Fewer organ transplant rejections thanks to a Belgian discovery

13/07/2023

This is a world first! A team from UCLouvain has just made a discovery linked to intestinal microbiota, namely that intestinal flora is thought to play an important role in the variability of anti-rejection drug dosage during organ transplants.

In Belgium alone, 1,600 people wait for a transplant every year, and over 40% of patients often have to wait more than a year before they can hope to receive one. When a transplant is possible, it is therefore essential to ensure its success, so as not to "waste" an organ.

One of the keys to successful transplants is the anti-rejection drug tacrolimus, which patients must take for the rest of their lives. Today, however, it is extremely difficult to dose this drug correctly, which can lead to major risks of transplant failure if underdosed, or very serious side effects if overdosed (diabetes, hirsutism, hair loss, neuropathy or nephrotoxic effects).

Two professors from UCLouvain's Louvain Drug Research Institute, Laure Bindels and Laure Elens, supported by FNRS candidate Alexandra Degraeve, therefore set out to investigate the links between this drug, its dosage and the microbiota.

After five long years of research, these two researchers were the first in the world to demonstrate that the presence of microbiota increases drug concentration in the blood. This could reduce the risk of transplant rejection, or conversely, increase the risk of side effects.

The Belgian scientists will continue to study the microbiota over a long period, to compare it before, just after and well after the transplant, and so gain an even clearer picture of the interactions between intestinal bacteria and the absorption of certain drugs, such as tacrolimus.

Let's hope that this discovery will soon have a positive impact on transplant success rates!