Flinders University researchers have identified a potential biological marker that could offer valuable insights into the health of older adults in long-term aged care.

Led by PhD candidate Sophie Miller from the College of Medicine and Public Health, the study suggests that a simple throat swab from the oropharynx may help detect health vulnerabilities in aged care residents.

“Our findings indicate that specific bacteria in the back of the throat could signal increased health risks in older adults,” says Miller.

While physical assessments, such as grip strength, are commonly used to identify frailty, this study proposes that microbial markers could provide additional insight into health risks.

“As we age, the balance of bacteria in our throat changes due to factors like multiple medications and frequent healthcare visits, potentially increasing susceptibility to disease and frailty,” she explains.

The study involved collecting throat swabs from 190 aged care residents across metropolitan South Australia and tracking their health over 12 months.

One bacterium, Staphylococcus aureus (S. aureus), was notably linked to poorer health outcomes. Residents carrying S. aureus were found to be nearly ten times more likely to die within a year compared to non-carriers.

“This suggests that the microbiome could serve as an additional marker to identify residents requiring extra care or monitoring,” Miller states.

Unlike its usual association with infections, S. aureus in this study was found to reflect broader health decline rather than causing specific infections. Residents who tested positive for S. aureus generally had more underlying health conditions.

“Interestingly, the presence of S. aureus was a stronger predictor of mortality risk than the number of existing health conditions, a commonly used measure of overall health in older adults,” Miller adds.

Even after accounting for comorbidities, medications, and other health factors, the association between S. aureus and mortality risk remained significantly high.

Senior author Professor Geraint Rogers, Director of the Microbiome and Host Health program at SAHMRI and Matthew Flinders Fellow at Flinders University, highlights the significance of these findings.

“It’s remarkable that we observe this link with S. aureus even without clear signs of infection,” says Professor Rogers.

“This suggests that the presence of certain bacteria, like S. aureus, could be an indicator of overall health decline rather than a direct cause of infection.

“This research represents a key step toward integrating microbial markers into healthcare strategies to enhance outcomes for aged care residents.”

While these findings are promising, further research is needed to validate the results and explore long-term implications.

“By expanding our studies to include larger groups of residents, we aim to develop better strategies for improving care and support for older adults,” Professor Rogers concludes.

Further investigation will be crucial to understanding how microbial markers can complement traditional health assessments to enhance care for older Australians.

Source: https://news.flinders.edu.au/blog/2025/03/07/throat-microbiome-holds-clues-to-older-australians-health/