It’s well-known that putting wholesome, nutritious food into your body helps it function at its fullest potential. What’s less-known is that achieving this result has a lot to do with satiating another body system you might not be aware of: the gut.
Our gut microbiome is critical for digestion and helps break down and absorb nutrients. It also bolsters our immune system, aids in metabolism, and produces nutrients our bodies need. Being in charge of so much, it’s no surprise that it’s pretty complex.
“Imagine it as a coral reef: As you snorkel around, you might see colorful fish, an octopus, some plants and algae, and maybe even a shark—it’s like its own ecosystem,” says Ruchit Shah, gastroenterologist at Capital Health in Borden-town. The gut’s “ecosystem” is a combination of bacteria, fungus, algae, viruses, archaea, and eukaryotes—which include other single-celled organisms like protozoa.
“The gut microbiome begins in the mouth, where bacteria begin breaking down food, which travels through the stomach, small intestine, and large intestine,” says Shah, noting that the stomach has the fewest bacteria because of its acidic environment, while the large intestine has the greatest and most diverse number of microorganisms—trillions, actually.
Keeping your gut microbiome healthy, Shah explains, is not so much about supporting “good” or eliminating “bad” bacteria—it’s about keeping your “ecosystem” balanced so that everyone gets along.
“When we first started learning about the gut microbiome, we used to think [its influence] was all gastrointestinal—IBS, Crohn’s, ulcerative colitis—but now we’re understanding the implications are far reaching. Obesity, diabetes, cardiovascular disease, and even Alzheimer’s and dementia are linked to it now,” he says.
A Whole-Food Diet Is Key
The best way to support the gut is by eating a wholesome diet.
“We humans have sustained ourselves for millions of years on a standard diet—but now our GI tract is seeing things it’s never seen before,” says Martin Blaser, Chair of the Human Microbiome and professor of medicine and pathology at Rutgers University in Piscataway.
“The chemical additives in the food we’re consuming didn’t exist before, and now they’re causing a big increase in GI issues.”
To avoid this, Blaser urges avoiding ultra-processed foods—or foods that are far removed from their original, natural state.
“A lot of processed foods have additives that are antibacterial and are designed to increase shelf life in the supermarket. Those additives also act against the beneficial bacteria in your gut,” he says, citing the importance of reading food labels and being aware of common preservatives such as BHA and BHT.
“Having an imbalanced gut microbiome makes you more susceptible to infections,” he says. “The double-edged sword is that antibiotics also cause imbalance and should truly only be used when absolutely necessary.”
If one’s gut microbiome is imbalanced, one may experience bloating, abdominal pain, constipation, change in bowel habits, brain fog, or a general sense of feeling ‘off.’
Keeping it healthy can improve these symptoms. One way to achieve this is by eating a whole-foods diet, especially one high in fiber.
“When you eat an apple, most of the nutrients get absorbed by your small intestine. The rest passes into the large intestine,” Blaser explains. The microbiome there “digests the leftover fiber, and in doing so, produces vital compounds we’re unable to produce on our own called short-chain fatty acids,” he says, adding their benefits range from reducing inflammation and supporting metabolism to helping produce vitamin K, which is necessary for blood clotting.
“A healthy gut microbiome is essential to our overall health,” says Blaser.
One Size Does Not Fit All
The tricky thing is that everyone’s gut system is so different that pinpointing specific changes to it for combating disease has yet to be discovered.
“We know that there’s a link between the gut microbiome and disease, but we don’t know how to modify it consistently to create improvements to disease,” says Keerthana Kesavarapu, associate professor of medicine at the Division of Gastroenterology and Hepatology at Robert Wood Johnson Medical School in New Brunswick.
“But we know nutrition plays a huge role, and eating a wholesome diet full of fruit, vegetables, and whole grains is your best bet.”
While many people turn to probiotics to offer additional support to their gut health, Kesavarapu discourages the use of those in pill form.
“Consuming prebiotics, or taking a supplement containing one, three, or even 10 different strains of probiotics, isn’t going to speak to the complexity of the gut,” she says, instead recommending those found naturally in food.
Kesavarapu explains that probiotics are live organisms found in fermented foods (including kefir, yogurt, sauerkraut, tempeh, kimchi, miso, and kombucha). Prebiotics, however, are foods that help feed the organisms themselves, and often include special types of fiber to help assist in the production of short-chain fatty acids. Foods containing prebiotic fiber, such as Inulin, include garlic, onions, fruits and vegetables, legumes, and chia seeds. Galacto-oligosaccharides are in foods like certain fruit peels, lentils, chick-peas, and beans, plus starchy foods like potatoes and rice. Beta-glucans are found in mushrooms and foods rich in polyphenols like berries, cacao, and green tea.
While these foods benefit most, some should be wary.
“For people with IBS or ulcerative colitis, eating prebiotics or high-fiber diets can worsen symptoms,” she says. “Always talk to your doctor before making changes to your diet.”
Just as our bodies change with age, so does our gut microbiome, and we can become less tolerant of certain foods.
“There’s not much we can do to control our changing bodies,” says Kesavarapu. “But what we can always control is choosing foods that help nourish and support it.”
TIPS FOR SUPPORTING YOUR MICROBIOME
Ruchit Shah, gastroenterologist at Capital Health in Bordentown
- Eat a wholesome, whole-foods diet. The Mediterranean diet is an excellent model.
- Limit consuming trans fats (found in meat and dairy).
- Choose polyunsaturated fats (found in fatty fish, walnuts, and flaxseeds) and monounsaturated fats (like avocados, nuts, seeds, and olive oil).
- Stay away from processed foods.
