‘The freeze-dried poop method’ might not sound like a weight-loss strategy that would catch on, but, as some researchers are now testing, it may be an effective way to slim down. A trial will offer some of the first human data on microbe transplants and weight. In a randomized, controlled clinical trial starting this year, researchers will test out such a fecal formula for the treatment of obesity. They’ll also try to glean critical details about the human microbiome and its role in our health and metabolism. The trial will involve taking fecal samples from lean, healthy donors then freeze-drying the stool, putting a gram or two into capsules, and giving them to 20 obese patients. Such poop-packed pills, which are designed to replace a person’s intestinal microbes with those from a donor via their feces, have proven effective at treating tenacious gut infections. This has led researchers to ponder whether the transplants could remedy other health problems, including obesity and metabolic disorders. A few animal studies and some anecdotal data in humans suggests the answer is yes. Patients will receive weekly poop doses for six weeks, then researchers will track their weight and health at three, six, 12 months, and possibly beyond depending on how the trial goes. If it works, we can do all of the detail-oriented work to try to figure out which microbial communities are being affected to give more information for targeted treatments in the future.