New study confirms indisputable” link between gut bacteria and Alzheimer’s

New study confirms indisputable” link between gut bacteria and Alzheimer’s

Alzheimer's disease is a growing global health problem, with the number of people affected expected to increase significantly in the coming decades. It is estimated that approximately 14 million people in the United States will suffer from Alzheimer's disease by 2050, up from 6.2 million in 2021. This increase in Alzheimer's cases highlights the urgent need for effective prevention strategies and treatments to mitigate the impact on individuals, families, and health systems.

A recent paper published in the Journal of Alzheimer's Disease shows a strong link between Alzheimer's disease and substances produced by gut bacteria. The researchers argue that their findings provide “indisputable” evidence that gut microbes play a crucial role in the development of Alzheimer’s disease.

The gut-brain axis has been the subject of considerable scientific study and discussion recently, as increasing evidence suggests that the microscopic inhabitants of our gastrointestinal tract directly influence our central nervous system. This bidirectional communication channel allows the brain to transmit chemical signals to the gut for appetite and digestion regulation, while gut bacteria are thought to release various metabolites that affect brain function.

This has led to theories that a person's microbiome composition could influence their risk of Alzheimer's disease, although this connection has remained unconfirmed. To resolve the debate, the authors of the new study recruited 89 participants aged 65 to 85, some of whom were healthy and others who experienced varying degrees of cognitive decline. Researchers used positron emission tomography (PET) to look for amyloid plaques typical of Alzheimer's disease in participants' brains and collected blood samples to study metabolites from gut bacteria.

The results showed that people with more amyloid plaques in their brains tended to have elevated levels of lipopolysaccharide in their blood. These molecules, present on the outer membrane of certain bacteria, are known to promote the formation of amyloid plaques and increase inflammation in the brain. Likewise, Alzheimer's patients had higher blood levels of short-chain fatty acids such as acetate and valerate, both produced by certain gut bacteria and linked to brain inflammation.

Higher levels of other compounds that interfere with endothelial cells and compromise the integrity of the blood-brain barrier have also been detected in people with elevated amyloid plaque levels, suggesting another possible pathway through which gut microbes could influence the development of Alzheimer's.

Conversely, lower amyloid plaque levels correlated with increased levels of a short-chain fatty acid called butyrate, which is known to protect neurons by reducing brain inflammation.

According to study author Moira Marizzoni, the “results are undeniable: certain bacterial products of the intestinal flora correlate with the amount of amyloid plaques in the brain.”

Still, co-author Giovanni Frisoni warns against celebrating too soon, as this knowledge is unlikely to lead to a cure for neurodegenerative diseases. Instead, it may facilitate more effective identification of those at risk and enable earlier interventions.

First, the bacterial strains in the “cocktail” have to be identified, he says. “Then a neuroprotective effect could only be effective at a very early stage of the disease, with the focus being on prevention rather than therapy.”

Alternative treatments and preventive measures

Alternative treatments and preventive measures have gained attention in the context of Alzheimer's disease. There are several lifestyle changes, supplements, and herbs that can contribute to brain health and potentially delay the onset or progression of Alzheimer's disease. These approaches should be viewed as complementary to the findings on the gut-brain axis.

1. Healthy eating:

   A balanced diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats can support overall brain health. The Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets are often recommended for their potential brain-protective effects.

2. Regular training:

   Regular physical activity has been shown to improve cognitive function and reduce the risk of developing Alzheimer's disease. Aerobic exercise, in particular, has been linked to increased hippocampal volume and improved memory function.

3. Mental stimulation:

   Participating in activities that challenge the brain, such as puzzles, games, and learning new skills, can help maintain cognitive function and reduce the risk of Alzheimer's disease.

4. Omega-3 fatty acids:

   These essential fatty acids, found in fish, nuts and seeds, have been linked to improved cognitive function and reduced inflammation. Some studies suggest that omega-3 supplementation may be beneficial in Alzheimer's prevention.

5. Curcumin:

   This compound found in turmeric has antioxidant and anti-inflammatory properties. Research shows that curcumin may help reduce amyloid plaques and improve cognitive function in Alzheimer's patients.

6. Ginkgo Biloba:

   This herbal supplement has been used for centuries to improve memory and cognitive function. Some studies suggest that ginkgo biloba may help slow cognitive decline in individuals with Alzheimer's disease.

7. Resveratrol:

   This antioxidant, found in red wine, grapes and berries, has been linked to improved cognitive function and reduced risk of Alzheimer's disease. However, more research is needed to confirm its effectiveness.

The growing body of research on the connection between gut bacteria and Alzheimer's disease offers new insights into possible preventive measures and treatments. Although a cure for Alzheimer's remains elusive, adopting a healthy lifestyle, including diet, exercise, and mental stimulation, as well as considering dietary supplements and herbs, can help maintain brain health and reduce the risk of developing this debilitating disease. By integrating these approaches, we can work toward mitigating the increasing impact of Alzheimer's disease on individuals and society.

Sources: