Fig. 4From: Short-chain fatty acids can improve lipid and glucose metabolism independently of the pig gut microbiotaHierarchical clustering heat map of significantly differential metabolites from serum of pigs in the ESI+ (a) and ESI− (b). Metabolites peak area were Z score transformed. Warm color and cold color indicate increased and decreased expression of the metabolites, respectively. GF, germ-free; FA, short chain fatty acidsBack to article page