Gut Microbiota and Food Allergy: A Review of Mechanisms and Microbiota-Targeted Interventions

Background: Food allergies (FAs) have become a major public health concern worldwide, with rising prevalence particularly among children. Traditional genetic and allergen exposure models do not fully explain this increase, prompting growing interest in the role of the gut microbiota. Early-life microbial colonization is now recognized as a critical determinant of immune development, with disruptions in microbial balance implicated in allergic sensitization. Objective: This review aims to synthesize recent human studies investigating the relationship between gut microbiota composition and food allergies, with an emphasis on underlying mechanisms and the potential of microbiota-targeted interventions. Methods: A literature search was conducted, including eligible studies concerning gut microbiota and food allergy. A total of 31 studies met the inclusion criteria. Results: The findings indicate that early-life factors, including delivery mode, feeding practices, antibiotic exposure, and environmental microbial diversity, have a significant influence on gut microbial colonization. Allergic children consistently exhibit reduced microbial diversity and lower levels of beneficial taxa such as Bifidobacteria, Faecalibacteria, and Clostridia. Microbial dysbiosis is associated with enhanced type 2 immune responses, reduced regulatory T cell activity, and altered profiles of short-chain fatty acids. Dietary modulation through prebiotics, probiotics, and synbiotics has shown potential in restoring microbial balance and promoting immune tolerance, although with varying degrees of efficacy depending on the strains, formulas, and timing of intervention. Conclusions: The gut microbiota plays a central role in the pathogenesis and potential prevention of food allergies. Microbiota-targeted dietary strategies, particularly in early life, offer promising avenues for promoting immune tolerance.