Variability and Potential Causes for Inconsistencies in Human Datasets

Analysis of shotgun metagenomic sequencing of microbial communities promises insight into the taxonomic and functional composition of the human microbiome. The accurate quantification of taxonomic groups and gene families requires numerous technical issues with pooled short-read data to be resolved, and there is therefore great potential for error in metagenomics studies. I will then describe several new methods developed in my lab that address these challenges, as well as simulation approaches to statistically evaluate the performance of analysis tools for shotgun metagenomes. Using these tools, we have shown that while there is not a strong taxonomic signature for obesity in gut microbiomes, the functional repertoires of human microbiomes differ more than was previously estimated, in part due to large variation in metabolic capabilities even amongst closely related bacteria.