The Human Superorganism: How the Microbiome Is Revolutionizing the Pursuit of a Healthy Life by Rodney Dietert
My rating: 3 of 5 stars
I first read about gut bacteria more than a decade (maybe two) ago, and was immediately intrigued by the implications. And as I continue to read on the topic, my interest only intensifies.
I think Dietert's term superorganism along with his comparison between a body and its microbes to a rain forest provide a wonderful analogy. While we generally think of bacteria as something bad that makes us sick, the truth is we are home to millions of microbes. And these bugs are more than just passengers or tenants. They are part of us. They digest things we can't, provide vitamins we need, influence our immune system, and produce chemicals that communicate with our brain. In fact, it is believed that the mitochrondria in our cells (our cellular powerhouses where energy is produced) were actually bacteria at one point that were engulfed by another more primitive cell.
In fact, we now know that bacteria can turn on portions of our DNA (epigenetics), effecting gene expression. It is also believed that once turned on, this change can be transferred to future generations. Furthermore, there is mounting evidence that under certain circumstances bacteria can transfer their DNA into human cells.
Bottom line: we really are a superorganism whose health is dependent not only on our human cells but also on the health and type of our microbial cells.
Dietert blames many of the non-communicable diseases like heart disease, auto-immune disorders, diabetes, metabolic syndrome and even cancer on changes to our microbiome. Over-prescription of antibiotics that not only kill harmful bacteria but also harm the beneficial bacteria, cesarean births which deny babies critical exposure to their mother's vaginal bacteria and ultimately impact their microbiome and immune system, use of baby formula instead of breast milk which actually contains sugars that can only be digested by bacteria cells, and a modern western lifestyle which does not nurture a healthy mix of microbes have left us either with an incomplete biome or an unhealthy one.
Unfortunately, I think he overstates what we know about the role of microbes as well as the future implications.
He also never quite describes exactly what constitutes a healthy microbiome, probably because we still don't know for sure.
From other sources I've read, the consensus seems to be that behaviors that support general health like eating a diet with lots of fruits and veggies along with daily exercise also support a beneficial and healthy microbiome, while eating a high-fat, high-calorie, nutrient-deficient diet doesn't. Beyond that, I'm not sure.
Interestingly, according to Dietrert we know that obesity is associated with a different microbiome. The question remains, why? Do the bugs cause the obesity or do the behaviors that cause obesity also cause certain bugs to flourish, or does the obesity itself account for the differences seen. Or maybe all the above, none of the above, or something in between. He cites how transplanting microbes from obese mice can actually lead to obesity in previously normal weight mice. This is fascinating, but I'm still not sure we know exactly what this means in the short or long term.
Dietrert also talks a lot about probiotics and prebiotics generally, but backs away from making any concrete recommendations probably because nobody really knows.
I tend to view probiotics like supplements. Most supplements are taken blindly, and we really have no way of knowing if they are helpful or hurtful over the long term. It seems more logical to focus on behaviors that we know are associated with better health as it is likely that they are also healthy for our microbes.
Definitely a fascinating topic that will continue to be explored and developed. Yet another piece to the puzzle that shows just how very complex our bodies and systems are and why you can't tweak one area without worrying about how it may be affecting the system as a whole. Being in medicine for many years, I've observed that many of our "cures" merely exchange one problem for another or treat symptoms as opposed to getting to the heart of the problem. I think our intimate relationship with microbes is another explanation for why. As our understanding of our microbiome increases, it may result in a more proactive and targeted approach to medicine. But for now, eat lots of fruits and veggies, whole foods, exercise daily, get adequate sleep, and manage your stress. Chances are these behaviors will also result in a healthier gut microbiome.