A taxonomic signature of obesity in a large study of American adults.
Peters BA, Shapiro JA, Church TR, Miller G, Trinh-Shevrin C, Yuen E, Friedlander C, Hayes RB, Ahn J
Sci Rep. Jun 2018. doi: 10.1038/s41598-018-28126-1
COMMENT: The microbiome is an enticing candidate to target for obesity prevention and treatment. Experiments in germ-free mice colonized with gut microbiota from wild-type mice, obese mice, or obese humans, demonstrate that microbiota play a critical role in adiposity in test systems; however, a consistent taxonomic signature of obesity has yet to be identified in humans.
In this article Peters and coworkers examined whether a taxonomic signature of obesity is present across two independent study populations. They assessed gut microbiome from stool for 599 adults, by 16S rRNA gene sequencing. They compared gut microbiome diversity, overall composition, and individual taxon abundance for obese (BMI ≥ 30 kg/m2), overweight (25 ≤ BMI < 30), and healthy-weight participants (18.5 ≤ BMI < 25) and they found that gut species richness was reduced (p = 0.04), and overall composition altered (p = 0.04), in obese (but not overweight) compared to healthy-weight participants.
Obesity was characterized by increased abundance of class Bacilli and its families Streptococcaceae and Lactobacillaceae, and decreased abundance of several groups within class Clostridia, including Christensenellaceae, Clostridiaceae, and Dehalobacteriaceae (q < 0.05). These findings were consistent across two independent study populations. When random forest models were trained on one population and tested on the other as well as a previously published dataset, accuracy of obesity prediction was good (~70%).
According to the author's conclusion:
Our large study identified a strong and consistent taxonomic signature of obesity. Though our study is cross-sectional and causality cannot be determined, identification of microbes associated with obesity can potentially provide targets for obesity prevention and treatment.