The Importance of a Healthy Gut

Photo: Masterfile

If you have heard of the microbiome at all, you likely have no idea what to make of it.

In recent years, scientists have published a series of discoveries linking changes in the trillions of micro-organisms that coexist peacefully in our skin, mouth and especially our gut-whose collective genomes are known as the microbiome-to health problems as diverse as asthma, cancer and obesity. Yet, apart from a growing chorus of questionable Internet gurus, advice on how to acquire a better microbiome is scarce.

There is good reason for that. Scientists emphasize that, while we know that microbiomes differ from culture to culture, person to person and even day to day, we don’t yet know exactly what a “good” gut composition looks like. However, at this point, the broad strokes of microbiome research point toward changes to our habits we know to be beneficial.

“The function and diversity of this community is affected by lifestyle choices, the most important of which is what you eat,” says Justin Sonnenburg, a microbiologist at the Stanford University School of Medicine in California and the co-author of a forthcoming book about the microbiome and health. “It’s early days, but if you take the whole body of literature
and distill it, it’s screaming some really obvious things at us.”

In two studies published together in an August 2013 issue of Nature, scientists from Danish, French, German, Chinese, Spanish, Dutch and British research centres reported that individuals with less diverse microbiomes tended to have more body fat and higher insulin resistance than those with more bacterial richness. In overweight individuals, a high-fibre diet with lots of fruits and vegetables increased bacterial richness and led to improved clinical symptoms of obesity. Fibre-rich foods, which we already know are better for us, are likely better for our microbiomes, too.

What about antibiotics, which kill the good bacteria along with the bad? These drugs are still our best line of defence against many common and potentially life-threatening ailments; when antibiotics are necessary, make sure to nurture your microbiome. A 2012 meta-analysis published in The Journal of the American Medical Association found that adults and children who consumed probiotic products had a lower risk of diarrhea after using antibiotics.