What I've thought about is replacing the DNA in cells of adults with an average of multiple samples of their DNA, to correct for the mutations in our DNA that a

What I've thought about is replacing the DNA in cells of adults with an average of multiple samples of their DNA, to correct for the mutations in our DNA that accumulates as we age. I think I've heard something about progress in this area, but I don't know what to google for. Does anyone know if there's any news in this area?