Bill Gates thinks understanding the body’s microbiome will help solve malnutrition

In 2017, just before legendary physicist Stephen Hawking passed away, the Cambridge Union Society inaugurated a fellowship in his name. The second-ever Professor Hawking Fellowship—created to honor impactful contributions to the STEM fields—was just awarded to Bill Gates.

In the fellowship lecture he presented at the Cambridge Union on Monday (Oct. 7), Gates discussed the strides he hopes—actually, predicts—we will see in global public health in the next 20 years. Reflecting the focus of his philanthropy through the Bill and Melinda Gates Foundation, Gates made a forecast that every country will soon be able to focus on improving lives, rather than playing catch-up to save them.

And a big part of that puzzle, he said, will be solving the problem of malnutrition.

Malnutrition contributes every year to the deaths of more than 2 million children under five—and in two decades, Gates said, we’ll have significantly cut down on those deaths. How? In his view, at least in part through scientific understanding of the microbiome, the community of bacteria that live in and on your body.

Gates was referring specifically to the microbiome of the digestive tract, which looks substantially different than normal in malnourished kids. Medical knowledge of these bacterial collectives is still in its infancy—there’s little to suggest the premium you pay for probiotic yogurt has any impact on your health, for example. But when it comes to the scourge of stunted growth, scientists have some leads that microbiome-targeted foods and treatments may help.

In his address, Gates referenced work by biologist Jeff Gordon from Washington University in St. Louis, who in 2013 published a study about the microbiomes of young twins. In some cases, one twin developed a severe form of malnutrition while the other remained healthy. In those cases, despite receiving the same therapeutic foods (and sharing genetics), each pair of twins had very different microbiomes. And when researchers transplanted the microbiomes from malnourished twins into mice, the animals themselves had trouble absorbing nutrients.

“So this study showed for the first time,” said Gates, “that the microbiome is not just a byproduct of your health but also is a key component of your nutritional health.”

Early research in mice is a far cry from solving global human malnutrition. But the field’s work has continued. This year, Gordon and collaborators around the globe published two follow-up studies in the journal Science that reinforce Gates’ assertion that foods and treatments tailored toward fostering healthier microbiomes could help kids absorb more nutrients and avoid the long-term effects of stunting, in addition to preventing deaths.

“These microbiome targeted therapies are still in early testing,” Gates acknowledged, “but I believe we’ll find a way to make them work.” Because they’re relatively inexpensive and easy to deliver, global distribution could be simplified, Gates added, leading to dramatic cuts in stunting. “That is as big a breakthrough as anything else we will do in health over the next two decades.”

It’s a provocative prediction. There are known challenges to developing effective microbiome-targeted therapies: Microbiomes act as communities, and collectively, they tend to hold on tight when interloping strains of bacteria appear. Most probiotic pills likely just get pooped out before they have the chance to change anything inside your organs. And while microbiome therapies have been studied to treat serious gut infections like Clostridium difficile, researchers have yet to identify the specific strains that are critical to unseat the bad bugs. Identifying the bacteria that have the greatest impact on nutrient absorption will likely be just as difficult.

Even if those issues with targeting and treatment efficacy pan out, the microbiome won’t be the whole solution: As Gates acknowledged, there are many causes of malnutrition, from food scarcity and micronutrient imbalances to infections and maternal nutritional deficiencies. An undeveloped microbiome is another—but it’s one of the only causes that we don’t already have a good understanding of. If there’s a place where research and innovation can make a real dent in the shape of global public health, this could certainly be one.