Exploring Gut Microbiota and the Influence of Physical Activity Interventions on Overweight and Obese Children and Adolescents: A Systematic Review

Impact of child summertime obesity interventions on body mass index and weight-related behaviors: A systematic review and meta-analysis

INTRODUCTION

Obesity during childhood is a critical public health issue. The summer break from school is a time when children are prone to accelerated weight gain. We aimed to investigate how obesity prevention or treatment programs implemented over the summer affect anthropometric measures or weight-related behaviors.

METHODS

Published studies examining the impact of obesity prevention/treatment interventions targeting the summer with anthropometric or weight-related behaviors in children (5-18 years old) were identified using systematic searches of Medline, Cochrane, Scopus, CINAHL, PsycINFO, and EMBASE until April 2024. The summarized effect estimate was computed by applying the random-effects approach. The evidence certainty was assessed using GRADE.

RESULTS

Forty-seven studies were identified for inclusion. The majority of studies identified focused on physical activity and dietary habits. Only six studies that examined the effects of prevention interventions on weight, body mass index (BMI), and waist circumference (WC) were meta-analyzed. There was no evidence that prevention interventions impacted children's weight, BMI, and WC. However, most of the studies included in the systematic review indicated beneficial effects of interventions for anthropometric measures.

CONCLUSION

There was no evidence that summertime obesity interventions targeting physical activity and dietary intake were effective in the prevention of obesity in children.

Impact of Ex Vivo Bisphenol A Exposure on Gut Microbiota Dysbiosis and Its Association with Childhood Obesity

Dietary exposure to the plasticiser bisphenol A (BPA), an obesogenic and endocrine disruptor from plastic and epoxy resin industries, remains prevalent despite regulatory restriction and food safety efforts. BPA can be accumulated in humans and animals, potentially exerting differential health effects based on individual metabolic capacity. This pilot study examines the impact of direct ex vivo BPA exposure on the gut microbiota of obese and normal-weight children, using 16S rRNA amplicon sequencing and anaerobic culturing combined methods. Results showed that direct xenobiotic exposure induced modifications in microbial taxa relative abundance, community structure, and diversity. Specifically, BPA reduced the abundance of bacteria belonging to the phylum Bacteroidota, while taxa from the phylum Actinomycetota were promoted. Consistently, Bacteroides species were classified as sensitive to BPA, whereas bacteria belonging to the class Clostridia were identified as resistant to BPA in our culturomics analysis. Some of the altered bacterial abundance patterns were common for both the BPA-exposed groups and the obese non-exposed group in our pilot study. These findings were also corroborated in a larger cohort of children. Future research will be essential to evaluate these microbial taxa as potential biomarkers for biomonitoring the effect of BPA and its role as an obesogenic substance in children.

Gut microbiome and obesity in late adolescence: A case-control study in "Children of 1997" birth cohort

PURPOSE

Although the gut microbiome is important in human health, its relation to adolescent obesity remains unclear. Here we assessed the associations of the gut microbiome with adolescent obesity in a case-control study.

METHODS

In the "Children of 1997" birth cohort, participants with and without obesity at ∼17.4 years were 1:1 matched on sex, physical activity, parental education and occupation (n = 312). Fecal gut microbiome composition and pathways were assessed via shotgun metagenomic sequencing. The association of microbiota species with obesity was evaluated using conditional logistic regression. We explored the association of the obesity-relevant species with adolescent metabolomics using multivariable linear regression, and causal relationships with type 2 diabetes using Mendelian randomization analysis.

RESULTS

Gut microbiota in the adolescents with obesity exhibited lower richness (p = 0.031) and evenness (p = 0.014) compared to controls. Beta diversity revealed differences in the microbiome composition in two groups (p = 0.034). Lower relative abundance of Clostridium spiroforme, Clostridium phoceensis and Bacteroides uniformis were associated with higher obesity risk (q<0.15). Lower Bacteroides uniformis was associated with higher branched-chain amino acid, potentially contributing to higher type 2 diabetes risk.

CONCLUSION

Adolescents with obesity had a distinct gut microbiota profile compared to the controls, possibly linked to metabolic pertubation and related diseases.

Early life factors that affect obesity and the need for complex solutions

The prevalence of obesity increases with age but is apparent even in early life. Early childhood is a critical period for development that is known to influence future health. Even so, the focus on obesity in this phase, and the factors that affect the development of obesity, has only emerged over the past two decades. Furthermore, there is a paucity of iterative work in this area that would move the field forward. Obesity is a complex condition involving the interplay of multiple influences at different levels: the individual and biological level, the sociocultural level, and the environmental and system levels. This Review provides a brief overview of the evidence for these factors with a focus on aspects specific to early life. By spotlighting the complex web of interactions between the broad range of influences, both causal and risk markers, we highlight the complex nature of the condition. Much work in the early life field remains observational and many of the intervention studies are limited by a focus on single influences and a disjointed approach to solutions. Yet the complexity of obesity necessitates coordinated multi-focused solutions and joined-up action across the first 2,000 days from conception, and beyond.

Research trends between childhood obesity and gut microbiota: a bibliometric analysis (2002-2023)

Background

In recent years, the prevalence of childhood obesity has escalated alarmingly, posing significant threats to the physical and mental well-being of children, with an elevated likelihood of persisting into adulthood. Notably, recent investigations have uncovered a profound association between intestinal microbiota, a crucial component of the internal milieu, and childhood obesity. Disturbances in intestinal microbiota and their by-products are now understood to be profoundly intertwined with the evolutionary pathway of childhood obesity. Bibliometric analysis offers a deep understanding of the current research landscape, so we apply it to a review of the emerging trends and patterns between childhood obesity and gut microbiota.

Materials and methods

We conducted a rigorous and extensive search of the Web of Science (WoS) Core Collection database, spanning the years from 1900 to 2023, to analyze scholarly articles pertaining to childhood obesity and gut microbiota. Utilizing VOSviewer, CiteSpace, the R package "bibliometrix," and the online bibliometric analysis platform (https://bibliometric.com/), we delved into the intricate details of research hotspots, academic collaborations, and emerging trends within this domain.

Results

The exhaustive search encompassed the globe, uncovering a cumulative total of 1,384 pertinent studies originating from 429 nations. The results were compelling, revealing a profound influence exerted by the United States and China in this specific field of research. Furthermore, it was observed that the volume of scholarly works pertaining to childhood obesity and gut microbiota is steadily growing year on year. The current hot topics in this field include "abuse," "maltreatment," "adverse childhood experiences," "students," and "food addiction".

Conclusion

This comprehensive review offers a meticulous exploration of the evolving trends and emerging research agendas pertaining to childhood obesity and gut microbiota over the past two decades. It strives to equip researchers with a thorough understanding of the key nations, institutions, journals, and potential collaborators in these specialized fields. Additionally, it sheds light on the current frontiers of research and strategic avenues for further exploration, thus serving as an invaluable resource for scholars delving deeper into the intricacies of childhood obesity and the gut microbiome.

The Ambiguous Correlation of Blautia with Obesity: A Systematic Review

Obesity is a complex and multifactorial disease with global epidemic proportions, posing significant health and economic challenges. Whilst diet and lifestyle are well-established contributors to the pathogenesis, the gut microbiota's role in obesity development is increasingly recognized. Blautia, as one of the major intestinal bacteria of the Firmicutes phylum, is reported with both potential probiotic properties and causal factors for obesity in different studies, making its role controversial. To summarize the current understanding of the Blautia-obesity correlation and to evaluate the evidence from animal and clinical studies, we used "Blautia" AND "obesity" as keywords searching through PubMed and SpringerLink databases for research articles. After removing duplicates and inadequate articles using the exclusion criteria, we observed different results between studies supporting and opposing the beneficial role of Blautia in obesity at the genus level. Additionally, several studies showed probiotic effectiveness at the species level for Blautia coccoides, B. wexlerae, B. hansenii, B. producta, and B. luti. Therefore, the current evidence does not demonstrate Blautia's direct involvement as a pathogenic microbe in obesity development or progression, which informs future research and therapeutic strategies targeting the gut Blautia in obesity management.

Characterization of the gut microbiota and fecal and blood metabolomes under various factors in urban children from Northwest China

Introduction

Children have regional dynamics in the gut microbiota development trajectory. Hitherto, the features and influencing factors of the gut microbiota and fecal and plasma metabolites in children from Northwest China remain unclear.

Methods

Shotgun metagenomic sequencing and untargeted metabolomics were performed on 100 healthy volunteers aged 2-12 years.

Results

Age, body mass index (BMI), regular physical exercise (RPE), and delivery mode (DM) significantly affect gut microbiota and metabolites. Lactobacillus, Butyricimonas, Prevotella, Alistipes, and predicted pathway propanoate production were significantly increased with age while Bifidobacterium breve, B. animalis, B. pseudocatenulatum, Streptococcus infantis, and carbohydrate degradation were decreased. Fecal metabolome revealed that the metabolism of caffeine, amino acids, and lipid significantly increased with age while galactose metabolism decreased. Noticeably, BMI was positively associated with pathogens including Erysipelatoclostridium ramosum, Parabacteroides distasonis, Ruminococcus gnavus, and amino acid metabolism but negatively associated with beneficial Akkermansia muciniphila, Alistipes finegoldii, Eubacterium ramulus, and caffeine metabolism. RPE has increased probiotic Faecalibacterium prausnitzii and Anaerostipes hadrus, acetate and lactate production, and major nutrient metabolism in gut and plasma, but decreased pathobiont Bilophila wadsworthia, taurine degradation, and pentose phosphate pathway. Interestingly, DM affects the gut microbiota and metabolites throughout the whole childhood. Bifidobacterium animalis, Lactobacillus mucosae, L. ruminis, primary bile acid, and neomycin biosynthesis were enriched in eutocia, while anti-inflammatory Anaerofustis stercorihominis, Agathobaculum butyriciproducens, Collinsella intestinalis, and pathogenic Streptococcus salivarius, Catabacter hongkongensis, and amino acid metabolism were enriched in Cesarean section children.

Discussion

Our results provided theoretical and data foundation for the gut microbiota and metabolites in preadolescent children's growth and development in Northwest China.