Scientists discovered that a type of helpful bacteria called Bacillus subtilis TO-A might help prevent the muscle weakness that comes with aging. In experiments with tiny worms, older worms that ate this bacteria stayed more active and had stronger muscles than worms that didn’t eat it. The bacteria appeared to protect muscles from damage caused by aging. While this research was done in worms, not humans, it suggests that this bacteria could one day help older people maintain their strength and ability to move around as they age.

The Quick Take

  • What they studied: Whether a specific type of probiotic bacteria could help prevent the loss of strength and movement ability that happens as we age
  • Who participated: The study used tiny worms (C. elegans) as a model to understand aging. Some worms were fed the special bacteria (Bacillus subtilis TO-A) while others were fed regular bacteria, and researchers compared how well they could move as they got older
  • Key finding: Older worms that ate the special bacteria stayed significantly more active and maintained better muscle structure than older worms that ate regular bacteria. The special bacteria appeared to protect muscles from age-related damage
  • What it means for you: This research suggests that probiotics might help prevent age-related muscle weakness in humans, but much more research is needed before we can recommend this for people. This is early-stage research that shows promise but isn’t yet ready for real-world use

The Research Details

Researchers used tiny worms called C. elegans as a model system to study aging and muscle function. These worms are commonly used in science because they age quickly and their biology shares important similarities with humans. The scientists divided the worms into groups: some were fed a special probiotic bacteria called Bacillus subtilis TO-A, while others were fed regular bacteria (E. coli OP50). They then measured how well the worms could move and how their muscles looked under a microscope as the worms aged.

The researchers also tested how well the worms could handle oxidative stress (a type of cellular damage) and examined which genes were turned on or off in the worms’ bodies. They used a special test called the paraquat assay to see how resistant the worms were to stress. Additionally, they studied mutant worms that lacked a specific protective gene to understand which genes were responsible for the bacteria’s benefits.

Using worms as a model helps scientists understand basic aging processes before testing ideas in humans. Worms age in just a few weeks, so researchers can study the entire aging process quickly. The worms’ muscles work similarly to human muscles, making them a reasonable starting point for understanding how probiotics might help prevent age-related muscle loss in people

This study was published in a reputable scientific journal (Communications Biology), which means it went through expert review. However, the research was conducted only in worms, not humans, so the results may not directly apply to people. The study provides good evidence that this bacteria has potential, but human studies would be needed to confirm these benefits work the same way in our bodies

What the Results Show

The main finding was that older worms fed the special bacteria (Bacillus subtilis TO-A) maintained significantly better movement and activity levels compared to older worms fed regular bacteria. When researchers looked at the worms’ muscles under a microscope, they found that the special bacteria helped preserve the structure of muscle fibers (called actin) that normally break down with age.

The worms eating the special bacteria also showed better protection against oxidative stress, which is a type of cellular damage that increases with age. These worms had higher survival rates when exposed to a stressful chemical, suggesting their cells were better protected from age-related damage.

Interestingly, the researchers found that a specific gene called gpx-7 appeared to be crucial for the bacteria’s protective effects. When they studied worms that lacked this gene, even the special bacteria couldn’t prevent muscle weakness, suggesting that this gene is essential for the bacteria’s benefits.

The study found that genes related to oxidative stress showed changing expression levels in worms fed the special bacteria, indicating that the bacteria influenced how the worms’ bodies handled cellular damage. The worms fed the special bacteria also showed improved survival when exposed to paraquat, a chemical that causes oxidative stress in cells. These findings suggest the bacteria works by helping cells better manage and repair damage from aging

Previous research had shown that this same bacteria (Bacillus subtilis TO-A) could extend the lifespan of worms. This new study builds on that finding by showing the bacteria doesn’t just help worms live longer—it also helps them stay active and strong as they age. This is important because living longer isn’t as valuable if you lose the ability to move and function. The findings align with growing evidence that probiotics may have benefits beyond digestion

This research was conducted only in worms, not humans, so we cannot yet say whether these benefits would occur in people. The study didn’t specify exactly how many worms were used in each experiment. The research focused on one specific bacterial strain, so other probiotics might work differently. Additionally, the study was done in laboratory conditions, which may not reflect how the bacteria would work in the complex environment of a living human body with different diet, lifestyle, and genetics

The Bottom Line

Based on this research alone, we cannot recommend that people take this specific bacteria as a supplement. The findings are promising and suggest further research is warranted, but human studies would be needed first. If you’re interested in maintaining muscle strength as you age, current evidence-based recommendations include regular exercise (especially strength training), adequate protein intake, and a balanced diet rich in antioxidants. Consult with your doctor before starting any new supplement

This research is most relevant to scientists studying aging and probiotics, and to people interested in preventing age-related muscle weakness (sarcopenia). Older adults concerned about maintaining strength and mobility should be aware of this research but should not change their habits based on this study alone. People with compromised immune systems should consult their doctor before considering any new probiotic, as this research doesn’t address safety in vulnerable populations

In the worm studies, benefits appeared to develop over the worms’ lifespan (about 13 days in the experiment). If similar effects were found in humans, it would likely take weeks to months of consistent use to see meaningful changes in muscle strength and mobility. However, this timeline is purely speculative based on worm research and cannot be applied to humans without further study

Want to Apply This Research?

  • Track weekly measurements of physical activity level (steps per day or minutes of exercise) and subjective strength assessments (ability to perform daily tasks like climbing stairs or carrying groceries) to monitor changes in mobility and muscle function over time
  • Users interested in maintaining muscle strength as they age could use the app to set reminders for strength training exercises (2-3 times per week), track protein intake at meals (aiming for adequate protein), and log daily physical activity. While this specific bacteria isn’t yet recommended, these evidence-based practices support muscle health
  • Establish a baseline of current activity levels and strength capacity, then track monthly progress in physical function. Users could log exercise type and duration, dietary protein intake, and subjective measures of strength and mobility. This creates a personal health record that can be shared with healthcare providers to discuss age-related changes and prevention strategies

This research was conducted in worms, not humans, and should not be used as a basis for personal health decisions. The specific bacteria studied (Bacillus subtilis TO-A) is not currently available as a consumer product and has not been tested for safety or effectiveness in humans. Before starting any new supplement or making changes to your health routine, especially if you have existing health conditions or take medications, consult with your healthcare provider. This summary is for educational purposes only and does not constitute medical advice.