- Scientists in Brazil recently conducted a review to see how the probiotic kefir affects Alzheimer’s disease.
- Alzheimer’s disease is the most common form of dementia, and since there is no cure available, researchers are interested in finding new ways to prevent and fight the disease.
- The scientists included seven studies in their review, including one that involved human participants.
- While the study pool was limited, the scientists learned that kefir can potentially improve symptoms.
As researchers learn more about how to combat Alzheimer’s disease, more
With that in mind, Brazilian researchers recently reviewed several studies to see whether kefir could be beneficial as a supplement for someone with Alzheimer’s disease. Since probiotics support gut health, which is suspected to impact brain health, the scientists wanted to look into kefir specifically since it has a “unique microbial composition.”
While the scientists were limited in the number of studies they included in their review, they still found the results promising. One study in humans showed that supplementing kefir improved cognitive functioning and memory tests.
The findings appear in the journal Brain Behavior and Immunity Integrative.
An estimated 7 million people in the U.S. have Alzheimer’s disease, and this number is projected to almost double within 25 years. Considering the physical, emotional, and financial toll that Alzheimer’s disease takes, scientists regularly look for ways to reduce the impact.
Some research has
Probiotics are important to gut health and can increase the amount of good bacteria in the microbiome, which can benefit the immune system, heart, and other parts of the body. Foods such as yogurt and sauerkraut have probiotics, and probiotics are also available in drink form, including the fermented milk beverage kefir.
Kefir comes from fermenting kefir grains with milk (both dairy and non-dairy). According to the review authors, kefir stood out because it includes “both bacteria and yeast in a symbiotic relationship.”
The scientists looked through multiple databases to find studies on kefir and neurodegenerative diseases. After narrowing down their search results, they were left with seven studies – one study involved humans, four studies involved rodents, and the other two studies involved flies.
The researchers were interested in howkefir possibly impacts cognitive functioning, neuroinflammation, and oxidative stress. According to the 2016 review, oxidative stress is “a process increased in the brain with aging” and can contribute to dementia.
After analyzing the different models, the review authors determined what impact kefir could have as an adjunct treatment to Alzheimer’s disease.
The study on humans lasted for 90 days and assessed people with Alzheimer’s disease; there were 13 participants in the study. The participants took a daily supplementation of kefir at a dose of 2 mL per kilogram of body weight.
Before beginning the kefir supplementation, the scientists gathered baseline data on cognitive functioning through the Mini-Mental State Examination (MMSE) and memory. They also gathered information on inflammatory biomarkers and oxidative stress.
Overall, the participants had a 28% improvement in their baseline MMSE scores after 90 days of kefir supplementation. They also experienced a 66% improvement in memory tests.
Additionally, these participants showed improvement in their inflammatory and oxidative stress biomarkers. While this seems promising, the authors of the review noted that an older study did not yield the same cognitive results, so they believe further research in humans is needed.
The animal studies also showed that kefir may have potential cognitive benefits. Both the rodent and fly studies demonstrated this.
One of the rodent studies delved into how kefir impacts the gut microbiota and the Toll-like receptor 4 (TLR4) pathway. This is significant as the TLR4 pathway is implicated in Alzheimer’s disease.
This study showed that kefir contributed to a “significant downregulation in the expression of TLR4.” This led to a reduction in neuroinflammation, thereby protecting brain tissue and improving cognitive functioning.
Another rodent study looked at how kefir works when added to a stem cell therapy treatment for Alzheimer’s disease; this resulted in lowered neuroinflammation as well.
The other two rodent studies analyzed kefir with either pioglitazone (an anti-diabetic medication) or simvastatin (a cholesterol-lowering medication). Both of these offered protective benefits.
One of the fly studies analyzed how kefir impacts amyloid buildup, and both of the fly studies looked at how kefir impacts motor skills.
Beta-amyloid plaques are a hallmark of Alzheimer’s disease. The fly study showed a reduction in amyloid buildup, which suggests that kefir could serve as a complementary treatment.
Both fly models showed an improvement in motor skills with kefir supplementation. Since people with Alzheimer’s disease experience a decrease in motor skills over time, this has the potential to be beneficial for them.
Peter Gliebus, MD director of cognitive and behavioral neurology at Marcus Neuroscience Institute, a part of Baptist Health South Florida, spoke with Medical News Today about the study.
“Kefir may support brain Health by helping to restore a balanced gut microbiome, reducing systemic inflammation, and strengthening the gut barrier, which can limit neuroinflammation,” Dr. Gliebus said when explaining how kefir may be helpful.
“[Kefir’s] bioactive compounds have antioxidant properties that could potentially protect neurons from oxidative stress. This protection can help preserve synaptic and mitochondrial function, potentially slowing down neurodegeneration.”
— Peter Gliebus, MD
While Gliebus explained the mechanisms by which kefir could potentially be helpful, he noted further research is needed on the probiotic and Alzheimer’s disease.
“The review positions kefir as a promising adjunct therapy due to its modulation of neuroinflammation and oxidative stress via the gut-brain axis, but current evidence is still very preliminary,” Gliebus emphasized. “While the biological rationale is strong, more robust clinical studies are necessary before recommending kefir as a routine component of [Alzheimer’s] management.”
Neurologist Joel Salinas, MD, MBA, MSc, FAAN, the co-founder and chief medical officer of Isaac Health, also spoke with MNT about the review.
“While early studies – mostly in animals and lab settings – suggest that kefir may help reduce inflammation and oxidative stress in the brain, we are still in the early stages of understanding how this might translate to people with Alzheimer’s. It’s promising, but more clinical research is needed before we can make definitive recommendations.”
— Joel Salinas, MD, MBA, MSc, FAAN
Salinas also noted that focusing on lifestyle changes, such as diet and exercise, could be helpful.
“Dietary interventions like kefir may complement these treatments by supporting brain health and overall well-being,” explained Salinas. “A holistic approach – including a balanced diet, physical activity, cognitive stimulation, and social engagement – may provide the most benefit for individuals at risk or in the early stages of Alzheimer’s.”
