The recent and extensive study of the microbiome has provided an enormous amount of
data concerning the type and possible functions of microorganisms present in the gut, airways, genital
tract, and skin. These data showed interpersonal differences in the composition of the microbiome
and these differences suggest a link between the microbiome, the immune modulation, and the
pathogenesis of allergic diseases.
This research is particularly relevant in paediatrics, since allergic diseases are constantly increasing
and there is evidence in the paediatric age that shows that the composition of the microbiome in the
foetal and neonatal period plays a key role in the development of the immune system: vaginal delivery,
breastfeeding, childhood spent in rural environments and/or in contact with animals result in
a greater biodiversity of the microbiome with the presence of protective species that reduce the activation
of Th2 lymphocytes, involved in allergic reactions.
Further studies are necessary to better understand the microbiota role in the pathogenesis of atopy
in order to understand if specific probiotics and prebiotics, administered orally or topically, can affect
the microbiota composition and modulate immune system functions, producing a therapeutic
effect in the treatment of allergic diseases.
This narrative review analysed the available literature regarding the correlation between the microbiome
and the development of allergic diseases and with special focus on paediatric studies. The
skin, gut or lung dysbiosis can be a cofactor in the pathogenesis of allergies and the remodulation
of the microbiome becomes an important therapeutic challenge.