Inside your gut is a living microbiome teaming with bacteria, around 100 trillion to be exact. Scientists are busy exploring the impact these gut-friendly probiotic bacteria have on your health. So far, it looks like they play a role in digestive and immune health, but there’s growing evidence that these diverse intestinal critters may also influence metabolic health and even how much you weigh.
But what about the world of fitness and athletics? Don’t be surprised if one-day athletic coaches recommend probiotic foods and supplements to athletes as some studies show probiotics may help athletic performance. Now, a new study points to the possibility that gut bacteria could have an impact on muscle strength as well.
Probiotics for Muscle Building?
In a study carried out at the National Taiwan Sport University, researchers supplemented mice for six weeks with Lactobacillus Plantarum TWK10, a type of probiotic bacteria. By the end of the six-week period, the mice had lost body weight while experiencing a gain in muscle weight. What bodybuilder wouldn’t love that? The supplemented mice also had greater grip strength and enhanced endurance after supplementation as well as fewer markers for muscle damage. That bodes well for muscle recovery after a workout.
Sounds like the ultimate performance enhancer, doesn’t it? The results are encouraging but difficult to apply to human performance due to inherent differences between mice and humans. Mice lead a sheltered life in a laboratory while humans are exposed to a variety of environmental variables that could make the results different in humans than in mice. Still, the idea that certain probiotic bacteria may increase muscle size and improve sports performance is an intriguing one that merits more research.
Gut Bacteria and Body Composition
Based on this study and others, gut bacteria that live in your gut can theoretically impact your body composition in a number of ways. If you do resistance training, the right composition of gut bacteria could give you an edge in terms of building muscle and strength. Plus, the tiny bacteria housed in your intestinal tract alter nutrient absorption, influence appetite hormones and, based on some studies, how easily you store fat.
Gut bacteria, based on preliminary studies, also modify the immune response and help to maintain a healthy balance by providing enough immune activity to fight off pathogens but not so much that it leads to inflammation. That’s important since inflammation plays a role in metabolic health and insulin resistance.
When you have the wrong composition of gut bacteria lining your gut, it creates conditions that can potentially damage your metabolic health and increase the likelihood of developing type 2 diabetes. In animals, the wrong mix of gut bacteria leads to obesity, and when you transfer bacteria from obese mice into healthy, lean ones, they, too, become obese. When a healthy population of gut bacteria is replaced by “bad guy” bacteria, it’s called dysbiosis.
The Birth of Gut Bacteria
So where do gut bacteria come from? Each of us has a unique composition of gut bacteria that we acquire early in life, as we pass through the birth canal. The second encounter with gut bacteria we have is from breast milk during breastfeeding. Babies born by Caesarian section or who aren’t breastfed may have gut bacteria that differ dramatically from breastfed babies born naturally. These initial encounters with bacteria set the stage for health. In fact, probiotics literally mean “for life.”
Although you were populated with gut bacteria at birth, your bacterial microbiome is modified throughout your existence by lifestyle factors, especially dietary changes. Other factors that can change your microbiome for the worse include exposure to toxins in the environments and medications, particularly antibiotics. Drinking chlorinated water can also kill healthy gut bacteria.
What’s disturbing is once gut bacteria are destroyed by antibiotics, it can take months or up to a year to restore a healthy balance. Taking antibiotics for an upper respiratory infection or other viral infection doesn’t heal the infection since such viruses don’t respond to antibiotics and can cause harm by destroying the probiotic gut bacteria your intestinal tract needs.
Improving the Health of Your Gut
While we need more studies to determine what role gut bacteria play in muscle strength and exercise performance, there’s no doubt these tiny critters are important for your health. It’s likely that certain strains of bacteria have benefits for particular conditions and there isn’t a “one size fits all” prescription for probiotics. When you eat more fermented foods, you treat your body to a diversity of probiotic bacteria. Unfortunately, in modern times, people rarely eat fermented foods with the exception of yogurt. You can expand your probiotic horizons by exploring other fermented foods like kefir, fresh (not canned) sauerkraut, kimchi, tempeh, and miso. You can even make your own sauerkraut and other fermented vegetables at home.
Along with eating more fermented foods, make sure you’re supplying the healthy bacteria you have with the “food” they need to survive and thrive. Prebiotics are what does that. Prebiotics are a type of fiber, meaning your body can’t break it down and absorb it, but gut bacteria can. Bacteria in the gut ferment prebiotic fiber and produce short-chain fatty acids that enhance the health of your gut. So, make sure you’re getting enough fiber in your diet to keep healthy gut bacteria well fed.
The Bottom Line
The idea that probiotic bacteria could enhance athletic performance and muscle size is an exciting one – but we need human research to confirm this. Until then, mind your gut bacteria by consuming more fermented foods and prebiotic food items to keep them well fed and help them thrive.
Nutraingredients-USA.com. “Truly Exciting”: Probiotic May Increase Muscle Mass, Energy, and Performance”
Berkeley Wellness. “Probiotics: Pros and Cons”
J Int Soc Sports Nutr. 2015; 12(Suppl 1): P36.
Nutrition & Metabolism201613:14 DOI: 10.1186/s12986-016-0067-0
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