The gut microbiota co-develops with its host from birth and has an important role in gut homeostasis and various diseases such as obesity. Although it has been suggested that the microbiota reaches a relatively stable adult-like state in the first three years of life, other evidence indicates that it continues to develop through adolescence. The goal of the present study was to compare the gut microbiota of obese and normal-weight children with short chain fatty acids production (SCFAs) and BMI z-scores to gain insights into the structure and activity of the microbiota in pediatric obesity. Materials and methods Seventy-eight children (36 males/42 females, 9-16 y) were enrolled in the study at the Pediatric Department of San Paolo Hospital in Milan and grouped in 36 normal-weight and 42 obese. Children’s BMI was calculated by reported weight/height2 (kg/m2) and transformed to age and sex-specific z-scores. Fecal samples were collected, total bacterial DNA were extracted and fecal SCFAs were quantified by capillary electrophoresis.16S rRNA gene sequencing was performed using Illumina MiSeq platform. Results The intestinal microbiota of obese children was enriched in Firmicutes (N: 60.9±14.1, O: 72.1±12.1) and depleted in Bacteroidetes (N: 30±12.6, O: 16.6±11.8). Accordingly, the Firmicutes/Bacteroidetes ratio was significantly elevated in obese children (p<0.0001).We observed significantly higher concentrations of acetate, propionate, and butyrate, as well as total SCFAs, in the stool of obese subjects. Both BMI z-score and SCFAs were significantly correlated with microbiota composition at every taxonomic level (operational taxonomic unit [OTU] to phylum; p<0.05) especially with Bacteroidetes and Firmicutes. Interestingly tInterestingly t Interestingly tInterestingly t Interestingly t Interestingly tInterestingly tInterestingly tInterestingly tInterestingly tInterestingly the he correlation network analysiscorrelation network analysiscorrelation network analysis correlation network analysiscorrelation network analysis correlation network analysis correlation network analysis correlation network analysis correlation network analysiscorrelation network analysiscorrelation network analysiscorrelation network analysiscorrelation network analysiscorrelation network analysis correlation network analysis described an increased correlation density and clustering of OTUs in obese children. Conclusion Obesity was associated with an altered gut microbiota, characterized by a more complex a more complex a more complex a more complex a more complex a more complex a more complex a more complex a more complex correlation correlation correlation correlation correlation structure structure structure in the the obese obeseobese gut microbiotagut microbiota gut microbiota gut microbiotagut microbiota . 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, with some positively and some negatively correlated with BMI z-score. In accordance with these observations, the main metabolites produced by gut bacteria, SCFAs, were significantly higher in obese children, suggesting elevated substrate utilization. Multiple taxa were correlated with SCFA levels and BMIz-score, 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.

Pediatric obesity is associated with an altered gut microbiota and discordant shifts in Firmicutes populations / A. Riva, F. Borgo, C. Lassandro, E. Verduci, G. Morace, E. Borghi, D. Berry. ((Intervento presentato al 44. convegno Congresso Nazionale della Societa' Italiana di Microbiologia tenutosi a Pisa nel 2016.

Pediatric obesity is associated with an altered gut microbiota and discordant shifts in Firmicutes populations

A. Riva;F. Borgo;C. Lassandro;G. Morace;E. Borghi;
2016-09-27

Abstract

The gut microbiota co-develops with its host from birth and has an important role in gut homeostasis and various diseases such as obesity. Although it has been suggested that the microbiota reaches a relatively stable adult-like state in the first three years of life, other evidence indicates that it continues to develop through adolescence. The goal of the present study was to compare the gut microbiota of obese and normal-weight children with short chain fatty acids production (SCFAs) and BMI z-scores to gain insights into the structure and activity of the microbiota in pediatric obesity. Materials and methods Seventy-eight children (36 males/42 females, 9-16 y) were enrolled in the study at the Pediatric Department of San Paolo Hospital in Milan and grouped in 36 normal-weight and 42 obese. Children’s BMI was calculated by reported weight/height2 (kg/m2) and transformed to age and sex-specific z-scores. Fecal samples were collected, total bacterial DNA were extracted and fecal SCFAs were quantified by capillary electrophoresis.16S rRNA gene sequencing was performed using Illumina MiSeq platform. Results The intestinal microbiota of obese children was enriched in Firmicutes (N: 60.9±14.1, O: 72.1±12.1) and depleted in Bacteroidetes (N: 30±12.6, O: 16.6±11.8). Accordingly, the Firmicutes/Bacteroidetes ratio was significantly elevated in obese children (p<0.0001).We observed significantly higher concentrations of acetate, propionate, and butyrate, as well as total SCFAs, in the stool of obese subjects. Both BMI z-score and SCFAs were significantly correlated with microbiota composition at every taxonomic level (operational taxonomic unit [OTU] to phylum; p<0.05) especially with Bacteroidetes and Firmicutes. Interestingly tInterestingly t Interestingly tInterestingly t Interestingly t Interestingly tInterestingly tInterestingly tInterestingly tInterestingly tInterestingly the he correlation network analysiscorrelation network analysiscorrelation network analysis correlation network analysiscorrelation network analysis correlation network analysis correlation network analysis correlation network analysis correlation network analysiscorrelation network analysiscorrelation network analysiscorrelation network analysiscorrelation network analysiscorrelation network analysis correlation network analysis described an increased correlation density and clustering of OTUs in obese children. Conclusion Obesity was associated with an altered gut microbiota, characterized by a more complex a more complex a more complex a more complex a more complex a more complex a more complex a more complex a more complex correlation correlation correlation correlation correlation structure structure structure in the the obese obeseobese gut microbiotagut microbiota gut microbiota gut microbiotagut microbiota . 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, with some positively and some negatively correlated with BMI z-score. In accordance with these observations, the main metabolites produced by gut bacteria, SCFAs, were significantly higher in obese children, suggesting elevated substrate utilization. Multiple taxa were correlated with SCFA levels and BMIz-score, 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.
Settore MED/07 - Microbiologia e Microbiologia Clinica
http://www.societasim.it/sim2016-info-generali.php
Pediatric obesity is associated with an altered gut microbiota and discordant shifts in Firmicutes populations / A. Riva, F. Borgo, C. Lassandro, E. Verduci, G. Morace, E. Borghi, D. Berry. ((Intervento presentato al 44. convegno Congresso Nazionale della Societa' Italiana di Microbiologia tenutosi a Pisa nel 2016.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/466680
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