The positive preventive effects of probiotics on GDM can be mediated by several mechanisms, including modulation of gut microbiota, increased production of short-chain fatty acids, regulation of inflammatory markers, improved insulin sensitivity, enhanced glucagon-like peptide-1 (GLP-1) production, reduced lipopolysaccharide (LPS) levels, increased production of peptide YY, and enhanced regulatory T cell (Treg) activity.[43–45] Probiotics alter the composition of the gut microbiota, leading to changes in the metabolic pathways and the regulation of glucose metabolism. The gene discussed is PYY; the disease is gestational diabetes.