It was published in 2016 (so may have been superceded by newer studies) but from The Gene: An Intimate History I read that all successful fecal implants to trea

It was published in 2016 (so may have been superceded by newer studies) but from The Gene: An Intimate History I read that all successful fecal implants to treat Clostridioides difficile required updates every six months to a year from healthy gut biomes - we have not yet figured out how to make a new biome thrive independently, and separately, all probiotic foods have a temporary effect on biomes, they have to be eaten regularly.