Zoe sequences my microbiome using a technology called shotgun metagenomics, which maps DNA. I prefer Viome’s app and what my husband calls “user experience.” But I prefer my results from Zoe. Zoe divides my microbes into “good” and “bad”—though I now have Antoine’s voice in my head reminding me it’s just association. My Blood Sugar Control is “Excellent.” My Blood Fat Control and Microbiome Biodiversity are “Good.”
I compare the two lists of microbes. There’s some overlap, and some divergence. Maybe my microbiome changed. Maybe the companies use different datasets for identification. Looking back and forth, it occurs to me that there’s no standardized dataset against which to compare results. There’s no universal terminology, no consensus about which variables matter and what causes them to vary.
More perplexing is what to do next. Viome instructs all clients to avoid sugar, flour, soda, and cured meat. My personalized list of “avoid” and “minimize” foods from Viome is short: cassava, couscous, barley, maple syrup, molasses, white rice, and breadfruit—plus red bell peppers because, apparently, my gut hosts a red bell pepper virus I’m obliged to starve out. Otherwise, I’m supposed to eat “superfoods”—like cabbage, fennel, and bamboo shoots—and take $199 worth of custom formulated precision supplements, prebiotics, probiotics, and oral lozenges, each month. (Each supplement pack arrives with my name printed on it, which is oddly flattering.)
Zoe doesn’t sell supplements. Its researchers advise me to avoid my “gut suppressors”—which include canned soup and cheese-flavored corn puffs—and eat “gut boosters,” including avocados, lentils, kale, collards, peas, chickpeas, kidney beans…and bell peppers. Zoe’s lead nutritionist, Federica Amati, tells me that this will provide a beneficial substrate for my good bacteria and ideally starve “the bad guys.” When I review all the recommendations side by side, they amount to avoiding processed foods and eating lots of plants. “I just don’t know that the science is quite there yet for recommendations to be that accurate on an individual basis,” is Raj’s assessment. Suzanne Devkota, director of the Cedars Sinai Human Microbiome Research Institute, is even less ambiguous. “The sequencing part of most of these tests is probably fine, but the recommendations they give you are all crap.” She recognizes the value in Viome’s data. “But what to do about it? We still don’t know.”
Because they aren’t FDA regulated, at-home microbiome tests can’t diagnose anything really worrisome. Even if there were an accepted microbial fingerprint for leaky gut, or depression, or insomnia, neither Viome nor Zoe would have been legally allowed to identify it to me. Devkota, who’s advocated for FDA oversight of at-home microbiome tests, believes the tests have a place in health assessment—she tells me: “I think everyone should have a healthy baseline, and that includes the microbiome. What I recommend is to only use one company, and buy a few of the kits and test yourself every six months. And only compare your data to yourself, and totally ignore where they put you on a plot.” I ask Alessio Fasano, MD, professor of nutrition at Harvard T.H. Chan School of Public Health and director of the Mucosal Immunology and Biology Research Center at MassGeneral Hospital for Children (he also sits on Viome’s advisory board), how science knows that if I follow my recommendations my microbes will move in the right direction. “That’s the $30 million question,” he says with a laugh. “And to make a long and complicated story short: It’s definitely a work in progress.”