Probiotic supplementation restores normal microbiota composition and function in antibiotic-treated and in caesarean-born infants. Flora

Background: Infants born by caesarean section or receiving antibiotics are at increased risk of developing metabolic, inflammatory and immunological diseases, potentially due to disruption of normal gut microbiota at a critical developmental time window. We investigated whether probiotic supplementation could ameliorate the effects of antibiotic use or caesarean birth on infant microbiota in a double blind, placebo- controlled randomized clinical trial. Mothers were given a multispecies probiotic, consisting of Bifidobacterium, Lactobacillus, and Propionibacterium strains, or placebo supplement during pregnancy and the infants were given the same supplement. Fecal samples of the infants were collected at 3 months and analyzed using taxonomic, metagenomic and metaproteomic approaches.Results: The probiotic supplement had a strong overall impact on the microbiota composition, but the effect depended on the infant's diet. Only breastfed infants showed the expected increase in bifidobacteria and reduction in Proteobacteria and Clostridia. In the placebo group, both birth mode and antibiotic use were significantly associated with altered microbiota composition and function, particularly reduced Bifidobacterium abundance. In the probiotic group, the effects of antibiotics and birth mode were either completely eliminated or reduced.Conclusions: The results indicate that it is possible to correct undesired changes in microbiota composition and function caused by antibiotic treatments or caesarean birth by supplementing infants with a probiotic mixture together with at least partial breastfeeding.背景：剖宫产娩出或接受抗生素治疗的婴儿，罹患代谢性、炎症性与免疫性疾病的风险升高，其潜在原因可能为关键发育时间窗内正常肠道菌群（gut microbiota）的稳态被破坏。本研究通过一项双盲、安慰剂对照随机临床试验，探究益生菌补充是否可缓解抗生素使用或剖宫产对婴儿肠道菌群造成的影响。研究期间，孕妇在妊娠期及产后被给予由双歧杆菌属（Bifidobacterium）、乳杆菌属（Lactobacillus）与丙酸杆菌属（Propionibacterium）菌株组成的多菌种益生菌或安慰剂，婴儿则接受相同的补充剂。研究人员在婴儿3月龄时采集其粪便样本，并采用分类学、宏基因组学及宏蛋白质组学方法进行分析。 结果：益生菌补充剂对菌群组成具有显著整体调控作用，但该效果依赖于婴儿的饮食模式。仅母乳喂养婴儿展现出预期的双歧杆菌属丰度升高，以及变形菌门（Proteobacteria）与梭菌纲（Clostridia）丰度降低的变化。在安慰剂组中，分娩方式与抗生素使用均与菌群组成及功能的显著改变显著相关，尤以双歧杆菌属丰度降低最为突出。而在益生菌组中，抗生素使用与分娩方式带来的菌群影响要么被完全消除，要么得到显著减弱。 结论：本研究结果表明，通过为婴儿补充多菌种益生菌并辅以至少部分母乳喂养，可纠正抗生素治疗或剖宫产分娩所引发的肠道菌群组成与功能的不良改变。