As space missions become longer and ambitions for deep-space travel grow, scientists are working to understand how life beyond Earth may affect every system in the human body.
Two years after her initial study took flight, Begum Mathyk, MD, and collaborators are continuing to push the frontier of women's health in space, this time by examining how altered gravity may affect female biology.
Begum Mathyk, MD (Photo by Ryan Rossy)
In a first-of-its-kind study, a team led by Mathyk, a physician-scientist in the USF Health Morsani College of Medicine Department of Obstetrics and Gynecology, set out to understand the impact of space travel on the vaginal microbiome.
Published in Frontiers in Microbiology, the study demonstrated that parabolic flight can induce acute physiological stress and alter host microbiome interactions. Their work provides the first evidence that altered gravity and spaceflight-related stress can significantly affect the vaginal microbiome in women, while having minimal effect on the oral microbiome.
"This study gives us an early indication that female biological systems respond differently to the unique conditions associated with space travel," Mathyk said.
The vaginal microbiome plays an important role in women's health, helping support immune function and maintain healthy tissue. Disruption to its microbial balance brought on by extreme physiological or psychological stress has been linked to inflammation, the increased potential for infection and altered immune responses. In conditions such as endometriosis, microbial dysbiosis is associated with chronic inflammation, altered immune responses and disease progression.
"Over the past few decades, the clinical relevance of the vaginal microbiome has extended beyond its traditional associations with bacterial vaginosis or vulvovaginal candidiasis," Mathyk said. "It has also emerged as a non-invasive biomarker for gynecological disease detection, cancer, pregnancy and health monitoring."
Despite its importance, changes to the vaginal microbiome have not yet been explored in space travel conditions, until now.
In the new study, four women of reproductive age participated in parabolic flights aboard a modified aircraft that simulates the periods of microgravity and hypergravity experienced similar to space travel. Mathyk and her colleagues found that parabolic flight caused greater site-specific changes in the vaginal microbiome than in the oral microbiome.
Participants also showed signs of increased physiological stress after spaceflight, including heightened cortisol levels, due to changes in their microbiomes. The findings point to the need for further research to determine the potential scope of those changes.
"These findings highlight the sensitivity of the vaginal microbial ecosystem to spaceflight stressors," Mathyk said. "They underscore the need for longitudinal and mechanistic studies to determine the persistence, clinical significance and potential health implications of these changes during longer-duration space missions."
Also contributing to the study were USF Health researchers Shalini Jain, Hariom Yadav, Rohit Shukla, Vivek Kumar, Sidharth Mishra and Anthony Imudia, as well as partners from the National Research Council Canada and the International Institute of Astronautical Sciences.
"Understanding how the microbiome responds to the unique physiological stressors associated with spaceflight is an important step toward understanding and protecting astronaut health, particularly women's health," said Jain. "Our study demonstrates that parabolic flight can induce site-specific changes in the microbiome of women, highlighting that different body sites may respond differently to the physical and physiological demands of spaceflight."
The findings, she adds, provide an important foundation for understanding how the microbiome may contribute to human adaptation to spaceflight and may ultimately help inform strategies to support astronaut health during future space missions.
"This work also highlights the value of collaborative, interdisciplinary research in advancing our understanding of the human microbiome in space," Jain said.
The study builds on Mathyk's previous work examining women's health in space, including the first gynecologic ultrasound studies in microgravity. Her research also includes an NIH-funded project using advanced tissue chips to better understand how the space environment affects female reproductive physiology and studies investigating how spaceflight may influence future fertility. She also collaborates with USF Health Voice Center researchers, Yael Bensoussan and Jamie Toghranegar to evaluate voice biomarkers for applications in space medicine.
Such work is becoming increasingly pertinent as space missions grow longer and the possibility of lunar habitation and deep-space travel moves closer to reality. In addition, astronaut corps include a growing proportion of women, and medical research has traditionally skewed toward males, leaving knowledge gaps in women's health and sex-specific responses to spaceflight.
"It's important to understand whatever we are exposed to as human beings," she said. "Is it just a physiological adaptation, or is there a point when it will cause a problem for us or turn into a disease? Is it something that can be reversed later on? The whole space community is trying to understand this."
As an OBGYN, she wonders what would happen if she has a patient one day who asks if there are any precautions she should take for space travel.
"Maybe they'll be staying there for a month or years, maybe going on a honeymoon, whatever the case might one day be," she said. "NASA is already talking about establishing a Moon base and future Mars missions. That raises so many health care questions for me and, of course, research and validation take time, so we need to begin building the evidence
