ИСТИНА

Background: The main dietary sources of trehalose (mycose) in traditional all-natural cuisines are yeast, mushrooms, and insect hemolymph. In the modern industrialized world, trehalose is used in the production of high-quality dried foods, as a saccharose substitute, sweetener and stabilizer. This results in the increased exposure of the population to “mushroom sugar”. In order to be absorbed, trehalose disaccharide needs to be cleaved into monosaccharides by a trehalase enzyme. There is increasing evidence that trehalase enzymopathy is more common than thought before. However, data accumulation is slow and comes from the clinical cases of patients with advanced gastrointestinal pathology. The alternative, more promising approach to assessing the risks of trehalose malabsorption is based on the analysis of TREH genotype and allele frequencies in different populations. It is known that trehalase activity is genetically determined: the G→A substitution in the rs2276064 locus of TREH results in the reduced enzyme activity, which is 29.3 IU/g prot. in GG*TREH homozygotes, 20.5 in the carriers of the AG*TREH genotype and as low as 10.2 IU/g prot. in AA*TREH homozygotes. Objective: To analyze the frequency of TREH (rs2276064) alleles and genotypes in the populations of European Russia, Caucasus, Siberia, and Central Asia. Methods: DNA samples from 1,716 unrelated subjects representing 28 population groups were genotyped using: 1) an Infinium iSelect HD Custom Genotyping BeadChip (Illumina, USA) and an iScan platform (Illumina, USA); 2) real-time PCR and a Bio-Rad CFX96 Touch amplifier. Results: In Russia, the frequency of the A*TREH allele increases from west to east. The lowest frequencies are observed in Northwest Russia (0.01-0.03), growing to 0.07 in the populations of Central Russia and the Volga region, increasing further to 0.15 in the Bashkir population of the Southern Urals and reaching maximum values in the Trans-Urals and Southern Siberia (0.19-0.27 for the Altai people). For the populations of Caucasus and Transcaucasia, A*TREH frequencies vary between 0.04 and 0.07. Asian populations exhibit a remarkable diversity. The diversity in Asian groups is very high. It should be emphasized that the A*TREH carrier increases with an increase in the proportion of anthropological features indicating the Central Asian origin of the population (from 0.08 for Tajiks to 0.14 for Uzbeks, and 0.30 for Kyrgyz, Tuvinians and Mongols). Conclusion: We have found that the rs2276064-А TREH allele is more frequent than it was previously concluded from clinical data. Up to 1% of the population of the European part of the Russian Federation have the AA*TREH genotype (i.e. trehalose intolerance in phenotype), and up to 15% (genotype GA*TREH) have a reduced ability to absorb the disaccharide. In the Asian regions (Siberia, Altai, Trans-Baikal) the genotype AA*TREH carriers constitute up to 13%, and GA*TREH up to 49-51%. Trehalose malabsorption is an underappreciated problem, especially in the regions where the proportion of Asian origin populations is fairly high. Today trehalose is actively used as a food supplement and an ingredient of functional sports drinks; therefore, it might be reasonable to consider trehalose labeling for foods and beverages.