We all know the typical astronaut accessories—the EVA suit, the oxygen tanks, the radio assembly. But there's an invisible part of each space mission that's often overlooked: the trillions of microorganisms that hitch a ride.
Observing responses of pathogens in space could help scientists figure out how to outsmart them when they cause trouble on Earth.
Dr. Sarah Wallace is a NASA microbiologist who aims to keep microbes from causing problems for U.S. astronauts aboard the International Space Station. According to Wallace, research on microorganisms in space has more than cosmic importance. It can also reveal things about our health here on Earth:
1) Avoiding disease isn't all about maintaining a sterile environment.
NASA has a great track record of keeping the crew healthy on space missions. But surprisingly, it's not from having kept the space flight environment as sterile as possible.
Wallace says, "We [monitor] the environment but unless we find something that's medically significant, or [in] super high numbers, we're not going to do anything."
Not only is it impossible for astronauts to live in completely sterile quarters—crew members, after all, are microbe-shedding machines—but it may not even be desirable, given what we now know about the human microbiome. Scientists have found that the entire community of microorganisms (bacteria, archaea, fungi, and viruses) living in and on us likely have an active role in keeping us healthy. This means that down on the ground we need to let go of the germophobe idea that eradicating all microbes is always better for our health.
2) Disease-causing microbes change their behavior under different conditions.
Remember the recent E. coli O157:H7 outbreak linked to romaine lettuce? We're still grappling with a lot of pathogen problems here on Earth. One reason is that scientists are still learning which strategies these disease-causing microorganisms are capable of employing under different conditions.
Space missions are associated with a major shift in gut microbiome composition—as shown in NASA's twin study.
Wallace says experiments with Salmonella Typhimurium showed that the pathogen became more virulent in space. Yet curiously, the opposite seemed to happen to Staphylococcus aureus under space-flight-like conditions—it became more benign.
"The way these organisms have evolved, certain triggers [in the space flight environment] might be dictating how they're responding," Wallace says.
Observing these responses could help scientists figure out how to outsmart the pathogen when it causes trouble on Earth. "It's giving us some great insights into how we could target them differently in the future," she explains.
3) Major shifts in the gut microbiome could affect health in specific ways.
Scientists still have a lot to learn about which changes in an adult's gut microbiome actually cause a change in health status. In fact, microbiome-focused therapeutics companies are in hot pursuit of these connections.
Space missions are associated with a major shift in gut microbiome composition—as shown in NASA's twin study, which followed astronaut Scott Kelly during a year aboard the ISS while his identical twin brother Mark (a retired astronaut) stayed on the ground. Scott experienced simultaneous changes in telomere length and bone formation; were these related to the gut microbial differences?
Wallace says a soon-to-be-published study of nine additional astronauts could help answer this question. The research may reveal how closely gut microbiome shifts track health outcomes, and the reversibility of the changes.
She emphasizes the science from her lab isn't meant to help only the small minority of humans who will ever go to space: "That's always our goal—that our research is helping people on Earth."
At age 52, Glen Rouse suffered from arm weakness and a lot of muscle twitches. “I first thought something was wrong when I could not throw a 50-pound bag of dog food over the tailgate of my truck—something I use to do effortlessly,” said the 54-year-old resident of Anderson, California, about three hours north of San Francisco.
In August, Rouse retired as a forester for a private timber company, a job he had held for 31 years. The impetus: amyotrophic lateral sclerosis, or ALS, a progressive neuromuscular disease that is commonly known as Lou Gehrig’s disease, named after the New York Yankees’ first baseman who succumbed to it less than a month shy of his 40th birthday in 1941. ALS eventually robs an individual of the ability to talk, walk, chew, swallow and breathe.
Rouse is now dependent on ventilation through a nasal mask and uses a powerchair to get around. “I can no longer walk or use my arms very well,” he said. “I can still move my wrists and fingers. I can also transfer from my chair to the toilet if I have two of my friends help me.”
It’s “shocking” that modern medicine has very little to offer to people with this devastating condition, Rouse said. But there is hope on the horizon. Yesterday, the U.S. Food and Drug Administration approved Relyvrio, a drug made up of two parts, sodium phenylbutyrate and taurursodiol, to treat patients with ALS.
“This approval provides another important treatment option for ALS, a life-threatening disease that currently has no cure,” said Billy Dunn, director of the Office of Neuroscience in the FDA’s Center for Drug Evaluation and Research, in a statement. “The FDA remains committed to facilitating the development of additional ALS treatments.”
Until this point, the FDA had approved only two other medications—Riluzole (rilutek) in 1995 and Radicava (edaravone) in 2017—to extend life in patients with ALS, which typically kills within two to five years after diagnosis. That’s why earlier this week, Rouse was optimistic about the FDA’s likely approval of a controversial new drug for ALS.
When Relyvrio is taken in addition to Riluzole, it appears to slow functional decline by an additional 25 percent and extend life by another 6 to 10 months, said Richard Bedlak, director of the Duke ALS Clinic. “It is not a cure, but it is definitely a step forward.”
“The whole ALS community is extremely excited about it,” he said the day before Relyvrio’s expected approval. “We are very hopeful. We’re on pins and needles.”
A study of 137 ALS patients did not result in “substantial evidence” that Relyvrio was effective, the agency’s Peripheral and Central Nervous System Drugs Advisory Committee concluded in March. However, after some persuasion from FDA officials, patients and their families, the committee met again and decided to recommend approving the drug.
In January 2019, following an ALS diagnosis in October the previous year, Jeff Sarnacki, of Chester, Maryland, was accepted into a trial for Relyvrio. “Because of the trial, we did experience hope and a greater sense of help than had we not had that opportunity,” said Juliet Taylor, his wife and caregiver. They both believed the drug “worked for him in giving him more time.”
In June 2019, Sarnacki chose an open-label extension, offered to patients by drug researchers after a study ends, and took the active drug until he died peacefully at home under hospice care in May 2020, five days after his 60th birthday. A retired agent with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives who later worked as a security consultant, Sarnacki lived about 19 months after diagnosis, which is shorter than the typical prognosis.
His symptoms had begun with leg cramps and foot drop in late fall 2017. At the end of life, he could only move a few fingers on his left hand and could not speak or eat by mouth; a feeding tube became necessary, Taylor said. He also took Radicava and Riluzole, the two previously approved drugs, for his ALS. “We were both incredulous that, so many years after Lou Gehrig’s own diagnosis, there were so few treatments available,” she said.
The dearth of successful treatments for ALS is “certainly not for lack of trying,” said Karen Raley Steffens, a registered nurse and ALS support services coordinator at the Les Turner ALS Foundation in Skokie, Ill. “There are thousands of researchers and scientists all over the world working tirelessly to try to develop treatments for ALS.”
Unfortunately, she adds, research takes time and exorbitant amounts of funding, while bureaucratic challenges persist. The rare disease also manifests and progresses in many different ways, so many treatments are needed.
As of 2017, the Centers for Disease Control and Prevention estimated that more than 31,000 people in the U.S. live with ALS, and an average of 5,000 people are newly diagnosed every year.
Most cases of ALS are sporadic, meaning that doctors don’t know the cause. There is about a one-year interval between symptom onset and an ALS diagnosis for most patients, so many motor neurons are lost by the time individuals can enroll in a clinical trial, said Richard Bedlack, professor of neurology and director of the Duke ALS Clinic in Durham, North Carolina.
Bedlack found the new drug, Relyvrio, to be “very promising,” which is why he testified to the FDA in favor of approval. (He’s a consultant and disease state speaker for multiple companies including Amylyx, manufacturer of Relyvrio.)
The “drug has different mechanisms of action than the currently approved treatments,” said Bedlack, who is also chief of neurology at the Durham Veterans Affairs Medical Center. He adds that, when Relyvrio is taken in addition to Riluzole, it appears to slow functional decline by an additional 25 percent and extend life by another 6 to 10 months. “It is not a cure, but it is definitely a step forward.”
T. Scott Diesing, a neurohospitalist and director of general neurology at the University of Nebraska Medical Center in Omaha, said he hopes the drug is “as good as people anticipated it should be, because there are not too many options for these patients.”
So far, Rouse's voice is holding up, but he knows the day will come when ALS will steal that and much more from him.
ALS is 100 percent fatal, with some patients dying as soon as a year after diagnosis. A few have lasted as long as 15 years, but those are the exceptions, Diesing said.
“If this drug can provide even months of additional life, or would maintain quality of life, that’s a big deal,” he notes, adding that “the patients are saying, ‘I know it’s not proven conclusively, but what do we have to lose?’ So, they would like to try it while additional studies are ongoing.” The drug has already been approved in Canada.
As his disease progresses, Rouse hopes to get a speech-to-text voice-generating computer that he can control with his eyes. So far, his voice is holding up, but he knows the day will come when ALS will steal that and much more from him. He works at I AM ALS, a patient-led community, and six of his friends have already died of the disease.
“Every time I lose a friend to ALS, I grieve and am sad but I resolve myself to keep working harder for them, myself and others,” Rouse said. “People living with ALS find great purpose in life advocating and trying to make a difference.”
The Friday Five covers important stories in health and science research that you may have missed - usually over the previous week, but today's episode is a lookback on important studies over the month of September.
Most recently, on September 27, pharmaceuticals Biogen and Eisai announced that a clinical trial showed their drug, lecanemab, can slow the rate of Alzheimer's disease. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend and the new month.
This Friday Five episode covers the following studies published and announced over the past month:
- A new drug is shown to slow the rate of Alzheimer's disease
- The need for speed if you want to reduce your risk of dementia
- How to refreeze the north and south poles
- Ancient wisdom about Neti pots could pay off for Covid
- Two women, one man and a baby