The function of ENSG00000088386 (SLC15A1, solute carrier family 15 member 1) is as follows. Electrogenic proton-coupled amino-acid transporter that transports oligopeptides of 2 to 4 amino acids with a preference for dipeptides. Transports neutral and monovalently charged peptides with a proton to peptide stoichiometry of 1:1 or 2:1 (By similarity) (PubMed:15521010, PubMed:18367661, PubMed:19685173, PubMed:26320580, PubMed:7896779, PubMed:8914574, PubMed:9835627). Primarily responsible for the absorption of dietary di- and tripeptides from the small intestinal lumen (By similarity). Mediates transepithelial transport of muramyl and N-formylated bacterial dipeptides contributing to recognition of pathogenic bacteria by the mucosal immune system (PubMed:15521010, PubMed:9835627). {ECO:0000250|UniProtKB:P36836, ECO:0000269|PubMed:15521010, ECO:0000269|PubMed:18367661, ECO:0000269|PubMed:19685173, ECO:0000269|PubMed:7896779, ECO:0000269|PubMed:8914574, ECO:0000269|PubMed:9835627}.