Human gut microbial functions are often associated with various diseases and host physiologies.Aging,a less explored factor,is also suspected to affect or be affected by microbiome alterations.By combinning functional featureselection with supervised classification,we aim to facilitate identification of age-related functional characteristics in metagenomes from several human gut microbiome studies (MetaHIT,MicroAge,MicroObes,Kurokawa et al.s and Gill et al.s dataset).