Your gut microbiome is made up of trillions of bacteria and other microorganisms — both friendly and unfriendly. Maintaining the right balance of bacteria in your gut is believed to improve digestion, reduce inflammation, decrease anxiety, and even improve brain function and mood. A healthy balance of gut bacteria is also said to boost metabolism, eliminate cravings, and help you shed unwanted weight. We will look at ways in which you can achieve this by the food you eat.
Scientists have identified a few species among the many trillions of microbes that live in your intestines that play a crucial role in gut health and maintaining a balanced immune system. Your dietary intake is vital to allowing these species to flourish and to preventing imbalances that can lead to disease. Prebiotics provide a good food source for certain populations of healthy gut bacteria, such as bifidobacteria, which, in turn, prevent intestinal inflammation. Studies have shown that prebiotics can be particularly beneficial for obese people, as they reduce insulin and cholesterol levels, while lowering the risk of heart disease and diabetes. Prebiotics can be bought as supplements, but they are also contained within foods including asparagus, leeks, bananas, garlic and Jerusalem artichoke.
Western diets tend to be rich in fat and sugar, with most of our food coming from only 12 plant and five animal species. However, following a diet rich in high-fibre foods such as apples, artichokes, blueberries, chickpeas, lentils, pease and beans can limit the growth of harmful bacteria and stimulate Bifidobacterium, lactobacilli and another healthy species called Bacteroidetes.
Fermented foods such as kimchi, kefir, kombucha, natural yoghurts and fermented soya bean milk have been shown to promote the abundance of healthy gut bacteria and reduce the levels of enterobacteriaceae, a family of bacteria linked to a number of chronic diseases. Natural yoghurt enriched with bifidobacteria has also been found to alleviate lactose intolerance in children and adults, while yoghurts enhanced with lactobacilli have had some beneficial results in patients with inflammatory bowel disease. Avoid flavoured yoghurts, which tend to contain high levels of sugar.
Polyphenols are plant compounds that are mainly digested by gut bacteria and are associated with a variety of benefits including reducing blood pressure, cholesterol and oxidative stress. They are found in foods including almonds, blueberries and broccoli as well as in green tea, cocoa and red wine. The types of polyphenols found in cocoa are linked to changes in the microbiome that reduce inflammation and triglyceride levels.
Artificial sweeteners such as aspartame are commonly found in food as replacements for sugar. However, aspartame has been found to alter gut bacteria in human and animal studies. These changes appear to result in elevated blood sugar levels and increased susceptibility to metabolic disease.
Our microbiome is continually developing during our first two years of life. A number of studies have shown that babies who are breastfed for six months develop a much healthier gut compared with those who are fed with formula. Children who have been breastfed are also less prone to allergies, obesity, leukemia and diabetes; this is thought to be linked to the microbiome.
Several studies have suggested that vegetarian diets may be good for the microbiome, with findings indicating that a largely plant-based diet decreases the levels of disease-causing bacteria such as E coli and Enterobacteriaceae. This may be particularly beneficial for obese people with type 2 diabetes or hypertension. One small study found that obese people who switched to a vegetarian diet had reduced levels of potentially harmful bacteria as well as lower levels of cholesterol and inflammation after one month.
The gastrointestinal tract is important to human health. In recent years, scientists have discovered that the GI system has an even bigger, more complex job than previously appreciated. It has been linked to numerous aspects of health that do not necessarily involve digestion, from immunity to emotional stress to chronic illnesses, including cancer and Type 2 diabetes.
There are trillions of bacteria found in the GI tract, which not only help us process food but also help our bodies maintain homeostasis and overall well-being. Experts say the key may lie in the microbiome—the makeup of bacteria and other microorganisms in the stomach and intestines, or, informally, the gut.
Research on the microbiome is still in its infancy. But studies have already found that certain environments, foods and behaviors can influence gut health for better or worse. Fermented food sources—like yogurt, kefir, sauerkraut and kimchi—that have other nutritional benefits as well, should be considered in the front lines of influencing gut flora.
Finally, there are the cutting-edge ways in which doctors are beginning to manipulate the gut microbiome directly. Fecal transplants, which introduce donor stool material containing healthy bacteria into the intestinal tract of a recipient, have been used to treat IBD as well as C. difficile, a dangerous infection that causes recurrent diarrhea. Researchers are also studying how bacteria-killing viruses can target strains of E. coli associated with Crohn’s disease. It is most beneficial to stick to natural food sources as much possible because a lot is still unknown about the microbiome and the effects of altering it.