Probiotics may boost memory in Alzheimer's patients: study

A daily dose of probiotics found in yogurt and supplements may help improve the thinking and memory in Alzheimer's patients, a new study has claimed.
Researchers found that a daily dose of probiotic Lactobacillus and Bifidobacterium bacteria taken over a period of just 12 weeks is enough to yield a moderate but significant improvement in the score of Alzheimer's patients on the Mini-Mental State Examination (MMSE) scale, a standard measure of cognitive impairment.
Researchers from Kashan University of Medical Sciences and Islamic Azad University in Iran conducted a randomised, double-blind, controlled clinical trial on 52 women and men with Alzheimer's between 60 and 95 years of age.

Half of the patients daily received 200 ml milk enriched with four probiotic bacteria Lactobacillus acidophilus, L casei, L fermentum, and Bifidobacterium bifidum), while the other half received untreated milk.
At the beginning and the end of the 12-week experimental period, the scientists took blood samples for biochemical analyses and tested the cognitive function of the subjects with the MMSE questionnaire which includes tasks like giving the current date, counting backwards from 100 by sevens, naming objects, repeating a phrase and copying a picture.
Over the course of the study, the average score on the MMSE questionnaire significantly increased (from 8.7 to 10.6, out of a maximum of 30) in the group receiving probiotics, but not in the control group (from 8.5 to 8.0).

Even though this increase is moderate, and all patients remained severely cognitively impaired, these results are important because they are the first to show that probiotics can improve human cognition.

"In a previous study, we showed that probiotic treatment improves the impaired spatial learning and memory in diabetic rats, but this is the first time that probiotic supplementation has been shown to benefit cognition in cognitively impaired humans," said Professor Mahmoud Salami from Kashan University.
Treatment with probiotics also resulted in lower levels of triglycerides, Very Low Density Lipoprotein (VLDL), high-sensitivity C-Reactive Protein (hs-CRP) in the blood of the Alzheimer patients, and likewise a reduction in two common measures (called "Homeostatic Model Assessment", HOMA-IR and HOMA-B) of insulin resistance and the activity of the insulin-producing cells in the pancreas.

"These findings indicate that change in the metabolic adjustments might be a mechanism by which probiotics affect Alzheimer's and possibly other neurological disorders. We plan to look at these mechanisms in greater detail in our next study," said Salami.
The study was published in the journal Frontiers in Aging Neuroscience.