One of the first readers makes a good point about the increased prevalence of certain autoimmune disease and inflammatory disorders in urban centers: our current problems are the result result of a tradeoff. The elimination of harmful bacteria through antibiotics was a game-changer. While the grave problems the misuse of antibiotics has caused in treating what should be easily-curable infections should makes us critical, the fact is that implementing good hygiene practices along with the occasional use of antibiotics has drastically reduced mortality rates everywhere.
What I think scientists who are advocating for the “old friend hypothesis,” including Jabr and Rook, are stressing is that our germ-phobic culture has swung too far to one extreme: all germs are bad and must be killed. Our thinking is simply wrong. Instead of viewing bacteria and helminthes as creatures to be avoided at all costs, we must instead think of them as we would any other animal: some are dangerous and should be avoided and others we can live in harmony with and even use to our benefit. The same paradigm shift can be seen in scientists studying the microbiome. The unpleasantly named practice of “fecal transplants” has quickly been recognized as a viable means of treating Clostridium difficile infection (CDI), and its success rests on the notion that we need bacteria in order to be healthy.
Continued research into these “old friends” of ours and a shift in our thinking may be what is necessary to maintain a healthy society in the near future, and I think Rook and Jabr do an excellent job in outlining why this field is so promising and so critical to the future of medicine.