低体温对极低出生体重儿肠道菌群的影响

Effects of hypothermia on gut microbiota in very low birth weight infants

摘要:

目的 了解入院低体温的极低出生体重儿肠道菌群失调的特征。方法 以前瞻性队列研究的方式选取出生胎龄<32周且出生身体质量<1.5 kg的早产儿。收集早产儿在出生后24 h内的胎粪样本。根据入院时体温将患儿分为两组：低体温组（体温<36℃）和正常体温组（体温≥36.5℃）。使用16S rRNA基因测序比较纳入对象的粪便样本菌群多样性、群落组成以及生物标志物分析。结果 从2022年4-12月共纳入34例受试者（低温组19例，正常体温组15例）。与正常体温组相比，低体温组中p＿Bacteroidota、c＿Clostridia和c＿Bacteroidia丰度显著增加（P值分别为0.031、0.042、0.031），低体温组Faecalibaculum、Dubosiella、Blautia、Faecalibaculum＿rodentium的相对丰度也明显增加（P值分别为0.008、0.008、0.005、0.008）。低体温组与正常体温组的总体微生物多样性存在显著差异。CCA结果显示剖宫产的r2值最大（r2=0.4484,P=0.001），剖宫产对肠道菌群结构的影响最大。结论 低体温组患儿在肠道菌群多样性及组成等方面存在菌群失调可能，优势属Faecalibaculum可能作为低温组的生物标志物。

Abstract:

: Objective To investigate the characteristics of gut microbiota dysbiosis in hypothermia among infants with very low low birth weight (VLBW). Methods In this prospective cohort study, preterm infants with gestational age<32 weeks and weight<1.5 kg were enrolled. Additionally, fecal samples were collected within 0 days after admission to the intensive care unit. Based on rectal temperatures upon admission, the VLBW infants were divided into the hypothermia group (body temperature<36 ℃) and the normothermia group (body temperature≥36.5 ℃). 16S rRNA gene sequencing was utilized to evaluate the gut microbial diversity, composition and biomarker. Results A total of 19 patients with hypothermia were enrolled from April 2022 to December 2022, alongside an additional cohort of 15 normothermic patients who were admitted during the same study period. Compared to the normothermia group, the hypothermia group exhibited a significant increase in the abundance of p_Bacteroidota, c_Clostridia and c_Bacteroidia in the hypothermia group (P=0.031, 0.042, 0.031, respectively). Furthermore, the relative abundances of Faecalibaculum, Dubosiella, Blautia and Faecalibaculum_rodentium were significantly higher in the hypothermia group (P=0.008, 0.008, 0.005, and 0.008, respectively). The overall microbial diversity exhibited a notable disparity between the hypothermia and normothermia groups. CCA results showed that the r2 value of cesarean section was the largest (r2 =0.4484, P=0.001), and cesarean section had the greatest impact on the structure of gut microbiota. Conclusion VLBW in the hypothermia group has imbalance in the diversity and composition of gut microbiota, which suggest that the dominant genus Faecalibaculum is a potential a biomarker for hypothermia group.