From Swiss to cheddar, cheeses depend on the action of microbes for their flavor and aroma. But it's far from clear how these teams of microbes work together to ripen cheese.
To a cheese-maker, that's just the beauty of the art. To a scientist, it sounds like an experiment waiting to happen.
A handful of scientists who study cheese recently gathered to share their latest findings at a farm in the English county of Somerset. They know cheese well here — after all, Somerset invented cheddar.
Somerset cheese-maker Jamie Montgomery hosted the conference. "We've been making cheddar here for three generations," he says. "My grandfather bought the estate in 1911."
Montgomery's cheese is particularly microbe-rich. That sets it apart from most supermarket-bought cheese, which is made from milk that is pasteurized to kill any potentially harmful bacteria. Then a few microbes are added back in to ferment the cheese.
But Montgomery and many other artisan producers never pasteurize their milk – it's raw. The milk's natural microbial community is still in there. This microbial festival gives it variety and richness that commercial cheeses can't copy.
"That's our defense, that's where the artisan cheese-maker is always going to have an edge," Montgomery says.
It's this complex community of microbes that intrigues the scientists and cheese-makers gathered in Somerset. For Rachel Dutton, whose lab at Harvard University studies everything from tangy stilton to creamy brie, cheese is a very cooperative subject, she says.
"I wanted to find a microbial community to study that I would be able to grow the organisms in the lab, deconstruct and reconstruct these communities," she says.
Dutton's team just finished a study of more than 130 different cheese samples from around the world. Different types of cheeses have different microbial tenants – less to do with geography, and more to do with cheese-making method, like whether you wash the rind of the cheese with brine, or age it, or keep it in a moist room.
Whatever type you favor, Dutton says that cheese could be affecting the microbes in your own body. Our guts are teeming with bacteria that help us digest food, and many of the bacteria found in fermented foods make it through the digestive tract unscathed.
But whether they interact much isn't clear, she says. "What they're doing, if anything, I think is still a wide-open question."
Cheese lovers would like to think that – like other microbe-rich foods – cheese could be good for us.
"There's a very good chance that consumption of them will influence the gut microbiome, and could in turn have some positive benefits," says microbiologist and cheesemaker Dennis D'Amico, who traveled to the meeting from his base at the University of Connecticut.
Those gains could include boosting metabolism, or stopping "bad" bugs from taking hold. But there's no evidence for this yet, because the microbes in our guts and in our foods are so complex that it's hard to work out how they affect each other.
Farm owner Jamie Montgomery is delighted that his cheese will be keeping scientists busy for a while yet. "They're all saying that in cheese, they're probably only scratching the surface. And I love that."
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