Emily

“I should acknowledge, I guess, that one reason I'm interested in TB is that I have obsessive-compulsive disorder, and my particular obsessive worries tend to circle around microbes and illness. Before the germ theory of disease, we did not know that around half the cells in my body do not, in fact, belong to my body - they are bacteria and other microscopic organisms colonizing me. And to one degree or another, these microorganisms can also control the body - shaping the body's contours by making it gain or lose weight, sickening the body, killing the body. There's even emerging evidence that one's microbiome may have a relationship with thought itself through the gut-brain information axis, meaning that at least some of my thoughts may belong not to me, but to the microorganisms in my digestive tract. Research indicates that certain gut microbiomes are associated with major depression and anxiety disorders; in fact, it's possible that my particular microbiome is at least partly responsible for my OCD, meaning that the microbes are the reason I am so deeply afraid of microbes.”
― John Green, Everything Is Tuberculosis: The History and Persistence of Our Deadliest Infection