Summary of the 13 regions within the 16S rRNA gene that were used in this study.

<p>Each sub-region was generated from the sequences in the V19 database.</p>a<p>The numbers in the parentheses represent the 95% confidence interval.</p>b<p>Sanger reads are estimated to be up to 800 bp and can be used to sequence the same molecule multiple times.</p>c<p>GS FLX Titanium reads average ∼400 bp (amplicon kit released 11/2009).</p>d<p>GS FLX reads average ∼240 bp.</p>e<p>Illumina reads average ∼200 bp.</p>f<p>The NIH Human Microbiome Project is considering these regions for their cross-sectional studies.