Mare milk and fermented mare milk alleviate dextran sulfate sodium salt–induced ulcerative colitis in mice by reducing inflammation and modulating intestinal flora

ABSTRACT: Mare milk (MM) and fermented mare milk (FM) are specialized animal milks with high nutritional value, containing a variety of functionally active substances that are capable of resisting inflammatory responses and oxidative stress. However, little relevant research on the maintenance of intestinal homeostasis has been performed. This study aimed to investigate the effects of MM and FM on the prevention of dextran sulfate sodium salt (DSS)-induced ulcerative colitis in a mouse model and to preliminarily elucidate the underlying mechanisms. The results showed that MM and FM had different degrees of protective effects against the damage caused by DSS and alleviated ulcerative colitis by inhibiting weight loss, reducing colon length shortening, and restoring intestinal structure. Additionally, MM and FM maintained intestinal tight junction protein levels to repair barrier function, downregulated inflammatory cytokines (e.g., IL-1β, TNF-α, IL-6, and iNOS) and bolstered the body's antioxidant defense system. Moreover, MM and FM regulated dysregulation of the intestinal microenvironment by improving the diversity of the gut microbiota and reshaping its structure, including increasing the proportion of Firmicutes and Bacteroidetes and the relative abundance of beneficial bacterial genera (e.g., Akkermansia). In summary, MM and FMM can serve as dietary resources for preventing ulcerative colitis and maintaining intestinal homeostasis.