title: Pediatric obesity is associated with an altered gut microbiota and discordant shifts in Firmicutes populations.
abstract: An altered gut microbiota has been linked to obesity in adulthood, although little is known about childhood obesity. The aim of this study was to characterize the composition of the gut microbiota in obese (n = 42) and normal-weight (n = 36) children aged 6 to 16. Using 16S rRNA gene-targeted sequencing, we evaluated taxa with differential abundance according to age- and sex-normalized body mass index (BMI z-score). Obesity was associated with an altered gut microbiota characterized by elevated levels of Firmicutes and depleted levels of Bacteroidetes. Correlation network analysis revealed that the gut microbiota of obese children also had increased correlation density and clustering of operational taxonomic units (OTUs). Members of the Bacteroidetes were generally better predictors of BMI z-score and obesity than Firmicutes, which was likely due to discordant responses of Firmicutes OTUs. In accordance with these observations, the main metabolites produced by gut bacteria, short chain fatty acids (SCFAs), were higher in obese children, suggesting elevated substrate utilisation. Multiple taxa were correlated with SCFA levels, reinforcing the tight link between the microbiota, SCFAs and obesity. Our results suggest that gut microbiota dysbiosis and elevated fermentation activity may be involved in the etiology of childhood obesity.
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Research Network Chemistry Meets Microbiology, University of Vienna, Althanstrasse 14, Vienna, Austria.|Department of Health Sciences, Università degli Studi di Milano, via di Rudinì, 8, Milan, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Riva
authors.affiliation: Department of Health Sciences, Università degli Studi di Milano, via di Rudinì, 8, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Borgo
authors.affiliation: Department of Pediatrics, San Paolo Hospital, via di Rudinì, 8, Milan, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Lassandro
authors.affiliation: Department of Pediatrics, San Paolo Hospital, via di Rudinì, 8, Milan, Italy.
authors.forename: Elvira
authors.initials: E
authors.lastname: Verduci
authors.affiliation: Department of Health Sciences, Università degli Studi di Milano, via di Rudinì, 8, Milan, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Morace
authors.affiliation: Department of Health Sciences, Università degli Studi di Milano, via di Rudinì, 8, Milan, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Borghi
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Research Network Chemistry Meets Microbiology, University of Vienna, Althanstrasse 14, Vienna, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Berry
mesh_terms: D000293:Adolescent; D041963:Bacteroidetes / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D002648:Child; D004032:Diet; D064806:Dysbiosis / Q000382:microbiology*; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D005260:Female; D005285:Fermentation / Q000235:genetics; D000068536:Bacillota / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D000069196:Gastrointestinal Microbiome / Q000235:genetics*; D006801:Humans; D008297:Male; D058889:Molecular Typing; D063766:Pediatric Obesity / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D005232:Fatty Acids, Volatile; D012336:RNA, Ribosomal, 16S