Inter‐Individual Variability in Insulin Response after Grape Pomace Supplementation in Subjects at High Cardiometabolic Risk: Role of Microbiota and miRNA

• Published in: Molecular nutrition & food research Vol. 65; no. 2; pp. e2000113 - n/a
• Main Authors: Ramos‐Romero, Sara, Léniz, Asier, Martínez‐Maqueda, Daniel, Amézqueta, Susana, Fernández‐Quintela, Alfredo, Hereu, Mercè, Torres, Josep Luís, Portillo, María P., Pérez‐Jiménez, Jara
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2021
• Subjects: Clinical trials; Deoxyribonucleic acid; Dietary supplements; DNA; Fatty acids; Fecal microflora; Feces; Firmicutes; food research; Gas chromatography; glycemic control; grape pomace; Grapes; Health risks; Insulin; insulin response; Intestinal microflora; intestinal microorganisms; Metabolic disorders; Metabolic syndrome; Microbiota; Microorganisms; microRNA; MicroRNAs; miRNA; nutrition; Polymerase chain reaction; Polyphenols; Prevotella; quantitative polymerase chain reaction; risk; Substrates; Variability; microbiota; miRNA; grape pomace; insulin response
• ISSN: 1613-4125; 1613-4133; 1613-4133
• DOI: 10.1002/mnfr.202000113

Scope Dietary polyphenols have shown promising effects in mechanistic and preclinical studies on the regulation of cardiometabolic alterations. Nevertheless, clinical trials have provided contradictory results, with high inter‐individual variability. This study explores the role of gut microbiota and microRNAs (miRNAs) as factors contributing to the inter‐individual variability in polyphenol response. Methods and Results 49 subjects with at least two factors of metabolic syndrome are divided between responders (n = 23) or non‐responders (n = 26), depending on the variation rate in fasting insulin after grape pomace supplementation (6 weeks). The populations of selected fecal bacteria are estimated from fecal deoxyribonucleic acid (DNA) by quantitative real‐time polymerase chain reaction (qPCR), while the microbial‐derived short‐chain fatty acids (SCFAs) are measured in fecal samples by gas chromatography. MicroRNAs are analyzed on a representative sample, followed by targeted miRNA analysis. Responder subjects show significantly lower (p < 0.05) Prevotella and Firmicutes levels, and increased (p < 0.05) miR‐222 levels. Conclusion After evaluating the selected substrates for Prevotella and target genes of miR‐222, these variations suggest that responders are those subjects exhibiting impaired glycaemic control. This study shows that fecal microbiota and miRNA expression may be related to inter‐individual variability in clinical trials with polyphenols. Subjects at high metabolic risk with higher levels of plasma insulin concentration are sensitive to grape pomace (Responders) while showing reduced levels of Firmicutes and Prevotella, along with increased expression of miR‐222. The variations in miR‐222 as well as in Prevotella could be indicators of responsiveness, suggesting that responders are those subjects showing impaired glycaemic control.