Methionine-Mediated Regulation of Intestinal Lipid Transportation Induced by High-Fat Diet in Rice Field Eel ( Monopterus Albus ).

An eight-week feeding trial explored the mechanism that supplemented methionine (0 g/kg, 4 g/kg, 8 g/kg, and 12 g/kg) in a high-fat diet (120 g/kg fat) on intestinal lipid transportation and gut microbiota of M. Albus (initial weight 25.03 ± 0.13 g) based on the diet (60 g/kg fat), named as Con, HFD+M0, HFD+M4, HFD+M8, and HFD+M12, respectively. Compared with Con, gastric amylase, lipase, trypsin ( P < 0.05), and intestinal lipase, amylase, trypsin, Na +/ K + -Adenosinetriphosphatase, depth of gastric fovea, and the number of intestinal villus goblet cells of HFD+M0 were markedly declined ( P < 0.05), while intestinal high-density lipoprotein-cholesterol, very low-density lipoprotein-cholesterol and microsomal triglyceride transfer protein of HFD+M0 were markedly enhanced ( P < 0.05); compared with HFD+M0, gastric lipase, amylase, trypsin, and intestinal lipase, trypsin, Na + /K + -Adenosinetriphosphatase, microsomal triglyceride transfer protein, very low-density lipoprotein-cholesterol, and apolipoprotein -A, the height of intestinal villus and the number of intestinal villus goblet cells of HFD+M8 were remarkably enhanced ( P < 0.05). Compared with Con, intestinal occ , cl12 , cl15 , zo-1 , zo-2 of HFD + M0 were markedly down-regulated ( P  <0.05), while intestinal vldlr , npc1l1 , cd36 , fatp1 , fatp2 , fatp6 , fatp7 , apo , apoa , apob , apof , apoo , mct1 , mct2 , mct4 , mct7 , mct12 , lpl , mttp , moat2 , dgat2 of HFD M0 were remarkably upregulated ( P < 0.05); compared with HFD+M0, intestinal gcn2 and eif2α of HFD+M8 were remarkably downregulated ( P < 0.05), intestinal occ , cl12 , cl15 , zo-1 , zo-2 , hdlbp , ldlrap , vldlr , cd36 , fatp1 , fatp2 , fatp6 , apo , apoa , apob , apof , apoo , mct1 , mct2 , mct8 , mct12 , lpl , mttp , moat2 , and dgat2 were remarkably upregulated ( P < 0.05). Compared with Con, the diversity of gut microbiota of HFD+M0 was significantly declined ( P < 0.05), while the diversity of gut microbiota in HFD+M8 was significantly higher than that in HFD+M0 ( P < 0.05). In conclusion, a high-fat methionine deficiency diet destroyed the intestinal barrier, reduced the capacity of intestinal digestion and absorption, and disrupted the balance of gut microbiota; supplemented methionine promoted the digestion and absorption of lipids, and also improved the balance of gut microbiota.