The effect of young blood plasma administration on dysbiosis and intestinal tissue gene expression involved in pathogen response in the middle-aged

Aging is associated with dysbiosis of the gut microbiota. Additionally, deformations in the intestinal tissue cause a reduction in the expression of genes in intestinal epithelial cells, which play a role in the pathogen response. This situation can have various repercussions, such as increased gut permeability, inflammatory bowel diseases, and chronic inflammation in tissues and organs, and can also affect behavioral and cognitive states. Therefore, various biological approaches that can reverse dysbiosis, especially with aging, and regulate the expression of genes involved in pathogen response are becoming increasingly important. Young blood plasma treatment appears to have the potential to be an alternative treatment method for addressing these problems. The aim of this thesis was to investigate the effects of young plasma transfer on the gut microbiota of the elderly and the regulation of gene expression involved in the pathogen response. To this end, blood plasma taken from 5-week-old male Wistar rats was transferred to 12-month-old middle-aged male Wistar rats, with each animal receiving 0.5 ml over 30 days. After plasma transfer, the rats from both the control and test groups were sacrificed. The cecal contents of the sacrificed rats were subjected to metagenomic analysis to determine the gut microbiota profiles. After RNA-seq analysis of the ileum tissues of the intestines, significant increases in the expression of E3 ubiquitin-protein ligase TRIM56, CD209 antigen-like protein C, complement component C7, and collectin-12 genes, and the increased and decreased values of syndecan-1 genes were determined by RT-qPCR. After detailed metagenome analysis, alpha diversity indices showed greater bacterial richness in the microbiota of plasma-administered rats than in the control group. Additionally, the Firmicutes/Bacteroidetes ratio significantly decreased in the plasma group microbiota, confirming the possible rejuvenating properties of young plasma. Furthermore, increased counts of Bifidobacterium longum, Coprococcus catus, and Romboutsia ilealis were observed in plasma-administered rats. Results obtained from RT-qPCR, consistent with RNAseq data, showed a significant increase in the expression of E3 ubiquitin-protein ligase TRIM56, CD209 antigen-like protein C, complement component C7, and collectin-12 genes, and a decrease in the syndecan-1 gene expression. The study results indicate that young plasma transfer plays a significant role in reversing the dysbiosis that occurs in the gut microbiota of the elderly and in regulating the genes involved in the pathogenic response of intestinal tissue.