本研究调查了α-酮戊二酸（AKG）对大鳞鲤（Songpu Cyprinus carpio）肠道健康的缓解作用，该健康问题是由大豆抗原蛋白引起的。饲料配制分为鱼粉（CON）、50%大豆粉（SBM）、甘氨酸蛋白和β-胱抑胺蛋白混合（11+7S），以及在11+7S中添加1%的AKG（AKG）。每天三次，连续六周，每个水缸内重复三次投喂鲤鱼（约4 g），直至出现饱食。与CON相比，SBM处理导致生长性能显著下降（P<0.05），而11+7S和AKG处理与CON没有显著差异（P>0.05）。在SBM和11+7S处理中，近端肠（PI）和远端肠（DI）中肿瘤坏死因子（TNF-α）和白介素-1β（IL-1β）的基因表达增加（P<0.05），PI和中肠（MI）中转化生长因子（TGF-β）的基因表达减少（P<0.05）。在SBM中DI中半胱氨酸蛋白酶-3（caspase-3）增加（P<0.05），而在11+7S中DI中半胱氨酸蛋白酶-3和半胱氨酸蛋白酶-9（caspase-9）增加（P<0.05）；相反，在AKG中PI和MI中TGF-β增加，在MI中TNF-α和IL-1β，DI中半胱氨酸蛋白酶-3和半胱氨酸蛋白酶-9减少（P<0.05）。在SBM中PI和MI中的靶向雷帕霉素（TOR），PI中的乙酰辅酶A羧化酶（ACC），MI和DI中的TOR都减少（P<0.05），在11+7S中PI和DI中的AMP激活蛋白激酶（AMPK），PI、MI和DI中的TOR，PI和DI中的ACC，DI中的4E结合蛋白（4E-BP）都减少（P<0.05）。AKG补充剂可恢复PI和DI中的AMPK，PI和MI中的ACC，PI、MI和DI中的TOR，PI和DI中的4E-BP（P<0.05）。AKG膳食治疗增加了脂类和类脂代谢、有机酸和衍生物代谢。总之，AKG减少了鱼类肠道炎症和凋亡途径的表达，并改变了鱼肠道中的甘油磷脂代谢和鞘脂代谢。© 2023. The Author(s), under exclusive licence to Springer Nature B.V.

The study investigated the alleviated effects of Alpha-ketoglutaric acid (AKG) on the intestinal health of mirror carp (Cyprinus carpio Songpu) caused by soy antigenic protein. The diets were formulated from fishmeal (CON), 50% soybean meal (SBM), the mixture of glycinin and β-conglycinin (11 + 7S) and adding 1% AKG in the 11 + 7S (AKG). Carp (~ 4 g) in triplicate (30 fish per tank) was fed to apparent satiation thrice a day for six weeks. Compared with CON, SBM treatment resulted in significantly poor growth performance (P < 0.05), whereas 11 + 7S and AKG treatments were not significantly different from CON (P > 0.05). Gene expression of tumor necrosis factor (TNF-α) and interleukin-1 β (IL-1β) in proximal intestines (PI) and distal intestines (DI) were increased (P < 0.05), and transforming growth factor (TGF-β) in PI and middle intestines (MI) was decreased (P < 0.05) in both SBM and 11 + 7S. The caspase-3 in DI increased in SBM (P < 0.05) and the caspase-3 and caspase-9 in DI increased in 11 + 7S (P < 0.05); conversely, TGF-β in PI and MI was increased, TNF-α and IL-1β in the MI, caspase-3, and caspase-9 in DI was decreased in AKG (P < 0.05). The TOR (target of rapamycin) in PI and MI, ACC in PI, MI and DI was decreased in SBM (P < 0.05), the AMPK in the PI and DI, TOR in PI, MI and DI, ACC in PI and DI, 4E-BP in DI was reduced in 11 + 7S (P < 0.05). AMPK in the PI and DI, ACC in the PI and MI, TOR in PI, MI, and DI, 4E-BP in PI and DI was recovered by AKG supplementation (P < 0.05). Lipids and lipid-like metabolism, organic acids and derivatives metabolism increased in AKG dietary treatment. In conclusion, AKG reduces the expression of intestinal inflammation and apoptosis pathway and changes glycerophospholipid metabolism and sphingolipid metabolism in the intestine of fish.© 2023. The Author(s), under exclusive licence to Springer Nature B.V.