family. Intriguingly, loss of Ruminococcaceae has been implicated in Hypoactive Sexual Desire Disorder in women. Why does Ruminococcaceae matter? These bacteria churn out butyrate, a vital SCFA that serves as the primary energy source for colonic enterocytes (intestinal absorptive cells). Low butyrate has been linked to inflammatory bowel disease. For references and more visit: secondlifeguide.com/post-finasteri…