I started getting questions about Netflix’s new gut-health documentary before it even came out. The trailer for “Hack Your Health: The Secrets of Your Gut” was pushed to multiple people in my life (including me), presumably based on our past viewing habits—I don’t typically watch things like that for fun, but I’ve been using my account for research purposes recently, so now I’m getting served all the wellness-y stuff. But it was also pushed to family members who don’t really go for that sort of thing, so maybe the algorithm is casting a wider net with this one.
Given the questions plus my general interest in gut health, I decided to watch this doc. I was ready for it to be full of overblown rhetoric about the gut’s role in well-being, but the hype was even more egregious than I’d anticipated—and with a level of casual fatphobia that felt out of place in 2024.
The film opens with Giulia Enders, a telegenic German medical doctor and researcher who is arguably the world’s biggest hyper of gut health, walking through a field of tall grass with a telescope. As we watch her set it up and peer through the lens, she explains in voiceover that humans have made incredible discoveries about this planet and even visited the moon, but that “hardly anyone has really adventured into their own gut.”
Despite the relative newness of gut research, she and the other featured experts are surprisingly confident in their claims. Within the first minute, we hear that the gut can determine whether we are “overweight” or “obese,” whether we get diseases like heart disease, autism, depression, anxiety. There’s footage of people eating fast food, meat, and soda, intercut with celebrities making wellness claims and four “regular people” expressing confusion about what to eat and how to be healthy. Then, the chorus of gut researchers, fronted by Enders, chimes in: looking at all of these issues through the lens of the gut makes everything clear. As the opening song crescendos, Justin Sonnenburg, another famous researcher and purveyor of gut-health hype, delivers the film’s thesis: the gut is “the center of a biomedical revolution.”
Of course, the gut microbiome is a hot area of research, and there may well be some cause for excitement. There is some observational evidence showing correlations between gut microbes and certain health outcomes, and while it’s still far too early to make the kinds of causal claims that get thrown around in the doc, I’m sure it’s an exhilarating time to be a researcher in this area—designing studies, testing theories, exploring what feels like a whole new universe. The film does a good job of capturing that heady feeling.
There are other things to like about it, too. The production values are great, as you’d expect from Netflix. There’s cute stop-motion animation with little woolen dolls and animals—though unfortunately it’s sometimes deployed in wildly weight-stigmatizing ways, like showing creatures blowing up like balloons and rolling away after eating certain foods. My favorite part was the four featured non-experts—particularly Maya Okada Erickson, a Michelin-starred pastry chef with an eating disorder, who is thoughtful about how her fear of food could play a role in her digestive issues, and who candidly says that the experts’ recommendations of foods to eat and avoid probably won’t be helpful given her tendency toward obsessiveness. I wish the film spent more time with these people and showed them getting some real help for their issues—three of the four seem to be struggling with some degree of disordered eating, and one has a history of chronic dieting.
Instead, the health claims really dominate this doc, which I think is to its detriment. There are too many to address here today, and I’ll likely continue to unpack some of them in my ongoing coverage of gut health. But today I want to focus on two claims: that the microbiome determines your weight, and that it can dictate what diseases you get. Both of these claims conflate correlation and causation, and neither is based on solid science. In fact, it’s surprising just how shaky the evidence for them really is.
