早产儿出生后4周内肠道微生物的产气差异

 目的 探究早产儿出生后4周内肠道微生物产气量及各种气体成分所占比例的差异。方法 本研究招募了2020年5月1日—6月1日期间生后即入上海市儿童医院治疗的19名早产儿。被纳入研究的早产儿均符合出生胎龄≥28周同时<37周，无畸形或代谢性疾病，被纳入前均获得父母书面知情同意。收集其出生后3天内，出生后第1周、第2周、第3周、第4周时自然排出的粪便，12h内送达实验室处理。通过体外发酵系统，将所收集的粪便接种到分别以乳糖（lactose，LAT）、低聚果糖（fructo-oligosaccharides，FOS）、2'-岩藻糖基乳糖（2'-Fucosyllactose，FL-2）和低聚半乳糖（galacto-oligosaccharides，GOS）作为主要碳源的培养基中进行体外发酵；另外检测肠道菌群的产气量、各种气体成分（二氧化碳、氢气、甲烷、硫化氢）等代谢指标。结果 培养基组早产儿的肠道微生物经体外发酵的产气量均逐渐增加。早产儿自出生起至第4周，肠道微生物体外产气中均测到甲烷。早产儿自出生2周后，其他气体普遍产生，肠道微生物的体外产气中二氧化碳占比最多，其次为氢气、甲烷和硫化氢。此外，不同日龄早产儿肠道微生物皆在以FL-2为碳源的培养基中产气量最少，以LAT为碳源的培养基中产气量最多。结论 早产儿出生后4周内，肠道微生物经体外发酵的产气量与其日龄呈正相关。早产儿出生后4周内所排粪便可能含产甲烷菌。

The difference of intestinal microbiota gas production in preterm infants within four weeks after birth

Objective To explore the difference of intestinal microbial gas production and the proportion of various gas components in preterm infants within 4 weeks after birth. Methods A total of 19 preterm infants admitted to Shanghai Children's Hospital,Shanghai Jiao Tong University from May 1,2020 to Jun 1,2020 were enrolled in this study.All preterm infants met the inclusion criteria that the gestational age ≥ 28 weeks and<37 weeks,and had no deformity or metabolic diseases. Written consent was obtained from all the parents of preterm infants before inclusion.The feces were collected within 3 days,1 week,2 weeks,3 weeks and 4 weeks after birth and sent to the laboratory for treatment within 12 hours.The collected feces were inoculated into the medium with lactose (LAT),fructo-oligosaccharides (FOS),2'-Fucosyllactose (FL-2) and galacto-oligosaccharides (GOS) as the main carbon sources for in vitro fermentation. The gas production of intestinal flora, various gas components (carbon dioxide,hydrogen,methane,hydrogen sulfide) and other metabolic indicators were detected. Results In the four culture media,the gas production of intestinal flora in preterm infants increased gradually.Since birth till 4 weeks after birth,methane was detected in the gas produced by intestinal microorganisms in vitro,while carbon dioxide,hydrogen and hydrogen sulfide were commonly produced in the second week after birth,and their descending proportion order was carbon dioxide,hydrogen, methane and hydrogen sulfide.In addition,the intestinal gas produced in medium with FL-2 was the least,in medium with LAT was the most. Conclusion The intestinal gas produced by intestinal flora in preterm infants increased with age during the first 4 weeks of life.The feces of preterm infants within 4 weeks after birth may contain methanogens.