Every so often someone asks me if gut health actually affects mood, usually a little sheepishly, like it sounds crazy to ask. Totally not crazy and deeply rooted in physiology! This is the actual chain of events, step by step, not just the concept. Ready?! It starts with fiber! Bet you didn't see that coming! When gut bacteria ferment fiber you can't digest yourself, they produce short-chain fatty acids. Those short-chain fatty acids reach cells lining your gut called enterochromaffin cells, and they upregulate an enzyme these cells use to make serotonin (Margolis et al., 2021). That's significant because enterochromaffin cells make over ninety percent of your body's serotonin, not your brain (Margolis et al., 2021). The serotonin doesn't just sit there. These same gut cells form direct, synapse-like connections onto vagus nerve fibers, physical contact points built for signaling (Margolis et al., 2021). So the serotonin produced from fiber fermentation activates the vagus nerve right at these contact points. One thing to be clear on now though: the serotonin itself never leaves the gut. It doesn't cross the blood-brain barrier, and it never reaches your brain directly (Margolis et al., 2021). What travels instead is the signal it triggers. The vagus nerve fires in response to that local serotonin activity, and that electrical signal is what actually makes the trip. :) (Lesson 2 of The Nervous System is up now in The Classroom, where we cover the vagus nerve in depth! Available to Premium Members!) From there, the vagus nerve carries that signal up to the brainstem, specifically to a region that also houses most of your brain's own serotonin-producing neurons (Margolis et al., 2021). So to recap: fiber intake to bacterial fermentation to serotonin synthesis to a physical nerve contact point to an electrical signal reaching a brainstem region tied to mood! This whole thing shows up clinically in IBS! People with IBS carry more than triple the risk of an anxiety diagnosis, and a year-long study found gut dysfunction often comes first, driving the mood symptoms rather than following them (Margolis et al., 2021).

First monograph in this category: Scutellaria lateriflora. One of my favorite nervines, and a plant we'll keep returning to as we move through the nervous system together. Save it, print it, mark it up!

Hi all! I'm Agy, and I'm really excited that you're here. Let me quickly introduce myself. I trained as a physician at Wrocław Medical University in Poland (MD, non-practicing). From there I moved into herbal medicine, earning my MSc in Herbal Medicine from the American College of Healthcare Sciences, where I'm now finishing up my DSc in Integrative Health. My clinical herbal training came from two beautiful schools, Heartstone Herbal School under Tammi Sweet, and Northern Appalachia School of Herbal Medicine, where I studied bioregional herbalism. I'm also published in the Journal of the American Herbalists Guild, where I wrote about the gut microbiome across the lifespan and which herbs are supportive at each stage. I'm a research NERD. Like, full-on. I love everything about it. With my medical background I have a soft-spot for science, and I'm also very much in respect toward the different traditions of herbalism that came long before modern research caught up to them. My work here is to help bridge those two worlds. Body First. Plants Second. This community runs on that motto, and I want to explain what it actually means. One of the issues I've run into in the herbalism world is that so many people are learning, memorizing, and building relationships with plants and their actions without ever developing a core understanding of how the body works. In my opinion, this is backwards. To build a meaningful herbal practice, we have to understand how the body functions without the herbs first. Once we have that foundation, we can actually investigate what's off and choose herbs that support the body with real confidence. That's the whole project here. Community Architecture The Community Feed is where I'd love for all the buzz to happen. Each week I'll be dropping mechanism questions, anonymized case puzzles, materia medica discussions, and the occasional spicy preparation debate. Jump in, push back, share what you're working through, ask the messy questions. This is the room where the conversations happen.