Home is Where the Gut is

For most of us, home is where the heart is, but for trillions of bacteria and other microbes that live inside you, home is your gut.

Microbes, or micro-organisms, are one-celled organisms like bacteria, fungi, and viruses that may help to either promote your health or harm it. Human beings acquire these microbes at birth during vaginal delivery when exposed to their mother’s bacteria. Babies born via cesarean acquire the bacteria through their mothers’ skin. Most of these micro-organisms, which add about four pounds to the bodyweight of an adult, and represent 1,000 different species, live in your gut, but some prefer your skin, oral cavity, nasal passage, or urogenital tract. Collectively, this vast community of one-celled organisms is called the microbiome.

When your gut is healthy, both helpful and potentially harmful microbes exist side by side, allowing your gut microbiome to function optimally and provide you with numerous benefits. These include synthesizing vitamins, such as K and B-12; aiding digestion; and strengthening your immune system. When an imbalance occurs between your beneficial and harmful microbes — due to the interaction of your genetic makeup with a host of external factors, like poor diet, overuse of antibiotics, and smoking — you develop inflammation and become susceptible to illness.

Although scientists do not yet know for sure if there is a causal link between your microbiome and disease, they report that there is much less diversity in the microbiome of an unhealthy person, and they continue to find evidence that the microbial composition and functioning of your gut is a key factor in achieving and maintaining good health. Several studies have shown a significant difference in diversity between the microbiome of individuals who live in urban areas, and those of indigenous populations who lead traditional agrarian lifestyles.

What makes a microbiome healthy?

Many researchers do agree on the varied factors that can harm or restore balance to your microbiome. A typical Western diet, for example, which includes refined carbohydrates, large amounts of sugar, and too little fiber, is a likely culprit in the degradation of your microbiome. A sedentary lifestyle, environmental stress, and the overuse of medication, especially antibiotics, can also wreak havoc. It has been suggested that these factors may lead to a host of inflammatory diseases, ranging from common allergies, rheumatoid arthritis, and diabetes, to inflammatory bowel disease. Fortunately, there are steps you can take to help modulate the microorganisms in your gastrointestinal tract, restoring balance in your gut and boosting your health and well-being.

Following basic, sound guidelines is an excellent start. Eat a healthful and varied diet consisting of complex carbohydrates, fruits and vegetables, nuts and seeds, and other high-fiber foods. Exercise regularly. Limit dairy, red and processed meats, and sugar. Get enough sleep and don’t smoke.

In addition, microbiome-targeted therapies have recently been used to alter the intestinal environment more directly. The use of probiotics, living microorganisms that help maintain a favorable balance in your gut, has been on the rise. They occur naturally in some fermented foods like yogurt with live, active cultures; buttermilk; sauerkraut; kefir (fermented milk); kombucha (fermented tea); miso (fermented soybeans); and fresh pickled vegetables. Studies show that probiotics can be especially beneficial in people with specific GI conditions, like irritable bowel syndrome. They can also minimize the side effects of antibiotics, which doctors prescribe to kill harmful bacteria, but which can also destroy beneficial ones.

Prebiotics, the foods that human probiotic microorganisms feed on, have been considered beneficial as well. These include high-fiber foods like whole grains, fruits, vegetables, and leafy greens. Probiotics and prebiotics are also available as dietary supplements.

For the most severe gastrointestinal disorders like Clostridium difficile, a bacterium producing fever, belly pain, inflammation of the colon, and life-threatening diarrhea, Fecal Microbial Transplant (FMT) is an option, although it is not a routine procedure. FMT is a cutting-edge therapy in which doctors manipulate the gut microbiome directly. Donor stool containing healthy bacteria is introduced into the intestinal tract of a patient, to help restore a balanced microbiome. It is also sometimes used to treat other GI conditions like irritable bowel syndrome and colitis.

Inflammatory bowel disease and the microbiome

Inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis, causes chronic inflammation of the gastrointestinal tract, resulting in cramps, diarrhea, weight loss, bowel urgency, and other symptoms. Several million people worldwide suffer from this ailment.

Although it is not yet clear whether changes in the microbiome are a cause or consequence of IBD, scientists have confirmed a significant difference in the number and diversity of gut microbes between healthy people and IBD patients. Current therapies include standard treatments like antibiotics, anti-inflammatory drugs, and steroids. Some people find probiotics and prebiotics helpful, and FMT is employed as well.

In the coming years, researchers will continue their exploration into the possible links between the microbiome and illness.

The hope for a definitive association persists, even as therapies involving microbiome modulation are enacted today. As scientists persist, they will surely help us deepen our understanding of how the gut’s trillions of microbes impact multiple aspects of human health.