Researchers from Oregon Health & Science University (OHSU) made a new discovery that solidifies the relationship between the gut microbiome and the brain. The animal study found a causal connection between gut bacteria and the behavioral and cognitive changes seen in Alzheimer’s disease.
“We found that modulating the gut microbiome by fecal implants in germ-free mice induces behavioral and cognitive changes in an Alzheimer’s disease model,” says senior author Jacob Raber, PhD, professor of behavioral neuroscience in the OHSU School of Medicine, in a statement. “To the best of my knowledge, no one has shown that before in an Alzheimer’s disease model.”
Previously, the team found a correlation between the gut microbiome composition and changes involved in developing Alzheimer’s disease. The new study provides stronger evidence of a causal not correlational relationship by experimenting on the guts of a mouse model of Alzheimer’s. Researchers report finding three different genotypes involved in changes in cognition and behavior between male and female mice. Two of the genotypes were connected with a higher risk of developing Alzheimer’s disease.
The findings suggest treatments working to improve the gut microbiome, such as using probiotics or fecal transplants, may help delay the onset of dementia. Although more research is needed to understand how other factors such as genotype and sex influence this connection.
“People can buy probiotics over the counter, but we want to make sure the right treatment is being used for each patient, and that it actually benefits them,” Raber said. “The gut microbiome is a complex environment. If you change one element, you’ll also change other elements, so you want to make sure to select a probiotic that promotes brain health and brain function for each patient, while limiting any negative side effects.”
The study is published in the journal Frontiers in Behavioral Neuroscience.