Introduction: Severe acute malnutrition (SAM) is a major cause of child mortality worldwide, however the pathogenesis of SAM remains poorly understood. Recent studies have uncovered an altered gut microbiota composition in children with SAM, suggesting a role for microbes in the pathogenesis of malnutrition. Objectives: To elucidate the metabolic consequences of SAM and whether these changes are associated with changes in gut microbiota composition. Methods: We applied an untargeted multi-platform metabolomics approach (gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS)) to stool and plasma samples from 47 Nigerian children with SAM and 11 control children. The composition of the stool microbiota was assessed by 16S rRNA gene sequencing. Results: The plasma metabolome discriminated children with SAM from controls, while no significant differences were observed in the microbial or small molecule composition of stool. The abundance of 585 features in plasma were significantly altered in malnourished children (Wilcoxon test, FDR corrected P < 0.1), representing approximately 15% of the metabolome. Consistent with previous studies, children with SAM exhibited a marked reduction in amino acids/dipeptides and phospholipids, and an increase in acylcarnitines. We also identified numerous metabolic perturbations
Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporationwhich have not been reported previously, including increased disaccharides, truncated fibrinopeptides, angiotensin I, dihydroxybutyrate, lactate, and heme, and decreased bioactive lipids belonging to the eicosanoid and docosanoid family. Conclusion: Our findings provide a deeper understanding of the metabolic consequences of malnutrition. Further research is required to determine if specific metabolites may guide improved management, and/or act as novel biomarkers for assessing response to treatment.
Powered by Editorial Manager® and ProduXion Manager® from Aries Systems CorporationDear Royston Goodacre, Editor-in-Chief MetabolomicsWe are very grateful for the valuable comments raised by the reviewers. Please see our responses below; we trust that these are appropriate. I have also attached a revised version of the manuscript with the changes highlighted.Please note that, in response to comments by reviewer 3, we have moved details of methodology to the main manuscript. This has increased the length of the manuscript but we trust that this is acceptable.Please do let me know if there are any remaining issues.
Sincerely, Stephen AllenReviewer #1: This study is about metabolic derangements identified through untargeted metabolomics in a cross-sectional study of Nigerian children with severe acute malnutrition. It is an interesting and relevant study because studies investigating the pathogenesis of SAM are lacking. To this respect the study presented in the manuscript has some qualities, however as the authors point it out it has several limitations. Only the plasma samples gave some resu...