In the present disclosure, a method for culturing and preserving the probiotic gut microorganism Eubacterium hallii is disclosed. The method provides an E. hallii preparation that is suitable for administration or ingestion to humans and that provides high E. hallii biomass yields. Preferably, the medium used for culturing E. hallii to high biomass yields comprises food grade components only, is free of any animal sources, and/or is kosher.