The present invention relates to pharmaceutical compositions suitable for the treatment of chronic diseases associated with the presence of abnormal or an abnormal distribution of microflora in the gastrointestinal tract of a mammalian host, which compositions comprise viable non-pathogenic or attenuated pathogenic Clostridia. The compositions further comprise one or more additional viable non-pathogenic or attenuated pathogenic microorganisms selected from the group consisting of Bacteroides, Eubacteria, Fusobacteria, Propionibacteria, Lactobacilli, anaerobic cocci, Ruminococcus, E. coli, Gemmiger, Desulfomonas, Peptostreptococcus, and fungi. The present invention also provides pharmaceutical compositions suitable for the treatment of the same chronic diseases comprising viable non-pathogenic or attenuated pathogenic Escherichia coli, at least one strain of viable non-pathogenic or attenuated pathogenic Bacteroides and at least one strain of viable non-pathogenic or attenuated pathogenic microorganism.