“We Are Only 10% Human” was the title of a previous post introducing our microflora. That may sound like an outrageous claim, but in all seriousness, microbial cells in the body outnumber human cells by 10 to one and account for 99.9% of our unique genes. An article published recently in the New York Times entitled,  “We Are Our Bacteria” discusses how the human microbiome is losing its diversity, much like other ecosystems across the globe. Dr. Martin J. Blaser, a specialist in infectious diseases at the New York University School of Medicine and the director of the Human Microbiome Program has studied the role of bacteria in disease for over 30 years. Dr. Blaser suggests a link between the declining variety within the microbiome and our increased susceptibility to serious chronic conditions such as allergies, celiac disease, and Type 1 diabetes. What could be the culprit? Antibiotics. Read more here about the article.

The epidemic of absence describes the lack of microflora populations in our human ecosystem.  This absence from antibiotic use leaves us vulnerable to a host of opportunistic parasites, which no longer have a mutualistic relationship with the host.  This intriguing TED talk  by Ed Yong tells us of many examples where parasites drive the behaviors of animals.  As data emerges on microflora and human behavior(1), we are left wondering just how our inner life of our human ecosystem, consisting of microbes to larger organisms, defines us, including our behavior.  As another New York Times article discusses, the microbes may be looking out for themselves and in order to survive, drive certain behaviors and cravings of the host to ensure its needs are met.  Dr. Katie Reid mentions in her TEDx talk the strong craving for free glutamates in foods support the survival of  some organisms that then become pathogenic.  These cravings are undoubtedly driven by the very organisms that need the chemical to survive and outcompete other organisms.

The concept that our inner world of organisms drives our actions brings a whole new meaning to the phrase “What’s bugging you?” .

Genna Brown, a college summer intern, contributed to this post.

(1) Cryan, J. F., and S. M. O’Mahony. “The microbiome‐gut‐brain axis: from bowel to behavior.” Neurogastroenterology & Motility 23.3 (2011): 187-192.