The belly is our second brain: gut bacteria are known to influence how our brain works.
The connection between these two parts of our body is such that the composition of our intestinal microbiota conditions our risk of one day developing Alzheimer’s disease, the leading cause of dementia in the world.
An avenue that has been considered for several years now: the microbiota of patients diagnosed with Alzheimer’s disease is indeed often altered.
To better describe this phenomenon, Swiss and Italian researchers * followed 89 patients aged 65 to 85 years.
Some suffered from Alzheimer’s disease or other neurodegenerative disorders causing similar memory disturbances. Others were spared from these attacks.
Blood inflammation under investigation
“Using the PET Scan imaging technique, we measured the formation of amyloid plaques at the origin of the neurodegenerative disorder, inflammatory markers in the blood, but also the proteins produced by intestinal bacteria **”, describes Moira Marizzoni, principal author of the study.
As a result, an imbalance in the intestinal microbiota favors the formation of amyloid plaques in the brain.
How to explain it? “Proteins produced by certain intestinal bacteria, identified in the blood of patients, could modify the interaction between immunity and the nervous system and thus trigger Alzheimer’s disease”, explains Prof. Giovanni Frisoni, one of the researchers. associated with the study.
“An inflammatory mechanism in the blood is the vector between the microbiota and the brain. “
Good bacteria and probiotics for prevention
According to scientists, “this study could help develop new preventive strategies based on the modulation of the microbiota of people at risk”.
One idea, “administering cocktails of bacteria or probiotics to feed the good bacteria in the gut.”
Small flat, however. “We must not rejoice too quickly,” warns Pr Frisoni. “We still have to find the precise composition of this cocktail of bacteria. “
Another point, “the neuroprotective effect could be effective only at the very early stage of the formation of amyloid plaques”. A potential complication as diagnoses often come late.
Note: still incurable, Alzheimer’s disease affects nearly 1 million patients in France.
*Université de Genève and le National Research and Care Center for Alzheimer’s and Psychiatric Diseases Fatebenefratelli (Brescia), University of Naples and the IRCCS SDN Research Center in Naples
** lipopolysaccharides and short chain fatty acids