Abstract Body: Introduction: ABO blood type is related to cardiovascular disease (CVD) and influence gut microbiota (GMB). ABO antigen glycans in the gut may influence GMB composition, with effects further modulated by fiber intake.
Hypothesis: Higher fiber intake is associated with lower CVD risk and favorable GMB and blood metabolite profiles in O blood group but not in non-O blood group.
Methods: We examined associations of total, soluble, and insoluble fiber intake with CVD risk in 11,238 participants free of CVD at baseline from the Hispanic Community Health Study/Study of Latinos during ~12 years of follow-up, stratified by O (53%) and non-O blood groups. In subsamples (N up to 3940), we identified fiber-associated GMB species and serum metabolites in O and non-O blood groups separately, followed by examining their associations with cardiometabolic traits and CVD risk.
Results: Higher fiber intake, especially insoluble fiber, was associated with lower CVD risk in O blood group (4^th vs. 1^st quartile: HR: 0.37; 95% CI: 0.19–0.72), but not in non-O group (P-interaction = 0.02; Fig. A). Insoluble fiber intake, specifically in O blood group, was associated with differences in 14 GMB species (e.g., increased Butyrivibrio crossotus) and 50 metabolites (35 are known to relate to GMB), compared to 6 GMB species and 22 metabolites specifically in non-O group. An overall higher fiber-related serum metabolite profile (indicated by an O-specific metabolite score) was associated with a higher fiber-related GMB profile (O-specific GMB score; Fig. B), more favorable cardiometabolic traits (Fig. C) and lower CVD risk (Fig. D). No such associations were observed in non-O group. The interaction between ABO blood type and insoluble fiber intake on CVD risk was attenuated (P-interaction = 0.07) after additional adjustment for O-specific metabolite score.
Conclusions: ABO blood group modifies the association between fiber intake and CVD, which might be related to different GMB and blood metabolite profiles associated with fiber intake between O and non-O blood groups.