[Bifidobacterium flora status of cosmonauts before and after completing space flights].

The state of bifidoflora was examined in eight cosmonauts before and after space flights of varying duration. Prelaunch quantity of bifidobacteria decreased drastically. In space flights of 30 days and longer the level of acid formation by bifidobacteria was reduced. The species composition of bifidoflora remained stable. The most typical intestinal species of bifidobacteria were B. Longum and B. adolescentis.