Pan Wenbo, Wang Fan, Xu Jia, Li Juntao, Gao Jian, Zhao Yuhua, Wang Qingchao
College of Fisheries Key Lab of Freshwater Animal Breeding Ministry of Agriculture Huazhong Agricultural University, Wuhan 430070, China.
Guangxi Key Laboratory of Marine Environmental Science Guangxi Academy of Marine Sciences Guangxi Academy of Sciences, Nanning 530012, China.
Aquac Nutr. 2024 Sep 26;2024:9632883. doi: 10.1155/2024/9632883. eCollection 2024.
Dietary betaine supplementation has been reported to alleviate the adverse effects of high-carbohydrate diets on , while the regulatory mechanism remains largely unknown. In the present study, a 79-day feeding trial was conducted with 450 juvenile (average weight 6.75 ± 0.10 g), which were fed with five high-carbohydrate diets (43%) supplementing betaine at 0% (CD group), 0.2% (0.2Bet group), 0.4% (0.4Bet group), 0.8% (0.8Bet group), and 1.6% (1.6Bet group), respectively. Results showed in 0.8Bet group exhibited the best growth performance, indicated by the largest weight gain ratio (142.88%) and least feed conversion ratio (1.63). Moreover, liver health was promoted in 0.8Bet group, with decreased number of non-nucleated cells and less lipid accumulation, which was accompanied by the lowest hepatosomatic index (1.38%). In order to further illustrate the regulatory mechanism, metabolites assay indicated that dietary betaine supplementation significantly increased plasma contents of methionine, serine, hypotaurine, and taurine, but did not affect plasma contents of cystathionine, cystine, or cysteic acid. Accordingly, the mRNA expressions of cysteine sulfinate decarboxylase in cysteine sulfinic acid pathway and cysteamine dioxygenase (ADO) in sulfinic acid (CS) pathway, which were both involved in taurine synthesis, were also upregulated in the liver. Meanwhile, the microbial communities in intestine were more stable and uniform with betaine supplementation. Therefore, dietary betaine supplementation may exert its protective roles in improving feed efficiency and liver health of via promoting de novo taurine synthesis and stabilizing intestinal microbial communities.
据报道，膳食补充甜菜碱可减轻高碳水化合物饮食对……的不利影响，但其调节机制仍 largely 未知。在本研究中，对 450 尾幼鱼（平均体重 6.75±0.10 克）进行了为期 79 天的饲养试验，分别用五种高碳水化合物饮食（43%）补充 0%（对照饮食组）、0.2%（0.2%甜菜碱组）、0.4%（0.4%甜菜碱组）、0.8%（0.8%甜菜碱组）和 1.6%（1.6%甜菜碱组）的甜菜碱进行投喂。结果表明，0.8%甜菜碱组的幼鱼表现出最佳生长性能，以最大增重率（142.88%）和最低饲料转化率（1.63）为指标。此外，0.8%甜菜碱组的肝脏健康得到改善，无核细胞数量减少，脂质积累减少，同时肝脏体指数最低（1.38%）。为了进一步阐明调节机制，代谢物分析表明，膳食补充甜菜碱显著增加了蛋氨酸、丝氨酸、亚牛磺酸和牛磺酸的血浆含量，但不影响胱硫醚、胱氨酸或半胱氨酸的血浆含量。因此，参与牛磺酸合成的半胱氨酸亚磺酸途径中的半胱氨酸亚磺酸脱羧酶和亚磺酸（CS）途径中的半胱胺双加氧酶（ADO）的 mRNA 表达在肝脏中也上调。同时，补充甜菜碱后，肠道中的微生物群落更稳定、更均匀。因此，膳食补充甜菜碱可能通过促进牛磺酸的从头合成和稳定肠道微生物群落，在提高幼鱼饲料效率和肝脏健康方面发挥其保护作用。
