Jonathan Jarry writes:

There is a kind of dark matter inside our intestinal tract. “Dark matter” is the phrase coined for the matter that is implied to be present in the universe based on physicists’ calculations but that cannot be seen yet. Scientists who study tiny living things are facing their own type of dark matter: invisible microbes that are indirectly detected. They call it “microbial dark matter.”

Much has been written about the bacteria that live inside our gut. This microscopic ecosystem, known as the microbiome, may play important roles in our health but scientists are only now beginning to understand very small elements of it. But the microbiome is not only made up of bacteria.

You may remember learning in school that there are two major empires of life. On one side, we essentially have single-celled living things whose genetic material floats freely inside them. These are the prokaryotes and they include bacteria. On the other side, we have organisms whose genetic material is contained within a little body inside the cell called the nucleus. These are the eukaryotes, and they include a multitude of organisms like the yeast we use for baking, trees, insects, and humans. But actually, since the late 1970s, we have known that this black-and-white division is not accurate. [Continue reading…]