ABCG2 and fetal growth restriction: As shown in Figure 8, IUGR increased (p < 0.05) the relative abundances of the ileal microbial genes involved in carotenoid biosynthesis, peroxisome, ABC transporters, tryptophan metabolism, lysine degradation, glyoxylate and dicarboxylate metabolism, and limonene and pinene degradation compared to the NBW piglets.