Statistical Methods for Detecting Differentially Abundant Features in Clinical Metagenomic Samples
Sequences were selected from a beta-binomial distribution with variable dispersions and group mean proportions p1 and p2. For each set of parameters, we simulated 1000 trials, 500 of which are generated under the null hypothesis (p1 = p2), and the remainder are differentially abundant where a*p1 = p2. For example, p = 0.2 and a = 2 indicates features comprising 20% of the population that differ two-fold in abundance between two populations of interest. Parameter values for p1 and a are shown above each plot.