Researchers tested whether two supplements together could help elderly people with weak muscles. They studied 78 older adults for one month, giving some a muscle-building supplement called HMB, others HMB plus a prebiotic (food for good gut bacteria), and a third group just regular food. The results showed that HMB alone helped build muscle strength, but when combined with prebiotics, it also improved gut health and reduced inflammation in the body. This suggests that treating both muscles and gut together might be a better approach for older adults losing muscle mass.

The Quick Take

  • What they studied: Whether combining a muscle-building supplement (HMB) with a prebiotic (food that feeds good gut bacteria) could help older adults regain muscle strength and improve their gut health
  • Who participated: 78 elderly patients (average age not specified) who had sarcopenia, which means they had lost significant muscle mass. They came from two hospitals in China and were divided into three groups randomly
  • Key finding: Both groups taking HMB showed improved muscle strength and muscle mass. The group taking HMB plus prebiotics had additional benefits: their gut barrier improved, and they had less inflammation in their bodies compared to the other groups
  • What it means for you: If you’re an older adult concerned about muscle loss, this research suggests that combining these two supplements might help more than taking just one. However, this is early research, and you should talk to your doctor before starting any new supplements

The Research Details

This was a randomized controlled trial, which is considered one of the strongest types of scientific studies. Researchers recruited 78 elderly patients with sarcopenia (age-related muscle loss) from two hospitals in China between January 2023 and January 2025. They randomly divided participants into three groups: Group A received a standard diet plus HMB supplement (32 people), Group B received a standard diet plus HMB and fructooligosaccharides, which is a prebiotic (31 people), and Group C received only a standard diet as a control group (15 people). All groups were followed for 30 days.

The researchers measured several things before and after the study period: muscle strength (using grip strength tests and measuring calf size), muscle mass (using a special index), gut barrier health (by measuring specific markers in the blood), and inflammation levels (using blood tests). They also checked nutritional status by measuring protein levels in the blood.

This research design is important because randomly assigning people to different groups helps prove that any differences in results are actually caused by the supplements, not by other factors. The 30-day timeframe is long enough to see meaningful changes but short enough to complete the study. Measuring both muscle and gut health together is valuable because these two systems are connected—a healthy gut helps the body absorb nutrients needed for muscle growth.

This study has several strengths: it’s a randomized controlled trial with a control group, it measured multiple related outcomes, and it was conducted at established medical institutions. However, there are some limitations to consider: the study is relatively short (only 30 days), the sample size is modest (78 people total), and the control group was smaller than the treatment groups. The study was published in a peer-reviewed journal, which means other experts reviewed it before publication.

What the Results Show

After 30 days, both groups receiving HMB (Groups A and B) showed significant improvements in skeletal muscle mass index and grip strength compared to the control group. This means their muscles got stronger and larger. The improvements were statistically significant, meaning they were unlikely to have happened by chance.

The group receiving HMB plus prebiotics (Group B) showed additional benefits beyond muscle improvement. Their intestinal barrier markers improved significantly, meaning their gut lining became healthier and better at protecting the body. This group also showed reduced inflammation markers in their blood, including lower CRP levels and a better neutrophil-to-lymphocyte ratio.

The control group, which only received a standard diet, did not show meaningful improvements in any of these measures. This confirms that the supplements, not just eating better, were responsible for the improvements seen in the treatment groups.

All groups had similar starting measurements before the study began, which confirms the random assignment worked properly.

Beyond the main findings, the HMB plus prebiotic group showed improvements in nutritional markers like albumin and prealbumin levels, which indicate better protein status in the body. The group also showed lower endotoxin levels, suggesting reduced harmful bacterial products in the bloodstream. These secondary findings support the idea that the combination treatment works through multiple pathways—building muscle directly while also improving gut health, which then helps the body absorb nutrients better.

Previous research has shown that HMB alone can help older adults maintain and build muscle. This study confirms those findings but goes further by showing that adding a prebiotic creates additional benefits for gut health. The idea of treating both the muscle and gut systems together is relatively new and represents an evolution in how doctors think about age-related muscle loss. Most previous studies focused on muscle alone, so this research adds an important new dimension.

The study lasted only 30 days, which is relatively short. We don’t know if the benefits continue after the study ends or if they fade over time. The sample size of 78 people is modest, and the control group was smaller (15 people) than the treatment groups, which could affect the reliability of comparisons. The study was conducted in China, so results might differ in other populations. The study doesn’t tell us the optimal doses of these supplements or whether they work better for certain types of older adults. Additionally, we don’t know about potential side effects or long-term safety.

The Bottom Line

Based on this preliminary research, the combination of HMB and prebiotics appears promising for older adults with age-related muscle loss (moderate confidence level). However, this is early-stage research, and more studies are needed. If you’re interested in trying this approach, discuss it with your doctor first, as individual needs vary. The evidence is stronger for HMB alone in improving muscle strength, while the prebiotic addition appears to offer extra gut health benefits (moderate confidence level).

This research is most relevant for older adults experiencing age-related muscle loss (sarcopenia), particularly those who want to explore nutritional approaches. It may be especially interesting for people with both muscle weakness and digestive concerns. However, people with certain medical conditions, those taking specific medications, or those with allergies to these supplements should consult their healthcare provider. This research is not yet strong enough to recommend for younger adults or those without muscle loss concerns.

Based on this 30-day study, you might expect to see improvements in muscle strength within 2-4 weeks if the supplements work for you. However, individual results vary significantly. Some people may see benefits sooner, while others may take longer. It’s important to give any new supplement at least 4-6 weeks before deciding if it’s working for you, and to maintain consistent exercise and good nutrition alongside supplementation.

Want to Apply This Research?

  • Track grip strength weekly using a hand dynamometer (available at pharmacies or gyms) and measure calf circumference monthly. Also log energy levels and muscle soreness daily to monitor overall progress and tolerance to supplements.
  • Start a simple resistance exercise routine 3-4 times per week (like chair squats or light weights) combined with taking HMB and prebiotic supplements at the same time each day. Log your supplement adherence and exercise sessions in the app to maintain consistency.
  • Create a monthly dashboard showing grip strength trends, calf circumference changes, and supplement compliance. Set reminders for weekly measurements and monthly check-ins with your healthcare provider to discuss progress and any side effects.

This research is preliminary and represents early-stage findings from a single 30-day study. These results should not replace professional medical advice. Before starting HMB, prebiotics, or any new supplement, consult with your healthcare provider, especially if you have existing medical conditions, take medications, or have allergies. This study was conducted in a specific population in China, and results may not apply to all individuals. The long-term safety and effectiveness of this combination have not been established. Always inform your doctor about any supplements you’re considering or taking.