The company and the Japan Aerospace Exploration Agency (JAXA) have been carrying out on-the-ground research for the past few years.
And last year a storage test of a capsule containing freeze-dried live probiotic bacteria (Lactobacillus casei strain Shirota) on board the ISS confirmed that the number of live probiotics in the flight sample was equivalent to those in the ground control samples.
“The capsules were subjected to a storage test on the ISS (KIBO) in order to analyse the effect of the space environment on the viability of probiotics,” the two organisations said.
“In April 2016, the capsules were launched to the ISS by SpaceX CRS-8 (Dragon), stored for about one month, and then returned to Earth for analysis. It was confirmed that the numbers of live bacteria were maintained on the ISS as compared with the numbers of live bacteria on the ground.”
Yakult and JAXA will begin the experiment on astronauts in space later this year.
“This will be a scientific study of the effect caused by the consecutive consumption of probiotics on the human immune system and intestinal microbiota of astronauts staying on the ISS for long periods of time,” said the company.
“This joint research aims to contribute to maintaining and improving the health and performance of astronauts. It is also intended to make contributions toward promoting human health in general by utilising the knowledge gained in this joint research for the development of probiotics research on the ground.”
As part of the project, saliva, solid waste and other samples will be taken from crew members before, during and after their stays aboard the ISS.
The collected samples will be analysed for signs of any changes in their intestinal floras and immune systems.