A new study suggests that a unique odor from urine can serve as a biomarker for Alzheimer's disease. The odor reportedly becomes distinct before pathological changes in the brain signaling the development of the disease begin to appear.
Researchers from the the U.S. Department of Agriculture (USDA), the Monell Center and other contributing groups believe the potential Alzheimer's biomarker can pave the way for early diagnosis. It could also be used to develop treatments that delay the disease's progression.
"Previous research from the USDA and Monell has focused on body odor changes due to exogenous sources such as viruses or vaccines," study author Bruce Kimball from the USDA's National Wildlife Research Center said in a press release. "Now we have evidence that urinary odor signatures can be altered by changes in the brain characteristic of Alzheimer's disease."
The researchers studied APP mice, which are used as models for Alzheimer's disease research. They found that the urine of APP mice produced a distinct odor that wasn't detected in control mice. The odor appeared before plaques began to build up in the APP mice's brains.
The study authors believe the distinct urine odor could be associated with a gene instead of just the pathological changes that developed in the mice's brains.
"While this research is at the proof-of-concept stage, the identification of distinctive odor signatures may someday point the way to human biomarkers to identify Alzheimer's at early stages," study author Daniel Wesson from the Case Western Reserve University School of Medicine said in the press release.
The researchers said further studies are needed to characterize this odor signature in humans.
"These initial data in animal models show that mutant APP gene expression entails a uniquely identifiable urinary odor, which if uncovered in clinical AD populations, may serve as an additional biomarker for the disease," the authors concluded.
The study was published online on Jan. 14 in the journal Scientific Reports.
