The topic of leaky gut syndrome is a popular buzzword nowadays on social media and a quick internet search brings up 424,000 citations. What is it, and why does it matter?

Our intestinal tract is approximately 30 feet long; when spread out, the absorptive surface can be the size of a double tennis court. In addition to helping us digest food, 70 percent of the body’s immune system and 80 percent of the neuroendocrine system are in the gastrointestinal tract. The intestinal tract helps us fight off infection, and communicates with the brain and rest of our body for our well-being. A healthy gut lining, therefore, is critical for our health.

When we eat, the food is first broken down by chewing, then by stomach acid and pancreatic enzymes and, finally, by the enzymes at the brush border of the intestinal cells. Then the digested nutrients—sugar, amino acid and fatty acids—are taken up by the intestinal cells, get passed on to blood vessels, and then are taken to where they are needed.

However, that is not the whole picture. This digestive process is aided by bacteria in our gut; our intestines are home to one hundred trillion bacteria, or microbiota. They line the intestinal wall like a lush growth of a tropical forest, with a biodiversity that rivals the Amazon jungle. What we eat, they eat. These bacteria help us digest food, process hormones and produce vitamins. They also form a protective layer, or biofilm, above our intestinal lining; this protects the intestines from invasion due to other pathogens. Common bacteria in our gut include clostridium, enterococcus, lactobacillus and bacteroides. In general, these bacteria stay in the intestines; however, if they cross the intestinal lining, problems can arise. At high levels, they can make us quite sick, but they can cause chronic inflammation even at low levels. Chronic inflammation can lead to chronic illness, such as coronary artery disease, diabetes, insulin resistance and dementia, to name just a few.

How is chronic inflammation connected to leaky gut?

Remember our gut lining is one cell layer thick. These cells are woven together with proteins like occludin and Zo-1, which hold the cells tightly so nothing can travel through the gut lining without proper permission from the cells. However, certain triggers can lead to disruption of this “tight junction”, including high fat diets, high sugar diets, bacterial infections, poorly digested food and other irritants. The intestinal wall then becomes “leaky”.

Particles that can leak through include partially digested food and small broken bits of the bacteria. Those are usually never allowed into body, but as they leak through the loosened tight junctions, they then enter the blood stream and are recognized by the body’s defense system as foreign. It may not cause any problem if the exposure is low and rare; however, with repeated exposures, the body will mount an immune response. This triggers inflammation in the body as a whole, contributing to symptoms like body ache, joint pain, poor memory, fatigue, rash, poor concentration, moodiness and more. If the particle is food, the body may produce antibodies against it, leading to food allergies. If the particle is bacteria and has a protein that looks very much like our own body’s tissue, the body may produce antibodies to fight off the bacteria. However, the same antibodies can attack the body’s tissue. Similarly, the broken bits of the injured intestinal cells can trigger antibodies production, leading to autoimmune diseases such as Hashimoto’s thyroiditis, inflammatory bowel disease or rheumatoid arthritis.

A classic example of leaky gut syndrome is celiac disease. Celiac disease is when a person develops a reaction to gluten—a wheat protein—which leads to antibody-directed intestinal injury that causes belly pain, bloating, diarrhea and anemia. They often have symptoms outside of the gut as well, such as joint pain, anxiety, poor concentration, fatigue, migraines, rashes and irregular periods. Additional autoimmune conditions, such as Hashimoto’s thyroiditis, are common with those that have celiac disease.

What can be done to prevent leaky gut?

Studies show high fat and sugar diets contribute to leakiness in the gut. A healthy diet rich in vegetables and fruits, and low in simple carbohydrates and saturated fats, is important to maintain a healthy microbiota. The health of the bacteria is often impacted by the food we eat. The fibers and complex carbohydrates from vegetables, fruits and legumes feed and maintain the good bacteria. Fermented food such as sauerkraut, kimchi, miso and kefir do as well. However, medications—such as chronic acid reducers, NSAIDs, antibiotics and certain food preservatives—will lead to bacterial imbalance. Early symptoms of bacterial imbalance may be bloating, stomach upset, gassiness, change in stooling (constipation or diarrhea) and stomach pain.

Most of us will likely have leaky gut once in a while; a stomach bug or travel-associated diarrhea are two common conditions that lead to transient leakiness of the gut. If we take extra care when we are sick, and take good care of ourselves in general, we can avoid leaky gut and the associated complications. If you believe you have leaky gut syndrome, start by changing your diet. Reduce saturated fats, simple sugars and simple carbohydrates in your diet. Increase fiber and probiotic-rich foods. Avoid processed foods and chemicals. Keep a food diary; this can help you see which foods trigger your symptoms. Consider avoiding these foods for a while. With time, the symptoms will resolve.

Yufang Lin, MD, is board certified in internal medicine and pediatrics and with the American Board of Holistic and Integrative Medicine. She practices in WCMG Integrative Medicine, located in New Canaan (203-920-1603) at 173 East Ave, and in New Fairfield (203-746-6000) at 96 Rte 37. For more information, visit WCMGIntegrativeMedicine.org.