背景:最近,口腔癌杆菌具核梭杆菌(F.核仁),与溃疡性结肠炎(UC)有关。这里,我们的目的是研究粪便微生物移植(FMT)是否可以通过恢复肠道菌群和消除口腔来源的F.核仁和毒力因子fadA来缓解UC。
方法:C57BL/6J小鼠随机分为健康对照组,葡聚糖硫酸钠基团(DSS),口服接种组(OR),上FMT组(UFMT),和较低的FMT组(LFMT)。疾病活动指数,体重,存活率,和组织病理学评分用于测量结肠炎的严重程度。通过对紧密连接蛋白Occludin进行免疫组织化学染色来评估肠粘膜屏障的功能。使用实时PCR评估nusG基因和毒力基因fadA的相对丰度。通过ELISA检测细胞因子水平。使用16SrRNA的全长测序来分析肠道菌群的变化和组成。
结果:核仁F.的口服孵育进一步加剧了结肠炎和肠道菌群失调的严重程度。肽链球菌科,肠球菌科,和大肠杆菌在OR小鼠中显著富集。然而,与UFMT小鼠相比,LFMT小鼠的疾病活动明显减少,在恢复肠道菌群和消除核仁F.方面更有效。拟杆菌,落叶松科,Prevotellaceae主要是LFMT小鼠的富集细菌。此外,属如乳酸菌,Allobaculum,发现拟杆菌与TNF-α呈负相关,IL-1β,IL-6像Romboutsia这样的属人,大肠杆菌志贺氏菌,肠球菌,发现梭菌与TNF-α呈正相关,IL-1β,IL-6
结论:经口孵育核菌进一步加重了DSS诱导的结肠炎小鼠的严重程度和菌群失调。此外,下肠道FMT可以通过恢复肠道菌群多样性和消除F.核仁和毒力因子fadA来改善结肠炎。
BACKGROUND: Recently, the oral oncobacterium Fusobacterium nucleatum (F. nucleatum), has been linked with ulcerative colitis (UC). Here, we aim to investigate whether Fecal Microbiota Transplantation (FMT) can alleviate UC by restoring gut microbiota and eliminating oral-derived F. nucleatum and virulence factor fadA.
METHODS: C57BL/6J mice were randomly divided into a healthy control group (HC), Dextran Sulfate Sodium group (DSS), oral inoculation group (OR), upper FMT group (UFMT), and lower FMT group (LFMT). Disease activity index, body weight, survival rate, and histopathological scores were used to measure the severity of colitis. The function of the intestinal mucosal barrier was evaluated by performing immunohistochemical staining of the tight junction protein Occludin. Real-time PCR was used to assess the relative abundance of the nusG gene and the virulence gene fadA. Cytokine levels were detected by ELISA. Full-length sequencing of 16S rRNA was used to analyze the changes and composition of gut microbiota.
RESULTS: Oral incubation of F. nucleatum further exacerbated the severity of colitis and gut dysbiosis. Peptostreptococcaceae, Enterococcaceae, and Escherichia coli were significantly enriched in OR mice. However, LFMT mice showed an obvious decrease in disease activity and were more effective in restoring gut microbiota and eliminating F. nucleatum than UFMT mice. Bacteroidota, Lachnospiraceae, and Prevotellaceae were mainly enriched bacteria in LFMT mice. In addition, Genera such as Lactobacillus, Allobaculum, and Bacteroidales were found negative correlation with TNF-α, IL-1β, and IL-6. Genera like Romboutsia, Escherichia Shigella, Enterococcus, and Clostridium were found positively correlated with TNF-α, IL-1β, and IL-6.
CONCLUSIONS: Oral incubation of F. nucleatum further exacerbates the severity and dysbiosis in DSS-induced colitis mice. Besides, lower tract FMT can ameliorate colitis by restoring the gut microbiota diversity and eliminating F. nucleatum and virulence factor fadA.