The One Nutrient Gastroenterologists Want You to Eat More Often (It's Not Fiber)

When it comes to gut health, dietary fiber and probiotics often take center stage in the conversation. But according to experts, there's one nutrient you may be overlooking: healthy fats.

When we say healthy fats, we're talking about polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs). These fats are associated with a number of health benefits, like lowering your risk of heart disease, per the Harvard T.H. Chan School of Public Health.

As it turns out, these fats have an important effect on the gut microbiome, too. Here's why gastroenterologists think you should incorporate more healthy fats into your diet — and where to get them.

A diverse gut microbiome is a marker of good gut health. It means that there's a wide array of different microorganisms, including prebiotic and probiotic bacteria, living in the digestive tract.

Bacterial diversity in the gut has been linked to improved immune function and may help treat and prevent chronic health conditions like obesity, diabetes, cancer and gastrointestinal disorders, according to a July 2019 article in ​Nutrients​.

Unsaturated fats play a role in promoting a diverse microbiome. When you eat them, these fats pass through the digestive system to the colon, undigested and intact. There, they serve as prebiotics, which feed the good bacteria and allow them to multiply, according to January 2022 research in ​Foods​.

There are two main types of long-chain fatty acids: omega-3s and omega-6s. Achieving a good balance between them is essential for good gut health, according to Chris Damman, MD, Gastroenterologist and Chief Medical/Science Officer at Muniq.

"Having less omega-3 than omega-6 in your diet contributes to inflammation in the body," Dr. Damman says. On the other hand, getting more omega-3s than omega-6s may improve your immune response and lower inflammation.

More specifically, omega-3s may help to decrease inflammation in the intestine, according to an October 2019 review in the ​International Journal of Molecular Science​. Intestinal inflammation is the signifying factor in inflammatory bowel disease (IBD)

Recent studies suggest that polyunsaturated fats may reduce inflammation in people with inflammatory bowel disease (IBD), according to a June 2017 review in the ​World Journal of Gastroenterology​.

The gut lining is a layer of mucus that protects it from invading organisms that can harm your health. It also plays a role in our absorption of nutrients, according to a January 2022 review in ​Biomedicines​.

But sometimes, the gut lining becomes damaged. Large holes form that allow undigested food, toxins and other bugs to pass through and enter the body — a condition called leaky gut syndrome, according to Harvard Health Publishing.

This often happens when there's an imbalance between helpful and harmful bacteria in the gut. But because healthy fats help those good bacteria to multiply, they may also reduce or prevent damage to your gut lining, per the January 2022 research in foods.

"Healthy fats like omega-3s promote cellular clean-up and help restore balance in the gut, which protects your intestinal lining," Dr. Damman says.

To best support your gut health, you don't want to focus on a single nutrient. Instead, try to eat a diet incorporating foods with a wide array of gut-supporting nutrients.

Luckily, many foods high in healthy fats have other nutrients that support a healthier gut. These include:

• Salmon
• Mackerel
• Flaxseeds
• Chia seeds
• Walnuts
• Olive oil

Fish contains collagen peptides, which may help strengthen and protect the gut lining, especially for people with IBD, per August 2019 research in ​Marine Drugs​.

Nuts are loaded with resistant starches, which function as prebiotics and support bacterial diversity in the microbiome, according to a July 2020 review in the ​British Journal of Nutrition​.

The monounsaturated fats and dietary fiber in avocados have both been connected to favorable changes in the gut, according to an April 2021 study in the ​Journal of Nutrition​. People who ate a daily serving of avocado for 12 weeks had an increased number of beneficial bacteria compared to a group that did not eat avocado.