IL1B and obesity due to melanocortin 4 receptor deficiency: Spearman rank correlations between microbiota family relative abundances, hepatic CLA concentrations, key gut barriers (FD4 and HRP fluxes, G, IAP activity) and obesity and low-grade inflammation (body weight, visceral adiposity index, plasma IL-1β) parameters were performed to highlight possible links between changes in microbiota and rat phenotype.