Robert Hettich: "Development of a Proteogenomic Approach for the Characterization of the Functions and Metabolic Activities of the Human Gut Microbiome"
The human gastrointestinal tract is a complex ecosystem containing a delicate balance of human and microbial cells involved in an intricate symbiotic relationship. In general, the microbial constituency helps maintain a healthy environment and aids in efficient digestion. However, environmental and/or genetic factors may result in an altered bacterial composition that manifests in a diseased condition, such as Crohn's disease.
In his talk, Robert Hettich will discuss how the recent availability of whole community genome sequencing and whole community proteomics has provided unique capabilities of profiling the compositions and activities of this microbiome without having to cultivate its membership.
He describes the development of a non-targeted, mass spectrometry-based proteomics approach to identify the microbial proteins in human fecal samples; how proteome samples were characterized via a multidimensional LC tandem mass spectrometric approach on a hybrid linear ion trap-Orbitrap, yielding greater than four thousand proteins per sample; how amongst the microbial membership, the Bacteroides and Bifidobacterium spoecies were the abundant, as expected since these are known to be common in the human gut.
The majority of the microbial proteins that were identified were classified into functional categories for translation, energy generation, and carbohydrate metabolism. Surprisingly, a number of innate human immunity proteins were also observed, suggesting a level of human regulation of microbial abundance. Finally, he explains how the results of his study demonstrate that it is possible to obtain high quality, extensive protein identifications by integrating metagenomic and metaproteomic information from human gut micro biomes.
Hettich is a scientist on the senior research staff with the organic and biological mass spectrometry group in the chemical sciences division at the Oak Ridge National Laboratory. He holds a Ph.D. analytical chemistry from Purdue University, a B.S. in chemistry from South Dakota School of Mines and Technology,?
and is an adjunct faculty member for genome sciences and technology at the University of Tennessee graduate school in Knoxville.