Bioengineering Interventions to Enhance the Capacity of the Gut Microbiota in Controlling Food Allergies

Food allergies arise when environmental factors, lifestyle choices, and genetic predispositions affect the integrity of the gut epithelial barrier. Under healthy conditions, gut microbiota supports intestinal tight junction integrity and promotes immune tolerance to dietary allergens. Disruption of this microbiota increases susceptibility to epithelial barrier leakage, thereby enabling food allergens to penetrate the bloodstream from the gut and leading to allergic sensitization. Restoring gut homeostasis through allergen-specific immunotherapy (AIT), executed via oral termed as oral immunotherapy (OIT), skin as subcutaneous immunotherapy (SCIT), or under the tongue in the form of sublingual immunotherapy (SLIT), remains a promising yet complex and multifaceted approach. In parallel, probiotics offer a simpler alternative to reinforce epithelial barrier function, restore cellular homeostasis, mitigate allergy symptoms, and represent the probiotics-based OIT. Recently, several bioengineering strategies have been developed toward enriching gut microbiota, such as using additives such as carbohydrates, polyphenols, and probiotics. While generic probiotics have shown efficacy, their undefined dosages and administration protocols pose challenges for clinical standardization in the form of OIT. Emerging developments include recombinant probiotics engineered to express the specific allergen in a controlled manner inside the gut. However, safety concerns regarding their clinical application remain under active discussion. This review highlights various bioengineering strategies to enhance the probiotic capacity, address safety considerations, and explore future prospects for managing food allergies.