Margherita Farnetano ¹ Laura Carucci ^1,2 Serena Coppola ^1,2 Franca Oglio ^1,2 Marica Cozzolino ^1,2 Antonio Masino ^1,2 Rita Nocerino ^1,2,3 Roberto Berni Canani ^1,2,4,5*

• ¹ Section of Paediatrics, Department of Translational Medical Sciences, University of Naples Federico II, Naples, Campania, Italy
• ² ImmunoNutritionLab, CEINGE Advanced Biotechnologies, University of Naples Federico II, Naples, Campania, Italy
• ³ Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Lazio, Italy
• ⁴ Task Force on Microbiome Studies, University of Naples Federico II, Naples, Campania, Italy
• ⁵ European Laboratory for the Investigation of Food Induced Diseases, Department of Medical Translational Sciences, University Federico II, Naples, Campania, Italy

Increasing evidence suggests that alterations in the gut microbiome (GM) play a pivotal role in the pathogenesis of pediatric food allergy (FA). This scoping review analyzing the current evidence on GM features associated with pediatric FA highlights the importance of GM as potential target of intervention for preventing and treating these common conditions in the pediatric age.Following PRISMA Guidelines, we performed a research on Pubmed and Embase using the keywords (gut microbiome OR dysbiosis OR gut microbiota OR microbiome signatures) AND (food allergy OR IgE-mediated food allergy OR food protein-induced allergic proctocolitis OR food protein-induced enterocolitis OR non-IgE food allergy OR cow milk allergy OR hen egg allergy OR peanut allergy OR fish allergy OR shellfish allergy OR tree nut allergy OR soy allergy OR wheat allergy OR rice allergy OR food sensitization). We included 34 studies reporting alterations of gut microbiome in children affected by FA compared to healthy controls.The GM in pediatric FA is be characterized by a higher abundance of harmful microorganisms (e.g., Enterobacteriaceae, Clostridium sensu stricto, Ruminococcus gnavus, Blautia spp.), and lower abundance of beneficial bacteria (e.g., Bifidobacteriaceae, Lactobacillaceae, some Bacteroides species).Moreover, we provided an overview of the mechanisms of action elicited by these bacterial species in regulating immune tolerance and of the main environmental factors that could modulate GM composition and function in early life. Altogether these data contributing to a better knowledge on the pathogenesis of FA can open the way to innovative diagnostic, preventive and therapeutic strategies against these conditions.