Did you know that up to 95% of your serotonin—the "happiness hormone"—is made in your gut, not your brain? This powerful connection between your gut and your mood is part of a fascinating system called the gut–brain axis. In this article, we’ll explore how your microbiome helps produce serotonin, why gut health matters for mental wellness, and the simple nutrition and lifestyle steps you can take to support both. If you’ve ever felt “off” in your digestion and your emotions, this is the science you’ve been waiting for.