You've probably heard the term “gut bacteria” being thrown around recently (especially in advertisements for yogurt and probiotics), and if you're like us, you've been wondering what the heck it means. Before you start cringing, hear us out. These bacteria help move things along in your digestive system, but the tiny organisms do more than just hang out in your intestines. From immune responses to mood boosters, your gut has some surprising talents. Here’s what you need to know about gut bacteria and how to keep yours functioning at their best.
What Is Gut Bacteria?
Gut bacteria, or intestinal microflora, refers to the complex community of bacteria in your intestinal tract. With a roll call of 100 trillion, they outnumber human cells ten to one—talk about a party! Collectively, intestinal flora weigh approximately 2.2 pounds, about the same as a human brain. This colony of bacteria has even been nicknamed the “forgotten organ,” thanks to its amazing ability to set the tone for our health.
Why Is Gut Bacteria Important?
You may get a queasy feeling when you hear the word bacteria—and we don’t blame you. We usually associate bacteria with illness and infections. But there’s an entire crew of good bacteria that wants nothing except the best for us. “These good bacteria are extremely important to the body’s ecosystem,” says clinical nutritionist Sue Petersen, MSACN. “We need them in order for our bodies to remain balanced.” By keeping our friendly flora diverse and healthy, they can work to their fullest potential. Here are a few of the ways they help us out:
Countless gut flora aid the intestinal tract. Their main goal is to provide energy and nutrients to the host (that’s you) from food intake. When you eat a meal, you do your part in the digestive process by chewing and swallowing food. Once the food hits your intestinal tract, the gut bacteria take it from there. “Bacteria make food more available to us so that our bodies can absorb it,” Petersen says. If it weren’t for the gut, the vitamins and minerals in healthy foods wouldn’t be as effective. Gut bacteria also “eat” insoluble fiber through fermentation. The by-products of this process nourish your intestinal bacteria and promote healthy excretion of waste.
“Gut bacteria are like the bodyguards of your immune system,” says Natalie Robertello, MS, RD, CDN. “They help fight off the bad bacteria, so everything can run smoothly.” These guardlike duties play a major role in our immune response. When the highly sensitive intestinal bacteria sense harmful pathogens, they produce antibodies in an attempt to boost your immune system.
As the guards, your gut bacteria are the first to notice when something goes wrong—and not just in your tummy. Have you ever felt nauseous from an injury? That's your gut bacteria on the job. When something is out of whack, your sensitive gut bacteria respond, causing inflammation that typically manifests as pain, redness, and swelling. You may not be able to feel that something is amiss inside your body, but you can certainly feel that stomachache. Of course, it could just be that you binged on cupcakes at a wedding shower that afternoon. But if you have stomach pain, that can be a clue for your doctor to run tests to determine if your gut bacteria were raising the flag for a different issue. Keeping your gut healthy will ensure that this crucial response happens just the way it should.
When it comes to weight control, the friendly flora do more than just absorb food. Research has found that prime bacterial health maximizes your body's ability to process glucose and calories, which reduces the number of extra calories that get stored in fat tissues. If you’re looking for a healthy approach to weight loss, try focusing on your gut health by upping your fiber intake, eating more yogurt, or taking probiotics. This doesn't mean excellent gut health is the only solution to weight loss; exercise and a well-balanced diet are still essential. But giving your gut some extra love can be a beneficial component of weight control.
Ever notice how good you feel after eating healthy meals? That's because the gut and brain are deeply connected and in constant communication thanks to the immune and nervous systems. A study in the Journal of Psychiatric Research found that depression and anxiety were most prevalent in individuals with low microbial diversity. From behavior patterns to societal interactions, stress responses are immune responses in disguise. And just like the rest of the immune system, these responses benefit from a healthy, thriving gut.
What Can Hurt Gut Bacteria?
Balance is key to protecting your gut. “If the amount of bad bacteria begins to outweigh the good, it leaves more opportunity for the bad to take over,” Robertello says. This is a common side effect of antibiotics, which are used to treat bacterial infections by destroying bad bacteria. As the antibiotic kills the culprits, it’s likely that the good guys will take a hit, too. For women, this imbalance often triggers yeast infections—and who wants to deal with that? This is why doctors may recommend taking probiotic supplements when on antibiotics.
Lack of sleep or exercise can endanger gut bacteria. An imbalanced diet void of wholesome, plant-based foods can also hurt. Studies have shown that a high-fat, high-sugar diet considerably disrupts the microbial balance. “Overconsumption of animal products and processed products is a threat,” Petersen says. Bad microflora also love sugar, so just remember to eat sweets and junk food in moderation. Don’t forget that healthy foods have sugar, too. For example, the juicing trend has its pros and cons. While it’s a delicious way to get your vitamins, the large amount of concentrated fruit yields a lot of sugar, and fiber is lost in the juicing process. The occasional juice is OK, but it all comes down to moderation.
How Do We Keep Gut Bacteria Healthy?
The amazing thing about gut bacteria is that they're always self-renewing. In twenty-four hours, you can produce healthier, more diverse bacteria by simply tweaking your diet. Aside from noshing on fresh fruits and veggies, focus on probiotics and prebiotics. Never heard of them? Robertello explains that probiotics are good bacteria, while prebiotics encourage the growth of probiotics. “Think of the prebiotics as the cheerleaders,” she says.
Together, prebiotics and probiotics promote microbial balance. The two major strains of probiotics are Lactobacillus and Bifidobacterium; you’ll find them in fermented foods such as yogurt, aged cheese, sauerkraut, kimchi, tempeh, and soy. These products have been cultured with added microorganisms, often producing a distinct sour or pickled taste. “Try adding two tablespoons of fermented food to one meal each day,” Petersen says. “Consuming it before the meal will give the bacteria proper nourishment.” The American Academy of Family Physicians recommends a daily intake of ten to twenty billion CFUs (colony-forming units) of probiotics. If you feel like you need an extra hand, probiotics and prebiotics are also available as supplements. Consult your doctor for the dose and frequency that work best for you.
Increasing your fiber intake can also make your gut bacteria happy. Fiber provides substrates that allow the good bacteria to ferment and flourish. Whereas the recommended intake for fiber is twenty-five to thirty grams a day, women ages 20 to 39 only get about fifteen grams. To up your fiber intake, turn to whole grains, bran cereal, almonds, and black beans. Other excellent sources include dark leafy greens, berries, apples, bananas, and oranges. It’s not a bad idea to choose whole fruit over juice, too. For example, a whole apple has about 4.4 grams of fiber, while a cup of apple juice only has 0.25 grams. Your gut will thank you.
Now that you know more about gut bacteria, we hope you’ve found a new appreciation for these tiny, hardworking organisms. The synergistic relationships in our bodies are pretty amazing and further prove that we are what we eat. Treat your body well, and it will return the favor. And don’t forget to trust your gut—literally!