Dear developer,
HUMAnN is an excellent software, but these three databases to be updated. Especially the utility_mapping database, which can easily regroup gene families into other functional categories.
Command: humann_databases
HUMAnN Databases ( database : build = location )
chocophlan : full = http://huttenhower.sph.harvard.edu/humann_data/chocophlan/full_chocophlan.v201901_v31.tar.gz
chocophlan : DEMO = http://huttenhower.sph.harvard.edu/humann_data/chocophlan/DEMO_chocophlan.v201901_v31.tar.gz
uniref : uniref50_diamond = http://huttenhower.sph.harvard.edu/humann_data/uniprot/uniref_annotated/uniref50_annotated_v201901b_full.tar.gz
uniref : uniref90_diamond = http://huttenhower.sph.harvard.edu/humann_data/uniprot/uniref_annotated/uniref90_annotated_v201901b_full.tar.gz
uniref : uniref50_ec_filtered_diamond = http://huttenhower.sph.harvard.edu/humann_data/uniprot/uniref_ec_filtered/uniref50_ec_filtered_201901b_subset.tar.gz
uniref : uniref90_ec_filtered_diamond = http://huttenhower.sph.harvard.edu/humann_data/uniprot/uniref_ec_filtered/uniref90_ec_filtered_201901b_subset.tar.gz
uniref : DEMO_diamond = http://huttenhower.sph.harvard.edu/humann_data/uniprot/uniref_annotated/uniref90_DEMO_diamond_v201901b.tar.gz
utility_mapping : full = http://huttenhower.sph.harvard.edu/humann_data/full_mapping_v201901b.tar.gz