Dr. David Orman

Q: How does the health of your gut microbiome influence not only digestion but also mood, sleep, and immunity?

A: Most people think of the gut only as a place where food is broken down. Yet within this living system exists trillions of microbes—tiny organisms that act like gardeners, tending to the soil of our inner world. When this microbiome is balanced, digestion flows easily, nutrients are absorbed, and waste moves along without effort. But the influence goes far deeper than the belly. These microbes create chemical messengers that speak directly to the brain, often called the “second brain,” shaping not only how we process food, but how we feel.

A flourishing gut helps regulate mood through neurotransmitters like serotonin, most of which is produced in the digestive tract. This explains why imbalance in the gut often shows up as anxiety, irritability, or even depression. The same microbes also play a role in immune defense, training the body to recognize what is friend and what is foe. When they are nourished by fiber-rich foods, fermented vegetables, and mindful eating habits, the body becomes less prone to illness and inflammation. The gut becomes a quiet guardian, protecting with resilience and grace.

Even sleep is touched by this hidden community. Signals from the microbiome help regulate the circadian rhythm, the natural clock that governs when we rest and when we wake. When gut health falters, sleep often becomes fragmented, restless, or shortened. Yet with care—through simple practices like mindful breathing before meals, herbs that calm digestion, and steady routines—the gut can once again align with nature’s rhythm. In this way, tending to the gut is not just tending to the body, but to the mind, the spirit, and the deep harmony that connects them all.