The effects of ultra-processed food intake on human gut health

Abstract

Introduction: Ultra-processed foods (UPFs), characterized by high levels of additives, preservatives, sweeteners, and artificial ingredients, have become prevalent in modern diets, particularly in developed countries. Growing evidence indicates that regular consumption of UPFs is associated with alterations in gut microbiota, increased intestinal permeability, and systemic low-grade inflammation, factors contributing to various chronic diseases, including gastrointestinal, cardiometabolic, and neuropsychiatric disorders. Methods: A comprehensive literature review was conducted using PubMed, Scopus, and Google Scholar. Peer-reviewed, open-access articles published in English from 2011 to 2022 were included. The review focused on observational and clinical studies examining the relationship between UPF intake, gut microbiota composition, and associated health outcomes. Results: UPF consumption was consistently linked to reduced microbial diversity and the depletion of beneficial bacteria such as Faecalibacterium prausnitzii, Roseburia, and Akkermansia muciniphila. Simultaneously, an increase in pro-inflammatory bacterial species was observed. Additives such as emulsifiers, artificial sweeteners, nanoparticles, and coloring agents were shown to disrupt the gut barrier, promote dysbiosis, and elevate systemic inflammation. High UPF intake correlated with greater prevalence of metabolic syndrome, inflammatory bowel disease (IBD), and mental health conditions. Discussion: The findings emphasize a strong connection between UPF-induced dysbiosis and chronic inflammation. Key mechanisms include decreased production of short-chain fatty acids (SCFAs), weakened gut barrier integrity, and endocrine-disrupting effects of food packaging chemicals like bisphenols. Emerging research also links gut dysbiosis to brain function via the microbiota-gut-brain axis, implicating UPFs in the development of cognitive and psychiatric disorders. Conclusion: UPFs significantly compromise gut health by disrupting microbial balance and enhancing intestinal permeability, which in turn fosters systemic inflammation and chronic disease. Public health efforts should focus on reducing UPF consumption through education, clearer labeling, and regulatory policies. Future research must further elucidate causal pathways and develop microbiota-targeted dietary interventions to protect gastrointestinal and overall health.