New research from Flinders University has identified a potential marker that could offer valuable insights into the health of older adults in aged care facilities.

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 risks in aged care residents. Our findings indicate that certain bacteria in the throat could signal greater health vulnerability in older adults says Miller.

While physical measures like grip strength have been used to assess frailty this research highlights the potential of a biological marker to provide additional insight into health risks.

As we age, the composition of bacteria and microorganisms in our throat shifts. Factors such as multiple medications and frequent healthcare visits common in later life can disrupt this balance she explains.

These age-related changes may contribute to physiological shifts that heighten vulnerability to diseases and frailty.

The study collected oropharyngeal swabs from 190 aged care residents across metropolitan South Australia tracking their health outcomes over 12 months.

One bacterium Staphylococcus aureus (S. aureus) typically linked to infections but not in this study’s context was strongly associated with poorer health outcomes. Residents carrying S. aureus were nearly ten times more likely to die within a year compared to non-carriers.

This finding highlights the potential of the microbiome as an additional marker for identifying residents who may need extra care or monitoring explains Miller.

Rather than indicating a specific infection the presence of S. aureus appeared to reflect broader health challenges. Residents who tested positive for the bacterium tended to have multiple health conditions reinforcing the idea that S. aureus carriage could signal overall poor health.

Notably, S. aureus was a stronger predictor of mortality risk than the number of comorbidities conditions commonly used to assess elderly individuals general health.

Even after adjusting for factors like existing health conditions medications and other health data the association between S. aureus and mortality risk remained significantly high says Miller.Professor Geraint Rogers highlights the significance of these findings noting the link between S. aureus and health decline even without signs of infection. He emphasizes that certain bacteria may indicate overall health deterioration rather than specific infections. This research marks a key step toward using microbial markers to improve aged care strategies. Further studies are needed to validate these findings and explore their long-term impact.

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