Unlocking the human microbiome

Katherine Pollard, senior investigator at the Gladstone Institutes, developed a suite of new statistical software to rapidly and accurately estimate the presence and function of microbes in a metagenome. Their programs--called MicrobeCensus, ShotMAP and PhyloCNV--made significant methodological improvements that allowed the scientists to accurately quantify the specific strains in the human microbiome using sequencing reads as short as 50 base pairs.

Using the new tools, Pollard's lab investigated a reported finding that obese people have a lower ratio of bacteria from the phylum Bacteroidetes to bacteria from the phylum Firmicutes compared with lean individuals. Although the scientific literature and the general media had heralded this association as noteworthy, several reports questioned its existence.

To test the validity of the association, Pollard's group conducted an extensive assessment of the relationship between body mass index (BMI) and the taxonomic composition of the gut microbiome. Their meta-analysis of data from multiple studies did not find a significant association between BMI and the relative abundance of any bacterial species.

For further details see the American Statistical Association.

Posted by Tim Sandle