You grow what you eat. No, really, you do. Our bodies are a breeding ground for microbes — bacteria, viruses, fungi and other microscopic organisms — and many of them hitch a ride inside us through the food we eat.
If that doesn’t freak you out, consider that the microbes inside your body outnumber your own cells by 10 to 1, according to the National Center for Complementary and Integrative Health.
But it’s a good thing! These microbes make up what is commonly called our “microbiome” or our “living organ,” residing primarily within our gut — the lining of our stomach and intestines. They help us metabolize foods and play a major role in our immune system.
“Research shows that around 80 percent of your immune system is housed within your gut,” says Ashya Walden, RD, LD, a dietician at OhioHealth Marion General Hospital who also has several years’ experience working in a food sensitivity lab dedicated to microbiome analysis and research. “The types of bacteria you want to flourish in your gut aren’t the type that give you an infection. These ‘good’ bacteria determine how well your body processes foods, which of course is going to determine whether you have different symptoms of disease.”
Walden says that good bacteria assist the enzymes your body produces on its own with fermenting and extracting nutrition from foods. “Their job is to help you get out of food what your body needs and eliminate the things you don’t.”
Planting the seeds for a healthy microbiome
It’s not entirely fair to blame our diet for the state of our microbiome. It does matter how you start, says Walden. “When you are born, your gut is completely sterile. It doesn’t fully mature until you’re about two and a half years old.” That leaves a lot of time to start building a microbiome that could seal the fate of our health as adults.
Walden says research has determined that babies born via vaginal delivery tend to have a greater number of good bacteria when compared to babies who are born via cesarean section. “It’s not that these babies can’t eventually develop a healthy microbiome, but they tend to be more prone to illnesses. Babies born naturally get helpful microbes from their mother as they pass through the birth canal.” Breastfeeding also makes a difference. “We get antibodies from breastmilk that are impossible to put into formula,” she says.
Antibiotics play a big role in diminishing the health of our microbiome too. “When you have children prone to illnesses who are constantly sick, they are often prescribed antibiotics, which don’t distinguish between good and bad bacteria. These antibiotics kill off some of the good bacteria a child could potentially need to fight infections in the future,” says Walden. Even as adults, it is good practice to keep your microbiome in mind when taking an antibiotic.
Cultivating a healthy microbiome
If “anti”biotics are bad for our microbiome, then “pro”biotics must be good for it, right? Not necessarily. Walden says there’s not yet enough research to say whether or not probiotics actually work. “A lot of people use probiotics because they contain live bacteria and the hope is by ingesting them you can recolonize your gut with good bacteria. But we don’t really know yet how effective they are, who benefits most or what doses are most appropriate. They can even cause severe side effects in immunocompromised people, so you should talk to your healthcare provider before taking them.”
But don’t throw out your yogurt just yet. She says there is some preliminary evidence that if you are generally healthy, using a probiotic for mild digestive symptoms like gas, bloating or diarrhea, or while on an antibiotic, can be helpful. “Just be careful to stop using them when you’re asymptomatic or once you’ve finished your round of antibiotics. They’re not a multivitamin and aren’t meant to be used long-term. Your body can even become resistant to probiotics, just like antibiotic resistance.”
Pruning your microbiome
Part of maintaining a healthy microbiome is recognizing when it’s not so healthy. Symptoms of an unhealthy microbiome range from intestinal dysfunction, like constipation and gas, to skin irritation, like eczema or severe acne, to mood swings and migraines. These symptoms are your body’s natural defense mechanism for fighting inflammation caused by microbes that are not supposed to be there. Over time, you could even develop conditions like irritable bowel disease, obesity (to some degree), metabolic syndrome or nonalcoholic fatty liver disease, says Walden.
“Just like everything in nutritional science, there is no one-size-fits-all approach to your microbiome,” she says. “It affects everyone differently. Everything you do and eat will either create the right environment for good bacteria to grow or invite bad bacteria to fester.”
If you notice recurring symptoms like these or have been diagnosed with one of these conditions, you may find relief by trying an elimination diet, says Walden. Start by identifying possible culprits of your digestive problems: sugar, wheat, dairy, corn and soy are the most common. Slowly, remove these foods from your diet, then after a period of three to six months, begin to gradually reintroduce them to your diet.
“It takes roughly three to six months for your red and white blood cells to turn over, so you won’t notice any significant changes if you reintroduce foods too early. Reintroduction of foods needs to occur with new cells,” she says.
It’s also important to wait at least a few days between food reintroduction. Depending on your unique microbiome, it could take 20 minutes to more than two days to see how it will react. If you reintroduce too many foods at once, you won’t know which one is actually causing the reaction.
Walden says, when done right, elimination diets frequently have positive results and symptoms improve or go away entirely. But, if you find that your symptoms are not a result of trigger foods, it could be that your diet is simply not varied enough. “Too much of a good thing can actually sometimes be bad. Your body may start to attack foods you eat all the time, even healthy options like fruits and vegetables. You should try to maintain variety in your diet and stick as close as you can to a whole-food, plant-based diet, avoiding added sugars, artificial ingredients and dyes.”
She says you should also think about your environment. “It’s not realistic to assume you can avoid everything you would need to, to keep your microbiome in top shape. But some people also develop symptoms from molds or chemicals in their environment that get into their bloodstream. Even being too clean and using too many sanitizers can be bad. You don’t need to live in fear, but try to live as naturally as you can.”
You can find tips and advice for maintaining a natural diet on the OhioHealth Blog, including probiotic options and healthy alternatives for people with food sensitivity issues.