Causal associations between gut Bifidobacteriaceae and transplantation failure: A Mendelian Randomization Study

Background: Transplant rejection and failure are the primary causes of short life in transplant patients, and the mechanism is yet unknown. A number of recent research findings point to a possible association between the gut microbiome and transplantation failure. However, it is unclear if part of the gut microbiota is the cause of transplantation failure. Methods A Mendelian randomization study was carried out to test the potential causal relationship between gut microbiota and transplantation failure. Three GWAS results were used, one for the gut microbiome, one for transplantation failure, and one for transplantation status. As instrumental variables, SNPs with a strong correlation to the abundance of gut microbiota were chosen. Results The abundance of Bifidobacteriaceae was discovered to be a causal factor for transplantation failure, with a protective effect (IVW p = 0.049, OR = 0.658, 95% CI: 0.433–0.998) after Mendelian randomization analysis. Furthermore, there was no relationship between Bifidobacteriaceae and transplantation status. Gene enrichment analysis revealed that the genes containing the instrumental variables of Bifidobacteriaceae were primarily enriched in synapse and membrane related terms. Conclusions These findings suggest that a decrease in the abundance of Bifidobacteriaceae in the gut may increase the risk of transplantation failure. This work contribute novel insights for further explaining the process of transplantation failure, and it is important in intervening and avoiding transplantation failure.