FENOTIPO E GENOTIPO DELLA PERCEZIONE GUSTATIVA, STATO NUTRIZIONALE E COMPOSIZIONE CORPOREA DI ANZIANI OSPITI DI RSA DON ORIONE GENOVA

ABSTRACT Candidate: Consuelo Borgarelli, identification number: 2320672 Session Of May 28, 2024 TITLE OF THE THESIS: PHENOTYPE AND GENOTYPE OF GUSTATIVE PERCEPTION, NUTRITIONAL STATUS AND BODY COMPOSITION OF THE ELDERLY GUESTS OF THE DON ORIONE GENOA RSA. Supervisor: Prof. Livia Pisciotta BACKGROUND: Taste is part of the five senses with which humans are endowed, and the mechanisms of taste perception begin at the level of the tongue, in the gustatory buttons via the gustatory receptors, which perceive the five primary tastes, namely bitter, sweet, salty, sour and umami, and subsequently the chemical information is translated into nerve signals. Taste perception provides information regarding the chemical characteristics of substances that come into contact with taste receptors as they enter the oral cavity. However, there is genetic and phenotypic variability in taste perception, which would appear to influence propensities or repulsions to foods and food choices. Differences in food preferences may therefore go to influence a different intake of the same, going to alter energy intake and thus potentially lead to alterations in nutritional status and health status in some cases. Moreover, taste perception undergoes changes during the physiological process of aging, and the losses of taste that occur can lead to poor appetite, lower energy intake and unhealthy food choices, factors that negatively affect generating nutritional vulnerability. The state of malnutrition is a clinical condition found mainly in institutionalized elderly patients and is a frequent and often underestimated clinical issue in RSAs. AIM OF THE THESIS: The aim of this observational study was to explore the correlation between taste phenotype and genotype, food preferences, nutritional status, and body composition by examining elderly subjects who were residents of the Don Orione Paverano RSA in Genoa, Italy. The 'main objective was to examine the possible association between taste perception and polymorphisms in genes known to influence taste ability and to assess their impact on nutritional status. MATERIALS AND METHODS: For the conduct of this study, a sampling of 70 residents of the RSA Don Orione in Genoa was carried out, who underwent anthropometric assessment, taste perception test, BIA Akern, 24-hour Recall, food preference questionnaire, MNA (Mini Nutritional Assessment) screening test, multidimensonal assessment, Hand grip strength assessed, genotyping by Illumina SNP arrays, on residual part of routine sampling serum. Statistical analyses were performed using JAMOVI software. RESULTS: Analysis of the data collected in our study revealed interesting results showing a correlation between genotype and phenotype, as well as between genotype and food choices, for several genetic variants examined. Specifically, we observed that subjects carrying the rare allele of the rs35874116 and rs9701796 variants of the TAS1R2 gene, which are implicated in the increased perception of sweet taste, prefer to consume sweets such as panettone, milk chocolate, eggnog and generally sweet-tasting foods. Similarly, they express a low liking for the bitterness of PROP and an aversion to bitter foods and bitter vegetables such as broccoli, cabbage, and chicory. In addition, subjects carrying the rare allele of the rs9701796 variant like salty taste and prefer spicy foods. The rs5400 variant of the SLC2A2 gene associated in the literature with increased sugar consumption was found to be negatively correlated with the CIRS scale score. Subjects carrying the rs7792845 variant of the GNAT3 gene, which is correlated in the literature with increased perception of sweet taste, are found to dislike bitter coffee and bitter quinine. In our sample, subjects with the linkage variants rs10246939/rs1726866 of the TAS2R38 gene, consistent with the literature have reduced perception of bitter taste. These subjects express a lower liking of bitter-PROP contrary to what is reported in the literature, in which usually non PROP bitter-tasters like bitter foods, while tasters and Super tasters show poor liking. Subjects carrying the rs6277 polymorphism of the DRD2 gene, who according to the literature tend to consume greater amounts of sweet foods, show an increase in the intensity of sour taste perception. Regarding the consumption of meat, and pasta with meat sauce, in our sample, subjects with the rs1800497 polymorphism in the ANKK1 gene and the rs5400 polymorphism in the SLC2A2 gene show a preference for these foods. In addition, the rare rs1800497 variant on the ANKK1 gene correlates with an increased aversion to the bitter taste of quinine. Therefore, these subjects appear to show a preference for fatty, high-calorie foods and a low propensity for consuming bitter foods such as vegetables; in fact, the literature reports an increased risk of developing obesity for subjects with this variant. Finally, regarding body composition, subjects with the rs1800497 polymorphism in the ANKK1 gene have significantly reduced BCM values, and those with the rs10246939/rs1726866 polymorphisms in the TAS2R38 gene are significantly correlated with increased ECW. Although the ANKK1 gene has been the subject of several studies regarding its possible involvement in obesity as well as the TAS2R38 gene would appear to correlate positively with obesity in the female population, there is currently no direct evidence that the ANKK1 gene is directly involved in the regulation of BCM and that the TAS238 gene is related to increased ECW. In light of these findings, it might be useful to investigate this further in a more diverse sample in terms of BMI and sex. CONCLUSIONS: Taste perception varies greatly at the individual level for multiple reasons such as age, gender, ethnicity, and past exposures. Our study highlights how taste perception and food preferences are partly determined by the genetic component that seems to influence food choices and generate individual differences in a sample of geriatric subjects.In addition, such genetic variants could influence the nutritional status of the subjects examined.However, further studies are needed to confirm these preliminary findings, preferably on a larger sample, which may allow us to further investigate the correlation between genetic factors with food preferences and nutritional status.