Testing performed at the Mars Society’s Mars Desert Research Station (MDRS) in the Utah desert revealed that Bulgarian yogurt could be easily prepared by analog astronauts participating in a two-week “mission” in a closed, Mars-like environment.
The yogurt, which is prepared using Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus, was also shown to have a positive effect on the astronauts’ overall well-being and gut health, according to the findings published in the Journal of Ethnic Foods.
“Highlighting [Bulgarian yogurt’s] ease of preparation in space conditions is a notable achievement, as providing varied and fresh food for astronauts has been a persistent challenge,” wrote scientists from the MDRS, Curtin University (Australia), Ritsumeikan University (Japan) and the Bulgarian Academy of Science. “Its adaptability as a space food option, coupled with its positive impact on astronauts’ overall health and well-being, emphasizes the need for further exploration and integration of this ancient dietary practice into modern space nutrition strategies.
“Based on these findings, we strongly recommend that homemade yogurt be included as a standard menu item for space crews. The benefits of yogurt consumption during space missions go beyond nutrition; it also contributes to crew morale and well-being, making it a valuable addition to future interplanetary expeditions.”
The challenges of extended space travel
Moving humanity beyond our terrestrial home has captured the imagination of scientists and science-fiction writers for decades. NASA, the US National Aeronautics and Space Administration, has stated that crewed missions to the Red Planet should be within reach by the 2030s.
Such missions are not without significant technological challenges, and while much mainstream attention will focus on rocket design and propulsion, supporting the health and wellness of the astronauts via the diet poses massive challenges. According to a 2011 review in the Journal of Food Science, a mission to Mars would require two sets of food: One would be pre-packaged foods, similar to those currently used on the International Space Station (ISS), which can be consumed in transit.
The second set of food would be a store of food located on Mars for the crew to eat on arrival. In this case, food in the Martian larder could be between three and five years old by the time an astronaut consumes the provisions. A third option is to find ways to grow produce or make their own food during the mission.
As noted by the researchers in the new MDRS study, Bulgarian yogurt offers an “effective and practical approach to maintaining a diverse and healthy gut microbiome”, linked to its long shelf life and probiotic properties.
Maintenance of a healthy gut microbiome during space travel—just like on earth—is critical for health. A 2019 paper in Scientific Reports led by scientists from the J. Craig Venter Institute reported that an astronaut’s microbiome is altered during space travel, with data indicating that the gastrointestinal microbiomes of astronauts aboard the International Space Station tended to be become similar across the crew. While there was some data to suggest a neutral or even beneficial shift in the microbiome during extended space missions, there were also some increases in genera associated with chronic intestinal inflammation (for example, Parasutterella).
A 2022 review in Life, led by scientists affiliated with the NASA Jet Propulsion Laboratory in Pasadena, CA, noted that the microbiome is linked to a number of health conditions, including immunity, bone health and cognitive function, and detrimental shifts in the microbiome during long-duration space travel could manifest in detrimental health outcomes for astronauts as missions extend from months into years.
Fresh Yogurt en route to Mars: Easy preparation, no training required!
“By prioritizing their gut health, astronauts will be better equipped to perform at their best and remain healthy throughout their mission on Mars,” stated the Journal of Ethnic Foods paper.
The researchers said that astronauts can feasibly prepare Bulgarian yogurt from powdered milk (freeze-dried) by adding small amounts of the starter cultures.
“The process requires minimal time and effort, and reliable temperature control is easily achievable through thermal insulation in a small container or by utilizing an existing heat-emitting device,” they wrote. “Any crew member can make it by following simple steps; no training is required.”
Source: Journal of Ethnic Foods
2023, 10, Article Number 46, doi: 10.1186/s42779-023-00211-5
“Can Bulgarian Yogurt enhance astronauts’ performance during the Mars Missions?”
Authors: I. Shopova, et al.
