When it comes to wellness topics, gut health often comes to mind — and it should. We’re learning that a healthy gut is an indicator overall well-being, and research has already shown that it can affect digestive, heart and brain health. Heck, what goes on in our gut community may even impact our weight and workout performances. A surprising amount of our immune system function can also be tied to gut health, also known as our microbiomes.
The human gut microbiota is a complex ecosystem that includes trillions of microorganisms on and in our intestines. And while you’ve probably heard a lot about probiotics when it comes to the microbiome, you might be less familiar with prebiotics and postbiotics — two more keys to achieving optimal gut health.
Here’s what you need to know about the “biotics” family and how to make them work harder for your best interests.
These are living microorganisms (mainly bacteria and yeasts) found in certain foods and beverages that can take up residence in your digestive tract. It may sound creepy when you think of it that way, but as you’ve probably learned in a yogurt commercial or two, probiotics have various health benefits. They’re known for improving nutrient absorption and immune functioning, and one recent study found evidence that a greater microbiome diversity was associated with higher levels of active vitamin D — a nutrient many people are deficient in.
In general, probiotics including Lactobacillus and Bifidobacterium help maintain a healthy population of microbiota (or flora) living in the gut, positively affecting digestion and overall well-being. And for the most part, probiotics are found in fermented foods such as yogurt, kefir and kombucha. It’s thought that regularly consuming probiotics helps to replenish the beneficial microorganisms in your gut and help counterbalance any less desirable bacteria residing there.
Don’t let the name similarities fool you — prebiotics and probiotics are two different things that have distinct functions within our bodies. They do, however, run in the same circles, so to speak.
While probiotics are little living creatures like bacteria and yeasts, prebiotics are certain components of foods including fibers, polyphenols and, surprisingly, omega-3 fat that feed and promote the growth of these healthy, or “good,” microorganisms living in our digestive tracts. In other words, prebiotics are the food probiotics require to reproduce and get to work on tasks such as improving your immune defenses. So, probiotics and prebiotics work as a team to make us healthier. This means you can take all the probiotic supplements you want and pound back all the yogurt in the refrigerated aisle, but it won’t have the maximum impact if you don’t give the probiotics a fuel source to thrive on as they take up residence in your gut.
Prebiotics are found in many whole foods you eat, such as fruits, asparagus, and legumes.
Those gassy after-effects from eating a bowl of chili result when the bacteria in your gut ferment the non-digestible dietary fiber contained within the beans and vegetables. Interestingly, breastmilk contains sugars that act as prebiotics, so we’re meant to be exposed to these very early on and they may play a role in cementing our microbiome for years to come.
These are not living microorganisms, but rather incredible compounds such as protein peptides that are produced when postbiotics feed on prebiotics. Keeping this all straight? For instance, postbiotics can be created when the micro-critters in your gut ferment indigestible prebiotic fibers such as inulin and oligosaccharides. In essence, they’re the third and final piece of the biotics puzzle working through the gut to support your health.
An example of a postbiotic is the short-chain fatty acid butyrate, an energy source for the cells in your colon and what appears to be an anti-inflammatory compound. When you consider that inflammation is the hallmark of several chronic diseases including cancer and heart disease as well as digestive conditions like Crohn’s disease, you see why creating more of this and other short-chain fatty acid postbiotics through better nurturing our microbiome is so important.
A lack of butyrate production resulting from poor diet choices is believed to play a role in the development of colorectal cancer. Evidence also suggests that the short-chain fatty acid propionate that is created when microorganisms ferment certain dietary fibers can help defend against the heart-damaging effects of high blood pressure.
Short-chain fatty acids also impact the release of gut hormones, such as Peptide-YY, that are involved in appetite and insulin secretion and can improve metabolic health. This could be one reason why high-fiber diets, which can increase postbiotic production via improved probiotic health, are especially satiating. And the short-chain fatty acid propionic acid appears to alter our metabolism in a way that makes it less likely to gain unwanted weight and develop type 2 diabetes.
You may have heard about the “gut-brain axis.” Well, we’re learning that postbiotic compounds are likely what mediate the impact that the microbiome has on brain health including the development (or not) of depression and anxiety. Postbiotics including caffeic acid and ferulic acid that are produced when bacteria work on polyphenols in the large intestine could be a reason why consuming more of these antioxidants can help protect us from several conditions, including heart disease and certain cancers. They’re even believed to modulate DNA methylation, a chemical process that takes place inside your body that can alter the behavior of genes. They do so in a way that can scale back the biological clock.
Though postbiotics are a boon to your overall health, it’s still not well-understood exactly how they work. But what’s now clear is that our diet has a profound impact on microbial composition in the gut, in turn affecting a range of metabolic, hormonal, and neurological processes.
Take for instance this study in the American Journal of Clinical Nutrition where scientists determined that people whose diets scored better on the Healthy Eating Index — meaning more vegetables, fruits, whole grains and less added sugars, alcohol and solid fats — had a more potentially beneficial bacteria and lower amounts of potentially harmful bacteria in their gut microbiome. Here are some other ways to build a gut-friendly plate to get more out of these biotics.
6 ways to improve your microbiome
1. Eat a greater variety of plants
Looks like scientists have given us a good reason to play the field when it comes to eating plants. As part of the American Gut Project, University of California San Diego School of Medicine researchers discovered that people who ate more than 30 different types of plant-based foods per week had a greater diversity of beneficial gut microbiota than those who ate 10 or fewer types of plant foods in any given week.
By eating an increased variety of veggies, fruits, legumes, nuts and seeds, you bring in a greater variety of prebiotics including fibers and polyphenols into your gut. This offers up a feast for the helpful critters in there so they can reproduce and outnumber the bad (pathogenic) bacteria that are lingering around. These same bacteria can then go about creating important postbiotics for better health.
On the flip side, some research suggests that a meat-heavy diet, especially at the expense of plant-based foods, can shuffle around the types of microbes thriving in the gut to favor less beneficial types.
2. Don’t be fresh obsessed
To help fertilize your gut with a new crop of probiotics, it’s a good idea to include a regimen of foods in your diet designed to promote microbial diversity — that is, foods and drinks that have gone slightly rotten via fermentation, which is a process where bacteria are infused into foods and drinks either directly by humans or indirectly through natural processes which historically served to extend shelf-life before the age of refrigerators (think kombucha or kimchi).
After analyzing blood and stool samples of 36 healthy adult participants, Stanford School of Medicine researchers discovered that a 10-week diet high in fermented foods including yogurt, kefir, kimchi, kombucha and sauerkraut boosts microbiome diversity and decreases markers of inflammation, suggesting improved immune function.
The sweet spot for daily fermented food servings to boost microbiome health is still unclear, and so is if certain options (i.e. kefir vs yogurt, kimchi vs sauerkraut) are more powerful than others. But it seems like a smart move for gut health to try to work in a few servings daily. This can mean tucking sauerkraut or kimchi into your sandwiches, using kefir as a base for smoothies or enjoying a steamy bowl of miso broth with dinner.
It’s also worth noting that certain postbiotics themselves might be found in any food including tempeh, which has been fermented by live bacteria.
3. Shop for inulin
Inulin belongs to a class of carbohydrates called fructans, which are plant carbohydrates that, because of their unique structure, resist digestion in the upper gastrointestinal tract but are quantitatively fermented in the colon by the microorganisms that reside here. Research shows that consuming more inulin not only results in a transition of the gut microbiome population towards more beneficial species including the Bifidobacterium genus but also great satiety and a lower desire for sugary, salty or fatty foods. And with consistent intake of inulin-rich foods gastrointestinal complaints such as bloating diminish.
You can source this prebiotic fiber from Jerusalem artichokes (a huge source of the stuff), chicory root, alliums including onions, leeks and garlic, asparagus, soybeans (which includes edamame), oats and whole wheat. Smaller amounts are found in a wider variety of plant-based foods, so you’ll get some inulin if you eat plenty of plants.
An increasing number of packaged foods including energy bars, cereals, protein powders and cookies are being fortified with inulin and other prebiotic fibers including fructooligosaccharides from sources such as chicory. These can be a useful way to work more of these gut-benefiting fibers into your diet, but it’s still important to look at the overall nutritional quality of the product. A high-fiber cookie remains a poor dietary choice if it’s also full of refined carbs, sugar and saturated fat.
4. Rise of the impostors
While we shouldn’t begin to consider the latest incarnations of meatless burgers, sausages and no-chicken nuggets as being superfoods, it does appear they may hold an advantage over animal-based versions when it comes to the microbiome.
A British study published in the peer-reviewed scientific journal Foods followed forty participants between the ages of 18 and 55 for four weeks with one intervention group replacing at least four meat-containing meals per week with meals cooked with plant-based meat alternatives (the study used products from a vegan brand called Meatless Farm) while another group continued eating a diet with daily meat, eggs and dairy. In comparing the changes in the composition and functionality of gut microbiota via stool samples, they discovered that the diet with the plant-based meats resulted in a positive shift in bacteria towards more helpful microorganisms and away from potentially detrimental ones. The study authors surmise that a greater intake of fiber and plant polyphenols, both prebiotics, that occurred with the consumption of meatless products was the main catalyst behind this microbiome population change.
But whether this gut bacteria shift is enough to bring on any positive health changes is not known or if it outweighs some of the downsides of consuming these products such as their typically high amounts of salt. The intervention group did report improved bowel movements, but also higher rates of gas and bloating likely caused by a sudden uptick in fiber.
5. Go nuts
Several recent studies including this one, this one and this one have discovered that daily consumption of nuts (about 1 to 1 1/2 ounces daily) including pistachios, walnuts and almonds can promote microbiome richness and diversity, thereby increasing the ratio of good to bad microflora. The fibers and phytochemicals present in nuts reach the colon, where they provide substrates for the maintenance of healthy and diverse microbiota. This includes bacteria that produce the postbiotic short-chain fatty acid butyrate which can impact genes involved in immunity and cardiovascular health.
6. Not-s0-hot potatoes
Emerging research suggests that a unique kind of carbohydrate could be a key to helping support the gut. What sets resistant starch apart is that unlike other types of starchy carbs which break down into simple sugars in your small intestine (the place where most of the food you eat is processed), resistant starch, so named because it “resists” digestion, stays intact until it reaches your large intestine (colon). And it’s here where the micro-bugs get their shot at this prebiotic to help bolster their numbers and produce important postbiotic short-chain fatty acids.
Studies including this one and this one found that boosting resistant starch intake can alter levels of hormones involved in appetite regulation such as leptin in a way that keeps you feeling more satiated throughout the day, an important part of curbing the needless snacking that can contribute to weight creep.
When cooked and then cooled for about 24 hours, the digestible starches in potatoes convert into the hardened resistant starch amylose, allowing for fewer carbs to be digested. Potato salad, anyone? The same process can also occur in previously cooked and cooled grains like brown rice. So consider batch cooking your potatoes and grains in advance and letting them chill in the refrigerator for at least 24 hours.
Various beans including pinto, black and chickpeas are a natural source of resistant starch, as are raw oats (think muesli). Interestingly, underripe bananas with green-tinged skin can contain up to 80 percent more resistant starch than do the fully ripened fruit, where the resistant starch has been converted to sugars. So try blending less-sweet unripened green bananas into your post-run smoothies or slice and scatter on yogurt or cereal.
Just be warned that if your current diet is low in resistant starch and fiber in general, it’s a good idea to gradually up your intake to limit uncomfortable digestive woes like bloating and gas.
Though a whole-foods, plant-heavy diet is the best way to get the most out of the trio of biotics, these products can offer an assist.
A no-added-sugar protein powder that is juiced with caffeine and prebiotic resistant starch including green banana flour. Your morning smoothie just got a gut check.
Each packet that dissolves effortlessly in any liquid contains a one-two punch of prebiotic inulin and 10 billion probiotic cultures.
Dried apricots are already delicious and nutritious, but these parched fruits go the extra mile with a big dose of belly-benefiting probiotics.
This nutrition-packed greens powder delivers probiotics to fertilize your gut with these beneficial critters, but also a range of polyphenol-rich veggies and fruits to give them a fuel source so they can make you more health-boosting postbiotics.
This next-level porridge is jacked with probiotics and 15 grams of protein from grass-fed whey to start you on your way to a day of better gut health and muscle-building. All made better by a cozy apple flavor.
Make your coffee work harder for you by whisking in this coconut-based creamer that is outfitted with probiotics and prebiotic fiber. You can also stir it into yogurt or blend it into smoothies.
Each bar offers up 11 grams of prebiotic fiber and 8 grams of plant-based protein. Bonus points for including real blueberries.