Beans tell a trickier story. Of course, we love ’em here at mbg–they’re full of fiber, protein, and important vitamins and minerals. But for some people, Means says they’re a sneaky spiker. “I can eat a can of beans, which is about four servings, and have no glucose response,” she says. “But there are other people who eat beans and [glucose] spikes through the roof.”
The reason, she admits, isn’t so clear, but she thinks it has something to do with the gut microbiome. She references a 2015 study in the journal Cell that put continuous glucose monitors on 800 healthy participants and gave them the same meals, assuming they would respond exactly the same. However, they found varying responses across the board–from no spikes to colossal spikes–and they discovered that their microbiome composition seemed to dictate those responses.
It’s not surprising, says Means: “The microbiome [does] a first pass on food,” she says. “They’re the ones who break down some of those early carbohydrates before it actually goes into the body. My co-founder David [Flinner] started eating huge amounts of chia every morning to get his fiber in, and over the course of the month after eating all this fiber day after day, he found that he no longer responded as much to beans.”
We need more research on beans in particular, but it does make sense that the microbiome would have some skin in the game.