This was local news throughout Minnesota a couple of years ago, but I just stumbled upon a New York Times article published on the subject this week.
Ultimately, I think this information can be synthesized to argue that the "progress" we've made over the last couple of generations can, uncontrolled, cause a lot of problems.
Living in a sterile, germ-free environment? Not a good idea. It's better to roll in the dirt than over-use hand sanitizer. The 32% nationwide c-section rate? A big problem. Administering antibiotics with such regularity? Yikes. Pumping our food animals with antibiotics? Triple-diple-doople-yikes. Eating easy, processed, denatured foods? A slow killer.
Scientists are not just finding new links between the microbiome and our health. They’re also finding that many diseases are accompanied by dramatic changes in the makeup of our inner ecosystems. The Imperial College team that discovered microbes in the lungs, for example, also discovered that people with asthma have a different collection of microbes than healthy people. Obese people also have a different set of species in their guts than people of normal weight.
In some cases, new microbes may simply move into our bodies when disease alters the landscape. In other cases, however, the microbes may help give rise to the disease. Some surveys suggest that babies delivered by Caesarian section are more likely to get skin infections from multiply-resistant Staphylococcus aureus. It’s possible that they lack the defensive shield of microbes from their mother’s birth canal.
Caesarean sections have also been linked to an increase in asthma and allergies in children. So have the increased use of antibiotics in the United States and other developed countries. Children who live on farms — where they can get a healthy dose of microbes from the soil — are less prone to getting autoimmune disorders than children who grow up in cities.
Some scientists argue that these studies all point to the same conclusion: when children are deprived of their normal supply of microbes, their immune systems get a poor education. In some people, untutored immune cells become too eager to unleash a storm of inflammation. Instead of killing off invaders, they only damage the host’s own body.