November 3, 2025, 10:06 am | Read time: 4 minutes
How much do body and mind decline with age? It apparently depends not only on genes or lifestyle but also on the trillions of microorganisms in the gut. A review shows how closely the gut microbiome is linked to processes such as muscle weakness, memory decline, and chronic inflammation. It also highlights the role of diet and exercise. Another study suggests that even a few minutes of exercise per day could have noticeable effects on fitness and health.
Gut Microbiome Determines How Healthily We Age
What was studied? A review published in the Journal of Biomedical Science summarizes current research on how the gut microbiome influences the aging process.1
The study examined the development of gut flora throughout all life stages and its role in age-related changes such as muscle weakness and memory decline. A central theme is chronic, low-grade inflammation in aging (“inflammaging”) and the weakened gut barrier that further drives this. These two processes reinforce each other, accelerating overall health decline. The goal is not just a longer life but a healthier and more self-determined one in old age.
Results: People who live long and healthy lives show more health-promoting bacteria like Akkermansia, fewer disease-promoting species, and an overall higher microbial diversity. Animal studies also show that transferring young gut flora extends the life of older animals. A diet rich in fiber, Mediterranean food, certain bacterial products (pro-, pre-, postbiotics), and regular low- to moderate-intensity exercise have positive effects.
Extremely high-intensity physical exertion, on the other hand, can temporarily impair the gut barrier. While the effect is usually temporary and generally benign, it may not be the best primary strategy.
Probiotics often have limited effects in older age because the gut microbiome is less adaptable. It’s important that the body continues to produce enough of these protective substances, even if the composition of the bacteria that produce them changes significantly. Calorie reduction can have life-extending effects, but should be used cautiously in older age due to potential muscle loss.
Significance: The gut microbiome is a modifiable factor for healthy aging. A plant-rich diet, moderate exercise, and targeted bacterial products can help reduce inflammation, delay muscle weakness, and maintain mental fitness. Since probiotics are less stable in older adults, postbiotics—the beneficial metabolic products of dead bacteria—could offer a safer and more targeted treatment strategy in the future. Additionally, new approaches like “phages,” viruses that specifically target harmful gut germs, could enable individualized treatments.
“Exercise Snacks” Significantly Improve Cardiorespiratory Fitness
What was studied? A review published in the British Journal of Sports Medicine evaluated 11 high-quality studies with a total of 414 participants.2
The researchers wanted to know if very short workouts of up to five minutes—so-called “exercise snacks”—at least twice a day on three days a week over four to 12 weeks affect physical fitness and health. The study focused on inactive adults and older people over 65.
Results: The short exercise sessions significantly improved cardiorespiratory fitness in adults, enhancing heart and lung performance. Older adults also showed a slight increase in muscle endurance. However, no noticeable changes were found in muscle strength, body fat percentage, blood pressure, or blood lipids. Participants adhered well to the programs, with 91 percent completing the exercises as planned and 82 percent remaining active throughout the study period.
Significance: Two or more short exercise sessions per day can effectively increase endurance. This is the case even if the total training time is only a few minutes. Notably, the weekly total volume of these short sessions often falls well below official exercise recommendations but still has an impact. Even moderate increases in cardiorespiratory fitness are associated with a significant reduction in mortality risk. These short activity breaks can be easily integrated into daily life. Because they are so flexible, participants stick to these programs better and longer than traditional training. Despite the positive results, the safety of the data was rated differently. The evidence for improved cardiorespiratory fitness is considered moderately secure. At the same time, the indications of better muscle endurance in older adults have very low certainty.