You might not have thought of it before, but you are an ecosystem. Ninety percent of the cells in your body are not human. We share our bodies with 100 trillion microbes, living on our tongues, teeth, and skin and in our intestine. While we have just over 20,000 human genes our microbes have eight million. These microbes are quite small, with all 100 trillion weighing only 3-4 pound in total, but, working together, they exert powerful effects. How are you caring for the ecosystem that is you?
This ecosystem develops right from birth. Infants with colic have more bacteria that are known to produce gas, whereas anti-inflammatory bacteria acquired from the vaginal canal are more common in colic-free infants. The right balance of microbes is essential to good health. They can lower blood pressure, decrease cholesterol and protect against diabetes.
Microbes are important in training our immune system on what to attack and what not to. Many of the diseases of modern life are caused by our own immune system attacking our body, and there is emerging evidence that exposure to diverse microbes can be protective. Autoimmune diseases like asthma, hay fever, type 1 diabetes and multiple sclerosis are much less common in the developing world and in children raised on farms or in large families. In contrast, asthma and hay fever rates are increased both in cities and in children given early antibiotics.
Antibiotics are a great innovation and continue to save countless live when used appropriately. Unfortunately antibiotics target not only the harmful bacteria. When bacteria in our intestines are disturbed by antibiotics, a common side effect is diarrhea. One way to limit side effects and prevent a resistant organism is to be sure to take a probiotic whenever you take an antibiotic. Probiotics are available in pill form and in food (yogurts, age cheeses, miso soup). Another key is limiting antibiotic overuse both in human medicine and in livestock. Using antibiotics for viral illness like the common cold doesn’t help, but can upset your protective microbial ecosystem.
We are only just beginning to understand the complex working of our microbes. But this much seems clear, the healthiest microbes are grown when the major ingredient in our diet is a diverse array of unprocessed plants. Eat a colorful array of vegetables and grow your healthy ecosystem.
Nathan Johnson, MD, is a Family Medicine Physician