Prebiotics: The first step in gut health | Corwell Health

You’ve heard of probiotics, but what about prebiotics?

Probiotics may be taking over the spotlight these days — and space on store shelves.

But if we want them to do their best and keep us healthy, we need to take care of what we give them.

This is where prebiotics come in.

It’s very important,” said Krista Gast, registered dietitian and health and wellness coach. Lifestyle Medicine Program at Corewell Health.

These two elements combine to create a healthy gut microbiome, which in turn supports digestion, the immune system, and physical and mental health.

Just explained how the role of the gut microbiome affects our health and suggested foods that can help keep it looking its best.

Support your immune system

“Prebiotics is an umbrella term that includes many things,” she said.

Mostly, it refers to plant foods that contain fiber, but it also includes resistant starch or fermented foods, as well as healthy fats.

“There’s an ecosystem that lives inside our gut. There’s easily 90 trillion microbes,” Gast said. “It’s really amazing.”

These microbes — the beneficial bacteria called probiotics — digest and ferment the prebiotics.

They produce short-chain fatty acids, also called postbiotics.

“The prebiotics are very anti-inflammatory,” Gast said. “70% of the immune system lives on the other side of the intestinal wall.”

The gut plays an important role in regulating the immune system, helping it to be active enough to fight infection but not overactive, which can lead to autoimmune diseases.

Post-biotic anti-inflammatories also suppress disease-causing bacteria — the so-called bad bacteria — in the gut.

On the other hand, a diet high in processed foods and low in fiber allows disease-causing bacteria to thrive.

Brain boost

Between the brain and the intestines the vagus nerve runs, like a highway allowing constant communication back and forth.

The gut microbiome plays a large role in the production of hormones, including serotonin, known as the feel-good hormone.

“Up to 90% of serotonin is produced with the help of the gut microbiome,” she said. “When our gut is not working properly, we can see a shift in our ability to respond to stress. It can also affect depression and anxiety.”

Short-chain fatty acids created in the gut can cross the blood-brain barrier and support brain function.

Researchers are studying the impact of the gut microbiome on cognition and even the development of chronic diseases such as Alzheimer’s.

“Preventing chronic disease could be another thing in our toolbox,” Gast said.

fueling fibres

Some fiber is insoluble — it adds bulk to stool and helps keep the digestive tract moving.

For prebiotics, look for foods that contain soluble fiber. Good sources include:

• onion
• garlic
• asparagus
• Beans and legumes
• Cruciferous vegetables such as broccoli and cauliflower
• leafy greens
• All cereal
• Fruits, including apples and berries

Jerusalem artichokes, also called sunchokes, are another rich source of prebiotic fiber. They look like ginger root and can be roasted like potatoes.

But if you try Jerusalem artichoke, Just advises taking it slow. “If you’re not used to it, it can cause gastrointestinal distress,” she said.

In general, Just suggests going “low and slow” in increasing the fiber content of your diet. This is especially true for those who suffer from constipation or inflammatory bowel disease.

More gut-friendly foods

Fermented foods are also good for the gut microbiome, including:

• sauerkraut
• kimchi
• kombucha
• Yogurt and kefir with live cultures

Foods that contain omega-3 fats also feed the probiotics. Good sources include:

• Chia seeds
• flaxseed
• Walnuts

Resistant starches also feed the beneficial bacteria in the gut. They are carbohydrates that resist digestion in the small intestine and are fermented in the large intestine, acting as prebiotics.

Examples include:

• green banana
• Potatoes that have been cooked, cooled, and reheated
• Cooked and cooled rice

The most and the merrier

Gast avoids calling any plant a “superfood”.

Instead, she suggests including a wide variety of fiber-containing plants.

“One of the greatest indicators of gut health is the diversity of flora that enters our gut microbiome,” Gast said.

Consider keeping track of the plant-based foods you eat for a week, and aim for a rich variety.

“Herbs and spices are important, too,” she said. “They really do have powerful antioxidants that microbes love.”

Researchers found that people who consumed 30 unique plant foods per week had significantly more diverse gut microbes than those who ate only 10.