I give picrust2 a list of 16s ASVs that map to biota at various taxanomic levels. Picrust2 creates a table of inferred per-sample abundances of KEGG genome orthologs (KO) and one of KEGG enzyme classifications (EC). The main output is a list of per-sample inferred pathway abundances that seems to take both of these into account.
Could I have a basic description of how this works and why? I did RTFM, but I'm inexperienced with pathway analysis and totally green in the context of the microbiome. So, while I can recite the steps picrust2 uses to go from ASVs to pathways, I humbly admit that I don't really understand what I'm doing or what this information ultimately means.