Fish fed a high plant protein diet exhibit intestinal inflammation, the mechanism of which needs to be clarified. We preliminarily elucidate the mechanism of the TLRs/MyD88-PI₃K/Akt signalling pathway in intestinal inflammation induced by plant proteins. The diets contained 60% fish meal (FM, controls), or had 45% of the fish meal protein replaced by soybean meal (SBM), peanut meal (PM), cottonseed meal (CSM) or cottonseed protein concentrate (CPC). After an 8-week feeding trial, fish were challenged by injection of Vibrio parahaemolyticus bacteria for 7 days until the fish stabilized. The results showed that the specific growth rate (SGR) of the FM group was higher than other groups. The SGR of the CPC group was higher than those of the SBM, PM and CSM groups. The catalase (CAT) contents in the serum of fish fed a plant protein diet were higher than in FM fish. The abundances of Rhodobacteraceae and Microbacteriaceae in the MI (mid intestine) were higher in the CPC group. The TLR-2 expressions in the MI and DI of plant protein-fed fish were up-regulated. The expressions of IL-6 in the PI and MI, of hepcidin and TLR-3 in the MI, and of TLR-3 in the DI, were all lower than those of fish fed FM. In the PI, MI and DI, the protein expressions of P-PI₃K/T-PI₃K in the SBM and PM groups were higher than in the FM group. After the challenge, the cumulative mortalities in the FM and CPC groups were lower than those of the SBM, PM and CSM groups. These results suggested that plant protein diets reduced antioxidant capacity and glycolipid metabolism, hindered the development of the intestine and reduced intestinal flora diversity. TLR-3 is involved in the immune regulation of the PI in CPC group, MI and DI in SBM, PM, CSM and CPC groups, while might be involved in the immune regulation of the PI in SBM, PM and CSM groups. Furthermore, PI₃K/Akt signaling does not participate in the regulation of PI and MI in the CSM group, MI and DI in the CPC group.

饲喂高植物蛋白饮食的鱼表现出肠道炎症，其机理尚待阐明。我们初步阐明了TLRs / MyD88-PI ₃ K / Akt信号通路在植物蛋白诱导的肠道炎症中的机制。日粮中含有60％的鱼粉（FM，对照），或含有45％的鱼粉蛋白被大豆粉（SBM），花生粉（PM），棉籽粉（CSM）或棉籽蛋白浓缩物（CPC）替代。经过8周的饲喂试验后，注射副溶血性弧菌挑战了鱼类细菌持续7天，直到鱼稳定下来。结果显示，FM组的比增长率（SGR）高于其他组。CPC组的SGR高于SBM，PM和CSM组的SGR。饲喂植物蛋白饮食的鱼血清中的过氧化氢酶（CAT）含量高于FM鱼。CPC组中MI（肠中）的红细菌和微细菌科的丰度较高。植物蛋白喂养鱼的MI和DI中的TLR-2表达上调。PI和MI中IL-6的表达，MI中铁调素和TLR-3的表达以及DI中TLR-3的表达均低于饲喂F​​M的鱼。在PI，MI和DI中，P-PI ₃ K / T-PI ₃的蛋白质表达SBM和PM组的K高于FM组。挑战后，FM和CPC组的累积死亡率低于SBM，PM和CSM组。这些结果表明，植物蛋白饮食降低了抗氧化能力和糖脂代谢，阻碍了肠道的发育并降低了肠道菌群的多样性。TLR-3参与CPC组，SBM，PM，CSM和CPC组中MI和DI的PI免疫调节，而可能参与SBM，PM和CSM组中PI的免疫调节。此外，PI ₃ K / Akt信号不参与CSM组中PI和MI的调节，而参与CPC组中MI和DI的调节。