Raw abundance of the functional characteristics of the bacterial communities analysed using PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States, Langille et al. 2013, doi:10.1038/nbt.2676). Functions were categorized into Kyoto Encyclopedia of Genes And Genomes (KEGG) pathways representing gene counts of each predicted metagenome. The KEGG 1 refers to 6 main functions identified in the dataset. The KEGG 2 pathway refers to specific functions within to the 6 main functions identified in the KEGG 1 pathway.