I read with great interest the many articles being published on gut bacteria and their effect on health. Hardly any day passes by without coming across a new research study about this fascinating new science. Trillions of bacteria live in the large intestine (colon) and they seem to have a major effect on many aspects of our health. New research is revealing that these bacteria also called gut flora secrete a variety of substances that affect the brain, immune system, metabolism and diabetes, as well as your heart. Largely ignored in the past, we are only beginning to understand their role. Gut bacteria play an important role in maintaining the integrity of the intestinal wall and preventing the so called “leaky gut syndrome” which is believed to be responsible for many inflammatory diseases including coronary artery disease. Gut bacteria secrete a number of substances that are absorbed into the blood stream and affect distant organs like the brain. Serotonin is a well-known neurotransmitter in the brain but 90 % of body serotonin is secreted in the gut. Studies have shown that germ free mice (mice with no bacteria living in their intestines) produce 60% less serotonin than those with regular gut bacteria. Low serotonin level in the brain is associated with anxiety and depression. Indeed, studies in a timid strain of mice, treated with antibiotics to change their gut bacteria composition, show a dramatic change in their behavior. In another experiment, transferring bacteria from timid strain mice into the gut of normally active mice changes the latter into more passive animals. Many other experiments mainly in mice prove that bacteria living in the colon affect brain function including behavior and mood. Interestingly, gut bacteria alter more than just your mood; they have a role in weight control. Bacteria from an obese mouse injected in the colon of a regular mouse lead to weight gain. Gut bacteria from obese individuals compared to lean ones show less diversity and predominance of one variety called Firmicutes. Gastric bypass in mice and humans lead to changes in gut bacteria that are associated with weight loss. The mechanisms behind these observations are still unclear. One thing for sure, however, maintaining a healthy gut flora seems to prevent a plethora of diseases and mental disorders.
How to Protect Healthy Intestinal Bacteria?
Like any living organism, bacteria need a suitable environment to thrive. Besides avoiding unnecessary antibiotics that decimate your bacterial flora, consuming a high fiber, plant based diet promote a healthy and diverse gut microbiome. According to Michael Pollan “With our diet of swiftly absorbed sugars and fats, we’re eating for one [kind of microbe] and depriving the trillion of the food they like best: complex carbohydrates and fermentable plant fibers. If you want to feed your gut bacteria, you need to eat a wide variety of fruits, vegetables, nuts and whole grains. Intestinal bacteria need fiber to thrive and Houstonians are not eating enough fiber in their diet. Take control of your life and minimize the consumption of processed food rich in salt and sugar and completely devoid of fiber. Let food be your medicine and rid yourself of obesity, heart disease and diabetes.