Recent research suggests that gut and brain health are linked, and this connection goes both ways. Scientists are now exploring how imbalances in the gut microbiome — the community of bacteria living in our digestive system — might play a role in Alzheimer’s disease and memory problems. In a recent study, researchers Kang-Chen Fan, Chen-Ching Lin, Yen-Ling Chiu, Seong-Ho Koh, Yi-Chien Liu and Yi-Fang Chuang looked at the gut bacteria of people with mild cognitive impairment (MCI), which can be an early sign of Alzheimer’s. They focused on how changes in specific bacterial species were linked to signs of Alzheimer’s, such as brain changes, memory performance and other biological markers. The study involved 439 people, including 119 with MCI. The researchers compared the types and amounts of gut bacteria with brain scans, blood tests and genetic information related to Alzheimer’s disease.
What they found:
• They identified 59 bacterial species that were clearly linked to MCI and Alzheimer’s markers. Interestingly, some bacteria from the same family had opposite effects. One species, Akkermansia muciniphila, was linked to lower levels of amyloid in the brain, which may mean it has a protective effect.
• They also found that certain bacteria were involved in processes like energy use and inflammation in the brain. The way these bacteria interact with each other seems to play a role in brain health. These results suggest that looking at bacteria at the species level (rather than just the family or genus level) gives a clearer picture of their role in Alzheimer’s. The study highlights the gut microbiome as a possible target for future treatments to slow down memory loss and brain decline.
https://link.springer.com/content/pdf/10.1186/s13195-025-01769-9.pdf
