Mystery metabolite may enable healthy life extension for dogs and humans

Scientists have identified a biomarker for aging in dogs that reveals biological age or predicts future health issues, which may also apply to humans. They found that molecules, especially post-translationally modified amino acids (ptmAAs), change with age.

The publication in Aging Cell examined 800 dog blood samples from the Dog Aging Project and found that aging altered 40% of molecules.

“These molecules, known as metabolites, are basically the building blocks of life,” says senior author Daniel Promislow, a senior scientist and scientific advisor at the Human Nutrition Research Center on Aging at Tufts University, US.

“They serve as the raw materials for forming proteins, DNA, and other cellular components, and play a critical role in keeping cells alive.”  

Kidney function and ptmAAs

PtmAAs are a rarely studied metabolite, note the researchers. They found strong links of ptmAA across aging dogs, regardless of breeds, sizes, and sexes. 

Promislow says: “These metabolites are created in two ways in the body. The bacteria in our guts can make ptmAAs as we digest our food, or they can show up when proteins break down.”

However, the source of ptmAAs remains a mystery, though researchers know that kidney function is essential. They found that as a dog’s kidney function declines, ptmAAs build up. This is because the kidneys filter out byproducts of protein breakdown in the blood.

Based on this, the researchers believe that it explains why some dogs age more healthily than others, which may also bring insights for humans.

Long-term testing 

Looking ahead, the researchers will track changes in metabolites in the same individuals over time. Their current study examined how the blood chemistry of younger and older dogs differed at a single point in time.

Longitudinal data will enable researchers to confirm whether the biomarkers track the pace of aging and predict future health or longevity. They would also be able to study potential anti-aging treatments that change these biomarkers. The team seeks to compare these patterns with changes in human metabolites.

The researchers will also identify potential gut microbes that could change in abundance with age and influence ptmAAs.

Furthermore, the researchers are interested in using dog data, provided from their owners, to check if muscle mass alterations are linked to ptmAAs as this phenomenon is common in aging dogs and humans.  

“We have a tremendous opportunity to understand the causes and consequences of aging and to discover ways to ensure that both species enjoy the healthiest aging trajectory possible,” concludes Promislow.