• Gut health is a key cornerstone of our overall health as it can affect many bodily systems.
• A diet high in fiber, fermented foods, and polyphenols can help support a healthy gut microbiome.
• Emily Leeming, a gut health expert and dietitian, sees her breakfast as a chance to boost her fiber intake.

A gut health scientist and dietitian shared the two breakfasts she often eats to help boost her gut microbiome.

Gut health is a key cornerstone to overall health because it is thought to influence everything from the immune and endocrine systems to the brain, Emily Leeming, a gut microbiome researcher at King's College London and a former private chef, told Business Insider. Experts consider a gut that contains a diverse community of microbes healthy.

What's great about the gut microbiome, the name for the trillions of microbes that live in the gut lining, is that what we eat shapes it, Leeming, who is based in London and the author of "'Genius Gut: The Life-Changing Science of Eating for your Second Brain," said.

Eating a diet packed with fiber, polyphenols — the compounds that contribute to the pigment in many fruits and vegetables — and fermented foods, can help those microscopic bugs thrive, she said.

Leeming sees her first meal of the day as a key time to boost fiber by adding some veggies or fruits if she's preparing something sweet. She also tries to get around 20 to 30 grams of protein in each meal, including breakfast.

"It's those simple small changes that we make on a regular basis that actually have the most impact," Leeming said.

She combines all those elements while making her meals taste great.

"Food has to taste delicious, otherwise life is sad," she said.

Roasted veggies and eggs on rye pumpernickel toast

Leeming is a big fan of pumpernickel rye bread as it's high in fiber. "For one slice, it's around seven grams of fiber," she said.

She loves to pair it with roasted vegetables and eggs. She places them all in a small oven dish and roasts them for 15 minutes at 392 degrees Fahrenheit.

"At the moment, I've been doing zucchini and baby tomatoes," she said, adding that she mixes in harissa and crumbles feta cheese on top.

At the end, she sprinkles some mixed seeds on top for added fiber and protein.

"What's really surprising to many people is that whole grains, beans, nuts or seeds actually tend to contain much more fiber than fruits and vegetables, although of course we still need to get fruits and vegetables," she said.

Overnight oats

Overnight oats prepared in batches are another breakfast favorite, Leeming said. She uses rolled oats and adds kefir, grated carrot, apple, blueberries, cinnamon, mixed nuts, chia seeds, and flax seeds.

Leeming's oats contain lots of gut-loving ingredients. Chia seeds feature about 30 grams of fiber per 100 grams, and berries tend to be higher in fiber than other fruits because they contain seeds, she said. They're also high in polyphenols.

She opts for kefir, a fermented milk drink, instead of yogurt because it tends to contain more probiotics, the good microbes.

• An epidemiologist and nutrition expert eats at least three fermented foods each day for gut health.
• Tim Spector shared his tips on how to incorporate fermented foods into your diet.
• These include starting small, checking food labels, and "backslopping."

You may have noticed a proliferation of kefir and kombucha in stores lately. Fermented foods are everywhere, but can be a little intimidating to people who aren't used to them.

Tim Spector, a British epidemiologist and cofounder of the nutrition company Zoe, eats at least three different types of fermented foods every day to aid his gut health.

Research on fermented foods is still developing, but, according to a 2022 review in the journal Nutrients, studies suggest that they can reduce risks of cardiovascular disease and type 2 diabetes, and increase the diversity of bacteria in the gut. The gut thrives on a varied diet, so this diversity is important for digestive and overall health.

Spector told Business Insider how he incorporates fermented foods into his diet.

Start small

"Little and often" is the best way to start adding fermented foods to your diet, Spector wrote in his cookbook "Food For Life," which is due to be published in the US in 2025.

This allows you to get used to the taste and your gut to get used to all the new bacteria.

Spector recommends adding a tablespoon of different fermented foods to your cooking — for example, kimchi in a stew for "flavor and crunch," or kefir to a soup for "creaminess and tang."

This chimes with what other experts told BI: Tanzil Miah, a dietitian specializing in gut health, said adding kimchi or sauerkraut to sandwiches or salads, and using yogurt as a sauce or marinade are easy ways to add fermented foods to what you're already eating.

Check out labels of shop-bought fermented foods

"My advice to the fermenting newcomer is to find some commercial fermented products you enjoy and slowly work up to fermenting your own," Spector wrote in "Food For Life."

When buying shop-bought fermented foods, such as kefir, kombucha, sauerkraut, or kimchi, he recommends looking for products that are:

• Low in added sugar.
• Have few/no chemical additives.
• Not pickled in vinegar, which kills live microbes.

Then make your own

When you're ready, Spector said you can expand the scope of fermented foods away from just pickles and kefir. He now makes his own homemade labneh and a fermented mushroom-and-garlic spread, for example.

Making fermented foods at home is also great for the environment and your wallet because it reduces food waste, he said.

And it's easy. "You can ferment just about any plant," he said, using only salt or honey.

BI previously reported a Michelin-star chef's techniques for making homemade kimchi, sauerkraut, and pickles.

Or, Spector said, you can make your own kefir from the dregs of a store-bought bottle with a technique called "backslopping." To backslop kefir, add a tablespoon of good-quality kefir to a bottle of full-fat milk, leave it at room temperature until it thickens, and then store in the fridge.