A new $3.2 million grant from the National Institute on Aging will support University of Wisconsin research into underrecognized factors that may contribute to pneumonia in older adults — including changes in oral health and impaired swallowing due to aging and bacteria that normally live in the mouth, nose and throat.
The study is led by Dr. Michael Pulia, associate professor with tenure and director of the Emergency Care for Infectious Diseases research program in the BerbeeWalsh Department of Emergency Medicine, University of Wisconsin School of Medicine and Public Health, and an emergency physician at UW Health.
Clinicians have traditionally distinguished aspiration pneumonia — pneumonia linked to food, liquid, saliva or other material entering the airway — from pneumonias typically attributed to bacteria or viruses acquired in the community or health care settings.
Researchers increasingly understand pneumonia as occurring along a continuum, with many cases potentially involving some degree of aspiration. In older adults, conditions such as dementia and muscle weakness can make it more likely that food, liquid and saliva containing bacteria from the mouth and nose can enter the lungs through aspiration and contribute to infection.
Poor oral health and oropharyngeal dysphagia, or swallowing dysfunction, are well-established risk factors for pneumonia. What remains less clear is how oral function, impaired swallowing and the airway microbiome work together to influence how pneumonia develops, which bacteria are involved and how severe the infection becomes.
“We believe these are synergistic, yet underappreciated factors that lead to the development of pneumonia,” Pulia said. “Understanding how they are related can help characterize the underlying mechanism of infection and guide more appropriate treatment.”
Pulia says prior studies, including work from his team, suggest that oral hypofunction and swallowing problems may be common in older adults with pneumonia and more pronounced in those with severe illness. But many studies have examined these factors separately or relied on limited diagnostic information, with little known about how characteristics of saliva may contribute to pneumonia development.
The new project aims to be the first observational study to comprehensively characterize oral and swallowing function in older adults with pneumonia and evaluate how those factors contribute to this common, life-threatening infection.
Researchers will assess older adults who come to UW Health emergency departments with pneumonia, using oral function measures, swallow imaging, saliva analysis, microbial culture and microbiome profiles. Studying patients in the emergency department allows the team to collect samples early in the disease process, before clinical deterioration, antibiotic therapy, intubation or hospitalization may alter the airway microbiome or other key measures.
According to Pulia, the emergency department is also a critical setting for study recruitment because it is often where older adults first enter acute care, including patients across a wide range of illness severity, backgrounds and access to care.
The issue is significant: Pneumonia accounts for more than one million emergency department encounters each year among adults 65 and older and is the leading infectious cause of serious illness and death in this population. “When a condition is this common and this consequential, we need new ways to understand the clinical, microbial and functional factors leading to pneumonia and how we can improve both prevention and treatment,” Pulia said.
The study’s findings could help clinicians identify older adults at risk for pneumonia earlier, support more targeted antibiotic use and guide referrals to swallowing rehabilitation and oral care interventions that may help prevent recurrent infection.
The study builds on Pulia’s previous research, supported by the School of Medicine and Public Health and UW–Madison Office of the Vice Chancellor for Research, which found that older adults with pneumonia often do not receive evaluation or care for dysphagia. It also advances work he conducted as a National Academy of Medicine Scholar in Diagnostic Excellence to improve diagnosis for older adults with suspected pneumonia.
Funding: This research is supported by the National Institutes of Health’s National Institute on Aging (R01AG097793), and Research Development funds from the UW School of Medicine and Public Health and the BerbeeWalsh Department of Emergency Medicine.
The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Principal investigator: Michael Pulia, MD, PhD
Co-investigators and collaborators (listed alphabetically): Hilary Faust, MD, MS; Ron Gangnon, PhD; Sheena Kerr, PhD; Nicole Rogus-Pulia, PhD, CCC-SLP; Nasia Safdar, MD, PhD; Eliot Stanton, PhD