The HUNT study identifies host genetic factors reproducibly associated with human gut microbiota composition.

The gut microbiota is associated with human health and disease. Here we conducted a genome-wide association study of host genetic factors influencing gut microbiota composition in 12,652 individuals from the Trøndelag Health Study (HUNT), with replication in Nordic cohorts (n = 16,017-21,976). We identified 12 reproducible SNP-species associations across six genomic loci, including known (LCT, ABO) and novel (HLA-DQB1, MUC12, SLC37A2, FUT2) regions. Additionally, we detected genetic signals associated with gut microbiota functional modules at three loci (LCT, ABO, FUT2). Follow-up analyses suggest that these host-microbiota associations are linked to the pathogenesis of celiac disease and hemorrhoidal disease. Mendelian randomization analyses provided evidence supporting a causal effect of body mass index on gut microbiota composition. These findings highlight the interplay between host genetics and gut microbiota for human health and disease.