Department of Food Science.
Department of Veterinary Clinical and Animal Sciences, University of Copenhagen.
J Pediatr Gastroenterol Nutr. 2019 May;68(5):727-733. doi: 10.1097/MPG.0000000000002259.
Preterm neonates have an immature gastrointestinal tract and show an altered bacterial colonization of the gut. However, it is not clear if such immature gut microbiota (GM) colonization is induced by specific delivery, diet, environment, and/or host factors related to preterm birth. Using piglets as models for infants, we hypothesized that both shortened gestational age (GA) and start of enteral feeding affect GM composition after caesarean delivery and rearing in identical environments.
Caesarean-delivered preterm and term pigs were reared in incubators and fed total parenteral nutrition (TPN) or gradually increasing early enteral feeding (EEF) for 5 days, followed by full enteral feeding with bovine milk until day 26. GM composition was determined by 16S rRNA gene-amplicon sequencing and luminal short-chain fatty acids (SCFAs) by GC-MS.
Both GA and EEF feeding affected GM composition on day 5, but only the GA effect persisted until day 26. On day 5, Enterobacteriaceae were dominant, with Lachnospiraceae members also being abundant. Enterobacteriaceae still dominated the GM at day 26 but with higher Akkermansia relative abundance in term pigs. Colonic concentrations of acetate and propionate were higher, and formate lower in term pigs, relative to preterm pigs on day 26.
Preterm and term piglets, born and reared in similar ways, show differences in GM colonization during the first 4 weeks of life, which may play a role for early and later gut dysfunction resulting from preterm birth.
早产儿的胃肠道尚未发育成熟，肠道内细菌定植也发生改变。然而，目前尚不清楚这种不成熟的肠道微生物群定植是否是由与早产相关的特定分娩、饮食、环境和/或宿主因素引起的。我们使用仔猪作为婴儿模型，假设剖宫产分娩和在相同环境中饲养会影响早产儿的肠道微生物组成，而胎龄（GA）和开始肠内喂养的时间是两个主要因素。
通过剖宫产分娩的早产和足月仔猪在保温箱中饲养，接受全胃肠外营养（TPN）或逐渐增加早期肠内喂养（EEF）5 天，然后用牛初乳进行全肠内喂养，直至第 26 天。通过 16S rRNA 基因扩增子测序和 GC-MS 测定腔内容物短链脂肪酸（SCFA）来确定 GM 组成。
GA 和 EEF 喂养均影响第 5 天的 GM 组成，但只有 GA 影响持续到第 26 天。第 5 天，肠杆菌科占优势，同时也存在丰富的lachnospiraceae 成员。第 26 天，肠杆菌科仍然主导 GM，但足月仔猪的 Akkermansia 相对丰度更高。与早产儿相比，第 26 天足月仔猪的结肠中乙酸和丙酸浓度较高，而甲酸浓度较低。
以相似方式出生和饲养的早产和足月仔猪在生命的前 4 周内表现出 GM 定植的差异，这可能对早产引起的早期和晚期肠道功能障碍起作用。
