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Key Takeaways
Have you ever wondered why yourpee is yellow?
Researchers have long known that pees unique color is down to urobilin, Hall told Verywell.
However, no one had been able to pinpoint exactly what created that chemical in our bodies.
Viktoriya Kuzmenkova / Getty Images
The specific enzyme encoded by gut microbes that perform this function hadnt been identified.
This discovery lays the foundation for understanding the gut-liver axis.
What Makes Pee Yellow?
When your body breaks down old red blood cells, it makes a yellow chemical substance called bilirubin.
Your liver uses this bilirubin to makebile, a fluid that helps digest food, Shusterman said.
Some of that bile goes directly to your intestines, and the rest is stored in your gallbladder.
Good bacteria in your intestines break down some of the bilirubin in your bile intourobilinogen, which becomes urobilin.
Thats why urine is yellow.
This is when enzymes like bilirubin reductase jump into the game.
They help make the byproducts soluble so they can be filtered out by the kidneys, said Brahmbhatt.
Why Isnt PeeAlwaysYellow?
The water essentially dilutes the urobilin.
Lemonade yellow is usually a good sign.
It means youre probably drinking enough water, said Brahmbhatt.
Blood in the urineeither you see it or its found on labsis a serious matter that requires a workup.
What This Means For You
An enzyme called urobilin makes pee yellow.
2024;9(1):173-184. doi:10.1038/s41564-023-01549-x
University of Maryland.What makes urine yellow?
UMD scientists discover the enzyme responsible.
