a twist on you are what you eat... your sourdough is microbially like you

Sourdough Hands: How Bakers And Bread Are A Microbial Match

If you bake a lot of sourdough bread, your hands might look like your loaves. Bacterially speaking, that is. The microbes found on bakers' hands mirror the microbes within their starters — the bubbly mix of yeast, bacteria and flour that's the soul of every loaf.

That's the surprising finding from a sourdough bake-off experiment, coordinated by ecologists Rob Dunn and Anne Madden. Fifteen sourdough experts from around the world arrived at a Belgian baking center with brand-new homemade starters, fed from the exact same ingredients sent from Dunn's lab. But before the bakers could get their hands into the dough, they held them out to Madden for bacterial swabbing.

Partnered with analysis of the starter's microbial ecosystem, Dunn and his collaborators were able to draw a close connection between bread, bakers and their bacterial species.

"It's a reminder that we have a really intimate relationship with our food," says Dunn. "Not only do we impact the species in our food, but the species in our food impacts the species on or in our bodies."

In his new book, Never Home Alone, released Nov. 6, Dunn explores the species behind what he calls the "wild life" of our homes. "There's a lot more life in our houses than we think," he explains. "To the extent that we've thought about it, we've tried to kill it."

It's no surprise, then, that Dunn's survey of indoor species (including insects) lands him in the bakery with sourdough, which is brought alive by microbes. The experiment delves into how cooking with fermented foods might affect the microbes of the people who make them. In the book, Dunn describes how he formed the hypothesis that our bodies and environments influence the taste of our food.

The following interview has been edited for brevity and clarity.

(read interview)
[npr.org]