GI Microbiota and Regulation of the Immune System (Advances in Experimental Medicine and Biology (635))

The idea that the microbial communities within the GI tract have a profound influence on general human health actually originated with Russian scientist Elie Metchnikov at the turn ofthe last century. Also known as the "fatherofimmunol­ ogy", Metchnikovbelievedthat putrefactivebacteriain the gut were responsible for enhancing the aging process. He theorized that ingestion ofhealthy bacteria found in fermented foods could counteract toxic bacteria and was the key to good health. His theories concerning good bacteria and health can be found in his treatise "The ProlongationofLife: Optimistic Studies".Thesewritings promptedJapanesescientist Minoru Shirotatobegin investigationofhow fermentative bacteriaimprove health. He succeededin isolating astrainofLactobacillusthat could survive passage through the intestine, while promoting a healthy balance ofmicrobes. The "Shirota strain" is still used today in the fermented beverage Yakult.It is clear from a commercial standpoint that these ideas have inspired the development of a probiotic industry, which has expanded greatly in the U.S. over the past 5-10 years.

Gary B. Huffnagle, PhD, is a Professor of Internal Medicine (Pulmonary

Diseases) and Microbiology and Immunology at the University of Michigan Medical

School. He holds a BS in microbiology from Pennsylvania State University and a

PhD in immunology from the University of Texas Southwestern Medical School.

In addition to conducting research, he teaches undergraduate and graduate classes

in eukaryotic microbiology, microbial symbiosis and experimental immunology

at the University of Michigan. Dr. Huffnagle’s research focuses on the regulation

of pulmonary immunity to infectious agents and allergens. In the past 5 years, his

attention has turned to the role of the indigenous microbiota in immune system

functioning, as well as the role of probiotics in animal and human health. He has

been awarded research grants from the National Heart, Lung and Blood Institute

(NHL BI), National Institute of Allergy and Infectious Diseases (NIAID), the Francis

Families Foundation and the Burroughs-Wellcome Fund. Dr. Huffnagle serves or

has served on editorial boards for the American Society for Microbiology (ASM)

and the American Association of Immunologists (AAI), as well as on advisory and

review panels for the National Institutes of Health (NIH).

Mairi C. Nove rr, PhD, is an Assistant Professor of Immunology and

Microbiology at Wayne State University Medical School. She earned a BA in biology

from Kalamazoo College in 1996 and a PhD in microbiology and immunology

from the University of Michigan in 2002. Dr. Noverr’s current research focuses on

investigating mechanisms of immunomodulation by the opportunistic yeast Candida

albicans during host-pathogen interactions and how interactions with other members

of the microbiota influence these interactions. Her laboratory is investigating

signaling compounds called oxylipins that are produced by both Candida and the

host, which can influence the microbiology of the fungus and the activity of host

immune system cells. Projects in the laboratory include molecular characterization

of the fungal oxylipin biosynthetic pathways and determining the effects of oxylipins

during Candida pathogenesis, in modulating host immune cell function, and

during fungal-bacterial interactions. She has been awarded research funding from

the Francis Families Foundation.