Differences in gut microbiota composition between obese and lean children: a cross-sectional study

Abstract

BackgroundAn altered gut microbiota composition has recently been linked to obesity. The principal aim of this study is to investigate and compare the gut microbiota composition in obese and lean children. Secondly, associations between analysed gut bacterial species, dietary compounds, energy intake and biochemical blood parameters are evaluated.MethodsIn this prospective cross-sectional study, 26 overweight/obese (mean BMI: 28.7 ± 6.5) and 27 lean (mean BMI: 16.5 ± 2.1) children aged 6 to 16 were included. Faecal samples were collected and subjected to selective plating and quantitative real-time PCR (qPCR) in order to determine the concentrations of bacterial species belonging to the genera: Bacteroides, Bifidobacterium, Clostridium, Staphylococcus and Lactobacillus. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was applied for an in-depth identification of species of Bacteroides fragilis group. Differences in the concentrations of gut bacterial species between obese and lean children were statistically analysed using Mann Whitney U test. Subsequently, random forest analysis and multiple linear regression analysis were performed in order to test associations between gut bacterial species, dietary compounds and blood parameters.ResultsObese children showed an elevated Firmicutes-to-Bacteroidetes ratio compared with lean children. Furthermore, low relative proportions of B. vulgatus and high concentrations of Lactobacillus spp. were observed in the obese microbiota. In all children, Staphylococcus spp. were positively associated with energy intake. Additionally, in obese children, Lactobacillus spp. were positively associated with plasma hs-CRP.ConclusionsOur findings corroborate a significant difference in the gut microbiota composition of important bacterial species between obese and lean children. In future, non-invasive manipulation of gut microbiota composition in early infancy could offer a new approach to manage childhood obesity and associated disorders.

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

“…Childhood and adult obesity are accompanied by changes in the composition of the gut microbiota (Karlsson et al ., 2012; Bervoets et al ., 2013; Borgo et al ., 2016). In the present study we found alterations in gut microbiota composition and SCFA levels in a cohort of 42 obese and 36 normal‐weight Italian children.…”

“…A recent meta‐analysis concluded that there were no statistically significant differences across multiple studies in the Firmicutes / Bacteroidetes ratio between obese and normal‐weight adults (Walters et al ., 2014). In agreement with this meta‐analysis, some pediatric studies have found an increase in Firmicutes and a decrease in Bacteroidetes (Bervoets et al ., 2013; Ferrer et al ., 2013) while others have not (Abdallah Ismail et al ., 2011; Payne et al ., 2011). Although in our study the Firmicutes / Bacteroidetes ratio was significantly elevated in obese individuals, we observed large variation in the ratio, particularly within the obese group.…”

Of the bugs that shape us: maternal obesity, the gut microbiome, and long-term disease risk

“…The metabolic activity of the gut microbiota is increased in obese children compared with lean children, thus gut dysbiosis is not limited to obesity in adulthood; it has also involved in the etiology of childhood obesity (18). As in the adult literature, there is evidence to suggest that not only are there shifts in fecal microbial populations in overweight children, but also variations in bacteria exist at the species levels (19).…”

Current Insight into the Role of Gut Microbiota in Mexican Childhood Obesity

“…and Staphylococcus spp. which was positively correlated with inflammatory markers such as C-reactive protein and energy intake, respectively [47].…”