A groundbreaking study by researchers at the University of Florida’s Gut Biome Laboratory has revealed a possible link between an infection caused by gut bacteria and the progression of Alzheimer’s disease.
The research found that the bacteria Klebsiella pneumoniae -? a common bacterium notorious for causing hospital-acquired infections -; it can migrate from the gut to the bloodstream and eventually to the brain. This bacterial invasion can lead to increased inflammation in the brain and impair cognitive functions, mimicking the symptoms seen in Alzheimer’s patients. The project was published on The Journal of Infectious Diseases.
Hospitalizations and ICU stays, combined with antibiotic exposure, can further reduce the diversity of the microbiome leaving older adults at high risk not only for digestive problems but also for extraintestinal pathologies such as neurodegenerative disorders through gut dysregulation – brain. axis.”
Ravinder Nagpal, assistant professor in the FSU College of Education, Health, and Human Sciences and director of the Gut Biome Lab
The study is the first to show a direct correlation between K. pneumoniae infection and Alzheimer’s pathology, fueling the emerging field investigating how infectious agents may trigger or exacerbate Alzheimer’s disease. It also paves the way for future research on how to deal with harmful infectious agents in vulnerable populations such as the elderly or those recovering from sepsis.
Research suggests that when antibiotics disrupt the gut, it can lead to problems not only in the gut but also in the brain. Using a preclinical mouse model, researchers showed that exposure to antibiotics reduces gut bacterial diversity and causes a microbiome imbalance, which promotes proliferation K. pneumoniae creating a favorable position.
When this happens, K. pneumoniae it can move from the gut into the bloodstream through the gut lining and eventually reach the brain, causing neuroinflammation and neurocognitive impairment.
The findings highlight the potential risk of hospital-acquired infections such as K. pneumoniae may contribute to the development of neurodegenerative diseases.
“Nosocomial and septic infections are one of the risk factors that may increase predispositions to future neuroinflammatory and neurocognitive impairments, especially in older adults,” Nagpal said.
The study highlights the need for innovative therapeutic approaches to combat the increasing prevalence of Alzheimer’s disease, in addition to existing amyloid and tau protein therapies. Further research could inform preventive strategies aimed at managing hospital-acquired pathogens and maintaining cognitive health in aging populations.
The research was funded by the Infectious Diseases Society of America and the Florida Department of Health.
The paper was authored by graduate researchers Ian Park, Saurabh Kadyan and Nathaniel Hochuli from FSU’s College of Education, Health and Human Sciences. Additional contributors were Professor Hazel K. Stiebeling, Gloria Salazar. Associate Professor of Psychology and Neuroscience Aaron Wilber. University of Florida researchers Orlando Laitano, Paramita Chakrabarty and Philip A. Efron; and Wake Forest University School of Medicine Associate Professor M. Ammar Zafar.
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Journal Reference:
Park, G., et al. (2024). An intestinal bacterial infection triggers neuroinflammation and neurobehavioral impairment in 3xTg-AD transgenic mice. The Journal of Infectious Diseases. doi.org/10.1093/infdis/jiae165.
