Ikeda Saiko, Takahashi Saki, Suzuki Norie, Hanzawa Fumiaki, Horio Fumihiko, Oda Hiroaki
Department of Nutritional Sciences, Nagoya University of Arts and Sciences.
Graduate School of Bioagricultural Sciences, Nagoya University.
J Nutr Sci Vitaminol (Tokyo). 2020;66(1):19-23. doi: 10.3177/jnsv.66.19.
Using rats, we previously found that vitamin C deficiency increases serum levels of interleukin-6 (IL-6) and glucocorticoid, and changes the gene expression of acute phase proteins (APP) in the liver. However, it remains unclear how vitamin C deficiency causes these inflammation-like responses. In this study, we investigated the possibility that changes in gut microbiota are involved in the induction of APP gene expression by vitamin C deficiency. ODS rats that cannot genetically synthesize vitamin C were divided into 4 groups based on the presence or absence of vitamin C or antibiotics and were raised for 15 d. Neomycin, vancomycin, and ampicillin were used as antibiotics, and 300 mg L-ascorbic acid/kg was added to the AIN93G diet. Vitamin C deficiency affected neither the wet tissue weights nor relative abundance of bacteria in the cecal contents. Antibiotic administration increased wet weights of the cecum, cecal contents, and colon, changed the relative abundance of some bacteria in the cecal contents, and decreased serum IL-6 level. However, antibiotic administration had no effect on serum concentrations of corticosterone and α1-acid glycoprotein (AGP), vitamin C concentration in the liver, and mRNA levels of haptoglobin and AGP in the liver. Therefore, disturbance of gut microbiota did not attenuate the increase in glucocorticoid level and induction of APP gene expression due to vitamin C deficiency. This suggests that gut microbiota is not involved in the inflammation-like responses caused by vitamin C deficiency.
我们之前利用大鼠发现，维生素C缺乏会增加血清白细胞介素-6（IL-6）和糖皮质激素水平，并改变肝脏中急性期蛋白（APP）的基因表达。然而，维生素C缺乏如何引发这些类似炎症的反应仍不清楚。在本研究中，我们调查了肠道微生物群的变化是否参与了维生素C缺乏诱导的APP基因表达。将无法通过基因合成维生素C的ODS大鼠根据是否补充维生素C或抗生素分为4组，并饲养15天。使用新霉素、万古霉素和氨苄青霉素作为抗生素，并在AIN93G饮食中添加300 mg L-抗坏血酸/kg。维生素C缺乏既不影响盲肠内容物中细菌的湿组织重量，也不影响其相对丰度。抗生素给药增加了盲肠、盲肠内容物和结肠的湿重，改变了盲肠内容物中一些细菌的相对丰度，并降低了血清IL-6水平。然而，抗生素给药对血清皮质酮和α1-酸性糖蛋白（AGP）浓度、肝脏中的维生素C浓度以及肝脏中触珠蛋白和AGP的mRNA水平没有影响。因此，肠道微生物群的紊乱并未减轻由于维生素C缺乏导致的糖皮质激素水平升高和APP基因表达的诱导。这表明肠道微生物群不参与维生素C缺乏引起的类似炎症的反应。
