The Unexpected Link Between Gut Bacteria and Food Cravings

It’s natural to daydream about sugary foods and other unhealthy snacks when you’re on a diet. But there may be another reason why you’re fixated on cookies: your gut microbiome. Never heard of it? It’s a microscopic world of trillions of microorganisms living in your digestive system that influence what you want to eat. “Our microbes can impact brain chemistry and therefore our food cravings,” says Marissa Meshulam, RDN, founder of MPM Nutrition.

When it comes to understanding the role our microbiome plays in our health, says Meshulam, we’re just at the tip of the iceberg. But here’s what we know so far — including a few tips on creating a healthier microbiome to possibly control cravings.

What Is the Gut Microbiome?

The gut microbiome consists of trillions of bacteria, fungi, parasites, and other microbes that live in our digestive tracts and play a vital role in the body’s daily functions. These microbes can be both helpful and harmful. They can also change: For example, the good bacteria that live in our bodies can sometimes turn “bad” due to environmental factors, an unhealthy diet, and medications. 

Some of the ways these microbes can benefit the human body include helping to break down toxic foods you eat and protecting your body from pathogens. But an imbalance in normal gut microbiota can also promote disease by contributing to low-grade intestinal inflammation, according to one study. The same research also shows that having an obese BMI could alter an individual's composition of gut microbiota. 

“We know that when the balance between bad and good bacteria in the gut becomes unfavorable, inflammation occurs that favors weight gain and makes weight loss harder,” says Lyssie Lakatos, RDN, who, along with her sister Tammy, runs the healthy-living business Nutrition Twins. 

How Can Gut Bacteria Affect My Cravings?

Our cravings may seem like they come out of nowhere, but research suggests otherwise. According to one study, intestinal microbes may trigger cravings for foods that have more of the macronutrients they need to live on (protein, carbohydrates, or fats). Although the study was done on laboratory mice, the study authors believe that gut bacteria could affect our choices by making substances like amino acids that prompt cravings for high-fat or high-sugar foods. 

Does Eating Sugar Make Me Crave Sugar?

There is still so much we don’t know about the gut microbiome, but this seems pretty clear: “Eating sugar and processed foods feeds unfavorable bacteria, and those bacteria feed on sugar,” says Lakatos. “As a result, your gut will crave sugar to feed the bacteria.” So those cravings you get for cookies and other treats are, in part, your “unfavorable” gut bacteria asking for what they need.
 
One way to reduce sugar cravings is to eat less sugar, which ultimately helps improve the health of your microbiome. “However, sugar cravings won’t immediately subside if the gut microbiome is still not ideal,” says Lakatos.   

3 Ways to Create a Healthier Microbiome 

The more diverse your diet is, the better off your gut will be. Including these foods in your daily diet can help keep the balance of gut bacteria in check — and may keep you from wanting unhealthy foods that can sabotage your weight loss. 

1. Eat Prebiotic-Rich Foods

Probiotics are the beneficial gut bacteria themselves, found in both supplements and fermented foods, whereas prebiotics are the food for probiotics. “Prebiotics are components in fiber — which our bodies can’t or don’t digest — like polydextrose, oligosaccharides, and inulin,” says Isabel Maples, RDN, a nutritionist based in Virginia. Generally, fiber is found in high levels in plant-based foods and not in animal-based foods. Since your body doesn’t digest these plant fibers, they are an excellent food source for the healthy bacteria in your gut. Research shows that a high-fiber diet can increase diversity in the microbiome and decrease inflammation.
 
Maples says that very good sources of prebiotics include asparagus, garlic, onions, leeks, Jerusalem artichokes, and chicory root. Other good sources include beans, peas, wheat bran, whole wheat, sweet potatoes, and bananas. 

2. Experiment With Fermented Foods

Fermented foods are made with the help of microorganisms, such as bacteria and yeast. They act as a natural probiotic supplement, populating the gut with beneficial microbes when we eat them. A study found that regularly including fermented foods in your meals improves the diversity of microbes in the gut and lowers markers of inflammation.
 
Reach for items such as yogurt, kefir, kombucha, miso, tempeh, sauerkraut, and kimchi to boost the fermented foods in your diet. Not sure what to do with some of these? Try using kefir in a smoothie, sip on kombucha instead of diet soda, add sauerkraut to a sandwich, or make your own salad dressing with miso paste. 

3. Cook With a Wide Variety of Plants

If you want a healthier gut, experiment with plant-based food choices. “Eating a wide variety of fruits and vegetables is one way to ensure we eat enough prebiotics to stimulate a healthy gut microbiome,” says Maples. 

Science backs up that concept: According to a study, people who eat 30 or more plant varieties per week have a more diverse gut microbiome compared with those who eat 10 varieties or less. So the next time you’re in the produce aisle or at the farmers market, try a few things you don’t regularly buy. You may find that you love the new flavors — and your gut bacteria will thank you, too.

 
Editorial Sources and Fact-Checking

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