In the mid to late 1800’s, physicians began to wonder why hay fever was on the rise. Since that time, physicians and scientists numbering in the thousands have expanded the question and asked why a wide range of immune disorders are on the rise. These inflammation-associated problems include allergies of all sorts, a broad spectrum of autoimmune diseases, as well as cognitive issues that likely include migraine headaches, anxiety disorders, and perhaps autism.

Fortunately, some solutions came into focus with the identification of several important factors that cause immune dysfunction in Western culture. These factors include vitamin D deficiency, chronic psychological stress, inflammatory diets, and a lack of physical exercise. However, after more than 150 years of suffering at the hands of immune dysfunction, the factor which seems to have the greatest impact on immune function in Western culture is only now coming into focus. Initially attributed to increasing hygiene, we now call this factor “biome depletion”.

The human biome is an ecosystem, like a forest.  When important species are missing, the biome is said to be depleted.   Photo courtesy of Thom Beales, copyright 2012

The human biome is an ecosystem, like a forest.  When important species are missing, the biome is said to be depleted.  Photo courtesy of Thom Beales, copyright 2012

"Biome depletion” refers to a loss of biodiversity from the ecosystem of the human body. The life associated with the human body (the human body’s biome) has dramatically changed in the last 150 years. The widespread use of toilets, water treatment facilities, refrigerators, processed foods, and even plastic storage containers has resulted in the annihilation of a large swath of the human body’s biome. These components of the biome were an important part of the forge that shaped our immune system in pre-industrial times. In other words, immunity’s forge has been disabled by modern culture. It is the great challenge of modern medicine to repair immunity’s forge. Public health depends on our ability to meet this challenge.

William is working to help establish the effects of biome depletion, especially in unexplored areas where biome depletion intersects with cognitive disorders and cancer. More importantly, William is working on ways to enrich the human biome and thus avert the consequences of biome depletion.

William has published his work with other scientists in a wide range of scientific and medical journals. A few of those articles are referenced below.


Bilbo, S.D., Wray, G., Perkins, S.E. & Parker, W. (2011) Reconstitution of the human biome as the most reasonable solution for epidemics of allergic and autoimmune diseases. Medical Hypotheses,77:494-504. PMID: 21741180 (Content featured in the New York Times, Sunday Review Section, August 26th, 2012.)

Parker, W. Perkins, S.E., Harker, M., & Muehlenbein, M.P. (2012) A prescription for clinical immunology: The pills are available and ready for testing. Current Medical Research and Opinion, 28:1193-1202. PMID: 22612580 (Editor’s Choice in issue) (Viewpoint featured in Men’s Health Magazine, December 2012)

Parker, W. & Ollerton, J. (2013) Evolutionary Biology and Anthropology Suggest Biome Reconstitution as a Necessary Approach toward Dealing with Immune Disorders. Evolution, Medicine, and Public Health, 2013:89-103. PMID: 24481190