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Jakarta – Scientists have finally uncovered an answer to share with the wider community regarding why urine is yellow.
For over 150 years, it has remained a mystery why human urine is yellow. However, a recent study published last week in the journal Nature Microbiology has cracked the code behind this 'yellow' phenomenon.
Urine is a mixture of water, electrolytes, and waste filtered by the kidneys. Researchers from the University of Maryland and the National Institutes of Health have identified bilirubin (BilR) as the key enzyme responsible for giving urine its yellow color.
Scientists had identified urobilin as the cause behind the yellow pigmentation in urine back in 1868. However, what caused this color remained puzzling to researchers until now.
"It's truly remarkable that an everyday biological phenomenon remained unexplained for so long, and our team is incredibly excited to finally unravel it," said Brantley Hall, assistant professor in the Department of Cell Biology and Molecular Genetics at the University of Maryland, on Wednesday.
Ilistrasi urine berbusa
- Alodokter
The process occurs when red blood cells reach the end of their six-month lifespan and degrade into bright orange bilirubin pigment.
Normally, the pigment begins to seep into the intestines, where it can either be excreted or partially reabsorbed.
Upon reaching the intestines, research found that gut microorganisms can transform bilirubin into various other molecules.
"Gut microbes encode the enzyme bilirubin reductase, which converts bilirubin into a colorless byproduct called urobilinogen," Hall remarked.
"Urobilinogen then spontaneously breaks down into molecules known as urobilin, responsible for the yellow color we all recognize,"
The discovery of what causes urine, which plays a vital role in aiding doctors to diagnose various diseases and abnormalities in the human body, to be yellow is praised as an extraordinary breakthrough that has unlocked much of the mystery behind a deeper understanding of the human body.
"If some of those old scientists had the technology we have today, they might have found the answer," Hall informed.
Hall, the lead author of the study, explained that uncovering the reason behind urine's yellow color could lead to further medical breakthroughs in helping people combat issues like inflammatory bowel disease and jaundice, a condition causing patients to have a yellowish tinge on their skin, mucous membranes, and eyes.
"One of the key findings from our research is that this gene is often absent in newborns," the scientists added.
The plan is to take the next steps in human research, particularly focusing on premature babies with high levels of jaundice.
"Now that we've identified this enzyme, we can start investigating how bacteria in our guts impact circulating bilirubin levels and related health conditions like jaundice," said co-author of the study and researcher at the National Institutes of Health, Xiaofang Jiang.
"This discovery lays the groundwork for understanding the gut-liver axis,"
This scientific breakthrough brings researchers one step closer to understanding the role of the gut microbiome in human health.
