Human Microbiome Project

In the average human, microbial cells outnumber our very own human cells by a factor of 10 to 1. Essentially, we are apartment complexes for a whole lot of bacteria, fungi, and protozoa. This means there are gobs of genetic material within us, carrying out functions, that hasn't been considered in relation to human health until recently.

The Human Microbiome Project was initiated in 2007 to try and understand the extent of the microbial diversity we carry around and how it affects our health. These organisms have been within us since the beginning of human evolution; they are intimately involved in human physiology. Emerging research from the HMP is revealing just how symbiotic the relationship is. The microbes provide certain vitamins we need but don't get regularly from our diet, they regulate our immune system, and potentially colonize areas that "bad" microbes could get to.

Each person has an unique "community" of microorganisms throughout their body, which, will be similar to their parents, and should include a core gang. Colonization by these thousands of species is dependent on our diet and environment as we develop. Certain species are proving to be so important that a recent study carried out "poop transplants" in patients with colitis, inflamed large intestine. "Normal" patient family members had the microbiota extracted from their poop and transplanted into the colitis patient. 13 out of 15 patients were relieved of their symptoms fairly quickly. It seems people prone to colitis have an excess of Clostridium difficile and it can be managed by letting "normal" microbes take over.

Microbes are also being given credit for obesity. Not all obesity is the same, but in certain cases it may come down to the efficiency of your GI microbiome. Studies are showing that with different communities we get a different dietary energy harvest, fat deposition, and systemic inflammation. Poop transplants in mice to create a good microbiota community are proving to be effective for these symptoms.

The most interesting research, I think, is being done with regressive autistic kids. This is the type of autism blamed on vaccinations, but research could never show a strong correlation. These children are normal until about age 2, then suddenly regress in their social and behavioral skills. They are plagued by distended bellies, inflamed intestines, diarrhea, and constipation. Because of these symptoms, and the fact that children communities should resemble adult communities by around age 2, researchers began to look at the microbiota of affected children in comparison to their parents. Several studies have shown regressive autistic children may have a displacement of the normal community by a specific bacterial order, Clostrodiales.

Some other conditions being looked at in relation to our microbiome include; asthma, allergies, acne, psoriasis, Chron's disease, and febrile illness.

• The Human Microbiome Project http://nihroadmap.nih.gov/hmp/
• Khoruts A, Dicksved J, Jansson JK, Sadowsky MJ. Changes in the composition of the human fecal microbiome after bacteriotherapy for recurrent Clostridium difficile-associated diarrhea. Journal of Clinical Gastroenterology. 2010. May-June; 44(5):354-60.
• Tsai F, Coyle WJ. The microbiome and obesity: is obesity linked to our gut flora? Current Gastroenterology report. 2009 August; 11(4):307-30.
• Researcher Dr. Allen-Vercoe discusses her autism research http://www.uoguelph.ca/mcb/people/faculty/faculty_allen-vercoe.shtml