Alteration of taste perception, food neophobia and oral microbiota composition in children with food allergy

Abstract

Currently, the mechanisms underlying sensory perception and sensory performance in children with food allergies are far from being understood. As well, only recently, single research afforded the oral host-commensal milieu, addressing oral microbial communities in children with peanut allergies. To bridge the current gaps in knowledge both in the sensory and microbial fields, a psychophysiological case-control study was performed in allergic children (n = 29) and a healthy sex-age-matched control group (n = 30). Taste perception, food neophobia, and liking were compared in allergic and non-allergic children. The same subjects were characterized for their oral microbiota composition by addressing saliva to assess whether specific profiles were associated with the loss of oral tolerance in children with food allergies. Our study evidenced an impaired ability to correctly identify taste qualities in the allergic group compared to controls. These results were also consistent with anatomical data related to the fungiform papillae on the tongue, which are lower in number in the allergic group. Furthermore, distinct oral microbial profiles were associated with allergic disease, with significant down-representations of the phylum Firmicutes and of the genera Veillonella spp., Streptococcus spp., Prevotella spp., and Neisseria spp. For the first time, this study emphasizes the link between sensory perception and food allergy, which is a novel and whole-organism view of this pathology. Our data indicated that an impaired taste perception, as regards both functionality and physiologically, was associated with food allergy, which marginally influences the food neophobia attitude. It is also accompanied by compositional shifts in oral microbiota, which is, in turn, another actor of this complex interplay and is deeply interconnected with mucosal immunity. This multidisciplinary research will likely open exciting new approaches to therapeutic interventions.

Figure 1

Boxplots showing the differences on both global (TTS) and single scores (Sweet Taste Score, Sour Taste Score, Salty Taste Score and Bitter Taste Score) as a function of allergic condition (ALL: Allergic group; C: Control group). The plots provide a representation of data distribution, individual raw observations, the median (horizontal line) ± IQR (box) within each group. Only statistically significant pairwise differences observed after post hoc Dunn’s test with Bonferroni correction are presented (**p < 0.01; ***p < 0.001).

Figure 2

Loading from PC1–PC2 of the double-centered PCA on food liking resulting in two taste-liking clusters of Sweet-Salty-Fatty Likers (n = 31) and Bitter-Sour Likers (n = 28). Dot in dark colors (red and blue) depicted the children in the control group while dot in light colors (pink and light blue) depicted allergic children.

Figure 3

Taxonomic composition of the salivary microbiota in allergic (ALL) patients compared to sex- and age-matched healthy controls (C). Average relative abundance of the most represented phyla, families and genera identified in the two groups. Only taxa whose relative abundance is > 3% in at least one group are included.

Figure 4

β-diversity analysis. The microbiota distances were visualized through Principal Coordinates Analysis (PcoA). The figure shows the taxonomic levels of phyla, families, and genera. The significance threshold (p-value) for the PERMANOVA was set < 0.001.