Countless people in the United States suffer from a condition called “leaky gut,’’ where the lining of the intestines becomes porous enough to allow toxins to seep through it and into the bloodstream.

Many are unaware of their condition, or that it can lead to serious health problems, such as chronic inflammation, type 2 diabetes, heart disease, dementia and even some types of cancer. The condition also can cause a variety of unpleasant gastrointestinal syndromes, such as indigestion, gas, bloating, abdominal pain and diarrhea.

In a new paper published in Gut, a leading high-impact international journal in gastroenterology and hepatology, USF Health researchers describe how the right balance of bacteria can deter leaky gut – and how the wrong mix can threaten a person’s health.

The study addresses how leaky gut can accelerate the progression of diabetes in overweight people, and how selective probiotics work to reduce that risk.

People with meat-rich diets are especially vulnerable, said Hariom Yadav, Ph.D., senior author of the study and director of the USF Center for Microbiome Research, Microbiomes Institute, and associate professor of Neurosurgery and Brain Repair.

Hariom Yadav, PhD

“We describe the unique role of the microbiome as a garbage cleaner of our body and our diet’s byproducts, such as how a meat-enriched diet increases the garbage in our gut that changes the microbiome,’’ he said. “This creates leaky gut and inflammation that ultimately induces diabetes.’’

The microbiome is the collection of microbes − bacteria, fungi, and viruses − that naturally live on our bodies. The balance of these tiny organisms can enhance or impair the body’s metabolic and immune functions.

Because everyone’s gastrointestinal tract is selectively porous, many of these organisms – along with nutrients − travel into the bloodstream. However, a person with increased intestinal permeability has too much “leakage,” allowing larger molecules into the bloodstream, creating inflammation. This inflammation impacts many organs in the body, potentially changing their normal functions if exposed for long periods of time and increasing the risk for developing such diseases as diabetes.

“These toxins keep circulating back and forth in our bodies and cause serious health problems,’’ Dr. Yadav added. “We wanted to know how these microbes work in the cleaning process, how they serve as garbage cleaners to remove toxins.’’

The new study discovered that leaky gut in both overweight people and mice diminished the microbiome’s capacity to metabolize a chemical called ethanolamine, a chemical found in beef and other animal food products. High levels of ethanolamine lead to increased permeability of the gut wall, and as a result, more proinflammatory molecules are released into the bloodstream.

Because ethanolamine is found in bovine muscle, people with diets heavy in beef ingest higher-than-normal levels of the chemical than people who eat meat less frequently.

“It’s an intrinsic part of animal meat,’’ Dr. Yadav said of ethanolamine. “So, eating a heavy meat diet contributes more of this chemical, and if the (probiotic) bacteria that metabolizes ethanolamine isn’t there to fight it, those people will be more likely to have leaky gut.’’

If ethanolamine-metabolizing bacteria are low or absent, then the accumulated ethanolamine acts on epithelial cells to cause leakiness. To counter this, the researchers suggest a novel probiotic therapy that would reverse elevated gut permeability, inflammation and dysfunction of glucose metabolism.

“What’s important is to know what kind of bacteria is in our gut and whether it can clear ethanolamine,’’ Dr. Yadav said. “Normally, people talk about what the microbiome produces, but in this study, we talk about what the microbiome utilizes or eats, and how it clears up all these toxins which either comes from our body or from diet. The therapy is where we put back these helpful bacteria in gut, and we can do this with oral probiotics therapy.’’

Dr. Yadav hopes this original research will benefit medical practitioners and policy makers in making better decisions on dietary guidelines.

Dr. Yadav has several ongoing research projects focused on the microbiome. Last year, he received a grant from the National Institute on Aging to help determine if a common medication can restore microbiome diversity in older patients who have a form of heart failure. Results of his three-year study could help prevent the subsequent problems that tend keep these patients inactive and cause their conditions to worsen. He also is working on another study funded by Florida Department of Health, called the Microbiome in Aging Gut and Brain (MiaGB) study, which focuses on how the microbiome impacts brain health, and teaches what to eat and avoid to keep the brain healthy during aging.

Armed with more knowledge about how the microbiome affects inflammation, type 2 diabetes, cardiovascular complications, dementia and even cancer, USF Health researchers hope to identify high-risk patient populations that could benefit from next-generation therapies. Rather than a general treatment, these people might receive more personalized care based on their microbiome and a leaky gut.

— Story by Kurt Loft for USF Health News; photo by Allison Long | USF Health