肝移植患者肠道双歧杆菌的生态结构

Molecular ecological structure of intestinal Bifidobacterium spp in liver-transplanted patients

目的探讨肝移植患者肠道双歧杆菌属细菌种群分子生态结构变化特点。方法采用荧光定量PCR技术分析健康人27例、肝硬化患者51例及肝移植后患者113例粪便双歧杆菌在属及种水平上的定性和定量变化。结果与健康人比较，肝移植及肝硬化患者肠道双歧杆菌总量、肠道假小链双歧杆菌或小链双歧杆菌组细菌及青春型双歧杆菌显著减少均P〈0．01；肝移植患者肠道长双歧杆菌显著增多（P〈0．01）。肝移植患者肠道假小链双歧杆菌或小链双歧杆菌、青春型双歧杆菌、短型双歧杆菌检出率显著低于健康人群均P〈0．01。肝移植组患者肠道双歧杆菌多样性显著低于健康人群（Х^2=20．1，P〈0．01）。结论肝移植及肝硬化患者肠道双歧杆菌种群生态结构均存在显著异常，尤以假小链双歧杆菌或小链双歧杆菌组及青春型双歧杆菌的数量及检出率降低最为显著，肝移植组患者肠道双歧杆菌多样性显著低于健康人群。

Objective To investigate the ecological structure of intestinal Bifidobacterium spp in liver-transplanted patients from the molecular ecological view. Methods Intestinal Bifidobacterium spp from all subjects（including 27 healthy volunteers, 51 patients with hepatic cirrhosis and 113 liver-transplanted patients） were quantified by real-time PCR using 16S rRNA gene-targeted genus and species specific primers. Results Total 16S rRNA gene copy numbers（per gram of wet weight of feces） of Bifidobacteria （P 〈0. 01, P 〈 0.01, respectively）, Bifidobacteriurn catenulaturn group （including Bi f idobacteriurn catenulaturn and Bi f idobacteriurn pseudocatnulaturn ） （ P 〈0. 01, P 0.01, respectively） and Bifidobacterium adolescentis （P 〈0. 01, P 〈 0.01, respectively） were lowered markedly in patients with cirrhosis or liver transplantation. The counts of Bifidobacteriurn longum in cirrhotic patients were markedly increased compared to that in healthy volunteers （P 〈 0.01）. The detection rates of faecal Bifidobacteriurn catenulaturn group （P 〈 0.01）, Bifidobacteriurn ado- lescentis （P 〈0. 01） and Bifidobacteriurn breve （P 〈0. 01） in liver-transplanted patients were significantly lower than those in healthy volunteers, respectively. The distribution diversity of Bifidobacteriurn species in patients with liver transplantation was remarkably less than that in healthy volunteers （Х^2= 20.1, P 〈 0.01）. Conclusions The obviously abnormal structure of Bifidobacterium communities is observed in liver-transplanted patients and cirrhotic patients. Both the counts and the detection rates of Bifidobacterium catenulatum group and Bifidobacterium adolescentis are decreased significantly. These results may provide theoretical bases for administration of some Bifidobacterium probiotics in patients with both liver transplantation and cirrhosis.