Intersections of ABO blood group, secretor status, and the gut microbiome: implications for disease susceptibility and therapeutics.

The human gut microbiome is a dynamic ecosystem. It is shaped by host factors, including genetic traits such as ABO blood type and associated secretor status (FUT2 gene). In secretor individuals (~ 80% of the population), ABO antigens are expressed on the gut mucosal surfaces. These antigens serve as adhesion sites and nutrient substrates for select microorganisms. Evidence links blood groups to gut microbial ecology, with taxa such as Bacteroidessp., Eubacteriumsp., and Faecalibacterium sp. exhibiting preferential colonization patterns influenced by mechanisms including mucin glycan foraging, pathogen adhesion, and competitive exclusion. ABO blood type further modulates susceptibility to infectious, metabolic, and autoimmune diseases by affecting microbiome composition. Secretor status impacts microbiota diversity and probiotic colonization Non-secretors exhibit altered Bifidobacterium sp. profiles and reduced norovirus adhesion. These insights suggest possible avenues for tailoring microbiome-based interventions; however, current evidence remains preliminary and requires validation through controlled clinical studies. We outline a conceptual model linking host genetics, microbial ecology, and health outcomes, recognizing that these associations are still being mapped. The idea of incorporating blood type and secretor status into precision microbiome approaches remains exploratory and requires rigorous validation.