Could Kefir Be the Key to Fighting Alzheimer’s Disease?

Could the Probiotic Kefir Help Fight Alzheimer’s Disease?

Alzheimer’s disease, the most common form of dementia, is a debilitating neurodegenerative condition that affects millions worldwide. As the aging population continues to grow, the prevalence of Alzheimer’s is projected to rise, with an estimated 7 million people in the United States currently living with the disease, and that number expected to nearly double in the next 25 years. Despite years of research, there is still no definitive cure for Alzheimer's, making it crucial to explore new avenues for treatment and prevention. A recent review study from Brazil has brought attention to the potential of probiotic kefir as an adjunct treatment for Alzheimer's disease.

What Is Kefir?

Kefir is a fermented beverage traditionally made by fermenting kefir grains in milk, which can be dairy-based or non-dairy, such as coconut or almond milk. The fermentation process results in a drink rich in probiotics, beneficial bacteria and yeast that support gut health. Kefir is known for its unique microbial composition, including both bacteria and yeast working in a symbiotic relationship, which differentiates it from other probiotic foods like yogurt.

Given the emerging understanding of the gut-brain axis, the relationship between the gut microbiota and brain health, researchers are increasingly interested in exploring how probiotics, like those found in kefir, can impact cognitive function and potentially aid in managing or preventing neurodegenerative diseases like Alzheimer's.

The Brazilian Review Study: Probiotics and Alzheimer's Disease

The Brazilian research team conducted a review of seven studies to evaluate the effects of kefir on Alzheimer's disease. This review focused on how kefir might influence key aspects of Alzheimer’s pathology, including neuroinflammation, oxidative stress, and cognitive functioning. These three factors are central to the progression of Alzheimer’s disease.

The review included a variety of models, ranging from rodent and fly studies to a human clinical trial. Although the study pool was limited, the results suggested that kefir supplementation may have potential as part of a broader strategy to fight Alzheimer’s.

Human Study: 28% Improvement in Cognitive Functioning

One of the standout studies in the review involved human participants. Over a 90-day period, 13 individuals with Alzheimer’s disease were given daily kefir supplementation, dosing at 2 mL per kilogram of body weight. The researchers assessed cognitive function before and after the supplementation period using the Mini-Mental State Examination (MMSE) and memory tests.

The results were encouraging: after 90 days, participants showed an impressive 28% improvement in their MMSE scores and a 66% improvement in memory tests. Additionally, these individuals demonstrated reduced levels of inflammatory biomarkers and oxidative stress, which are often elevated in individuals with Alzheimer’s disease.

While these results are promising, the researchers noted that there were contradictory findings in an earlier study, highlighting the need for more rigorous clinical trials to better understand the full effects of kefir on Alzheimer’s disease.

Animal Studies: Kefir’s Impact on Inflammation and brain health

While the human study provides the most direct evidence for kefir’s effects, the animal studies in the review also show potential benefits. The research team reviewed rodent studies that focused on kefir’s role in gut microbiota modulation and its influence on pathways involved in neurodegenerative diseases, particularly the Toll-like receptor 4 (TLR4) pathway.

The TLR4 pathway is implicated in neuroinflammation, a key driver of Alzheimer’s progression. One rodent study showed that kefir downregulated the expression of TLR4, which reduced neuroinflammation and helped protect brain tissue. This aligns with previous studies that have shown the impact of probiotic-rich foods on the immune system and gut health, which in turn can influence brain health.

Additionally, a separate rodent study combining kefir with stem cell therapy showed reduced neuroinflammation and improved cognitive functioning. The results of these animal studies suggest that kefir may not only support cognitive health but also work synergistically with other treatments to reduce Alzheimer’s-related damage.

Fly Studies: Reducing Amyloid Buildup and Improving Motor Skills

Fly models are commonly used to study neurodegenerative diseases like Alzheimer’s because of their genetic similarity to humans in terms of aging and memory. Two fly studies included in the review demonstrated that kefir supplementation led to improvements in motor skills and amyloid-beta plaque reduction.

Amyloid plaques are one of the hallmarks of Alzheimer’s disease and are associated with neurodegeneration. The fly studies suggest that kefir may help reduce the buildup of amyloid plaques, which could be a promising step toward reducing the progression of Alzheimer’s. Furthermore, the improvement in motor skills observed in the fly models aligns with the need for potential treatments that address motor function in Alzheimer’s patients.

The Gut-Brain Axis: Kefir’s Potential Mechanisms

Dr. Peter Gliebus, a cognitive and behavioral neurologist, highlighted the potential mechanisms by which kefir could support brain health. He explained that kefir could help restore a balanced gut microbiome, reduce systemic inflammation, and improve the gut barrier, which might limit neuroinflammation. Additionally, kefir contains bioactive compounds that have antioxidant properties, which could protect neurons from oxidative stress, thereby preserving synaptic function and slowing neurodegeneration.

However, while the bioactive compounds in kefir hold promise, Dr. Gliebus emphasized that more robust clinical studies are necessary before kefir can be recommended as a routine part of Alzheimer’s management.

Conclusion: Promising but Preliminary Findings

While the evidence from animal studies and the human trial is promising, the research on kefir as an Alzheimer’s treatment is still in its early stages. The current body of research suggests that kefir may be a beneficial adjunct to conventional Alzheimer’s treatments, especially in terms of reducing neuroinflammation, oxidative stress, and possibly improving cognitive function.

Dr. Joel Salinas, a neurologist, also cautioned that more clinical research is needed to determine how kefir’s effects might translate into significant benefits for people with Alzheimer’s disease. He emphasized that lifestyle changes, including a healthy diet, exercise, and cognitive stimulation, should be part of a comprehensive approach to managing Alzheimer's.

For now, kefir stands out as a potential complementary treatment for Alzheimer’s patients, with its gut health benefits, anti-inflammatory properties, and ability to support brain health. As more studies are conducted, it could become a valuable tool in the fight against Alzheimer’s disease, but further evidence is needed before kefir can be formally recommended as a treatment option.

Learn more: https://www.sciencedirect.com/science/article/pii/S2949834125000133