References:
Lozupone CA, Hamady M, Kelley ST, Knight R. Quantitative and Qualitative β Diversity Measures Lead to Different Insights into Factors That Structure Microbial Communities . Applied and Environmental Microbiology. 2007;73(5):1576-1585. doi:10.1128/AEM.01996-06.
Lozupone C, Lladser ME, Knights D, Stombaugh J, Knight R. UniFrac: an effective distance metric for microbial community comparison. The ISME journal. 2011;5(2):169-172. doi:10.1038/ismej.2010.133.
Lozupone C, Knight R. UniFrac: a New Phylogenetic Method for Comparing Microbial Communities. Applied and Environmental Microbiology. 2005;71(12):8228-8235. doi:10.1128/AEM.71.12.8228-8235.2005.
QIIME list of available metrics
FUKUYAMA J, MCMURDIE PJ, DETHLEFSEN L, RELMAN DA, HOLMES S. COMPARISONS OF DISTANCE METHODS FOR COMBINING COVARIATES AND ABUNDANCES IN MICROBIOME STUDIES. Pacific Symposium on Biocomputing Pacific Symposium on Biocomputing. 2012:213-224.link