Deep in your gut, 40 trillion chemists are hard at work helping you digest your meals, making essential nutrients you can’t produce on your own, protecting you from disease, and even shaping which parts of your DNA manifest and which remain dormant.
These talented creatures are fungi, bacteria, and other single-celled organisms. And they are a bigger part of who you are than you have probably ever imagined!
While your body includes about 22,000 human genes, it also hosts as many as two trillion microbial genes that are technically not “you,” but rather benevolent guests working in exquisite harmony with your body. Some of these microbes flourish on your skin, but the vast majority take up residence in your digestive tract.
Study of the microbiome — the community of microorganisms living inside your body — could well be the most compelling frontier of health science.
The digestive process breaks down food and beverage particles so that your body can absorb the nutrients it wants and excrete the rest. Trillions of organisms join in the effort.