Years of antibiotic use (either by prescription drugs or by eating conventionally-raised meats), eating sugar-laden food, and eschewing microbe-feeding fibers are all making you fat—but not for the reason you think. This pattern of drug use and poor eating has also armed the bad bacteria who live in your gut with the weapons they need to overtake the good guys. And when your good gut bugs are depleted, they not only won't be able to fend off weight-inducing inflammation, they also can't help you keep your metabolism humming, your immune system healthy, and your mind keen.
That's because research has shown that our gut microbes play a significant role in regulating our health and weight. And even more research has suggested a way we might mend this imbalance: by eating foods full of probiotics (and by also cutting out bad-microbe-feeding sugars and loading up on prebiotics.) You may have heard about probiotics before, but you're about to turn the corner and see what they're all about!
Probiotics are live bacterial cultures that we consume in fermented foods. They're called "pro" because they're believed to be beneficial to our health, although the science behind it has yet to prove how. (Or even if they are effective—as live probiotics often do not survive the harsh environment of the stomach—which is why the FDA has yet to approve using probiotic supplements to treat health problems.) A possible mechanism, described by a summary in the journal Gut, is that probiotics help rebalance your gut bugs by creating an environment where the good guys can regain strength.
Preliminary findings are promising. A study published in the British Journal of Nutrition found that overweight women who were put on a calorie-restricted diet and given a probiotic supplement for 12 weeks showed significantly higher weight loss than those given a placebo. Other studies have found probiotics can help alleviate IBS and IBD symptoms, eczema, infectious diarrhea, and may help prevent allergies and colds. The A-lister usually mentioned is yogurt, but probiotic sources go way beyond breakfast. Here are some of the best sources of natural probiotics you can consume to get your gut back in check—and to win the battle once and for all.
Dark chocolate is like getting a superhero and a sidekick in just one bar. That's because it's been found to be a source of prebiotics and probiotics. Prebiotics are a source of food for the microbes in your gut, which convert the candy into anti-inflammatory compounds, researchers at the American Chemical Society found. And probiotic bugs will colonize your belly to assist with digestion and strengthen your belly bugs so you can fix an off-kilter gut. The reason? Chocolate is actually a fermented food. Who knew? To reap the benefits, the ACS researchers recommend a cacao content of 70 percent or above, consuming about two tablespoons of cocoa powder or three-quarters of an ounce (usually a square) of a bar.
The most popular probiotic, yogurt is made by adding two strains of bacteria, Streptococcus thermophilus and Lactobacillus bulgaricus, into pasteurized milk. The milk thickens up from the lactic acid that's produced by the bacteria, becoming the creamy product that you trust to build muscle. But while most Greek yogurts can be a trusted source of protein, not all will provide probiotics. Some products are heat-treated after fermentation, which typically kills most of the beneficial active cultures, so be sure to check the label for the phrase "live active cultures." And be sure to stay away from the ones with added sugars which will do more for the bad bacteria than they will for the good.
Probiotics in peas? Japanese researchers say there are! A 2014 study published in the Journal of Applied Microbiology found that green peas contain Leuconostoc mesenteroides, a potent probiotic often associated with fermentation under low-temperature conditions. The bugs stimulate your immune system, helping to protect the mucosal barrier, a.k.a. the body's second skin, which runs through your digestive tract and is the first line of defense against bad bugs and toxins. Pass on the canned stuff, but add fresh ones to pasta, salads, and omelets.
Don't let its association with hot dogs sully your opinion of this food. Sauerkraut is lacto-fermented cabbage, and it contains natural compounds that have potent cancer-fighting and belly-slimming properties. When unpasteurized, sauerkraut is rich in Lactobacillus bacteria—even more so than yogurt—which boosts the healthy flora in the intestinal tract, bolsters your immune system, and even improves your overall health: Mice fed a probiotic-rich sauerkraut extract had reduced cholesterol levels, found a study published in World Journal of Microbiology and Biotechnology. Again, examine the label before you pick up a kraut for probiotic purposes. Store-bought, shelf-stable sauerkrauts can be pasteurized and prepared using vinegar, which does not offer the beneficial bacteria but mimics the same distinctive sour-taste which is traditionally produced by the fermented lactic acid. To get an authentic product, check out what the folks over at Farmhouse Culture are doing.
Kombucha is a slightly effervescent (aka it's bubbly!) fermented drink made with black or green tea and a symbiotic culture of bacteria and yeast, known as a SCOBY. This functional food will only impart its probiotic benefits if it isn't pasteurized, which means the time between when it's on the shelf and when it gets to your mouth increases the risk of contamination. In fact, unpasteurized kombucha drinks have been linked to bacterial infections, allergic reactions, and liver damage. So if you want to heal your gut, make your own at home and drink it within a couple days. As for the refrigerated shelf versions? Only drink it if you like the taste—it likely won't be benefiting your belly.
Kimchi is an Asian fermented veggie dish, made with cabbage, radishes, and scallions. That distinctive red color comes from a seasoned paste of red pepper, salted shrimp, or kelp powder. The unique strains found in kimchi won't just heal your gut, they might also help you stay slim: Researchers at Kyung Hee University in Korea induced obesity in lab rats by feeding them a high-fat diet and then fed one group of them Lactobacillus brevis, the culture strain found in kimchi. The probiotic suppressed the diet-induced increase in weight gain by 28 percent!
Beer & Wine
These shouldn't be your go-to source of probiotics, but fermented alcoholic beverages like beer and wine do actually provide some benefits when consumed in moderation. The vitamins from the barley grain that beer is made out of surviving the fermentation and filtering process and can lead to good cholesterol and decrease blood clot formation. And wine has been found to be a potent source of free-radical fighting antioxidants. To see how else drinking your glass of bubbly or red can be good for you, check out these 23 Surprising Healthy Benefits of Alcohol!
Double martini, please—and by double we mean the olive. Salt-water brined olives undergo a natural fermentation, and it's the acids produced by the lactic acid bacteria which are naturally present on the olive which give these little fruits their distinctive flavor. Two strains of live cultures, Lactobacillus plantarum and Lactobacillus pentosus, have been isolated in olives, and L. plantarum shows great potential for getting you that flat stomach you're after: This strain can balance your gut bugs and decrease bloating, particularly in people with irritable bowel syndrome, according to a study published in the American Society for Clinical Nutrition.
It might look funky, but natto is one of the healthiest foods for women—and here's why: this Japanese dish of fermented soybeans is unique in that it's the highest dietary source of vitamin K2, a vitamin which is important for cardiovascular and bone health as well as promoting skin elasticity to help prevent wrinkles. On top of that (and the reason it's on this list) natto is a potent source of gut-healing probiotics. A healthy gut can keep inflammation at bay, which researchers say may affect the health of our skin since many troubles like acne, eczema, and psoriasis stem from inflammation.
Although this smoothie-like dairy drink resides next to yogurt, if you have a dairy-intolerance, this might be your better pick. That's because kefir has been found to counteract the effects of the milk's stomach-irritating lactose: Ohio State University researchers found that knocking back this fermented drink can reduce bloating and gas brought on by lactose consumption by 70 percent! What's even more promising about kefir is that its bacteria have been found to colonize the intestinal tract, which makes them more likely to confer their healing benefits to your gut.
Pickles are another classic fermented veggie option. "But it's important to distinguish that not all pickled vegetables are fermented," say dieticians Willow Jarosh MS, RD, and Stephanie Clarke, MS, RD, co-owners of C&J Nutrition. "In order to get the health benefits from eating fermented foods, you'll want to be sure that the pickled veggie you're eating is, in fact, fermented—and not just pickled." Shelf-stable products are the first sign a pickle is just pickled because the product would be pasteurized first, which kills off any bacteria—even the good ones. Make your own fermented pickles, and other veggies, at home with a starter, salt, and water.
We love miso, and you will too when you hear of its gut-friendly benefits! You're probably familiar with it in the appetizer miso soup you get in restaurants, but you can also find this traditional Japanese paste in supermarkets. It's made by fermenting soybeans with salt and koji—a fungus called Aspergillus oryzae. Not only is it a complete protein (meaning it contains all 9 essential amino acids) because it comes from soybeans, but miso also stimulates the digestive system, strengthens the immune system, and reduces the risk of multiple cancers.
Contrary to what you may think, sourdough is not a flavor; it's actually the fermentation process where wild yeast and friendly bacteria break down the gluten and sugar in the wheat flour, turning it into good-for-you proteins, vitamins, and minerals. The "sour" aspect is the taste from the wild yeast which comes from the air around you, and will often vary based on your location. Because the starches from the grains are predigested by the bacteria, this bread is much easier to digest than other types of over-processed white breads.
The probiotic trend has uncovered products virtually unknown to American markets, which is why you've probably never heard of Kvass. This drink originated in Russia, traditionally made in a similar way to a yeast beer but with stale rye bread rather than barley. Beet Kvass, on the other hand, uses beets as the source of starch and whey to speed the lacto-fermentation process. The longer the beets are left to ferment, the more developed the flavor will be. Beets are already a great source of potassium and dietary fiber, so fermenting them amplifies their positive digestive properties even more.
Like yogurt, not all cottage cheeses will contain live and active cultures. But one of the products that do is from a company called Good Culture. Though dairy products are packed with slow-digesting, muscle-building protein and have been shown to enhance probiotic absorption, this option might not be your best bet; Many cottage cheeses are full of sodium, which can cause bloating and put you at risk of hypertension when eaten in excess.
You'll often seen tempeh as the vegan alternative to bacon—and, believe us, it's much better for your gut. Tempeh is a fermented soy product made with a yeast starter that has a meaty, tender bite with a neutral flavor; it's an open canvas for all your favorite seasonings. Besides the belly benefits, a standard 3-ounce serving of tempeh boasts 16 grams of protein and 8 percent of the day's recommended calcium.
Soft, Aged Cheese
Many cheeses are created by fermentation, but not all fermented cheeses contain probiotics. Aged, soft cheeses—such as cheddar, gouda, parmesan, and swiss—are typically the only type which will maintain the beneficial bacteria. These cheeses start with adding a lactic acid bacterial culture to milk, which will form lactic acid and cause the milk to form curds and whey. The longer the cheese ages, the more beneficial bacteria for your belly.