Dietary fat source induces gut microbiota alterations and impacts chronic murine graft- versus-host disease severity

Abstract

Abstract It has been observed that a constriction of the gut microbiome occurs with high fat diet, and likewise decreased microbiome diversity is directly correlated with more severe graft-versus-host disease (GvHD) following allogeneic hematopoietic stem cell transplantation. Taken together it is plausible that not only fat content, but source of dietary fat could influence gut microbiota and GvHD outcome. We sought to address this question and developed experimental rodent diets that have the same fat content (25% kcal fat, a moderate increase in fat content from normal chow) which differ only by fat source: animal- versus plant-derived fat and found that these diets drive alterations in gut microbiota diversity. Both diets yielded similar outcomes in an acute model of GvHD, however we found that mice fed the animal-derived fat diet exhibited worse survival and outcomes in a model of chronic GvHD, than mice fed the plant-derived fat diet. These findings correlated with increased inflammation and alterations in intestinal immune cell populations following chronic GvHD induction. Collectively, our data show that diets that are equal in macronutrient content but different in fat source can promote different gut microbiomes and in turn alter intestinal homeostasis and chronic GvHD outcome. Century for the Cure - Philanthropic Fund