A lot has been written about human health and how it relates to our environment. Whether it’s toxins in our environment, cues to over eat or exercise, and global climate change, there are numerous effects on human health from the environments in which we live. New evidence suggests there is another extremely complex environment that has dramatic effects on our health: the bacteria that live inside us.
Michael Pollan, author of The Omnivore’s Dilemma, wrote an interesting piece in the New York Times about how the 100 trillion bacteria that live inside us have dramatic effects on our health, and in this environment may be modifiable to improve or harm our health.
He quotes Justin Sonnenberg, a microbiologist, who describes the human being as “an elaborate vessel optimized for the growth and spread of our microbial inhabitants.” The state of the microbes in our body is called our “microbiome.” It is now possible to “sequence” your microbiome and compare it to others.
Our microbiome seems to influence weight, immune function, metabolism, and the production of neurotransmitters. That’s pretty incredible! Not only have studies in mice showing that obese mice transplanted with the gut bacteria of lean mice lose weight, but this finding has been partially supported in humans when “fecal transplants” of bacteria from lean patients to those with metabolic syndrome caused significant improvements in the metabolic syndrome without any other intervention.
Some researchers believe that the increase in autoimmune diseases in Western cultures has to do with changes in the microbiome of Westerners because of their diets and exposure to antibiotics. And gut bacteria influence the production of serotonin, the neurotransmitter that antidepressants seek to increase.
Breastfeeding appears to play a role in the proper population of gut bacteria in newborns. One of the components of breast milk – oligosaccharides – are not capable of being broken down by newborn gut enzymes. It’s now clear that oligosaccharides enhance the growth of bacteria – called bifidobacteria – in the newborn’s gut. These bacteria appear to improve the lining of the intestines, and reduce the likelihood of some infections.
One of the vexing diseases of hospital-acquired infections is Clostridium difficile, which can became recurrent and life threatening. A number of early studies indicate that transplantation of healthy fecal microflora into patients with recurrent Clostridium difficile leads to a dramatic reduction in the recurrences.
It seems to me that we, patients and providers, need to pay attention to this emerging literature and understand how our diets, habits (gardening, for example), use of antibiotics, and ingestion of organic foods (because of their reduced likelihood of introducing endocrine disruptors) may improve our internal microbiology, and therefore our health.
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