In 2020, Abhishek Chaki began having mysterious pain in his abdomen, bloody diarrhea and bouts of fatigue. Sometimes his symptoms necessitated trips to the emergency room. Other times flareups left him bedridden. “It came out of nowhere,” he says. Having read that the body is influenced by the gut microbiome—the rich, vital community of bacteria, viruses and fungi that coexist within the digestive tract—he stumbled across a startup called Viome Life Sciences Inc. He bought its standard at-home stool-testing kit, which the company uses to analyze an individual’s gut microbiome and recommend a customized diet based on their unique biochemistry. “Got digestive issues?” Viome’s marketing asks. “We got solutions.”

Testing one’s gut is not for the squeamish. While Viome sells $259 standalone gut health tests, like the one Chaki bought, it heavily promotes its $399 signature Full Body Intelligence test, which involves mailing in fresh stool (to test the gut microbiome), saliva (to test the oral microbiome) and blood samples (to assess “cellular function”). This requires spooning out a pea-size amount of poop and pricking a finger to squeeze out enough blood to fill two pipettes. The company’s artificial intelligence technology analyzes the mailed-in samples; within a few weeks, customers receive a report and a detailed action plan for avoiding harmful foods and consuming “superfoods.” There’s also a health assessment dictating suggested improvements, such as “inflammation response” or “metabolic fitness.” To address any nutrient deficiency or replace a blacklisted food, the company offers a fix, too: a subscription to customized Viome supplements. It also recommends repeating the entire process every four to six months.