Over the past decade or so, there’s been a significant increase in our understanding of the importance of the gut microbiome, the complex ecosystem of beneficial bacteria, fungi, and protists that inhabit the gastrointestinal tract. While we don’t typically like to think about bacteria inhabiting our bodies, the body is actually comprised of slightly more bacterial cells than human cells. It’s true; the average human body contains about 38 trillion bacterial cells compared to 30 trillion human cells. However, because bacteria are so much smaller than the majority of your body cells, even though you have even more of them than you do human cells, the bacterial cells amass to only about 0.2 kg (0.44 pounds) of the total weight of a 154-pound person.
Before you start worrying that your bacterial residents are bad for you and potentially making you sick, read this: the vast majority of the microbes (bacteria, fungi, and protists) are actually the unsung heroes of your body—these “good” bacteria together comprise the gut, oral, skin, and vaginal microbiomes and perform a variety of vital physiological functions to keep you healthy. For example, the good bacteria and fungi in the gut help digest and absorb nutrients in the food we eat, maintain the integrity of the intestinal barrier, produce vitamins, reduce inflammation in the body, fend off pathogenic microorganisms, and signal the immune system to produce more white blood cells.
Therefore, keeping your gut microflora healthy and robust is important for proper digestion, immune support, inflammation control, and overall wellness. But how do you do this? Probiotics get most of the attention and credit for being the go-to salve for the gut, but prebiotics are just as important. If you’ve never heard of prebiotics, don’t worry: you aren’t alone, and you’re probably already getting some in your diet. However, if you want to feel better on your runs and promote your digestive regularity and fortify your immune system, keep reading to learn everything you need to know about prebiotics for gut health.
What are Prebiotics?
Prebiotics are compounds comprised of oligosaccharides, inulin, lactulose, and glycan, which are dietary fibers (carbohydrates) that are indigestible for humans but are the preferred source of fuel and nutrients for our good bacteria in the gut. In fact, prebiotics selectively feed the beneficial bacteria in the gut, rather than any harmful pathogens. If we envision the gut microbiome as a garden, the healthy bacteria are the plants and prebiotics are the fertilizer, offering the helpful bacterial plants a nutritive elixir to support their growth. In contrast, using the same analogy, probiotics are seeds or seedlings for more plants. In this way, the prebiotics feed or fuel probiotics and the other beneficial microorganisms already inhabiting our gut.
What are the Benefits of Prebiotics?
As mentioned, prebiotics are nutritious fuel for the beneficial bacteria in our gut, and accordingly, they have been shown to help support healthy bacterial colonization of the microbiome. Additionally, since prebiotics are a type of fiber, they inherently carry the benefits of dietary fiber such as adding bulk to the stool, aiding bowel regularity, lowering blood sugar, promoting fullness, and reducing circulating triglycerides. Because the gut microbiome plays an integral role in supporting the immune system and keeping systemic inflammation in check, supplementation with prebiotics has been found to improve allergies, reduce weight, and lower the risk of obesity and metabolic syndrome.
What Foods Contain Prebiotics?
Prebiotics are found as fermented fiber in many fruits and vegetables, as well as some seeds and grains. The following foods are rich in natural prebiotics:
- Jerusalem Artichokes (also known as sunchokes)
- Raw Dandelion Greens
- Wheat Bran
- Chicory Root
For a runner-friendly, prebiotic-rich breakfast, consider steel cut or overnight rolled oats or barley with sliced apples, bananas, cinnamon, and flaxseeds.
Are there Prebiotic Supplements?
As is often the case, the increased consumer demand for prebiotics have driven companies to develop commercially-available prebiotics in supplement form. The key is to look for a supplement that uses high-quality ingredients that contain functional prebiotic fibers. For example, MegaPre from MicroBiome Labs contains the oligosaccharides that beneficial, keystone species in your gut microbiome like Akkermansia muciniphila, Faecalibacterium prausnitzii, and Bifidobacteria feed off of. These species have been shown to contribute to a healthy metabolism, body composition, and intestinal barrier function. MegaPre is specifically engineered to selectively feed the keystone species in the gut, and reinforce the positive microbial diversity encouraged by quality probiotic supplements. Its ingredients are sourced from potent, natural oligosaccharides like non-GMO green and gold kiwi and non-GMO corn cob.
Can I Consume Prebiotics and Probiotics Together?
Absolutely! Consuming prebiotics and probiotics in the same meal is perfectly safe, and may actually increase the effectiveness of the probiotics. Foods that contain natural probiotics include yogurt, kefir, sauerkraut, kimchi, miso, tempeh, natto, kombucha, sourdough bread, and some cheeses. Many supplements combine both together as well.
What Is the Recommended Daily Intake?
As runners, we want to do what’s best for our bodies, and this includes following nutritional recommendations. Naturally, this leads us to the question of how much or how many grams of probiotic fibers we should consume each day. When considering general dietary fiber, the recommendations are to consume between 25-38 grams per day as a minimum, though health benefits often increase beyond this range. For prebiotic fiber specifically, research shows that 5-20 grams per day stimulates the growth of Bifidobacteria and Lactobacilli in the gut.
Keep in mind that not all of the fiber contained in prebiotic-rich foods are actually oligosaccharides, inulin, or other prebiotic fibers, so if you are aiming to get your daily intake from food alone, you will want to eat more than simply 5 grams of dietary fiber from those foods.
What are the Drawbacks?
Prebiotics are generally considered safe for adults and children. With that said, because prebiotics are indigestible fibers, an excessive intake can cause gas, bloating, and loose stool. To minimize the risk of gastrointestinal distress, gradually increase your daily intake as tolerated. If you suffer from irritable bowel syndrome (IBS), or frequently deal with runner’s trots, you might find that you have to limit your intake of prebiotics and other dietary fibers.
Will Prebiotics Help Me Run Better?
Consuming prebiotics probably won’t directly make you a faster runner, but they certainly contribute to overall health, which can indirectly improve your fitness. For example, because they play a key role in inhibiting inflammatory pathways in the body, prebiotics can support your body’s recovery from training. They support the immune system because your beneficial bacteria help prevent the colonization of pathogenic microorganisms and signal the body to upregulate the production of white blood cells. A robust immune system will help your body fend off colds and viruses that might sideline your training and derail consistency. Lastly, because the gut microbiome plays a key role in the digestion and absorption of nutrients, the production of vitamins and metabolites, and the maintenance of an active metabolism, prebiotics can help your body function optimally and perform like the athlete you are meant to be.