Randomized nutrient bar supplementation improves exercise-associated changes in plasma metabolome in adolescents and adult family members at cardiometabolic risk

Correction: Randomized nutrient bar supplementation improves exercise-associated changes in plasma metabolome in adolescents and adult family members at cardiometabolic risk

[This corrects the article DOI: 10.1371/journal.pone.0240437.].

Childhood and Adolescent Obesity with Somatic Indicators of Stress, Inflammation, and Dysmetabolism before and after Intervention: A Meta-Analysis

There have been numerous attempts to establish a correlation between obesity and stress, inflammatory, and dysmetabolism biomarkers in children and adolescents. Here, we performed a meta-analysis of existing studies to shed light on the elusive correlations of childhood and adolescent obesity with physiological indicators of stress, inflammation, and metabolism before and after lifestyle interventions. Observational studies, meta-analyses, narrative and systematic reviews were excluded. From a total of 53 articles, 11 were selected according to specific criteria. The biomarkers examined were circulating glucose, insulin, HDL, LDL, triglycerides, adiponectin, leptin, CRP, TNF-alpha, interleukin (IL)-6, systolic and diastolic blood pressure, and HOMA-IR. All analyses were performed using IBM SPSS Statistics Version 28.0.1.0 (142). The current meta-analysis provides evidence of a beneficial effect of a lifestyle intervention and/or drugs in children and adolescents living with obesity or overweight, consistent with a significant reduction in body fat-but not in BMI or waist circumference-an increase in circulating adiponectin and/or a reduction in serum insulin levels and diastolic blood pressure, and a trend towards a reduction of circulating leptin and glucose levels, as well as of the HOMA-IR. This meta-analysis indicates that lifestyle interventions could reduce overweight-/obesity-associated systemic inflammation and dysmetabolism even without an apparent decrease in BMI.

Accounting for the clustering and nesting effects verifies most conclusions. Corrected analysis of: "Randomized nutrient bar supplementation improves exercise-associated changes in plasma metabolome in adolescents and adult family members at cardiometabolic risk"

In a published randomized controlled trial, household units were randomized to a nutrient bar supplementation group or a control condition, but the non-independence of observations within the same household (i.e., the clustering effect) was not accounted for in the statistical analyses. Therefore, we reanalyzed the data appropriately by adjusting degrees of freedom using the between-within method, and accounting for household units using linear mixed effect models with random intercepts for family units and subjects nested within family units for each reported outcome. Results from this reanalysis showed that ignoring the clustering and nesting effects in the original analyses had resulted in anticonservative (i.e., too small) time x group interaction p-values. Still, majority of the conclusions remained unchanged.

Errors in the implementation, analysis, and reporting of randomization within obesity and nutrition research: a guide to their avoidance

Randomization is an important tool used to establish causal inferences in studies designed to further our understanding of questions related to obesity and nutrition. To take advantage of the inferences afforded by randomization, scientific standards must be upheld during the planning, execution, analysis, and reporting of such studies. We discuss ten errors in randomized experiments from real-world examples from the literature and outline best practices for their avoidance. These ten errors include: representing nonrandom allocation as random, failing to adequately conceal allocation, not accounting for changing allocation ratios, replacing subjects in nonrandom ways, failing to account for non-independence, drawing inferences by comparing statistical significance from within-group comparisons instead of between-groups, pooling data and breaking the randomized design, failing to account for missing data, failing to report sufficient information to understand study methods, and failing to frame the causal question as testing the randomized assignment per se. We hope that these examples will aid researchers, reviewers, journal editors, and other readers to endeavor to a high standard of scientific rigor in randomized experiments within obesity and nutrition research.

Plasma Ceramides Pathophysiology, Measurements, Challenges, and Opportunities

Ceramides are a family of lipid molecules, composed of sphingosine and a fatty acid, and transported by lipoproteins (primarily by low-density lipoproteins) in the bloodstream. They are not only structural lipids, but multifunctional and bioactive molecules with key roles in many important cellular pathways, such as inflammatory processes and apoptosis, representing potential biomarkers of cardiometabolic diseases as well as pharmacological targets. Recent data reported ceramide modulation by diet and aerobic exercise, suggesting nutrients and exercise-targeting sphingolipid pathways as a countermeasure, also in combination with other therapies, for risk and progression of chronic disease prevention and health maintenance. In this review, we focus on the available data regarding remarks on ceramide structure and metabolism, their pathophysiologic roles, and the effect of dietary habit and aerobic exercise on ceramide levels. Moreover, advancements and limitations of lipidomic techniques and simplification attempts to overcome difficulties of interpretation and to facilitate practical applications, such as the proposal of scores, are also discussed.

Sphingolipids in foodstuff: Compositions, distribution, digestion, metabolism and health effects - A comprehensive review

Sphingolipids (SLs) are common in all eukaryotes, prokaryotes, and viruses, and played a vital role in human health. They are involved in physiological processes, including intracellular transport, cell division, and signal transduction. However, there are limited reviews on dietary effects on endogenous SLs metabolism and further on human health. Various dietary conditions, including the SLs-enriched diet, high-fat diet, and vitamins, can change the level of endogenous SLs metabolites and even affect human health. This review systematically summarizes the main known SLs in foods concerning their variety and contents, as well as their isolation and identification approaches. Moreover, the present review discusses the role of dietary (particularly SLs-enriched diet, high-fat diet, and vitamins) in endogenous SLs metabolism, highlighting how exogenous SLs are digested and absorbed. The role of SLs family in the pathogenesis of diseases, including cancers, neurological disorders, infectious and inflammatory diseases, and cardiovascular diseases, and in recently coronavirus disease-19 outbreak was also discussed. In the post-epidemic era, we believe that the concern for health and the need for plant-based products will increase. Therefore, a need for research on the absorption and metabolism pathway of SLs (especially plant-derived SLs) and their bioavailability is necessary. Moreover, the effects of storage treatment and processing on the content and composition of SLs in food are worth exploring. Further studies should also be conducted on the dose-response of SLs on human health to support the development of SLs supplements. More importantly, new approaches, such as, making SLs based hydrogels can effectively achieve sustained release and targeted therapies.