Differences in gut microbiome diversity attributed to eating habits in obese children

In a recent study published in Microbiological spectrum, the researchers found that differences in the eating habits of normal-weight children and those who were overweight or obese contributed to variations in gut microbiome diversity, gut bacterial virulence factors, and metabolic function.

Study: Gut microbiome virulence factors are associated with BMI and metabolic blood parameters in obese children. Image Credit: Africa Studio / Shutterstock.com

Background

A growing body of evidence indicates that the gut microbiota plays an important role in various aspects of host metabolism, including digestion, energy harvesting, and induction of low-grade inflammation. Additionally, host genetic factors, along with other characteristics such as age, diet, immunity, and sex, influence the composition of the gut microbiome.

Research shows that the bacterial diversity in the gut and the individual’s functional capacity vary between people with normal weight and obese people. Variations in the gut microbiome profile have also been linked to metabolic disorders, lipid accumulation and inflammation.

Lipogenesis in the liver and hormone regulation of appetite are also associated with gut microbiome genes.

Besides its role in adipogenesis, superoxide reduction, and vitamin metabolism, the gut microbiota also regulates innate immunity and low-grade systemic inflammatory state that can contribute to fat deposition and obesity. Therefore, dysbiosis, which is the imbalance of the intestinal microbiota, associated with diet, probably has an important role in the development of obesity.

About the study

In the current study, researchers conducted a cross-sectional analysis of data from 45 children aged 6 to 12 to determine the association between gut microbiota and obesity.

Questionnaires were used to obtain information on food frequencies, sex, age and body mass index (BMI). Based on World Health Organization (WHO) z-scores, in which BMI is adjusted for gender and age, children were classified into two categories of overweight and obesity ( OWOB) and normal weight (NW).

Data from food frequency questionnaires were used to classify children’s eating habits into two nutritional patterns. To this end, Model 1 was characterized by complex carbohydrates and protein, while Model 2 included simple carbohydrates and saturated fat.

Shotgun metagenomics was used to assess gut microbiota taxonomic diversity and metabolic capacity from genomic deoxyribonucleic acid (DNA) extracted from fecal samples. Clade-specific markers were used for taxonomic and functional assessment of gut bacteria. In addition, Simpson’s and Shannon’s inverse diversity indices were calculated.

The virulence factor database was used to screen for virulence factor genes, while multivariate linear modeling was used to determine the association between taxa, virulence factors, and gut microbe function and covariates of diet, serology and anthropometric measurements.

Study results

Significant differences between alpha and beta diversity of the gut microbiota were observed between children in the NW and OWOB groups, suggesting that specific phyla of bacteria contribute to higher levels of energy harvest.

Additionally, species such as Ruminococcus species, Victims of going, Mitsuokella multacid, Alistip species, Clostridium species, and Acinetobacter johnsonii were linked to healthier metabolic parameters.

In contrast, an increase in the abundance of bacteria such as Veillonellaceae, Lactococcal, Fusicatenibacter saccharivorans, Fusicatenibacter prausnitzii, Eubacterium, Rose Buria, dialer, Coprococcus catus, BifidobacteriumAnd Bilophile has been identified in children with pro-inflammatory conditions and obesity.

Bacteria such as Citrobacter europaeus, Citrobacter youngae, Variety Klebsiella, Enterococcus mundtii, Gemella morbillorumAnd Citrobacter portucalensis were associated with higher lipid and sugar intake, as well as higher blood biochemical values ​​and anthropometric measurements.

Diets high in fat and simple carbohydrates have been linked to an abundance of Citrobacteria And Klebsiella species in the intestine. Additionally, previous studies have indicated that these bacterial species are potential markers of inflammation, obesity, and increased fasting blood sugar.

Menaquinone and gamma-glutamyl metabolism were negatively associated with BMI. Additionally, the microbiomes of children in the NW group retained a more consistent alpha diversity of virulence factors, while the OWOB microbiomes exhibited dominance of virulence factors.

Differences in metabolic capacities relating to the biosynthetic pathways of vitamins, transporters, amino acids, nucleotides, nucleosides, amines and polyamines, as well as the degradation of nucleotides, nucleosides and carbohydrate sugars, have also been identified. found between the NW and OWOB groups.

conclusion

Dietary profiles and gut microbiota diversity have been shown to be interconnected and associated with changes in metabolic parameters, dominance of virulence factors and obesity. Changes in the diversity and relative abundance of the gut microbiome have been linked to obesity, inflammatory responses, and metabolic disorders.

Taken together, the study results suggest that the prevalence of virulence factors, as well as the metabolic and genetic roles of the gut microbiota in increasing inflammation, may help identify those at increased risk for childhood obesity. .