We all have that friend with a cast iron stomach who travels to foreign countries and hits the buffet with impetuous abandon, never suffering a food hangover or gaining a pound. And then there are the rest of us, whose mercurial middles are prone to weight gain, indigestion, and even more.
What’s going on? Well, we can thank (or indict) our gut’s microbial makeup.
By the time we hit the ripe old age of three, our microbiome, a colony of micro-organisms, is established. “The microbes in your gut when you’re a baby educate your immune system, priming it to know what to respond to,” says Dr. Emma Allen-Vercoe, a microbiologist and gut microbe researcher at the University of Guelph. This microbial profile is diverse and unique to each of us, similar to a fingerprint, and a reflection of the organisms we picked up early on. Consider it a draft of our early years.
This living, thriving, working microscopic ecosystem accounts for one to two pounds of our body weight and has an important role, akin to an organ, with as much metabolic activity as our liver. Our microbiome is comprised of between 500 and 1,000 species of bacteria that have evolved over the years. Eighty-five percent reside in the human gut, with the remainder on our skin and in our saliva and mucus. We have a whopping 100 trillion microbial cells, outnumbering all other body cells 10 to one. “We are our microbes,” says Dr. Allen-Vercoe.
Over the past decade, there has been an avalanche of new research emanating from the Human Microbiome Project that focuses on helping experts understand how bacteria relates to overall health. Here are the top ways the state of our gut is affecting our well-being, from weight management to immunity.
1. Your gut bacteria affects your weight
Researchers studying the link between gut bacteria and weight gain have discovered that the lack, or presence, of certain bacteria in our gut may influence our ability to gain or lose weight. In a study recently published in the British Journal of Nutrition, women who supplemented their diet with specific bacteria called lactobacillus rhamnosus experienced sustained weight loss compared to those who took a placebo. Additionally, a recent study published in Cell found that the presence of Christensenellaceae bacteria, a gut microbe that some people seem to inherit, is strongly correlated with a lower body mass index. Its introduction has even led to weight loss in animal studies.
Try it: Nurture your gut microbiome daily, beginning at breakfast. Load up on probiotic-rich plain yogurt with fiber-rich fruit.
2. Your gut bacteria affect your cravings
Itching for another piece of chocolate or pining for fried foods? It appears that it may be our gut calling. In an article published in BioEssays, researchers found that our gut microbes may influence the foods we crave and our eating behavior. Some of these manipulative bugs have the capacity to signal for the fuel they need to thrive on, including fat and sugar.
Furthermore, it seems that they can induce a state of dysphoria until their request is met. The good news? A gut that is well balanced in microbiota isn’t constantly sounding the alarm of discontent, allowing us to make more nutritious choices.
Try it: Add a Korean-inspired meal to your weekly menu. Kimchi, a traditional Korean side dish made of fermented vegetables, is loaded with healthy bacteria. It’s a simple way to ramp up your intake, and it goes well with everything from fish tacos to pulled pork sandwiches.
3. Your gut bacteria protect against sickness
When our microbiome is functioning well, it makes us resilient and able to withstand the onset of disease. “It will protect you against everything from food poisoning to allergies to asthma,” says Dr. Allen-Vercoe. The key component of a healthy gut is diversity. Simply put, a wide variety of healthy bacteria will do your body the most good. One of the more commonplace culprits of an unfit microbiome is antibiotics. Those drugs we take (often without a second thought) to help us fight illness may, in fact, make us sick.
Antibiotics work by attacking the bad bacteria, which are the source of our infection or illness, but, inevitably, good bacteria get swept up in the raid, too. This can reduce microbial numbers and create a “vacuum” in the microbiome.
For most of us, our guts will sort this out on their own, but for an unlucky few, this space may be filled by foodborne pathogens like salmonella (a type of food poisoning that can cause fever and diarrhea) or other pathogens like C. difficile (a bacteria that causes swelling and irritation of the large intestine, triggering belly cramps and diarrhea).
Try it: When you’re on antibiotics, supplement with probiotics to temporarily or load up on prebiotics to stimulate growth of the resident microbiota.
How to Achieve Healthy Gut Bacteria
The healthiest gut contains a plentiful network of bacteria but not all of the same variety. In fact, researchers are now linking a lack of diversity in the microbiome with a host of chronic diseases including IBS, Crohn’s disease, multiple sclerosis, autism, obesity and diabetes, says Earl Brown, a virologist at the University of Ottawa. Talk to your doctor about including healthy microbiome strategies in your whole body health plan. Your gut could be a serious weapon in the war on disease. Want to improve your gut health? It’s as simple as incorporating more prebiotic and probiotic foods into your day, as well as making a few changes to your dietary habits.
Give P’s a chance
Prebiotics are plant-based fibers that nourish and fertilize our “good” gut bacteria. Foods rich in prebiotics include asparagus, onions, leeks, Jerusalem artichokes and legumes.
Probiotics are good bacteria that can help promote a healthy gut, improving nutrient absorption and increasing immunity. They are living strains that fall into two categories: lactobacillus and bifidobacterium.
These strains are available as supplements or in fermented foods such as yogurt and kefir, soy products such as tempeh and miso and fermented plant foods such as kimchi, sauerkraut and pickles. Look for “live and active cultures” on labels to ensure you’re getting the highest possible dose of friendly bacteria.
Adopt a trial and error approach when consuming probiotics, either via supplements or via bacteria-rich food sources. According to Dr. Allen-Vercoe, the beneficial effects of some probiotics are transient and will only occur while the person is taking them because probiotics can’t colonize the gut. A better strategy may be to combine prebiotics and probiotics, she says, as they can work synergistically to improve digestive flow and overall health.
Don’t starve yourself
Long periods of starvation or a diet lacking in fiber may cause microbes to die out or resort to using the human host as a food source, says Dr. Allen-Vercoe, so it’s important to eat well and often (three to five times a day). Consume a diet rich in fruits and vegetables and dietary fiber. Switch up meal options to encourage a diverse and abundant gut composition.
What’s encouraging is that we can shape our microbiome with our food choices. “It’s the easiest and safest method,” says Dr. Allen-Vercoe. “Everyone is different, so there’s no one-size-fits-all strategy. Each person must learn what foods are right for them.”
Good thing, then, that there’s an abundance of choice. We suggest you go with your gut on this.