Variation of wine preference amongst consumers is influenced by the composition of salivary proteins.

The preferences of consumers for different flavours and aromas in wine are varied and may be explained by inherent factors such as cultural background, wine education and personal taste of the wine consumer. Wine flavour, as perceived in the mouth, includes aroma compounds released through the retronasal pathway, which are shaped by interactions with saliva. Saliva and wine interactions could provide an explanation as to why wine tasters express different preferences for wine. To test this hypothesis, 13 Western and 13 Chinese experienced wine tasters were recruited. Sensory evaluation was performed in formal surroundings to acquire free description-based and perceived sensory intensity data using the Pivot® Profile and continuous scale assessment, respectively. Participants' saliva samples were collected before the sensory evaluation and spiked into a wine sample to investigate the impact on the wine's volatile release using comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC-MS). Saliva samples were subjected to enzyme activity assays and protein composition profiling by Tandem Mass Tag (TMT) quantitative proteomics. The wine tasters showed differences in wine flavour perception, which was supported by the difference in wine volatile release resulting from the addition of saliva. The two groups of participants did not have significant differences in total salivary protein concentrations or the amounts of esterase and α-amylase. However, statistically significant variations in the concentrations of specific proteins (proline-rich proteins (PRPs) and lipocalin-1 (LCN-1); p < 0.01) were found between the two groups. Significant correlations between perceived intensities of wine attributes and concentrations of PRPs and LCN-1 were observed. These results indicate that the composition of proteins in saliva is a factor that influences wine perception and preference. Our results provide a biochemical basis for understanding preference for food based on interactions between aroma compounds and salivary proteins and could be used to suggest foods or beverages to particular cultural groups.

The salivary microbiome shows a high prevalence of core bacterial members yet variability across human populations.

Human saliva contains diverse bacterial communities, reflecting health status, dietary patterns and contributing to variability in the sensory perception of food. Many descriptions of the diversity of the salivary microbiome have focused on the changes induced by certain diseased states, but the commonalities and differences within healthy saliva have not been fully described. Here, we define and explore the core membership of the human salivary microbial community by collecting and re-analysing raw 16S rRNA amplicon sequencing data from 47 studies with 2206 saliva samples. We found 68 core bacterial taxa that were consistently detected. Differences induced by various host intrinsic and behaviour factors, including gender, age, geographic location, tobacco usage and alcohol consumption were evident. The core of the salivary microbiome was verified by collecting and analysing saliva in an independent study. These results suggest that the methods used can effectively define a core microbial community in human saliva. The core salivary microbiome demonstrated both stability and variability among populations. Geographic location was identified as the host factor that is most associated with the structure of salivary microbiota. The independent analysis confirmed the prevalence of the 68 core OTUs we defined from the global data and provides information about how bacterial taxa in saliva varies across human populations.

In vitro effect of 4-pentylphenol and 3-methyl-4-nitrophenol on murine splenic lymphocyte populations and cytokine/granzyme production.

Gasoline exhaust particles (GEP) and diesel exhaust particles (DEP) are considered to be some of the most important air pollutants. Among the many constituents in these pollutant particles, 4-pentylphenol (PP) and 3-methyl-4-nitrophenol (PNMC) are considered important phenolics in GEP and DEP, respectively. The aim of this study was to investigate the effect of in vitro exposure to commercially-supplied PP and PNMC on populations of, and production of interleukin (IL)-2, IL-4 and granzyme-B by, mouse splenic lymphocytes. After in vitro exposure to PP or PNMC for 48 h, splenocyte viability was measured, cell phenotypes, e.g. B-cell (CD19), T-cells (CD3), T-cell subsets (CD4 and CD8), were quantified by flow cytometry and production of IL-2, IL-4 and granzyme-B was assessed via ELISA. The oxidative toxicity of PP and PNMC toward the splenocytes was also evaluated using measures of hydroxyl radical and malondiadehyde production and changes in glutathione peroxidase and superoxide dismutase activities. Results showed that in vitro exposure to PP and PNMC inhibited splenic cell parameters in a dose-related manner. Exposure to PP and PNMC decreased splenic T-lymphocyte populations and splenocyte production of cytokines and granzyme B, as well as induced oxidative stress in the splenocytes. The results also showed that the percentages of CD3(+) T-cells overall and of CD4(+) and CD8(+) T-cells therein, among exposed splenocytes, were reduced; neither compound appeared to affect levels of CD19(+) B-cells. Overall, the suppressive effects of PP were stronger than PNMC. The data here provide support for the proposal that PP-/PNMC-induced toxicity in splenocytes may be due at least in part to oxidative damage and that PP and PNMC - as components of GEP and DEP - might significantly impact on splenic T-cell formation/release of cytokines/granzymes in situ.