Our intestine is home to three pounds of bacteria. We feed them and they feed us. They help us break down proteins, lipids, and carbohydrates from our food into nutrients that we can then absorb. Without them, we would not reap the benefits of the many foods we consume.
As an example, gut microbes contain genes that code for enzymes which break down plant polysaccharides we can then digest. Without our gut microbes, we would not be able to obtain nutrients from these carbohydrates. But where did our gut microbes get these genes in the first place? (more…)