Fig. 4

DHA/EPA accelerates glutamate degradation and rescues glutamate-induced β cell apoptosis. a Schematic overview of the differential metabolites involved in glutamate metabolism (n = 5 male and n = 5 female per group). Red circle represents up-regulated metabolites, blue circle represents downregulated metabolites, and open circle represents no change. Microbial gene encoding glutamate dehydrogenase (K00261) was upregulated by DHA/EPA. b, c Representative images of insulin staining in pancreases. Scale bar, 100 μm. d, e Apoptosis of β cell was determined by ELISA. Data are normalized to the db/db group (n = 6 male and n = 6 female per group). f, g mRNA expression of GLT1 and inflammatory cytokines in the pancreas. Groups with different superscript letters are significantly different (P < 0.05)