基于高通量测序分析早产认知障碍大鼠肠道菌群结构特征

Structural features of intestinal flora in preterm rats with cognitive impairment: an analysis based on high-thorough sequencing

目的分析早产认知障碍大鼠肠道菌群结构特征,探讨肠道菌群改变与早产认知障碍的关系.方法给孕16~17 d Sprague-Dawley大鼠连续2 d腹腔注射脂多糖(LPS)建立认知障碍模型,以腹腔注射PBS为对照.孕21 d行剖宫术,将早产大鼠随机分配给代母鼠喂养.于生后30 d利用Morris水迷宫中的定位航行实验对早产大鼠进行认知评估,并分为早产认知障碍组(n=21)与正常对照组(n=10).采用苏木精-伊红染色观察两组大鼠海马病理改变,提取各组大鼠粪便进行16S rRNA测序并分析.同时对两组大鼠肠道菌群进行主成分分析(PCA).结果与对照组相比,早产认知障碍大鼠海马可见大量神经元变性坏死;肠道菌群丰富度及多样性降低(P<0.05);门水平上变形菌门丰度增加(P<0.05);目、科、属水平上,普氏菌属、乳杆菌属等丰度显著降低,葡萄球菌科、寡养杆菌属等丰度显著增加(P<0.05).PCA显示两组大鼠在肠道菌群构成上差异明显.结论早产认知障碍大鼠肠道菌群结构发生明显变化,可为早产认知障碍导致的微生态变化的治疗及干预提供依据.

Objective To study the structural features of intestinal flora in preterm rats with cognitive impairment and the association of the change in intestinal flora with cognitive impairment in preterm rats. Methods Sprague-Dawley rats at 16-17 days of gestation were intraperitoneally injected with lipopolysaccharide for two consecutive days to establish a model of cognitive impairment, and the rats treated with intraperitoneally injected phosphate-buffered saline were established as the control group. Cesarean section was performed on day 21 of gestation, and preterm rats were randomly assigned to healthy maternal rats for feeding. The place navigation test in the Morris water maze was used to evaluate cognition on day 30 after birth. According to the result, the preterm rats were divided into cognitive impairment group with 21 rats and normal control group with 10 rats. Hematoxylin and eosin staining was used to observe pathological changes of the hippocampus, and fecal samples were collected for 16S rRNA sequencing and analysis. A principal component analysis (PCA) was performed for intestinal flora. Results Compared with the normal control group, the cognitive impairment group showed degeneration and necrosis of a large number of neurons in the hippocampus. Compared with the normal control group, the cognitive impairment group had significant reductions in the abundance and diversity of intestinal flora (P<0.05), with a significant increase in the abundance of Proteobacteria at the phylum level (P<0.05), as well as significant reductions in the abundance of Prevotella and Lactobacillus and significant increases in the abundance of Staphylococcaceae and Oligella at the order, family, and genus levels (P<0.05). PCA showed a significant difference in the composition of intestinal flora between the two groups. Conclusions There is a significant change in the structure of intestinal flora in preterm rats with cognitive impairment, which provides a basis for the treatment and intervention of microecological changes due to cognitive impairment after preterm birth.