On Microbiomes

Your body has about ten times the number of microbial cells as it does human cells. Collectively this bacteria weighs about three pounds, about the same as your brain. The evolution of our understanding of these bacteria has been evolving rapidly over the past twenty years, and I expect its findings to be the most impactful on our health and wellness in the coming decades.

The New Yorker has a fantastic article by Michael Specter that starts and ends with our changing perception of heliobacter pylori, linked to gastritis and peptic ulcers, but whose absence in children (it used to be universal, now fewer than 5% of children in the US carry it in their guts) is linked to asthma. It also has consequences for weight:

There is equally convincing evidence that destroying H. pylori could alter metabolism in ways that increase the risk of obesity. Several research groups, including Blaser’s, have found a strong relationship in humans between the bacterium and two stomach hormones, ghrelin and leptin, both of which play central roles in regulating our appetites […] The more ghrelin you have in your bloodstream, the more likely you are to overeat. Leptin functions in the opposite way, suppressing appetite and increasing energy levels. For people whose stomachs are infected by H. pylori, ghrelin became far less detectable after a meal. For the others, levels of the hormone remained high, and the effects are evident. […]

That finding was not a complete surprise. Roughly three-quarters of the antibiotics consumed in the United States are fed to poultry, cows, and pigs, not to treat illness but as dietary supplements to promote faster growth. […] Until recently, the biochemical reasons for that weight gain, and its unsettling implications or humans, were murky. […] “A lot of things are happening at once,” he said. “The rise in obesity, celiac disease, asthma, allergy syndromes, and Type 1 diabetes. Bad eating habits are not sufficient to explain the world-wide explosion in obesity.

The environment inside our body is as complex and varied as the one outside our body and responds just as unpredictably to wholesale changes to its ecosystem. I’d recommend reading the entire article, unfortunately it’s not available in its entirety on the New Yorker’s site, however here’s a PDF of the entire thing.

11 thoughts on “On Microbiomes

    1. Chefs Consortium of the Hudson River Valley is a perfect example a clean, self-sustaining local food endeavor. This is one of many small but promising groups who have made it their mission to inform and support local farms and local food producers. Collectively, we stand a good chance to take a dent into corporate farming.

  1. Fascinating read, thank you very much.

    However it fascinates me that despite the fresh experience of new knowledge, researchers still do not see an inherent flaw in their world-view best expressed in this sentence near the end of the article: “But the microbiome is never static or simple; often it’s a battleground between species. The difficult job of medicine is to control that battleground”.

    The best doctor I’ve had the pleasure of visiting with, many years ago, was one who gave caring attention and postponed giving any medication. He would sometimes offer Chinese acupuncture as a support for the energetic body. Medication was a last resort. He kept watch and let the body heal itself. It worked.

    We would, I believe, be much better off with a more humble outlook in which we are participants and not controllers. Also why the violent metaphor of a battleground. Is that really a metaphor that can fuel a healing mentality? I

    When antibiotics were invented it was thought they would “grant us control” and “help us fight” bacteria. They did, but only now we are learning of the destructive consequences of that science. Next came genetics and now bacteria. The poisonous “control and conquer” is at the root of so many of our illnesses and a limiting factors on so many of our “cures”.

    This bacteria research is again proving that we are participants in a an infinitely complex ecosystem of life. When we lose sight of that tight integration between us and the world around us we become unhealthy. Then we start placing patch after healing patch while we continue a process of disconnection. It starts in how we come into the world (one third of US births are cesarean, in China one half, in Romania 60%). It continues in how we live, what we eat, how we relate to each other … and it seems to have led us into a hyper-intellectual age that is blind to its own limited nature. It has led us to become abusive and disrespectful.

    When I saw the word “scorched earth” in the article it struck me that it is true both within our bodies and on the planet we inhabit.

    Sidenote: just today I came across this musician’s story (http://www.joshfreese.com/ – scroll down to “2011 update”) of how he and his wife scheduled an induced birth (not necessarily cesarean) to fit it into his tour schedule. That is to me a horrible sign of our times. We do not have time to let a child be born into this world … for a rock concert? Are these (becoming?) our socially normative priorities? Do we really believe that any medical intervention (present of future) will heal such mentalities?

  2. The co-evolution of larger organisms with bacteria implies their ecology undoubtedly is disrupted by antibiotics. As is the case for any ecology, however, quick and easy theories of how to settle the trade-offs may be premature.