College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, 010018, PR China.
College of Animal Science, Inner Mongolia Agricultural University, Hohhot, 010018, PR China; College of Vocational, Inner Mongolia University of Finance and Economics, Hohhot, 010070, PR China.
Microb Pathog. 2019 Sep;134:103557. doi: 10.1016/j.micpath.2019.103557. Epub 2019 May 30.
Escherichia coli (E. coli) O-induced diarrhea is associated with intestinal microbial imbalance, however, the results of using oral antibiotics still remain poor. To overcome such problem, our study investigates the role of metabolites from stable flies (MSF) in the occurrence of diarrhea. The amino acid composition and molecular weight analysis of MSF by RP-HPLC and GPC, respectively. Besides the normal control group, SPF mice in other group were inoculated with E. coli O1 received treatment as follows over a period of 7 days saline solution (E. coli control), ciprofloxacin (0.13 g/kg; positive control) and MSF (2, 4 and 8 mg/kg) dosage. Throughout the experiment, defecation and body weights were examined and recorded. On the eighth day, after administering anesthesia, blood, tissue of small intestine samples were obtained for immunological and anti-oxidant. Small intestinal tissues and cecum contents samples were used for histopathological and 16S rDNA sequencing analysis. Our showed that MSF was rich in isoleucine, and its molecular weight less than 400 Da is 60.03%. MSF (4 and 8 mg/kg) and ciprofloxacin, significantly decreased IL-6, IL-8 and TNF-α levels, whereas, increased IL-2, IL-4, IL-10, INF-γ, IgA and IgG levels in mice having diarrhea. These treatments also reversed intestinal flora imbalance as indicated by the increased in Firmicutes-to-Bacteroidetes ratio and Clostridium levels (P < 0.05) and improved 5-HT, CAT and SOD levels. MSF favored diarrhea management as compared to ciprofloxacin, suggesting that MSF can be used in the management of E. coli O-induced diarrhea, in normal gut microbiota and normal intestinal antioxidant function.
大肠杆菌（E. coli）O 型诱导的腹泻与肠道微生物失衡有关，但口服抗生素的效果仍然不佳。为了解决这个问题，我们研究了稳定蝇（MSF）代谢物在腹泻发生中的作用。通过 RP-HPLC 和 GPC 分别对 MSF 的氨基酸组成和分子量进行分析。除了正常对照组外，其他组的 SPF 小鼠用 E. coli O1 接种，在 7 天的时间里接受以下治疗：生理盐水（E. coli 对照组）、环丙沙星（0.13g/kg；阳性对照组）和 MSF（2、4 和 8mg/kg）剂量。在整个实验过程中，检查并记录排便和体重。在第八天，给予麻醉后，采集血液、小肠组织样本进行免疫和抗氧化分析。从小肠组织和盲肠内容物样本中进行组织病理学和 16S rDNA 测序分析。我们发现 MSF 富含异亮氨酸，其分子量小于 400Da 的部分为 60.03%。MSF（4 和 8mg/kg）和环丙沙星显著降低了腹泻小鼠的 IL-6、IL-8 和 TNF-α 水平，而增加了 IL-2、IL-4、IL-10、INF-γ、IgA 和 IgG 水平。这些治疗方法还通过增加厚壁菌门与拟杆菌门的比值和梭菌水平（P<0.05）和改善 5-HT、CAT 和 SOD 水平来逆转肠道菌群失衡。MSF 对腹泻的管理效果优于环丙沙星，表明 MSF 可用于管理大肠杆菌 O 型诱导的腹泻，维持正常肠道菌群和正常肠道抗氧化功能。
