What is Your Gut Telling You? Part I

In Functional Medicine, the gut—or gastrointestinal (GI) tract—is often considered the gateway to health. Most of us limit our understanding of gut function to eating and digestion, but when we explore the deep connections between the gut and the rest of the body, we realize there’s so much more. Important aspects of gut health include barrier function, nutrition, immune balance, the microbiome, and even mental status.

Consider this: the GI tract is like a hollow tube running through the body, with an opening on either end. In this way, the inner space of the gut (called the lumen) is technically “outside” of the body, making it our largest interface with the external environment. If you were to flatten out all the folds of the gut lining, the surface area would equal half a badminton court—about 20 by 20 feet! The integrity of the gut lining is critical. It serves as a protective barrier while still allowing for nourishment—keeping the “bad” out and letting the “good” in. This remarkable balance is a form of astounding biological intelligence at work.

The immune system is an integral collaborator with our GI tract. Incredibly, it is estimated that the gut-associated immune system accounts for 70–75% of our entire immune system! It provides an additional vital layer of protection from external environmental threats. At the same time, the interplay between the gut and the immune system influences immune function. Exposures in the gut teach the immune system to tolerate things that are not threatening and to react to things that are potentially harmful. When a healthy gut is working well, the immune system “learns,” for example, that a peanut should be safe and an infectious organism is not.

Caring for our Personal Eco System

We can’t talk about gut health without talking about the gut microbiome—the microorganisms in our GI tract, also known as our gut flora. Consisting primarily of bacteria (but also fungi and viruses), our gut microbiome is made up of approximately a trillion cells (similar to the number of cells in our entire body) and contains 100 times more genes than the human genome. The composition of our microbiome—favorable versus unfavorable organisms—greatly influences the health of our gut and, in turn, our overall health and vitality. This ecosystem is easily thrown off by things such as dietary choices, toxin exposures, and medications we may need to take (think antibiotics).

One of the most fascinating connections to health and well-being is the so-called “gut-brain axis.” This is a bidirectional path of communication between the gut and the brain and is strongly influenced by our gut microbiome. Information between brain and gut flows through nerves (especially the vagus nerve), hormones, metabolic channels, and the immune system. These modes of communication allow the brain to influence intestinal activities—and the gut to influence mood, cognition, and mental health. Ever experience nausea or sudden diarrhea when stressed? How about making a decision from your gut? This is the gut-brain axis in action.

Gut health can be compromised for many reasons, and we don’t always experience this as GI symptoms—problems can manifest in the skin, brain, joints, and more. Thus, when working with my patients, we usually start by assessing gut health, often with the aid of specialized testing that examines the microbiome, digestive function, inflammatory markers, and more. Many tools are available for healing and optimizing gut health. This effort alone can have a profound impact on one’s quality of life.

In upcoming articles, we’ll take a deeper dive into GI health and associated conditions. In the meantime, consider these first steps with your diet—go plant-centered with more fiber-rich vegetables while minimizing processed foods and refined sugars.

Dr. Katherine Bayliss, MD

This article was originally published in the Shepherd Express.

Bayliss, K. (2022c, July 7). What is your gut telling you? Shepherd Express. Body