LONDON (Reuters) - Russians will soon be able to combine healthy eating with history by tucking into a yogurt containing bacteria taken from the saliva and guts of some of the space program's most distinguished astronauts.

Nadezhda Lizko, who led the yogurt project at the Institute of Biomedical Problems in Moscow, told the magazine astronauts made ideal culture donors for live yogurts.

``They are under constant and strict observation of a whole range of medical specialists. The slightest change in their physical condition is instantly noticed,'' she said.

The stresses of space flight can upset astronauts' immunity, allowing potentially dangerous bacteria to oust benign inhabitants of an astronaut's guts.

In the early 1980s, microbiologists attached to the Soviet space program began developing the yogurts as a remedy to these problems. They fed them to astronauts before they headed into orbit.

Once just another tool in the Soviet battle for space supremacy, the yogurt is now a potential Russian money spinner.

Lizko and her team have diversified their range to include fruit-flavored yogurts, cottage cheese and traditional Russian cheeses studded with garlic and herbs, the magazine said.

They hope to produce two tones of dairy produce a day from the autumn.

``Although samples have not been collected since 1993, Lizko has 1,000 cultures of astronaut's gut bacteria -- enough to sustain the business indefinitely,'' the magazine said.