The gut microbiome has recently become the focus of a lot of biomedical research, as we begin to understand how important the microbes living in our gastrointestinal tracts are for our overall health. While it’s still unclear what exactly makes your gut microbes healthy or unhealthy, previous research has shown that probiotics shift the balance in the right direction. Probiotics are live bacterial or yeast cultures often found in fermented foods like yogurt, sauerkraut, and pickles. These cultures seem to increase the proportion of “good” microbes in your gut. While the gut microbiome is clearly important for gastrointestinal health, recent studies suggest that it can also influence the brain. Scientists have coined the term “microbe-gut-brain axis” to describe this close relationship.
In a study published in Frontiers in Aging Neuroscience, researchers from Iran attempted to determine whether probiotics could be beneficial for dementia patients. They randomly divided sixty patients diagnosed with Alzheimer’s disease into two groups. One group received milk containing a mixture of probiotics, while the other group received regular milk as a control. The study had a double-blind design, meaning neither the researchers or the subjects knew who received each type of milk until after the data analysis was completed. This design helps to ensure that unconscious biases do not influence the results. Additionally, none of the subjects were allowed to consume probiotic-rich foods like yogurt during the study, ensuring that any gut microbiome differences would be due to the experiment and not any dietary interference.
After twelve weeks consuming the milk on a daily basis, the subjects took a mini-mental state exam, which is used to assess memory and cognition. The probiotic group scored an average of 28% better on the exam compared to their score before starting the treatment. In contrast, the control group’s score decreased by an average of 5%. This difference was statistically significant, indicating that the probiotics substantially improved memory in these subjects.
The researchers also tested the subjects’ blood for many different biochemicals. The probiotic group had improved markers of insulin metabolism, suggesting that the treatment might be helpful in reducing the risk of insulin resistance, a condition associated with type 2 diabetes. They also had lower levels of triglycerides, a type of body fat.
Despite the sample size of this study being fairly small, the dramatic improvement in cognitive status after only three months of probiotic treatment suggests that the gut microbiome could be intimately involved in dementia. Probiotics have no known health detriments, and are proven to assist in gastrointestinal health. While we wait for larger studies to provide a conclusive answer on probiotics’ utility in Alzheimer’s disease, it can’t hurt to try increasing them in our diets, or in the diet of a loved one with dementia.