Lycium barbarum polysaccharide attenuates myocardial injury in high-fat diet-fed mice through manipulating the gut microbiome and fecal metabolome

•Lycium barbarum polysaccharide (LBP) changed the fecal microbiota and metabolic profiles in mice.•LBP could increase indole derivatives of tryptophan metabolites in the gastrointestinal tract.•LBP alleviates cardiac dysfunction in high-fat diet-fed mice.