Unhealed trauma keeps the body's sympathetic nervous system in a constant state of "fight or flight." This chronic stress continuously weakens the gut microbiome and immune system, undermining any benefits from healthy eating, exercise, or sleep. Healing trauma is therefore a prerequisite for physical healing.

Instead of obsessing over "fixing" issues like fatigue or bloating, reframe them as signals from your body. Listening to these cues allows you to understand and address underlying root causes, rather than just masking the symptoms with temporary solutions.

The gut microbiome exists in a stable state with a resilience that makes it difficult to alter permanently. After short-term disruptions like antibiotics or diet changes, it often 'snaps back' to its original composition. This means meaningful, long-term change requires sustained effort to establish a new, stable microbial state rather than temporary interventions.

The goal of fiber is to feed gut bacteria that produce butyrate, a key acid for gut health. However, you can bypass this. Being in a ketogenic state directly provides beta-hydroxybutyrate (a ketone) to the gut, strengthening the microbiome without requiring high fiber intake.

Contrary to popular belief, the majority of stool weight is not leftover food. Approximately 60% is composed of the trillions of microorganisms that make up your gut microbiome. This fact reframes bowel movements as a direct indicator of your internal ecosystem's health and composition.

When you cook and then cool starchy foods like beans, potatoes, or bread, you create "retrograde starch." This process transforms simple carbohydrates into complex resistant starches, which are a powerful food for your gut bacteria. This enhances the food's nutritional quality and lowers its glycemic index.

Instead of adhering to a strict diet label like vegan or pescatarian, Dr. Bolsiewicz advises focusing on nutrient quality. A gut-healthy, anti-inflammatory diet is achieved by consistently consuming these four "workhorses," which support the microbiome and calm the immune system, regardless of the diet's name.

In a head-to-head study, a diet high in fermented foods like yogurt and kimchi significantly increased microbiome diversity and lowered markers of inflammation. A high-fiber diet did not consistently produce these effects, suggesting that introducing live microbes is a more direct strategy for improving gut health and immune status in Western populations.

Increasing fiber intake may not improve gut health if an individual's microbiome is already depleted. Research suggests many people in the industrialized world have lost the specific microbes needed to break down diverse fibers. Without these microbes, the fiber passes through without providing benefits, highlighting the need to first restore microbial diversity.