How gut bacteria can predict Alzheimer's disease
Many people with Alzheimer's also suffer from gastrointestinal problems. However, this link between the degenerative disease in the brain and a disturbed gut flora could advance the treatment of Alzheimer's in the future.
As is so often the case, the gut is also involved in Alzheimer's disease. More precisely: the composition of the intestinal flora. Many Alzheimer's patients suffer from symptoms that can be traced back to a disturbance in the bacterial composition of the gut. A study has now shown that this dysbiosis (disruption of the intestinal flora) can be detected even before the first Alzheimer's symptoms appear. The exciting thing about this is that the intestinal flora could not only be an early warning system for the onset of the disease, but may even be useful for the treatment or prevention of Alzheimer's.
What is cause, what is effect?
The crucial question here is similar to that of the chicken and the egg. Which came first? Do the changes in the intestinal flora cause the symptoms in the brain, or do the deposits in the brain typical of Alzheimer's disease lead to a disruption in the intestinal flora? There are various hypotheses on this, but they have not yet been confirmed.
In the present study, stool samples from 164 senior citizens who had taken part in a (different) study on the early detection of Alzheimer's were analysed. The test subjects were symptom-free at the time of the study. However, an early stage of Alzheimer's was diagnosed in 49 of them using proven detection methods. At this early stage of the disease, the intestinal microbiome of those affected was already altered. The disruption of the intestinal flora is therefore at the beginning of the disease. However, this study cannot answer whether it is the cause.
Screening the gut microbiome to diagnose Alzheimer's
Independently of this, the change in the intestinal flora at an early stage of the disease could be used to diagnose Alzheimer's disease by screening stool samples. The hope is that drug treatment of the disturbed gut microbiome can also influence the course of Alzheimer's disease. However, research into this is still in its infancy. At best, early diagnosis of the composition of the gut bacteria could prevent the onset of dementia.
The authors have already announced the next study, in which they will investigate whether the changes in the intestinal flora are a trigger or consequence of Alzheimer's disease.
Cover photo: Photo by Polina Tankilevitch/Pexels
Science editor and biologist. I love animals and am fascinated by plants, their abilities and everything you can do with them. That's why my favourite place is always outside - somewhere in nature, preferably in my wild garden.