Since microbes were the first living beings to evolve on earth, all life that came after developed in an environment covered in microbes. Because of this, plants and animals developed ways to tolerate these microbes and even figured out how to benefit from some of them.
How do they benefit? Great question!
There are many things required to keep complex animals like humans thriving, all of which require energy. Rather than waste our own energy trying to reinvent the wheel, we have outsourced certain tasks to the microbes in our bodies. (Why would you buy a lawnmower if your land is covered in cows that happily maintain the grass for free?)
For example, humans do not have the ability to digest cellulose, the main component of plants. As a result, we rely on specific microbes in our gut to break down and digest the plants we eat. We collect most of our microbes from our diet, so when we eat plants, we fill our bodies with more microbes that eat plants.
We also use the products microbes create when digesting food for a wide variety of things that keep our body healthy. For instance, some microbes have the ability to turn fiber into “short-chain fatty acids” or SCFA’s. These substances are used to reduce inflammation and keep the lining of the gut in tact.
These are just two examples of the beneficial effects of the microbiome on our health. In reality, there are so many benefits that it is impossible to list them all. Our bodies are so intimately dependent on microbes that it is hard to imagine what we would do without them!