Documented awareness of the connection between humans, illnesses, and microbes dates to the 1840s, when pediatricians wrote about the role of altered intestinal microbes in children with diarrhea.
Fast-forward to 2012, when the Human Microbiome Project showed that the number of bacteria colonizing our body far out-number human cells. Even more dramatic was the estimate that the microbes living within us contribute 2-20 million genes, compared to our mere 20,000 human genes.1 These facts give a perspective on the human-microbe relationship that is quite different from the germ theory allegation that all microbes are bad. We now know that 95% of identified bacteria are beneficial to our health and support every aspect of being human. As for the other 5%, we need to keep them in check while being mindful that bacteria have been around much longer than humans and have the ability to rapidly pivot as needed to survive in hostile conditions.