Synthetic Food Colorants and Gut Microbiota: A Systematic Review of Preclinical Studies

Abstract

Growing evidence suggests that industrial food processing, including the excess consumption of food additives, might have a negative impact on human health. Despite regulatory safety evaluations, their impact on gut microbiota remains poorly characterized. The aim of this study was to systematically review current evidence on food additives and gut microbiota in preclinical models. A systematic research identified 47 studies evaluating E110 (sunset yellow FCF), E129 (Allura Red AC), E171 (titanium dioxide), E173 (aluminum), E174 (silver), and E175 (gold) on gut microbiota‐related outcomes in murines. Both acute and chronic exposure to specific food colorants induced β ‐diversity shifts, compositional dysbiosis, and impaired intestinal barrier integrity. Histopathological alterations included epithelial disorganization. Functional consequences encompassed microbiota‐driven metabolic dysregulation, intestinal and hepatic toxicity, and altered enteric neuronal activity. Colitis was the most frequent phenotype, accompanied by systemic effects, including impaired glucose metabolism, chronic inflammation, and obesity. Collectively, these mechanistic findings suggest that synthetic food colorants may disrupt gut microbiota and host physiology, highlighting the importance of continued evaluation of their use in food products within the context of emerging evidence on gut health and broader physiological outcomes.