Biochemical and immunological markers of the adaptive response in olfacto-odorimetric studies

Abstract

The purpose of the study is to determine whether exposure to odours of model food odourants can lead to a change in biochemical and immunological parameters that we previously used when examining the population in the area of food industry enterprises location using the method of quantitative olfacto-odorimetry. Methods. The specified concentrations of aerosols of three food flavours (orange, cognac and coffee) were supplied to the participants of the studies with a help of ECOMA T08 olfactometer. Quantitative composition of the aerosols was controlled by GC/MS. In participants saliva samples taken before, during and at the end of each experiment, the intensity of luminol-dependent chemiluminescence, the content of secretory IgA, IL-1β, IL-6 and IL-8, the activity of α-amylase and N-acetyl-β-D-glucosaminidase were determined. For data analysis, paired Friedman and Wilcoxon tests were used with Bonferroni correction for the problem of multiple comparisons. Results. A reliable effect of the smell of food odourants was found on one indicator only - the activity of salivary α-amylase - when combining data from 5 separate experiments (n=45): 93.3[24.3;160.0] U/ml at the end of the experiments against background values of 109.9 [42.5; 216.7] U/ml;, p=0.0096 with a significance level of p=0.05/3=0.017. A decrease in the average values of salivary α-amylase activity was shown to hide opposite changes in individual values: an increase in activity in people with low background values (below the median of the initial distribution) and an amplitude-dominant decrease - in people with high background values (above median). The revealed phenotypic polymorphism of α-amylase regulation contributes to one of relevant Post-COVID areas - the study of the ability of people to perceive odours and react to them. Limitations. The use of olfacto-odorimetry to study effect of odours on human health indicators is promising, but requires design of protocols with extended exposure time. Conclusion. A decrease in average values of salivary α-amylase activity with distinctive forestall of the upper quartile may be a sign of human reflex re sponse to the emission of odourous substances in the areas of food industry.