Department of Surgery, School of Medicine, University of California, Davis, California, USA.
Center for Alimentary and Metabolic Science, University of California, Davis, California, USA.
Physiol Rep. 2022 Jul;10(13):e15363. doi: 10.14814/phy2.15363.
In humans and animal models, Cesarean section (C-section) has been associated with alterations in the taxonomic structure of the gut microbiome. These changes in microbiota populations are hypothesized to impact immune, metabolic, and behavioral/neurologic systems and others. It is not clear if birth mode inherently changes the microbiome, or if C-section effects are context-specific and involve interactions with environmental and other factors. To address this and control for potential confounders, cecal microbiota from ~3 week old mice born by C-section (n = 16) versus natural birth (n = 23) were compared under matched conditions for housing, cross-fostering, diet, sex, and genetic strain. A total of 601 unique species were detected across all samples. Alpha diversity richness (i.e., how many species within sample; Chao1) and evenness/dominance (i.e., Shannon, Simpson, Inverse Simpson) metrics revealed no significant differences by birth mode. Beta diversity (i.e., differences between samples), as estimated with Bray-Curtis dissimilarities and Aitchison distances (using log[x + 1]-transformed counts), was also not significantly different (Permutational Multivariate ANOVA [PERMANOVA]). Only the abundance of Lachnoclostridium [Clostridium] scindens was found to differ using a combination of statistical methods (ALDEx2, DESeq2), being significantly higher in C-section mice. This microbe has been implicated in secondary bile acid production and regulation of glucocorticoid metabolism to androgens. From our results and the extant literature we conclude that C-section does not inherently lead to large-scale shifts in gut microbiota populations, but birth mode could modulate select bacteria in a context-specific manner: For example, involving factors associated with pre-, peri-, and postpartum environments, diet or host genetics.
在人类和动物模型中，剖宫产（C -section）与肠道微生物组的分类结构改变有关。这些微生物种群的变化被假设会影响免疫、代谢和行为/神经等系统。目前尚不清楚分娩方式是否会改变微生物组，还是 C 剖术的影响具有特定的上下文，并涉及与环境和其他因素的相互作用。为了解决这个问题并控制潜在的混杂因素，在匹配的饲养、交叉寄养、饮食、性别和遗传品系条件下，比较了通过 C 剖术（n=16）和自然分娩（n=23）出生的约 3 周大的小鼠的盲肠微生物群。总共检测到了 601 种独特的物种。通过出生方式，没有发现 alpha 多样性丰富度（即样本内的物种数量；Chao1）和均匀度/优势度（即 Shannon、Simpson、Inverse Simpson）指标有显著差异。通过 Bray-Curtis 不相似性和 Aitchison 距离（使用 log[x+1]-转换计数）估计的 beta 多样性（即样本之间的差异）也没有显著差异（Permutational Multivariate ANOVA [PERMANOVA]）。只有 Lachnoclostridium [Clostridium] scindens 的丰度通过统计方法（ALDEx2、DESeq2）发现存在差异，C 剖术小鼠的丰度显著更高。这种微生物与次级胆汁酸的产生和糖皮质激素代谢为雄激素的调节有关。根据我们的结果和现有文献，我们得出的结论是，C 剖术不会导致肠道微生物组种群的大规模变化，但分娩方式可能会以特定的方式调节特定的细菌：例如，涉及与产前、围产期和产后环境、饮食或宿主遗传有关的因素。
