Feel good INSIDE Why and how to build a healthy gut

Research suggests that two groups of bacteria that live in your gut play key roles in your overall health. In the future, they could lead to new treatments and maybe even diabetes prevention

Even when you’re sitting alone in a room, you’re completely outnumbered. Inside your body is a microbiome made up of trillions of living organisms that help you fight disease and process nutrients, and can also make you sick. These critters live all over your body, but the largest microscopic world is in your gut. Researchers are working to uncover the secrets of the gut microbiome, which may offer promising new treatments for diabetes.

WHAT MAKES A HEALTHY GUT?

We’re all born with a clean slate, gut-wise, and start acquiring microbes at birth. Everyone’s belly contains a unique combination of organisms, carrying a few hundred of the roughly 1000 known species of microbes.

That variation makes it tough to define a healthy gut, says Dr Robert Karp, program director for genomic and microbiome studies at the US National Institute of Diabetes and Digestive and Kidney Diseases. “There isn’t just one healthy version, and there are many ways to get one,” he says.

But research suggests diversity is a crucial aspect of good health.

“The general idea is that a diseased microbiome is relatively depleted,” Dr Karp says. “It doesn’t have the variety of microbes a healthy microbiome does.”

One danger to your gut seems certain: antibiotics.

They can change your gut’s composition, and some people never recover – scientists can’t yet predict who will be affected permanently. “Don’t use them unless you absolutely have to,” Dr Karp says. (See Action Steps, page 99.)

THE GUT-BRAIN CONNECTION

Research suggests microbial variety matters because these belly dwelling bacteria perform so many functions and also send feedback to the brain.

“They process what we have in our bodies then send signals back to us,” says endocrinologist Dr Betul Hatipoglu.

Just as the gut microbiome changes – due to antibiotics, diet and sleep disturbances

– so do those signals.

“When we start growing more of the bad bacteria for whatever reason, they work against us,” Dr Hatipoglu says. “They produce chemicals that go to our liver and then to our blood, causing changes in our system. They make us more insulinresistant, prompt inflammation and cause blood glucose to rise.”

YOUR GUT AND DIABETES

Along with the insulin connection, your gut is related to diabetes in other ways.

When it comes to obesity and type 2, research strongly suggests two specific groups of bacteria play the largest roles: Bacteroidetes and Firmicutes. Though not all studies agree, multiple comparisons of the gut flora of lean and obese people found there was a higher proportion of Bacteroidetes in lean participants.

“The Bacteroidetes group are involved in protein and carbohydrate digestion,” Dr Hatipoglu says. “Firmicutes are involved more in fat processing. People with more Firmicutes seem to have an increased risk of obesity and type 2 diabetes.”

Today, scientists are examining the roles those two bacteria groups play to determine whether it’s the amount of each or the ratio that matters most. They’re also looking for ways these new discoveries could treat or prevent all types of diabetes.

Some doctors are exploring customised dietary plans based on each person’s unique gut microbiome. Others are examining the potential for treatments using faecal transplants from non-diabetic donors. (Yes, we mean poo! That’s where your gut bacteria ends up eventually, and faecal transplants are a relatively straightforward process.)

Because the science is still so new here, experts recommend caution before jumping on any fast-fix bandwagons.

“We’re just on the cusp of understanding this,” says Dr David A. Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School and editor of the textbook

The Gut Microbiome.“We’re starting to get into the evidence that meaningful differences can come from simple things – maybe just from changing your diet.”

ACTION STEPS

So what can you do today to improve your gut microbiome? While scientists don’t know exactly which bacteria – or how much of each group – our bodies need, experts agree that certain behaviours can throw off the balance in our bellies.

“It’s like buying a plant,” Dr Hatipoglu says. “If you don’t give it sun and water, it’s going to die. You have to give the right environment to those good bacteria so they’ll keep growing and help you.”

To give those bacteria what they need to stay healthy:

• Eat more fibre

Bacteroidetes, which several studies have found to be the “good guys”, tend to thrive on a plant-heavy diet.

• Try kimchi

Scientists don’t know exactly why yet, but fermented foods act like a natural probiotic in our bellies, supporting the growth of healthy bacteria. Naturally fermented foods include kefir, yoghurt with live and active cultures, kimchi,

kombucha and homemade sauerkraut and pickles (storebought are sterilised and lose their probiotic effect).

• Get more sleep

Studies in mice and humans have shown a disruption in circadian rhythm (such as from insomnia or jet lag) can affect the mix of bacteria in your gut.

• Skip probiotic supplements

“When you take these, you’re changing whatever your basic bacteria is – you’re preselecting an organism that maybe didn’t have as strong a presence before,” Dr Johnson says. “We don’t know yet which probiotic works for which patient.”

• Be sure about antibiotics

Avoid using them unless your doctor thinks you won’t be able to recover without them.

“Regardless of which antibiotic you take, it’s changing out some bacteria,” Dr Johnson says. “These are major, profound changes that may not be good – and they’re certainly longlasting.” If you need antibiotics, support your gut with a diet that’s rich in fibre.