Here’s Why Some People Have More Bellybutton Lint Than Others

The secret is on your stomach

Beth Dixson/Corbis

Some have innies. Some have outies. But not all have lint inside their navels. How come? New answers are here thanks to the BBC’s Jason G. Goldman, who reports on the findings of an Australian researcher on a quest to find out the secrets of bellybutton fuzz.

Goldman reports that when “Dr. Karl” Kruszelnicki, who hosts a popular science radio show in Australia, got a letter asking how bellybutton lint forms, he became obsessed with finding an answer. After conducting a widespread survey, he concluded that navel fluff is driven by stomach hair, which collects lint from clothing and puts it on a one-way path to the bellybutton.

Kruszelnicki’s work is just the beginning, writes Goldman — other researchers have looked at everything from what bellybutton lint is really composed of (cellulose, dust, skin, and other debris) to the navel’s unique microbiome (one bellybutton can host over 2,300 unique microscopic critters).

In case you get hungry while contemplating the world of crud that could be in your bellybutton right this second, take heart: scientists have also found out how to make cheese using bellybutton lint. FoodBeast’s Charisma Madarang reports that after using microbes from bellybutton fuzz to culture cheese, a group of artists and researchers concluded that “the cheeses’ odors were true to their sources.” There’s, um, food for thought.

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