Title : The hidden threat of erythrosine (FD&C Red No. 3) on gut microbial ecosystems and gastrointestinal health
Abstract:
The human gut microbiota constitutes a dynamic and densely populated ecosystem of over 1013 microorganisms whose compositional and functional integrity is essential for nutrient metabolism, epithelial barrier maintenance, immune regulation, and prevention of chronic non-communicable diseases. Among the most underestimated modulators of this community are synthetic food colorants, which are consumed globally on a daily basis with limited awareness of their microbiome-disrupting potential.
Erythrosine (FD&C Red No. 3, E-127), a xanthene-class synthetic dye with approximately 58% iodine content by molecular mass, has been historically used in confectionery, dairy products, processed meats, beverages, pharmaceuticals, and cosmetics. Despite its widespread application over more than six decades, mounting toxicological evidence prompted the U.S. Food and Drug Administration (FDA) to officially enact its ban from food products in January 2025. However, billions of consumers in markets outside the United States-including Latin America, parts of Asia, and Africa-continue to be exposed to this additive on a daily basis.
Emerging research demonstrates that erythrosine exerts significant disruptive effects on gut microbial ecosystems. Experimental evidence indicates that this colorant can reduce the abundance of beneficial taxa such as Lactobacillus spp., promote dysbiosis, and impair gut barrier integrity, leading to increased intestinal permeability and systemic inflammatory signaling. These microbiome-mediated mechanisms are further compounded by erythrosine's genotoxic and oxidative stress-inducing properties: Studies using comet assays have demonstrated substantial DNA damage in gastrointestinal tissues of exposed animals, alongside histopathological evidence of inflammatory infiltration and degenerative changes in the stomach, intestine, and colon. Furthermore, erythrosine acts as an endocrine disruptor by inhibiting thyroid peroxidase, reducing T3/T4 synthesis, elevating TSH, and promoting thyroid cell proliferation in a dose-dependent manner.
From a food systems perspective, this presentation will address: (i) The chemical and toxicological profile of erythrosine and its interactions with the gut microbiome; (ii) The mechanistic links between erythrosine-induced dysbiosis, Reduced Short-Chain Fatty Acid (SCFA) production, and gastrointestinal inflammation; (iii) The regulatory history and the reasons for delayed action by global food safety agencies; and (iv) The availability of safe, functional natural colorant alternatives-including anthocyanins, betalains, and carotenoids-capable of replacing synthetic dyes without compromising technological performance in food matrices.
This contribution integrates concepts from nutritional microbiology, food toxicology, and precision nutrition to highlight the urgent need for evidence-based regulatory action and consumer education, particularly in regions where erythrosine remains legally permitted. A global, microbiome-centered approach to food safety is no longer optional-it is a public health imperative.
Keywords: Erythrosine, Gut Microbiota, Gut Dysbiosis, Food Additive, Genotoxicity, Endocrine Disruptor, Intestinal Inflammation, Food Safety.
