Chart of data from sample groups in study
A chart showing data from the various sample groups used in the study of the microbiomes of older adults living in nursing homes by The Jackson Laboratory and the UConn Center on Aging. Credit: Contributed image / The Jackson Laboratory

Researchers knew that the human skin goes through a “remodeling” during puberty, but what about after?

“Very little is known in terms of the composition and the changes in the microbiome in aging particularly in the skin as well as the oral microbiome,” said Julia Oh, an associate professor at the Jackson Laboratory (JAX) Center for Aging Research in Farmington.

Communities of microorganisms that live in or on a particular body, such as the skin or the gastrointestinal tract, are known as microbiomes.

Researchers at JAX as well as the UConn Center on Aging, based at UConn Health in Farmington, recently published their findings from a study of what happens as the skin ages. The paper – titled “Frailty-Associated Dysbiosis of Human Microbiotas in Older Adults in Nursing Homes” – was published in October.

What they found was that how frail a person is – as opposed to chronological age – determines how they are impacted.

Through the study, researchers compared the skin, oral, and gut microbiomes of healthy adults younger than 55 years old with two other groups of older adults – one consisting of those over 65 years of age living in skilled nursing homes, and another of older adults still living at home. 

Oh said that while everyone ages, and with age there are more challenges associated with infection risk and other declines, not everyone ages in the same way.

“You could have a healthy 90 year old whose microbiome would look more similar to a younger adult than an institutionalized, more frail, say, 70 year old,” Oh said.

Another major finding, according to Oh, is how the skin, while it has a relatively low total number of microbes compared to the gut and the mouth, had the most striking changes in the microbiome composition, as well as potential infection risk reservoirs.

“And these would include things like the presence of known pathogens,” including staphylococcus aureus, and also antibiotic resistance genes, Oh said.

Dr. George A. Kuchel, director of the UConn Center on Aging, said this study is one piece of the puzzle. 

“The fact is a lot of people are frail in the community as well. Whatever lessons we learn will also be applicable to other people who are not in nursing homes,” Kuchel said. “We want to keep them out of nursing homes.”

While the just-completed study provides a foundation, researchers “will need more studies to dissect how changes in microbiomes translate to chronic disease in older adults across various residential settings and how geroscience-guided interventions designed to improve frailty and slow the onset and progression of multiple chronic diseases might restore the microbiomes to a state characteristic of younger or less frail individuals,” according to the paper.

Kuchel added that, ultimately, researchers may be able to come up with a signature based on a sample of skin using a swab or a Q-tip that would allow doctors to see whether their patients will face certain health challenges in the future.

The next study, Oh and Kuchel said, will identify people who are leaving nursing homes, and to what extent they maintain microbiome signature.

The findings of this study and others show how important team science is, Kuchel said.

“It really illustrates the tremendous power of team science, which is something we are very passionate about in the Center of Aging,” he said. “We strongly believe that it is the only way to tackle and understand important challenges facing us such as aging through multi-disciplinary team science.”