How fungus in the mouth is affecting immune health in older adults
New research by Pushpa Pandiyan, PhD, published in Frontiers in Immunology, explores how microorganisms living in the mouth play a key role in inflammation that negatively affects the immune system.
As people age, the immune system gradually becomes less effective, a process known as immunosenescence. This decline is often accompanied by chronic, low-grade inflammation (also referred to as inflammaging), which is affected by numerous factors, including the oft-overlooked oral microbiome.
Now, new research published in Frontiers in Immunology from Pushpa Pandiyan, PhD, associate professor of biological sciences at Case Western Reserve University’s School of Dental Medicine, sheds light on how changes in the microorganisms living in the mouth—particularly fungi—play a key role in that process.
“This research is significant because it uncovers how the tiny organisms in our mouths can influence the aging process and immune health, offering new hope for understanding and potentially slowing the decline in immunity that comes with age,” said Pandiyan.
The study found that adults over age 60 tend to have higher levels of the fungus Candida in their mouths. This increase appears to be associated with changes in key immune cells known as Regulatory T cells (Tregs), which normally help maintain balance in the immune system by preventing excessive inflammation.
While Candida is normally present in the mouth, it can alter how immune cells behave as its levels increase with age. Pandiyan observed that Tregs become more abundant in older adults, but they may also become less effective at controlling inflammation.
“These discoveries highlight that our oral health, particularly the balance of resident fungi, plays a crucial role in the aging of our immune system and the development of chronic inflammation,” she said.
The study also identified higher levels of inflammatory signaling molecules—including TLR-2 and IL-6—in the saliva of older adults, which are associated with inflammatory responses and may further contribute to immune imbalance. Similar patterns were found among both healthy older adults and individuals living with HIV, suggesting that the relationship between oral fungi and immune aging may affect a broad range of people.
The research opens new possibilities for understanding how oral health intersects with overall well-being. In the future, monitoring oral fungi could potentially help clinicians predict immune health or identify individuals at risk for chronic inflammation. This highlights the growing importance of microbiome research and underscores how seemingly minor changes in the body can have far-reaching effects on long-term health.
“Ultimately, this work inspires us to see oral health as a gateway to overall well-being and reminds us that even the smallest changes in our bodies can have a big impact on how we age,” Pandiyan stated. “Taking care of our oral microbiome could become a vital part of aging well, and future research will likely reveal even more ways to harness this connection for better health.”
