Dr. Pierre Chaurand
Dr. Pierre Chaurand, University of Montreal, Montreal, Quebec, Canada
Mass spectrometry imaging of the gut microbiome
Abstract
With more than 100 trillion bacterial cells, the gastrointestinal microbiota is the largest microbial community within mammals. Multiple lipid have been shown to mediate host-microbe interactions, which are essential for maintaining the symbiotic relationship between the mammalian and bacterial cells. Understanding their spatial distribution in the gut can help identify the role of bacterial lipids on host biology, which remains unclear to date. We therefore developed MALDI MSI methods to spatially resolve the microbiome biofilms across the intestine. Initial high-resolution images (10-5 µm) of different intestinal regions produced an array of lipid signals. Data analysis highlighted numerous lipid signals clearly differentiating the intestine wall from the lumen. A thorough library search using exact mass narrowed down our search list for lipid signals that originate from bacterial cells around or within the gut lumen region, which were further confirmed by MS/MS. Further, bacterial lipid gradients were also detected along the gut, presumably showing the localization of a variety of different bacteria. In addition to bacterial lipid detection, gradients for certain mammalian lipids were also observed across the length of the small intestine, which may be a consequence of lipid transfer from bacterial to mammalian host cells as a metabolic pathway for immunomodulation. Work is also being performed to assess bacterial-specific metabolite distributions within the gut to further characterise the various bacterial populations and the relationship with their host.
Bio
Dr. Pierre Chaurand earned his PHD from the Universite of Paris Sud, Orsay in 1994 and followed it with a post doc at Heinrich Heine University (Dusselorf Germany) from 1994 to 1998. He joined Vanderbilt University as a Research Associate Professor from November 1998 to 2009, when he transferred to University of Montreal where he is now a Professor of Chemistry.
With over 30 years of MS expertise, he is one of the pioneers of mass spectrometry imaging (MSI) technology and this took place mostly during his tenure in the late nineties and early 2000s at Vanderbilt University. Pierre has published over 100 publications (118 to be precise) and was cited close to 6000 times.