Get Dirty

Plus five other moves that bolster your good bacteria – and make you happier and healthier.

Portrait of Tammy Strobel

Plus five other moves that bolster your good bacteria – and make you happier and healthier.

This mud will keep you healthy.
This mud will keep you healthy.

You’ve no doubt heard about gut bugs and how important they are to your whole-body health. Studies have linked a balanced microbiome, as a community of such bacteria is known, to a more robust immune system, a trimmer body, a stronger heart, and a happier mood.

And, until recently, much of the buzz surrounding the good -for-you germs has focused on diet – specifically, probioticpacked yogurt and fermented vegetables. But while there’s no doubt that these foods help your microbes flourish, they are only part of the equation. Scientists now know that these good bacteria also live throughout your body, including your skin and nasal passages.

“Research indicates that things like how frequently you exercise, how often you get outside, and how you handle stress all affect your internal bacteria,” says Daniel McDonald, a researcher for the American Gut Project at the University of California, San Diego in the US. So keep eating your yogurt.

However, to really build up your bugs, start doing these other moves, too.

Avoid soaps made with triclosan, an antibacterial chemical that can kill good bacteria.
WASHED UP Avoid soaps made with triclosan, an antibacterial chemical that can kill good bacteria.

Adopt a daily fitness plan

People who exercise three or more times a week have more diverse gut bacteria than those who hit the gym less frequently, according to the American Gut Project. Working out speeds your digestion, which means food spends less time sitting in, and causing the inflammation of, your intestinal tract, where the lion’s share of your body’s healthy bacteria live, explains Christian Evans, an associate professor at the US-based Midwestern University.

The influence of exercise on your microbiome can even help keep you slim. Beyond torching calories, physical activity appears to encourage the growth of a specific bacteria linked to leanness while suppressing others associated with obesity, Christian adds.

In American Gut Project research, daily exercisers had the most diverse bacteria of all. But it is possible to go overboard. Studies show that some extreme athletes, like elite marathon runners, have a lower diversity. Too much exercise may overstimulate the immune system, which could have a negative effect on gut microbes. Balance your hard workouts with days dedicated to lowerintensity activities like yoga or walking.

Sign up for a mud run

Or take up hiking, gardening, or any other activity that requires you to get dirty. “When you play with soil, beneficial bacteria in the environment repopulate the community of bacteria on your skin,” says Dr Robynne Chutkan, a leading gastroenterologist, bestselling author of The Microbiome Solution, and founder of The Digestive Center for Women in the US. Without regular contact with these natural microorganisms, your own bugs can fall out of balance, resulting in a weaker immune system and even a slower metabolism.

Just opening your windows when it’s nice out or getting a few potted plants can help introduce healthy outdoor microbes into your system, says Justin Sonnenburg, an associate professor of microbiology and immunology at Stanford University in the US.

Use milder soap

Being too hygienic can kill off your beneficial bugs as well, Justin says. So limit your use of soaps and body washes labelled “antibacterial” or “antimicrobial”.

They indiscriminately wipe out a broad spectrum of bacteria, which could leave you open to skin irritation and even weaken your immunity. Instead, opt for mild cleansers. They’re less damaging to your skin’s microflora and are just as effective at keeping colds and fl u at bay.

Pay attention to mealtime

Gut microbes set their schedule based on what and when you feed them, says Vanessa Leone, a postdoctoral fellow at the University of Chicago Department of Medicine in the US. If you typically eat between 8am and 6pm, the bacteria responsible for digesting food will learn to become more active then and turn off during the hours you’re asleep.

If you suddenly start snacking at midnight or travel across time zones and begin eating at drastically different hours, your microbes won’t make that switch along with you, leading to improper food digestion. “They metabolise what you eat less efficiently, which can cause you to gain weight,” Vanessa says.

Maintain regular mealtimes as best you can and, when travelling, try to eat when you normally would at home. If that’s not possible because you’re in a different time zone, fill up on fibre. “Fibre fuels our good microbes and seems to help them adjust to our new eating rhythms,” Vanessa says.

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Become a dog person

Pup owners have a more diverse skin microbiome than their petless peers, according to research from the University of Colorado, Boulder in the US. That’s because a dog’s mouth is home to some powerhouse microbes rarely found on human skin.

Petting your pooch, sleeping with him, and letting him shower you with doggy kisses can help transfer his healthy bugs to you , Justin says. And since the bacteria that reside on your skin are your immune system’s first line of defence, that may help ward off viruses and illness-causing bugs, Dr Chutkan explains.

So far, it’s not clear whether cat owners enjoy the same perks. But a study in the journal Pediatrics found that babies who grew up around felines were less likely to get sick than those who didn’t.

Keep calm

There’s a biological reason that stress can make you feel sick to your stomach, says Dr Mladen Golubic, medical director of the US-based Center for Lifestyle Medicine Wellness Institute at the Cleveland Clinic. Researchers at Ohio State University in the US found that chronic anxiety can throw off your ratio of healthy-to-harmful gut bugs. That imbalance can cause glycaemic index issues and leave you more susceptible to illness, because 70 to 80 per cent of your immune cells reside in your intestinal tract.

Dr Golubic says that doing relaxing activities throughout the day – yoga in the morning, stretches or deep breathing at work, reading or listening to music before bed – can help keep stress at a minimum. The result: a happier, healthier microbiome


Antibiotic meds can wipe out the good bugs in your system. But if you have an infection, you don’t have much choice. Here’s how to protect friendly bacteria when have to take them.


Doctors tend to prescribe broadspectrum antibiotics because they require fewer daily doses. Before yours writes you a prescription, ask if there’s a medication that specifically targets your condition. You may have to take more pills, but the antibiotic will kill fewer strains of good bacteria in your gut, says Lauri Hicks, medical director of the Get Smart: Know When Antibiotics Work programme at the Centers for Disease Control and Prevention in the US.


Resist the temptation to rush back to work after your first or second day on antibiotics. It will place added stress on your microbiome and body in general.


Several studies have shown that probiotic supplements protect intestinal microbes against antibiotics, reducing side effects like diarrhoea. Look for a brand containing the lactobacillus and bifidobacteria strains, recommends Dr Chutkan. “Start taking them at the same time and continue for at least a month after you finish your course.”


Feed your body’s good bacteria with . . .

RESISTANT STARCHES such as green peas, lentils and white beans. Your gut bacteria ferment these filling complex carbs, producing nourishing short-chain fatty acids, Dr Chutkan says.

INULIN-RICH FOODS such as leeks, garlic, onions, artichokes, Jerusalem artichokes, and chicory root. Inulin is a natural sugar that is like fuel for your intestinal microbes.

FIBRE-DENSE VEGETABLES such as broccoli, asparagus and dark, leafy greens. They deliver a decent dose of both soluble and insoluble fibre, a combination healthy bugs will feast on.