Stomach Bugs And Memory Loss: How Helicobacter Pylori Increases Risk For Alzheimer's Disease

A growing number of scientists believe pathogens lie at the root of Alzheimer’s disease. One such pathogen is the herpes virus, which lies dormant in almost everyone.

But there’s another pathogen lurking in over 40 percent of Americans that’s also suspected in triggering Alzheimer’s disease. This one is not a virus but a bacterium. A stomach bug called Helicobacter pylori (H. pylori).

If you’ve ever had the misfortune to suffer from a peptic ulcer or gastritis (redness or swelling in the stomach), you can probably put the blame H. pylori. Here’s what you need to know…

Key Takeaways

• H. pylori (helicobacter pylori), the bacteria that causes stomach ulcers, is now being linked to the development of Alzheimer's disease.
• Active H. pylori infection is believed to allow these bacteria to travel to the brain through the gut-brain axis and damage brain cells directly, as well as cause system-wide inflammation that affects memory and cognition.
• H. pylori is believed to be a modifiable risk factor for Alzheimer's disease and treating H. pylori infection through antibiotics and effective natural remedies can help protect your memory.

Stomach Ulcers and Memory Loss

If you’ve ever had the misfortune to suffer from a peptic ulcer or gastritis (redness or swelling in the stomach), you can probably put the blame on Helicobacter pylori infection (H. pylori).

It also has a more sinister role in causing stomach cancer. And yet most of the time these bacteria live happily in our stomach without causing any symptoms.

Suspicions of H. pylori infection harming the brain have led to several studies. In the research H. pylori infection has been associated with various neurological effects, including poor cognition, neurologic impairment, cerebrovascular disease, and an increased risk of developing Alzheimer's disease and other neurological disorders such as Parkinson's disease.

Several studies have suggested a potential link between H. pylori infection and mild cognitive impairment, which is considered a precursor to Alzheimer's disease. Additionally, higher levels of neuro-inflammation have been found in Alzheimer's disease patients infected with H. pylori, and eradication of H. pylori has been shown to improve cognitive and functional abilities.

Furthermore, H. pylori infection has been associated with changes in the composition of the gastrointestinal microbiome, which can potentially alter the outcome of neurological disorders. In fact, a systematic review conducted in 2016 suggesting “a significant positive association between H. pylori infection and dementia.” Another review published in 2021 came to the same conclusion.

So it begs the question...

How Does H. Pylori Infection Harm the Brain?

The findings from these studies and others suggest that H. pylori infection may play a role in the development of Alzheimer's disease, possibly through its impact on systemic inflammation and other mechanisms that allow it to reach the brain.

It’s surprising to consider that bacteria in your stomach can so easily reach your brain, but there are actually a number of ways that this can happen.

First, it could potentially travel to the brain through the nasal passages or a disrupted blood-brain-barrier, your body's first line of defense to protect your brain from damage. This might lead to neuroinflammation that hurts brain cells.

Another possible mechanism is via the gut-brain axis. Gut microbiota can communicate with the brain through the microbiome–gut–brain axis. This includes the neuronal route, the endocrine route, the metabolic route and the immunological route. If disrupted by H. pylori infection the gut-brain axis could activate multiple pathways leading to the over-secretion of both the bacterial toxin, liposaccharide, and amyloid, the protein that’s strongly linked to Alzheimer’s disease.

Finally, if chronic H. pylori infection causes structural damage to the gastric mucosa (the stomach lining) it could lead to B12 and iron deficiency, both of which are associated with dementia.

H. Pylori Infection in Brain Health Research

Helicobacter is a genus of Gram-negative bacteria colonizing the stomach, intestine and liver. The research shows the role of H. pylori infection in the development and progression of neurological disorders. However, hardly anything is known about other Helicobacter species and the brain.

What the science has shown is that a chronic H. pylori infection evades the immune system in a way that creates inflammation system-wide. What's more, it can lead to the release of several brain neurotransmitters such as acetylcholine, adrenaline, noradrenaline, serotonin, and dopamine which can affect the balance in the brain. If that's not enough, H. pylori infection might directly damage brain cells.

Existing studies into the relationship between H. pylori infection and dementia have small numbers of participants and are at a high risk of bias due to limitations in their methodology, thus making the findings unreliable.

Researchers wanted a much larger, more robust study to see if the association between H. pylori infection and developing Alzheimer's disease was valid. So, a team at McGill University in Montreal, Canada carried out such a study looking specifically at Alzheimer’s disease.

H. Pylori Infection Increases Alzheimer’s Disease Risk by 11 Percent

The researchers utilized the United Kingdom's Clinical Practice Research Datalink of 18 million registered patients. From this database they analyzed a remarkable 4,262,092 Alzheimer’s-free subjects aged 50 or more and followed them up after 11 years. During this time, 40,455 developed Alzheimer's disease.

Their findings showed there was an increased risk of developing Alzheimer's disease, which became statistically significant after eight years. The increased risk peaked at 24 percent after ten years before falling back. The overall findings were that people with symptomatic H. pylori infection had an 11 percent higher risk of developing Alzheimer's disease.

Dr. Paul Brassard, senior author of the study published in the journal Alzheimer's & Dementia in December, explained, saying, “We hope the findings from this investigation will provide insight on the potential role of H. pylori infection in dementia in order to inform the development of prevention strategies, such as individualized eradication programs to reduce infections at the population level.”

Healing Helicobacter Pylori Infection

Dr. Brassard and his team estimate eradicating the bug could lead to a 0.7 percent decrease in the prevalence of the disease. While this seems small it would prevent around 200,000 cases of Alzheimer’s disease globally each year.

Eradicating the bug means taking a combination of antibiotics multiple times a day for several weeks. Because of rising resistance to antibiotics this is only 80 percent effective. Is there an alternative?

Natural Agents to Beat H. Pylori infections

Thirty-nine patients who tested positive for H. pylori completed a two week course of a combination of nonprescription remedies chosen because previous studies suggested they were effective. These were:

• Mastic gum: a resin from the mastic tree with antimicrobial and anti-inflammatory properties.
• Oil of oregano: an herb from the oregano plant which has antibacterial, antiviral, and antifungal properties.
• Bismuth: slows the growth of bacteria.
• Probiotics: a broad-spectrum probiotic containing 5 billion colony forming units of 10 probiotic strains.

Results showed that “29 participants (74.3 percent) had converted to negative, suggesting complete biological eradication of H. pylori.”

In separate research, scientists are looking into the protective effects of ginkgo biloba extract against H. pylori infection. Animal studies suggest that this antioxidant-rich plant extract can heal gastric ulcers. As a result, scientists are hopeful that ginkgo biloba will provide additional help for people suffering from chronic H. pylori infection.

Summary

There's a growing belief among scientists that pathogens, including bacteria, may contribute to the development of Alzheimer's disease. H. pylori, a bacterium found in over 40 percent of Americans, triggers Alzheimer's disease in the latest research, in addition to its known role in causing stomach ulcers and stomach cancer. Researchers found an 11 percent increased risk of developing Alzheimer's disease in individuals with symptomatic H. pylori infection. It's important to treat H. pylori using antibiotics or natural agents, such as mastic gum, oil of oregano, bismuth, and probiotics, which have shown promise in eradicating H. pylori in some studies.

Frequently Asked Questions

What bacteria causes Alzheimer's disease?

Alzheimer's disease is believed to be caused by a combination of genetic, lifestyle, and environmental factors that affect the brain over time. Research has linked pathogens such as H. pylori infection and herpes infection with the development of Alzheimer's disease. It is generally believed the disease develops from multiple factors rather than a single pathogen.

Which common stomach bacteria may be linked to higher risk of Alzheimer's disease?

H. pylori, a bacterium found in over 40 percent of Americans, is linked in research to Alzheimer's disease, in addition to its known role in causing stomach ulcers and stomach cancer.

Can H. pylori affect the brain?

Yes. H. pylori infection has been associated with various neurological effects, including poor cognition, neurologic impairment, cerebrovascular disease, and an increased risk of developing neurological disorders such as Parkinson's disease and Alzheimer's disease. Several studies have suggested a potential link between H. pylori infection and mild cognitive impairment, which is considered an early phase of Alzheimer's disease. Additionally, higher levels of neuro-inflammation have been found in Alzheimer's disease patients infected with H. pylori, and eradication of H. pylori has been shown to improve cognitive and functional abilities. Furthermore, H. pylori infection has been associated with changes in the composition of the gastrointestinal microbiome, which can potentially alter the outcome of neurological disorders. The potential for H. pylori to stimulate the expression of Alzheimer's disease-associated risk genes and trigger neuroinflammation in the brain tissue has also been reported.

Can Helicobacter cause memory loss?

Several health research studies have suggested a potential link between H. pylori infection and mild cognitive impairment, which is considered a prodromal phase of Alzheimer's disease. Additionally, higher levels of neuro-inflammation have been found in Alzheimer's disease patients infected with H. pylori, and eradication of H. pylori has been shown to improve cognitive and functional abilities. Furthermore, H. pylori infection has been associated with changes in the composition of the gastrointestinal microbiome, which can potentially alter the outcome of neurological disorders. The potential for H. pylori to stimulate the expression of Alzheimer's disease (AD)-associated risk genes and trigger neuroinflammation in the brain tissue has also been reported. However, while there is evidence suggesting a potential role of H. pylori in neurological disorders, including its impact on the brain-gut axis, further research is necessary to fully understand the clinical importance of these interactions and to evaluate the specific mechanisms through which H. pylori may affect the brain.