Statistical analysis of 16S rRNA gene libraries.

Simpson diversity index and Choa1 nonparametric estimates were used to compare species diversity in the different regions of the GI tract. For Chao1 phylotype richness estimations, OTUs were binned to genera.本研究采用辛普森多样性指数（Simpson diversity index）与Chao1非参数估计法，对比胃肠道（gastrointestinal tract，GI tract）不同区域的物种多样性。针对Chao1系统型丰富度估计，将操作分类单元（Operational Taxonomic Units，OTU）聚类至属级水平。