阴道菌群接种对剖宫产婴儿体质指数及过敏风险指数影响的随机对照研究

Many studies suggested that caesarean-delivered children were at higher risks of developing metabolic and allergic diseases like obesity and asthma, possibly because newborns born by caesarean section were lack of exposure to maternal vaginal flora. It is urgently needed to explore a simple, convenient, and safe intervention strategy to reduce caesarean-related risks. A very recent study demonstrated that exposure of caesarean-delivered newborns to maternal vaginal fluid at birth (i.e., vaginal seeding) could partially restore the microbiota of them, but the long-term health consequences of restoring the microbiota of caesarean-delivered infants remain unclear. In this randomized controlled study, we aim to recruit totally 106 pregnant women scheduled for caesarean delivery, and randomly assign them to either vaginal seeding group or the control group. Infants born to those women will be followed up to 24 months after birth, and their height and weight will be measured at 6, 12, 18 and 24 months; venous blood will be also taken at 24 months for the measurements of multiallergen. We then calculate the body mass index and the allergy risk index according to the measurements of height and weight and the multiallergen, respectively. We evaluate the effects of vaginal seeding on body mass index as well as allergy risk index by comparing their mean levels between the two groups, which will be of particular importance for future investigation into the effects of vaginal seeding on the prevention of metabolic and allergic diseases like obesity and asthma.

系列研究证据提示，剖宫产分娩子代因缺乏母亲产道菌群暴露，罹患肥胖及哮喘等代谢与过敏性疾病风险增高，亟待探寻简便易行、安全有效的针对剖宫产分娩儿的干预措施。有研究提示，将剖宫产分娩新生儿暴露于母亲阴道菌群（即阴道菌群接种）能有效改善其生后30天内菌群分布，但阴道菌群接种能否降低剖宫产分娩儿肥胖及哮喘等疾病发生风险有待证实。本研究拟通过随机对照研究，募集选择性剖宫产孕妇106例，随机分配到阴道菌群接种组与常规处理组，随访两组产妇所生新生儿至满24月龄，于6、12、18和24月龄测量婴儿身长和体重，并于24月龄采集婴儿静脉血进行过敏原检测。依据身长体重测量结果及过敏原检测结果，计算婴儿体质指数与过敏风险指数，比较阴道菌群接种组和常规处理组婴儿体质指数与过敏风险指数分布差异，进而评价阴道菌群接种对婴儿体质指数及过敏风险指数的影响，为今后深入评价阴道菌群接种对肥胖与哮喘等慢性疾病的预防效果打下基础。

系列研究证据提示，剖宫产分娩子代因缺乏母亲产道菌群暴露，罹患肥胖及哮喘等代谢与过敏性疾病风险增高，亟待探寻简便易行、安全有效的针对剖宫产分娩儿的干预措施。有研究发现，将剖宫产分娩新生儿暴露于母亲阴道菌群（即阴道菌群接种）能有效改善其生后30天内菌群分布，但阴道菌群接种能否降低剖宫产分娩儿肥胖及哮喘等疾病发生风险有待证实。.本研究募集选择性剖宫产孕妇120例，随机分配到阴道菌群接种组（60例）与常规处理组（60例），计划随访两组产妇所生新生儿至满24月龄，于6、12、18和24月龄测量婴儿身长和体重、采集婴儿粪便样本，并于18月龄采集婴儿静脉血进行过敏原检测。依据身长体重测量结果及过敏原检测结果，计算婴儿体质指数与过敏风险指数，比较阴道菌群接种组和常规处理组婴儿体质指数与过敏风险指数分布差异；依据粪便微生物16SrDNA测序结果，比较两组婴儿肠道菌群多样性和菌群结构的差异；进而评价阴道菌群接种对婴儿肠道菌群、体质指数及过敏风险指数的影响。截至2020年12月底主体上完成了现场研究工作，对目前收集到的基线数据及6、12、18月龄随访数据的初步分析结果提示，阴道菌群接种对婴儿6月龄、12月龄的肠道菌群结构和多样性无明显影响，也未见其有效降低婴儿18月龄时的过敏风险指数及过敏性症状、过敏性疾病的发生风险。阴道菌群接种未能有效改善剖宫产分娩婴儿6月龄、12月龄和18月龄的体质指数，但次要结局分析结果提示其可能会降低婴儿发生超重肥胖的风险，需进一步开展研究加以验证。阴道菌群接种是一项国际关注的试图用于改善剖宫产儿健康的前沿性干预措施，本随机对照研究为评价其有效性和安全性提供了重要科学证据。从现有研究结果来看，剖宫产分娩婴儿通过阴道菌群接种的获益有限，尚不适宜在临床普遍推广应用该措施。