08/10/2026
Do you think American's ultra processed diets are contributing to chronic Lyme and co-infections?
A diet high in ultra-processed foods (UPFs), industrially formulated products with additives, refined ingredients, high sugar/salt/fat, and minimal whole foods is associated with negative effects on the immune system, primarily through chronic low-grade inflammation, gut microbiome disruption, and impaired immune regulation.
(1) Promotes chronic low-grade inflammation (“metainflammation”): UPFs are linked to higher levels of biomarkers such as CRP, IL-6, IL-8, systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), and others. A large NHANES analysis of US adults found positive associations between higher UPF calorie intake and multiple immune-inflammation indices, even in generally healthy people. This persistent inflammation can dysregulate immune responses, contributing to metabolic issues and reduced ability to handle acute challenges effectively.
(2) Disrupts the gut microbiome and barrier: UPFs are typically low in fiber and polyphenols (which feed beneficial microbes) and high in emulsifiers, artificial sweeteners, and other additives. This reduces microbial diversity, decreases short-chain fatty acid (SCFA) producers (e.g., beneficial bacteria like those generating butyrate), and increases pro-inflammatory taxa. Emulsifiers can thin the mucus layer and increase intestinal permeability (“leaky gut”), allowing bacterial products (like LPS) to enter the bloodstream and trigger systemic inflammation and immune activation.
(3) Affects immune cell function and tolerance: Mechanisms include oxidative stress from the nutrient profile of UPFs (high sugar/saturated fats, low micronutrients/antioxidants), advanced glycation end products (AGEs) that activate inflammatory receptors on immune cells, and direct modulation of T cells or innate responses by additives. This can impair immune tolerance, potentially raising risks of allergies, inflammatory bowel disease (e.g., higher Crohn’s risk), and other dysregulation.
