The Microbiome

Rob Knight studies the microbes that live in our body, known as the microbiome. Those microbes constitute about 1-3% of our body mass (3 pounds in our gut alone), and account for great diversity between individuals. While there are about 20,000 human genes, there are between 2 and 20 million microbial genes. Although two individuals will share about 99.99% of their genetic make-up, they will share only 10% of the microbial DNA. Within one individual, gene sequencing shows that the microbes that live in the oral, skin, vaginal and fecal communities are extremely different.

What's really interesting about microbes, though, is the effect they have on our health and wellbeing. If you have been puzzled why mosquitoes seek you out while avoiding people around you, it's because your distinctive skin microbes have attracted them. Microbes have also been implicated in bowel disease, heart disease, obesity, autism and depression. Children born by C-section are particularly susceptible to certain diseases, likely because they didn't acquire their quotient of vaginal microbes as they passed through the birth canal.

Society's heavy use of antibiotics is having a huge impact on our microbiome. But we could also look to treating various conditions through treating the microbiome. Knight ventured that we might be only 2-5 years away from such microbiome medicine.

We've already seen it in the treatment of Clostridium Difficile, a nasty condition that's very hard to treat. Spoiler alert: gross medical fact coming up. The most successful treatment for C Diff is fecal microbiota transplanation. (Yup, when you carefully assess that formal-sounding medical name, it's just what you think.)