Editorial: Going with Your Gut

Four years ago, I wrote an editorial entitled “To Trust or Not To Trust (Your Gut)?” (Oct. 2016, p. 3), which discussed intuition and the gut feeling we get when we know something is right but are not able to articulate why. This issue’s special section on microbiome engineering gives new meaning to the phrase going with your gut. In “Leveraging Bugs as Drugs” (pp. 39–43), Sebastien Guery et al. point out that the gut microbiome, which consists of more than 3,000 microbial species, is so closely linked to the host that the composition of the gut microbiome is specific to an individual — similar to a fingerprint or DNA.

I learned about that as I was binge-watching episodes of Scorpion, a TV series about a team of super-geniuses who serve as the last line of defense against extremely complex, high-tech threats around the globe. In one episode, Team Scorpion is hired to inspect the artificial intelligence system of a doomsday bunker. The bunker is controlled by an AI module called Dorie, which provides cutting-edge security that combines facial recognition with a breath analyzer. The bunker door does not have a lock (which could be picked) or a password (which could be hacked). Instead, the owner gains access by blowing onto a sensor. A “National Institutes of Health study recently found each person has unique gut flora,” explained Quincy Berkstead, the psychiatrist who helped design the bunker. “Like a gastronomic fingerprint,” Florence, the chemist working with the team, pointed out.

A series of plot twists led to Dorie activating a protocol that would release a deadly neurotoxin gas, which the team realized could be stopped only if they could get Quincy out of the bunker to blow onto the sensor. But Quincy, to avoid being exposed to the gas, had locked himself safely inside a hermetically sealed chamber. Fortunately, the geniuses realized that they didn’t need Quincy — only his gut flora. So they removed the carbon scrubber canister filtering the chamber’s air, used an electrostatic charge to capture the microbes that Quincy had exhaled, and placed the microbes into a can of compressed air. They managed to get the can out of the bunker and sprayed the microbe-containing air onto the sensor. Dorie recognized Quincy’s gut flora, canceled the gas-release protocol, and opened the bunker door — with one second to spare.

The writers of that Scorpion episode might have been inspired by the work of Eric Franzosa, a research associate at Harvard’s T. H. Chan School of Public Health. He and his colleagues analyzed publicly available data produced through the Human Microbiome Project, which surveyed microbes in stool, saliva, skin, and other samples from over 200 people. They found that individuals could be uniquely identified based on their microbiomes, and in the case of the gut microbiome, over 80% of individuals could be identified up to a year later. That’s impressive, since as Guery et al. note, “these ecosystems are in a constant state of flux, changing daily based on the host’s food and medicine intake, lifestyle choices, and geographic location.”

While there appears to be a scientific basis for that episode, I would want better odds than an 80% chance the AI system would recognize me and let me into my bunker. My gut tells me this technology is not yet ready for prime time.

Cynthia F. Mascone, Editor-in-Chief