So if you haven’t heard, healthy bacteria in our digestive tracts are good for us. What you may not have known is really HOW important these bacteria are, in addition to the viruses, fungi and other organisms that live in us.
Before you run over to the hand sanitizer, let’s look at the research. According to scientists, humanity’s microbial inhabitants, known as the “microbiome” is more diverse, more complex and more intricately involved than we once thought.
A 5-year, $175 million U.S. Human Microbiome Project is underway in which scientists are sampling the mouth, airway, skin, gut and urogenital tract of healthy adults and deciphering the genetic codes of key microbes. Yes..these bugs are everywhere and are associated with vital functions such as digesting food, absorbing essential nutrients and fighting off disease causing entities. They may even be able to use microbes as markers to determine the onset of a variety of diseases.
So why do some people get diseases more readily, such as tooth decay, asthma, ulcerative colitis and even cancer and others don’t? Studies are underway to look at exactly this question.
One interesting finding is that babies born by C-section miss out on these crucial organisms acquired through the mother’s birth canal. The birth canal is heavily colonized with bacteria. The lack of this bacteria soup may predispose a child to asthma and allergies according to Maria Dominguez-Bello, a University of Puerto Rico biologist who has been studying microbiota around the world. After looking at the overuse of antibiotics to treat ear infections and the antibiotics added to animal feed, we see how easy it is to wipe out this healthy flora. Our ancient microbiota is being altered by the extensive use of antibiotics in pregnancy and in children.
According to Sarkis K. Mazmanian of the California Institute of Technology, gut bacteria has figured out a way to network with our immune system so it doesn’t attack them. The interaction between these two systems has a remarkable way of dampening the inflammatory response, especially from hyperactive immune systems. Inflammation plays a role in many diseases including asthma and food allergies, as well as metabolic syndrome, diabetes, heart disease and many forms of cancer. Those that don’t have enough of these bacteria, have a higher incidence of these diseases.
Could this play a role in our obesity problem? Some studies have indicated that these gut microbes secrete messengers to the cells lining the gut and turn “off” or “on” certain hormones, such as leptin and ghrelin. These hormones regulate metabolism, hunger, and a sense of fullness. For example, thin mice get fatter when their gut bacteria is replaced with the microbes of obese animals.
Research is also emerging about these microbes and how they affect the brain. Together with genetics, this may influence brain chemistry and the corresponding behaviors such as anxiety, stress, depression, ADHD and even autism.
There’s alot to learn about these amazing bugs that we acquire from the time we are born. By respecting their complexity, we hope to find clues to their roles in how they keep people healthy and cause illness.
Reference: Stein, R. “Good bugs’ may be key to staying healthy”, The Washington Post, Oct. 11, 2011.