GCG and Glucose intolerance: Hwang I et al. [47] analyzed how the use of antibiotic therapy (vancomycin and bacitracin) generates changes in the microbiota of obese rodents, finding a decrease in the proportion of Firmicutes and Bacteroidetes and an increase in Proteobacteria, which has been linked to improved systemic glucose intolerance and insulin resistance, through increased secretion of GLP-1.