You are made of approximately 10 trillion body cells. As if that wasn’t amazing enough, your body is host to many trillions of microorganisms such as bacteria, yeasts, viruses and fungi. These live all over and in your body, with a large contingent found in your “gut,” also known as the gastrointestinal system. The gut runs a complex path from the mouth to the esophagus, stomach, small then large intestine, and finally the rectum and anus. The roughly 100 trillion microorganisms that inhabit the gut (mostly in the large intestine) exist “symbiotically” with humans. This means we provide them with a place to live and they help us digest certain foods, help provide a balance against unhealthy microorganisms, create vitamins K and biotin, and perhaps, even help regulate our body weight. These trillions of organisms can even be considered an essential organ in the body, as important as any other.
You may already be aware that bacteria digest foods we don’t break down well. Beans are indeed a “musical fruit” as gut bacteria process the stachyose (a natural sugar) that was not digested by the human gut. In fact, this sugar and other carbohydrates such as fiber, are important foods for your gut bacteria. The addition of “prebiotics” to foods such as yogurt and bread is intended to support the growth of these bacteria.
A common prebiotic is the fibre “inulin.” You will find this in Kashi granola bars and some flavours of Nature’s Path cereal, available at London Drugs.
You may also have heard how important the balance of “good” to “bad” microbes is. Indeed, of the trillions of organisms in our bodies, not all are beneficial for us. A good example is Clostridium difficile. This bacteria is fairly widespread in nature but only causes problems under certain circumstances, such as, for example, when you take an antibiotic to treat an infection. In this case, the drug destroys some of the normal, helpful bacteria as well as the bacteria causing the illness. Without enough healthy bacteria, C. difficile can grow out of control. For this and other reasons, it is very important not to overuse antibiotics.
Bacteria also help with our nutrition. One example of this is vitamin K. This vitamin is required for normal blood clotting. Foods, such as leafy green vegetables, provide about half the vitamin K required for healthy adults while gut bacteria (good old E. coli) produce the rest. Interestingly, newborns lack the bacteria in their intestines to produce vitamin K so they are usually given vitamin K supplements, either as a shot or by mouth, before discharge from the hospital.
The idea that weight could be affected by gut microbes, particularly bacteria, has been gaining traction in recent years. Studies have been done on mice and on humans, and while there are no absolutes yet, it appears that leaner mice and people have different types of gut bacteria as well as a more diverse population- that is, more types of bacteria. And at least one study suggests that a high fiber, low fat diet is more supportive of microbes that promote a healthy body weight.
The Human Microbiome Project (HMP), sponsored by the National Institutes of Health, was established in 2008, with the mission of defining our microbial community and analyzing its role in human health and disease. This project is made possible with the help of thousands of volunteers who send in samples from their skin, mouth, feces and other sites. At least 10,000 different microbes have been identified. As the research proceeds, it will be possible to better understand which microbes are most useful for human health and perhaps how to help them flourish in our systems.
Stay tuned for more exciting developments about the “forgotten organ.” Anticipate a future where we think about our health and the health of trillions of our closest friends.
Barbara Allan RD
Registered Dietitian
Certified Diabetes Educator
