Gut health in space: Personalized prebiotic and probiotic cocktails

10 Sep 2020 --- Nutrition countermeasures based on prebiotics and probiotics hold great promise to protect space travelers, according to a new review. The researchers note that there are many parallels between the health issues of returning astronauts and older people, with these fields potentially helping to inform each other.

Some of these topics include sarcopenia, weakening of the immune system, sleep disturbances and cognitive changes, Silvia Turroni, a professor at the University of Bologna, Italy, tells NutritionInsight.

Turroni led the review along with Martina Heer, a professor at the University of Bonn, Germany. 

“Improving the gut microbiota health of astronauts with personalized pre- and probiotic cocktails could have an important translational implication in the field of the physiology of aging,” points out Turroni. 

The researchers have more studies planned, and ultimately aim to develop a diet enriched in prebiotics or probiotics as a targeted counter-measure for space travelers on long-term exploration missions. 

This is hoped to improve gut microbiome health and body health outcomes related to metabolism and other physiological systems.

“The well-being of the gut microbiome of space travelers should be among the primary goals of long-duration exploratory missions. To ensure the success of the mission, we must not overlook the myriad of microorganisms that reside in our gastrointestinal tract and make sure they are in balance,” says Heer.

The impacts of space
The review, published in Frontiers in Physiology, sheds light on a variety of negative effects that space can have on humans, including on metabolism, bone and muscle health, immunity and mental health. 

Stability will be a major R&D challenge to overcome for extraterrestrial pre- and probiotics.Many studies examined in the review also point to the disruption of the gut microbiome. One study found that space travelers’ microbiomes on the same mission became more similar to each other during the journey. There was also an increase in bacteria associated with intestinal inflammation and a decrease in those with anti-inflammatory properties.

Solutions as simple as nutritionally balanced meals with lots of fiber to kickstart microbial metabolism in the gut could help mitigate some of these problems. 

Other options could be more targeted, including microbial supplements, such as bacteria that secrete immune-boosting substances, or those that synthesize vitamins required for bone growth.

However, Turroni acknowledges that there is still a great deal of work to be done before these microbiota manipulation tools can actually enter the clinical practice of space flights.

“Even the studies on Earth are not conclusive. However, they bring attention to many precision aspects that should be carefully considered in the choice of pre- or probiotics to maximize their effectiveness. 

“There are also added concerns about their stability – and survival for probiotics – under microgravity conditions, but the first test has provided encouraging data,” she explains. 

Industry’s role
While space travelers may well benefit from a number of existing products, they also have unique needs. This type of travel demands great stability to stay safe and effective in extreme conditions, notes Turroni.

As far as she is aware, industry has not yet explored gut health products in relation to exploration missions. “However, these topics are very hot, and new products have just come out or are about to do so for other terrestrial issues.”

Earlier this year, a study revealed that astronauts excrete less sodium in space than on land, which could have major implications for the heart health of future space travelers. 

Meanwhile, red romaine lettuce was successfully cultivated onboard the International Space Station and was found to be at least as nutritious as Earth-grown plants.

By Katherine Durrell