Alzheimer's disease: referred to as stomach bacteria

Alzheimer's disease is the most common form of dementia. It is characterized by the gradual deterioration of neurons leading to memory loss, language disorders, mood changes, and decreased thinking skills.

Today, approximately 50 million people suffer from dementia worldwide, including 60 to 70% of Alzheimer's disease cases. The forecast is alarming, with cases likely to triple by 2050 if a cure is not found.

Faced with this observation, the search for modifiable risk factors capable of reducing the spread of the disease has become urgent.

Helicobacter pylori, which is a very common bacteria

Helicobacter pylori (H. pylori) is a bacterium that colonizes the stomach and causes inflammation of the gastric mucosa. It is widespread, infecting half of the world's population, and its rates reach 80% in some developing countries.

Although it is often asymptomatic, H. pylori is responsible for several stomach diseases such as ulcers and stomach cancer. Eliminating it with antibiotic treatment makes it possible to treat these conditions or significantly reduce their risks.

A study on the relationship between Helicobacter pylori and Alzheimer's disease

A recent study published in the journal Alzheimer's and Dementia looked at the possible relationship between H. pylori infection and the risk of developing Alzheimer's disease.⁽¹⁾.

The study covered a large group of 4.2 million adults over the age of 50, and analyzed the health data of people who were tested for Helicobacter pylori. After adjusting for several confounding factors, the researchers found that people with symptoms of infection had an 11% increased risk of developing the disease compared with uninfected people, and even more than 10 years after infection, with a 24% increased risk of infection.

Although retrospective, this observational study offers robust methodology. Their findings suggest a link between H. pylori and Alzheimer's disease, although more work will be necessary to confirm this link and understand its mechanisms.

Can you explain the link?

There are several hypotheses that could explain the observed association. We know, for example, that H. pylori disrupts the balance of certain substances in the blood associated with brain function, such as cortisol or thyroid hormones.

Moreover, as he pointed out Antoninus Doros“When the stomach is damaged by these microbes, it is also no longer able to absorb vitamin B12 or iron effectively, which also increases the risk of dementia,” said the pharmacoepidemiologist and co-author of the study.

A study in animal models also showed that proteins released by H. pylori can accumulate abnormally in the brain, such as the amyloid plaques characteristic of Alzheimer's disease.⁽²⁾.

Finally, bacteria can exert a systemic pro-inflammatory effect, contributing to neurodegeneration. But more research is needed to support these different hypotheses.

The last word

This discovery of the link between H. pylori and Alzheimer's disease opens promising prospects. By targeting these widely circulating bacteria, we can hope to prevent or slow the onset of the disease in some patients.

More broadly, this study highlights the importance of adopting a global approach to health. In fact, our brain can be affected by seemingly distant disorders, such as gastritis. A better understanding of the interactions between our organs will undoubtedly make it possible to advance toward new treatments against this devastating disease, Alzheimer's.

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