In a study published in the journal Cell Reports, researchers at McGill University, Kyoto University and INSERM/University of Paris show that an organic compound produced by the intestinal flora, the metabolite 4-Cresol, exhibits protective effects against type 1 and type 2 diabetes by stimulating the proliferation and function of insulin-producing beta cells in the pancreas. These results pave the way for new therapeutic options that could improve the situation of millions of patients.