Could the probiotic kefir help fight Alzheimer’s disease?

• 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 evidence piles up to support the notion that gut health may play an important role in brain health, including helping prevent and reduce characteristics of dementia. 

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 examined whether probiotics are helpful to people with Alzheimer’s disease, and the scientists in the present review wanted to see whether the probiotic kefir has the potential to be beneficial. 

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.