广西医学

目的探讨氨基酸配方（AAF）替代喂养对重度牛奶蛋白过敏（CMPA）婴儿肠道菌群特征的影响。方法纳入23例确诊为重度CMPA且人工喂养的≤3月龄婴儿，采用同一品牌AAF进行喂养干预。干预前及干预3个月后，收集所有婴儿的粪便样本，通过16S rRNA高通量测序及生物信息学分析评估肠道菌群的特征变化。结果干预前后，重度CMPA婴儿肠道菌群Chao1指数、Shannon指数、observed species指数、 Simpson指数差异具有统计学意义（P<0.05），Beta多样性具有差异，且组间差异大于组内差异。门水平的相对丰度分析及LEfSe分析结果均显示，AAF干预后重度CMPA婴儿肠道中厚壁菌门、拟杆菌门显著富集。属水平的相对丰度分析结果显示，AAF干预后重度CMPA婴儿肠道中拟杆菌属、粪杆菌属、双歧杆菌属的相对丰度较干预前明显升高，弓形菌属、克雷伯菌属、梭菌属的相对丰度较干预前降低，LEfSe分析结果显示拟杆菌属、粪杆菌属、弓形菌属、克雷伯菌属为在丰度上有显著差异的标志物种。在种水平上相对丰度排名前10的菌群中，产气荚膜梭菌、产酸拟杆菌、丁酸梭菌、格氏乳杆菌、罗伊氏乳杆菌的相对丰度显著升高。结论 AAF替代喂养可使得重度CMPA患儿肠道菌群多样性增加，拟杆菌、厚壁菌等的丰度增加。

Objective To investigate the effect of replacement feeding by amino acid formula (AAF) on intestinal flora characteristics in infants with severe cow's milk protein allergy (CMPA). Methods A total of 23 infants ≤3 months old who were confirmed as severe CMPA and received artificial feeding were enrolled. AAF with the same brand was used to perform feeding intervention. Before intervention and after 3 months of intervention, fecal samples of all infants were collected, and characteristic changes of intestinal flora were evaluated by using the 16S rRNA high-throughput sequencing and bioinformatics analysis. Results Before and after intervention, there were statistically significant differences in Chao1 index, Shannon index, observed species index, Simpson index of intestinal flora between severe CMPA infants (P<0.05), and there was a difference in Beta diversity, as well as the difference between groups was larger than the difference within groups. The results of relative abundance analysis of phylum level and LEfSe analysis revealed that Firmicutes and Bacteroidetes were significantly enriched in intestines of severe CMPA infants after AAF intervention. The results of relative abundance analysis of genus level indicated that after AAF intervention in severe CMPA infants, the relative abundance of Bacteroidetes, Faecalibacterium, and Bifidobacterium in intestines was significantly elevated, whereas the relative abundance of Arcobacter, Klebsiella, Clostridium in intestines was decreased as compared with before intervention; in addition, the results of LEfSe analysis interpreted that Bacteroidetes, Faecalibacterium, Arcobacter, and Klebsiella were marker species with significant difference in abundance. Among the top 10 flora in relative abundance at species level, the relative abundance of Clostridium perfringens, Bacillus acidogenes, Clostridium butyricum, Lactobacillus grigeri, and Lactobacillus reuteri was significantly elevated. Conclusions AAF replacement feeding can increase intestinal flora diversity in infants with severe CMPA, and increase the abundance of Bacteroidetes and Firmicutes, etc.