Estimating Taxonomic and Functional Diversity in Shotgun Metagenomes

• Activity Number: 671
• Type: Invited
• Date/Time: Thursday, August 13, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Katherine Snowden Pollard*
• Companies: Gladstone Institutes, UCSF
• Keywords: microbial communities ; metagenomics ; estimation ; simulation ; metabolism ; gene family

Abstract

Analysis of shotgun metagenomic sequencing of microbial communities promises insight into the taxonomic and functional composition of the human microbiota and other microbial communities. Shotgun metagenomes provide many challenges for accurate quantification of the abundances of taxonomic groups and gene families. I will describe several new methods developed in my lab that address these problems, including normalization for average genome size which can confound abundance estimates, as well as simulation approaches to statistically evaluate the performance of analysis tools for shotgun metagenomes. Using these methods, we have shown that while there is not a strong taxonomic signature for obesity in gut microbiomes, the functional repertoires of microbial communities living in the human body differ more than was previously estimated, in part due to large variation in metabolic capabilities amongst closely related bacteria.