Background: Persistent gut microbiota (GM) imbalance has been associated with metabolic disease development. This study evaluated the mediating role of waist circumference in the association between GM and insulin resistance (IR) in children. Methods: This cross-sectional study included 533 children aged between 6 and 12. The anthropometry, metabolic markers, and relative abundance (RA) of five intestinal bacterial species were measured. Path coefficients were estimated using path analysis to assess direct, indirect (mediated by waist circumference), and total effects on the association between GM and IR. Results: The results indicated a positive association mediated by waist circumference between the medium and high RA of S. aureus with homeostatic model assessments for insulin resistance (HOMA-IR) and for insulin resistance adiponectin-corrected (HOMA-AD). We found a negative association mediated by waist circumference between the low and medium RA of A. muciniphila and HOMA-IR and HOMA-AD. Finally, when we evaluated the joint effect of S. aureus, L. casei, and A. muciniphila, we found a waist circumference-mediated negative association with HOMA-IR and HOMA-AD. Conclusions: Waist circumference is a crucial mediator in the association between S. aureus and A. muciniphila RA and changes in HOMA-IR and HOMA-AD scores in children.

Background: Imbalance in the intestinal microbiota can lead to chronic low-grade inflammation. Diet may influence this association. In this study, we aimed to evaluate the interaction between Akkermansia muciniphila (A. muciniphila) and dietary patterns using a proinflammatory index. Methods: We conducted a cross-sectional study with school-aged children. We quantified the relative abundance (RA) of A. muciniphila in feces using a polymerase chain reaction. We collected dietary information through employing a food frequency questionnaire and generated dietary patterns using principal component analysis. We generated a proinflammatory index from serum levels of interleukin-6, interleukin-10, tumor necrosis factor alpha, and adiponectin validated by receptor operating characteristic curves. We evaluated the association between A. muciniphila and the proinflammatory index using logistic regression, including an interaction term with dietary patterns. Results: We found that children with a low RA of A. muciniphila and a high intake of simple carbohydrates and saturated fats had increased odds of being high on the proinflammatory index. However, when the consumption of this dietary pattern is low, children with a low RA of A. muciniphila had decreased odds of being high on the proinflammatory index. Conclusions: Our results suggest that the simultaneous presence of A. muciniphila and diet have a more significant impact on the presence of being high on the proinflammatory index compared to both factors separately.

In Mexico, 4 out of every 10 women aged 15 or older have been exposed to some violence in the last year. Violence has been linked to adverse mental health outcomes, such as depression and higher rates of substance use among women. This study is based on the “self-medication” model, proposing that women turn to addictive substances as a coping mechanism following experiences of violence. The main aim was to examine the role of depression as a potential mediator in the association between the health consequences of violence and tobacco and alcohol consumption. We analyzed data from four Mexican nationally representative surveys for 2000, 2006, 2012, and 2018. First, we used different regression models to assess the associations between the health consequences of violence and tobacco and alcohol consumption. Subsequently, for the mediation, we used causal mediation analysis in STATA 18 (StataCorp LLC, College Station, TX, USA), based on the potential outcomes framework and bootstrapping to assess confidence intervals and uncertainty of the estimations. We found that the health consequences of violence are associated with increased tobacco and alcohol consumption in both adults and adolescents. Adolescents with health consequences of violence had 2.4 times the odds of binge. No significant association was found among adults. Depression mediated the association between health consequences of violence and tobacco consumption, but its role as a mediator in alcohol consumption was inconclusive in adults. Mediation analysis suggests the directionality and magnitude of causal pathways, facilitating the selection of possible intervention or prevention strategies. Our findings provide valuable insights suggesting intersecting dynamics of violence, mental health, and substance use among Mexican women, emphasizing the need for holistic approaches. Comprehensively studying these phenomena provides us with relevant information to mitigate the adverse impact of violence and promote the well-being of women in Mexico.

During early life, the human microbiota contributes to the development of immune, metabolic, and neurological functions. Antibiotic exposure, inflammation, and dietary changes can alter microbial community structure and function, with potential implications for pediatric health. In April 2026, the symposium “Pediatric Microbiota: Evidence and Future” was held in Mexico City, bringing together experts to discuss current advances in pediatric microbiome research. This conference report summarizes the major topics and perspectives presented during the symposium. Several presentations examined how microorganisms and microbial metabolites are transferred from mother to infant. The speakers also discussed the contribution of colostrum immunoglobulins, particularly IgA, to early microbial colonization. Sessions reviewed evidence supporting probiotic use in pediatric gastrointestinal disorders and explored the microbiota–gut–brain axis in autism spectrum disorder and sleep regulation. In addition, speakers discussed the interactions among diet, starch digestion, microbial fermentation, and metabolic health, and their associations with obesity, insulin resistance, and cardiometabolic risk. Important knowledge gaps were identified in pediatric oncology, where evidence remains limited regarding the microbiome’s influence on cancer susceptibility, immune responses, treatment outcomes, and therapy-related toxicities. Participants agreed that the field would benefit from longitudinal studies in well-characterized pediatric cohorts, particularly in Latin America, as well as from studies examining biological mechanisms through multi-omics approaches. This research could eventually inform precision nutrition and microbiome-based interventions, but the evidence discussed at the symposium was not considered sufficient to support their routine clinical use.