Fig. 1: Composition of the salivary microbiota at the end of the 3 experimental periods.

Composition of the salivary microbiota at the end of the pre-diet, cheese-diet, and post-diet periods by 16 S rRNA sequencing. A Alpha diversity is represented by the observed species richness for the standard-diet (red), ionised cheese-diet (green), and cheese-diet (yellow) groups (n = 27/group). Observed species richness values are means ± SEMs compared via one-way ANOVA followed by a Tukey’s post hoc test. * indicates p value < 0.05; ** indicates p value < 0.01, and *** indicates p value < 0.001. B Principal coordinates analysis (PCoA) multi-dimensional scaling (MDS) of Bray–Curtis dissimilarities (β-diversity) for the standard-diet (red), ionised cheese-diet (green), and cheese-diet (yellow) groups (n = 27/group). Each point of the PCoA analysis represents one animal. PCoa values were compared with a permanova test. SD, standard diet, CD, cheese diet, and ICD, ionised cheese diet. C Average relative abundance of the salivary bacterial genus for each group (n = 27/group) at the end of the three periods. The relative abundances (%) at the genus level were compared by using a Kruskal‒Wallis test followed by a Dunn post hoc test. Each letter denotes a significance (p-value < 0.05) of the compared groups: a (pink) = CD vs. SD group, b (blue) = ICD vs. SD group, and c (green) = ICD vs. CD group.