Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, CA, United States.
Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, United States.
Front Cell Infect Microbiol. 2021 Dec 17;11:794610. doi: 10.3389/fcimb.2021.794610. eCollection 2021.
The gut microbiome has been linked to breast cancer immune, inflammatory, and hormonal mechanisms. We examined the relation between adolescent breast density and gut microbial composition and function in a cohort of Chilean girls. This cross-sectional study included 218 female participants in the Growth and Obesity Cohort Study who were 2 years post-menarche. We measured absolute breast fibroglandular volume (aFGV) and derived percent FGV (%FGV) using dual energy X-ray absorptiometry. All participants provided a fecal sample. The gut microbiome was characterized using 16S ribosomal RNA sequencing of the V3-V4 hypervariable region. We examined alpha diversity and beta diversity across terciles of %FGV and aFGV. We used MaAsLin2 for multivariable general linear modeling to assess differential taxa and predicted metabolic pathway abundance (MetaCyc) between %FGV and aFGV terciles. All models were adjusted for potential confounding variables and corrected for multiple comparisons. The mean %FGV and aFGV was 49.5% and 217.0 cm, respectively, among study participants. Similar median alpha diversity levels were found across %FGV and aFGV terciles when measured by the Shannon diversity index (%FGV T1: 4.0, T2: 3.9, T3: 4.1; aFGV T1: 4.0, T2: 4.0, T3: 4.1). %FGV was associated with differences in beta diversity ( 0.012, =0.02). No genera were differentially abundant when comparing %FGV nor aFGV terciles after adjusting for potential confounders (q > 0.56 for all genera). We found no associations between predicted MetaCyc pathway abundance and %FGV and aFGV. Overall, breast density measured at 2 years post-menarche was not associated with composition and predicted function of the gut microbiome among adolescent Chilean girls.
肠道微生物群与乳腺癌的免疫、炎症和激素机制有关。我们在智利女孩队列中研究了青春期乳腺密度与肠道微生物组成和功能之间的关系。这项横断面研究包括生长和肥胖队列研究中的 218 名女性参与者，她们在月经初潮后 2 年。我们使用双能 X 射线吸收法测量绝对乳腺纤维腺体体积（aFGV）并得出纤维腺体体积百分比（%FGV）。所有参与者都提供了粪便样本。通过 16S 核糖体 RNA 对 V3-V4 高变区进行测序来描述肠道微生物组。我们检查了 %FGV 和 aFGV 三分位数之间的 alpha 多样性和 beta 多样性。我们使用 MaAsLin2 进行多变量线性建模，以评估 %FGV 和 aFGV 三分位数之间的差异分类群和预测代谢途径丰度（MetaCyc）。所有模型均调整了潜在混杂变量，并对多重比较进行了校正。研究参与者的平均 %FGV 和 aFGV 分别为 49.5%和 217.0cm。当用 Shannon 多样性指数测量时，在 %FGV 和 aFGV 三分位数中发现了相似的中位数 alpha 多样性水平（%FGV T1：4.0，T2：3.9，T3：4.1；aFGV T1：4.0，T2：4.0，T3：4.1）。%FGV 与 beta 多样性的差异有关（ 0.012，=0.02）。在调整了潜在混杂因素后，比较 %FGV 或 aFGV 三分位数时，没有分类群的丰度存在差异（所有分类群的 q>0.56）。我们没有发现预测的 MetaCyc 途径丰度与 %FGV 和 aFGV 之间的关联。总的来说，在智利青春期女孩中，月经初潮后 2 年测量的乳腺密度与肠道微生物群的组成和预测功能无关。
