Abstract Immune stimulators are essential to the development of the aquaculture industry. Cinnamaldehyde (CA) and Bacillus spp. are promising immunostimulatory feed additives, as demonstrated by their beneficial effects in several fish species. This study investigated the effects of dietary CA and Bacillus subtilis either alone or in combination on the growth, digestive enzyme activity, and non-specific immunity of tongue sole, Cynoglossus semilaevis. A total of 240C. semilaevis (188 ± 5 g) were randomly assigned to four dietary treatments. Diets containing no additives (the control group, D), 0.1 g/100 g CA (Dcin), 107 CFU/g B. subtilis (DBac), and CA combined with B. subtilis (Dcin+Bac) were used to feed fish for 60 days. The results revealed significant improvements in the weight gain, specific growth rate, feed conversion ratio, and protein efficiency in the fish fed diets containing either CA or B. subtilis, and there were more significant improvements in the group with the combined supplementation (Dcin+Bac) compared with the control group. Fish fed diets with CA or CA combined with B. subtilis had higher intestinal proteinase, amylase, and lipase activities than the control fish. Dietary CA and B. subtilis singularly or in combination improved the antioxidant capacity and the immune status by stimulating SOD, CAT, and T-AOC activities and GSH-Px levels, by reducing malondialdehyde (MDA) content, and by increasing lysozyme activity in the serum, liver, mid kidney, and spleen. The results of the two-way analysis of variance revealed the synergistic effects of CA and B. subtilis in improving feed conversion ratio, protease activities in the foregut and midgut, and part of the antioxidant parameters. In addition, significant shifts in the overall intestinal microbial community and diversity were analyzed using high-throughput sequencing of the V3/V4 region of the 16S rRNA gene. The results showed that both dietary supplementation of CA alone or in combination with B. subtilis increased the abundance of the probiotic bacterial genera Bacillus, Lactobacillus, and Bifidobacterium. In conclusion, dietary supplementation of cinnamaldehyde and B. subtilis both solely and in combination are beneficial for improving the growth performance, digestive ability, non-specific immunity, and intestinal microbiota community of the tongue sole, Cynoglossus semilaevis.

中文翻译：

---

膳食肉桂醛和枯草芽孢杆菌提高生长性能、消化酶活性和抗氧化能力，并塑造舌底、半滑舌鲆的肠道微生物群

摘要 免疫刺激剂对水产养殖业的发展至关重要。肉桂醛 (CA) 和芽孢杆菌属。是很有前途的免疫刺激性饲料添加剂，正如它们在几种鱼类中的有益作用所证明的那样。本研究调查了单独或组合使用 CA 和枯草芽孢杆菌对舌鲆 Cynoglossus semilaevis 生长、消化酶活性和非特异性免疫的影响。总共240C。semilaevis (188 ± 5 g) 被随机分配到四种饮食处理中。使用不含添加剂的日粮（对照组，D）、0.1 g/100 g CA (Dcin)、107 CFU/g B. subtilis (DBac) 和 CA 与 B. subtilis (Dcin+Bac) 组合喂鱼60 天。结果表明，增重、比生长率、饲料转化率、和含有 CA 或 B. subtilis 的鱼饲料中的蛋白质效率，并且与对照组相比，联合补充 (Dcin+Bac) 组有更显着的改善。用 CA 或 CA 与枯草芽孢杆菌联合喂养的鱼比对照鱼具有更高的肠道蛋白酶、淀粉酶和脂肪酶活性。通过刺激 SOD、CAT 和 T-AOC 活性和 GSH-Px 水平，通过降低丙二醛 (MDA) 含量，以及通过增加溶菌酶活性，膳食 CA 和枯草芽孢杆菌单独或组合提高抗氧化能力和免疫状态。血清、肝、中肾和脾。双向方差分析结果揭示了CA和枯草芽孢杆菌在提高饲料转化率、前肠和中肠蛋白酶活性方面的协同作用，和部分抗氧化参数。此外，使用 16S rRNA 基因的 V3/V4 区域的高通量测序分析了整体肠道微生物群落和多样性的显着变化。结果表明，单独或与枯草芽孢杆菌联合添加 CA 的膳食补充剂均增加了益生菌芽孢杆菌属、乳杆菌属和双歧杆菌属的丰度。总之，单独或联合添加肉桂醛和枯草芽孢杆菌的膳食补充剂有利于改善舌鲛 Cynoglossus semilaevis 的生长性能、消化能力、非特异性免疫和肠道微生物群落。使用 16S rRNA 基因 V3/V4 区域的高通量测序分析了整体肠道微生物群落和多样性的显着变化。结果表明，单独或与枯草芽孢杆菌联合添加 CA 的膳食补充剂均增加了益生菌芽孢杆菌属、乳杆菌属和双歧杆菌属的丰度。总之，单独或联合添加肉桂醛和枯草芽孢杆菌的膳食补充剂有利于改善舌鲛 Cynoglossus semilaevis 的生长性能、消化能力、非特异性免疫和肠道微生物群落。使用 16S rRNA 基因 V3/V4 区域的高通量测序分析了整体肠道微生物群落和多样性的显着变化。结果表明，单独或与枯草芽孢杆菌联合添加 CA 的膳食补充剂均增加了益生菌芽孢杆菌属、乳杆菌属和双歧杆菌属的丰度。总之，单独或联合添加肉桂醛和枯草芽孢杆菌的膳食补充剂有利于改善舌鲛 Cynoglossus semilaevis 的生长性能、消化能力、非特异性免疫和肠道微生物群落。subtilis 增加了益生菌芽孢杆菌属、乳酸杆菌属和双歧杆菌属的丰度。总之，单独或联合添加肉桂醛和枯草芽孢杆菌的膳食补充剂有利于改善舌鲛 Cynoglossus semilaevis 的生长性能、消化能力、非特异性免疫和肠道微生物群落。subtilis 增加了益生菌芽孢杆菌属、乳酸杆菌属和双歧杆菌属的丰度。总之，单独或联合添加肉桂醛和枯草芽孢杆菌的膳食补充剂有利于改善舌鲛 Cynoglossus semilaevis 的生长性能、消化能力、非特异性免疫和肠道微生物群落。