Does the lingual film intervene in the perception of taste?

International audienceThe biological film at the surface of the tongue, composed of saliva and microorganims, is an important interface between exogenous taste molecules and receptors involved in taste perception. However, the relationships between the composition of the lingual film and the perception of taste are not fully described. Thus, the aim of the present work was to study the differences in the biochemical (protein concentration, metabolite profiles) and microbiological compositions of the tongue films from 20 adult subjects, and to explore the possible relationships between composition and taste sensitivity assessed by means of a rapid at-home test. Preliminary results showed that intra-subject variability in film composition was smaller than inter-subject variability. The pH of the lingual film varied between 6.40 and 7.40. For one given subject, the tongue film pH was always higher than the saliva pH. The range of protein concentration was 0.4-1.0 mg/g of film and the mean number of bacteria was around 3×108 CFU/g of film sample. qPCR will also be performed to complete these results using phyla-specific primers (Firmicutes, Bacteroidetes, Fusobacteria, Actinobacteria, β-Proteobacteria, γ-Proteobacteria) and genus-specific primers (Veillonella, Streptococcus, and Prevotella). In conclusion, lingual film composition reveals variability between subjects that could be linked to variability in taste perception