Hollister Emily B, Foster Byron A, Dahdouli Mahmoud, Ramirez Jesica, Lai Zhao
1 Texas Children's Microbiome Center , Department of Pathology, Texas Children's Hospital, Houston, TX.
2 Department of Pathology and Immunology, Baylor College of Medicine , Houston, TX.
Child Obes. 2018 Feb/Mar;14(2):122-130. doi: 10.1089/chi.2017.0122. Epub 2017 Oct 13.
Variations in gut microbiota composition and diversity have been associated with childhood adiposity, although most studies describing this have been cross-sectional in nature. Our objective was to evaluate associations between body weight and the gut microbiota over time in obese preschool-age children.
Obese, preschool-age, Hispanic children provided stool samples at baseline and following a 6-month behavioral intervention. Normal-weight (NW) children also provided stool samples. Stool microbial community composition was characterized using 16S rRNA gene sequencing. Estimates of within-sample diversity were calculated on operational taxonomic unit (OTU) count data, and the Firmicutes:Bacteroidetes (F:B) ratio was determined on per-sample basis. Estimates of between-sample diversity were generated using the weighted Unifrac metric, differential abundances were evaluated using Wilcoxon rank-sum tests, and associations of microbiome features with clinical data were quantified using Spearman rank correlations.
For the 30 obese children sampled preintervention and postintervention, a decrease in body mass index (BMI) z-score from 2.55 to 2.34 (p = 0.004, paired t-test) was observed. Bacteroides massiliensis was significantly enriched in obese children, while B. plebius was significantly enriched in NW controls. We identified significant correlations between multiple Bacteroides-like OTUs and BMI z-score, but neither F:B ratios nor OTU-level abundances were altered in conjunction with weight change in the obese children. Rather, highly individualized OTU-level responses were observed.
Although differences exist between the gut microbiota of obese and NW children, we detected highly individualized responses of the gut microbiota of obese children over time and following weight loss.
肠道微生物群组成和多样性的变化与儿童肥胖有关，尽管大多数描述这一关系的研究本质上都是横断面研究。我们的目的是评估肥胖学龄前儿童体重与肠道微生物群随时间的关联。
肥胖的学龄前西班牙裔儿童在基线时以及在进行为期6个月的行为干预后提供粪便样本。正常体重（NW）儿童也提供粪便样本。使用16S rRNA基因测序对粪便微生物群落组成进行表征。根据操作分类单元（OTU）计数数据计算样本内多样性估计值，并在每个样本的基础上确定厚壁菌门：拟杆菌门（F:B）比率。使用加权UniFrac度量生成样本间多样性估计值，使用Wilcoxon秩和检验评估差异丰度，并使用Spearman秩相关量化微生物组特征与临床数据的关联。
对于30名在干预前和干预后采样的肥胖儿童，观察到体重指数（BMI）z评分从2.55降至2.34（p = 0.004，配对t检验）。马西利亚拟杆菌在肥胖儿童中显著富集，而平民拟杆菌在NW对照组中显著富集。我们确定了多个类拟杆菌OTU与BMI z评分之间存在显著相关性，但肥胖儿童的F:B比率和OTU水平丰度均未随体重变化而改变。相反，观察到高度个体化的OTU水平反应。
尽管肥胖儿童和NW儿童的肠道微生物群存在差异，但我们检测到肥胖儿童的肠道微生物群在随时间变化和体重减轻后有高度个体化的反应。
