Adding to the steaming pile of unsubstantiated hype over probiotics, the New York Times ran an uncritical article this week suggesting that a probiotic of heat-killed bacteria can treat obesity.
Of course, the data behind the story does not suggest that. In fact, the study is so small and the data so noisy and indirect, it’s impossible to come to any conclusions about efficacy. There’s also the nit-picky complaint that the study deals with dead bacteria, while probiotics are generally defined as being live bacteria. More importantly, the study was authored by researchers with a clear financial stake in the treatment succeeding. They hold a patent on the treatment and have started a company based on it—two details the New York Times seems to have forgotten to mention.
In many ways, the study is pretty typical of those on probiotics. The field is riddled with underpowered and/or poor-quality studies that use a wide mix of methods, metrics, and surrogate endpoints—that is, stand-ins for actual clinical outcomes, like measuring tumor shrinkage rather than actual cancer survival to assess a new therapy. According to a recent review of probiotics, the field’s hard-to-compare studies form a mucky mess, “collectively leading to conflicting, ambiguous, and debatable overall conclusions.”
The premise of probiotics isn’t a crazy one. Generally, the buggy drugs aim to manipulate the multitudes of microbes in our guts to boost health. There’s good reason to think that’s possible; our wee residents seem to dabble quite a bit in our well-being, influencing metabolic disorders, inflammation, hormone cycling, and our defenses against invading germs. As such, researchers are diligently studying the large, complex communities in our innards—our gut microbiomes—and getting closer to understanding their structure, function, ebbs and flows, and potential to be harnessed for good.
But the microbiome field is still littered with open questions, and companies and supplement makers have leapt over the holes to make remarkable claims with flimsy studies—and hawk unsubstantiated products. Just as bogus stem cell clinics profit off the potential of regenerative medicine research (and blinding people in the process), probiotic makers are exploiting excitement over the microbiome and getting ahead of the data.
Just last week, researchers suggested that a particular microbe in the guts of elite athletes may have a hand in making them elite. And the researchers started a company. But the study involved poop samples from just 15 runners and the—slight—performance boost was only seen in a small group of mice running on treadmills. On average, they ran a few minutes longer than control mice…[ ]