Microbial signatures in gut, mouth linked to cognitive impairment in older adults
Posted on: Thursday, June 4th, 2026
Did you know that the bacteria in your body—especially in your gut and mouth—may play a role in brain health? Researchers at UT Health San Antonio recently studied older adults and found differences in these “microbiomes” between those with and without memory or thinking changes.
“This was our first microbiome study at the Biggs Institute, and it was very important to us to focus on South Texas,” said Tiffany F. Kautz, PhD, assistant professor with the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases (Biggs Institute) and the Division of Geriatrics, Gerontology and Palliative Medicine, Department of Medicine in the Joe R. and Teresa Lozano Long School of Medicine (Long School of Medicine). “We wanted to investigate how the microbiome may influence cognitive impairment in an understudied patient population.”
“Our study fits into that broader pattern,” said Bernard Fongang, PhD, associate professor in the Departments of Biochemistry and Structural Biology and Population Health Sciences in the Long School of Medicine and the Biggs Institute. “What we’re seeing is not causation, but an association between cognitive impairment and disruptions in both gut and oral microbiomes.”
While this research does not prove that bacteria cause cognitive decline, it highlights an important connection: people with cognitive impairment tended to have fewer “helpful” bacteria and more bacteria linked to inflammation.
The study also found that changes in the mouth—especially bacteria linked to gum disease—may be connected to brain health, reinforcing the idea that oral health matters beyond your smile.
Read the full article at the UT Health San Antonio Newsroom.