Early understanding of the microbiome provides ripe space for scientists — and marketers
By Bill Briggs | Illustration by Breanna Welsh
Some of the tiniest life forms are generating some of the biggest hype. Our microbiomes — ecological communities of bacteria and fellow microbes residing within us — are fertile ground for shaky medical claims and shady websites vowing to cure everything from anxiety to autism.
Hucksters hoping to profit from the legitimate excitement springing from this Lilliputian landscape are increasingly drawing criticism from scientists working to crack the microbiome's tantalizing promise. Some researchers use a Twitter hashtag to call out such quackery: #microbiomania.
"The science here has enormous potential and I do not want that potential to be damaged by the BS and the hype," said Dr. Jonathan Eisen, an evolutionary biologist at the University of California, Davis. He uses his science blog, "The Tree of Life," to pick apart what he sees as microbiome lies or misconceptions.
"The microbiome is ripe for snake oil because it is so complex and thus easy to lie about and oversell," Eisen said.
Let's put some common microbiome claims under the microscope.
"This is not true," said Fred Hutch's Dr. David Fredricks, who studies patterns of gut bugs in cancer patients who have blood stem cell transplants. "Indeed, the probiotic strains of bacteria tend to be minority species. The normal inhabitants still dominate."
A container of yogurt typically has a few billion helpful bacteria. But a healthy human gut is home to tens of trillions of bacteria and other microbes.
That means yogurt makers cannot legally say eating their products will regulate digestion. In 2010, Dannon ran afoul of the Federal Trade Commission for a series of ads featuring actress Jamie Lee Curtis claiming one daily serving of Activia probiotic yogurt relieves irregularity. In an agreement reached with the FTC, Dannon agreed to pay a $21 million fine and to stop making that assertion.
The theory is called the "gut-brain connection" — the idea that bacteria in your digestive tract may have some influence on your thoughts and feelings. A 2013 study led by researchers at the California Institute of Technology found that when mice with autism-like symptoms were fed a common bug called Bacteroides fragilis, it changed their microbiome and appeared to make them less anxious.
While this and other preclinical studies have provided "very good data" on an apparent microbial link between belly and brain, science still lacks clinical proof tying the microbiome to mental conditions, said Dr. Ted Dinan, a psychiatrist and microbiome researcher in Ireland.
"Many large-scale, spurious claims are (nonetheless) being made" about the health benefits of swapping out your gut bugs, Dinan told the FiveThirtyEight blog. For example, a psychology magazine recently published six steps to balance your intestinal bugs in order to balance your moods. One of their suggested steps: "Eat probiotic foods."
Welcome to the "hygiene hypothesis," which poses that exposing kids to germs early will prevent asthma later. In 2015, a New York City geneticist told journalists, "I would advise any new parent to roll their child on the floor of the New York subway."
"This is part of microbiomania where people somehow have forgotten about infectious disease and how, not only did it kill billions, it still is one of the biggest killers on the planet," said Eisen.
"No, rolling around in dirt or licking the floor or your toilet is not a good idea," he said. "Yes, increasing microbial exposure on average can be beneficial."
And when it comes to scrubbing away germs, the FDA says there's no evidence that antibacterial soaps stave off illness any better than plain ol' soap and water.
For some patients whose bodies harbor the potentially lethal bacteria Clostridium difficile, transplanting donated poop from a healthy person via colonoscopy may restore the natural balance of bugs that restrain C. diff. For now, that's the most definitive statement scientists can make on the procedure.
But a handful of physicians are stretching that truth. At a national medical conference in 2012, a well-known gastroenterologist said "even more exciting is the use of fecal transplantation for a wide range of diseases (including) Parkinson's disease, multiple sclerosis (and) autism."
Citing that same doctor, an alternative-medicine website now proclaims that fecal transplants have "been proven to be a highly effective treatment" for patients with Parkinson's disease, clinical depression, and multiple sclerosis. The website shows readers how to do DIY fecal transplants by liquefying donated feces with a kitchen blender, pulling the poop into a rectal syringe, emptying the syringe into the rectum and advising readers to keep "the liquefied feces inside your colon for at least 2 hours or longer" to be cured.
The website caught Eisen's critical eye. He called it "snake oil" and said such unscientific claims are "dangerous," adding that real risks come from "dishing out false hope."