Probiotics and Cognition

This morning, I read about a really interesting randomized, double-blind study[i] done on 60 patients with Alzheimer’s disease.  30 of the patients were in the control group, and were just given ordinary milk.  The 2nd group of 30 was given milk with a mixture of high-dose probiotics.  The probiotic mixture had four kinds of probiotic bacteria: Lactobacillus acidophilus, L. casei, L. fermentum, and Bifidobacterium bifidum (approximately 400 billion bacteria per species – so a total of around 1.6 trillion organisms).  At the end of the 12 week-long trial, scientists looked at both blood work and cognitive functioning. While the treated group remained significantly cognitively impaired, they did show statistically significant improvement over the controls.  They also noted that blood work improved, including C-reactive protein, which is a marker for inflammation.

This is the first time that probiotics have been proven to improve cognition in humans.

Science Daily, which covered this story, quoted an Alzheimer’s researcher’s (not involved in this study) comments on the paper:

 “This early study is interesting and important because it provides evidence for gastrointestinal (GI) tract microbiome components playing a role in neurological function, and indicates that probiotics can in principle improve human cognition. This is in line with some of our recent studies which indicate that the GI tract microbiome in Alzheimer’s is significantly altered in composition when compared to age-matched controls…”[ii]

The implications of this are huge, obviously.  We know, for example, that the microbiome is altered in autism, and most cases of autism are associated with cognitive deficits.  What other “mental illnesses” associated with cognitive loses then might probiotic therapy help?!


[i] Elmira Akbari, Zatollah Asemi, Reza Daneshvar Kakhaki, Fereshteh Bahmani, Ebrahim Kouchaki, Omid Reza Tamtaji, Gholam Ali Hamidi, Mahmoud Salami. Effect of Probiotic Supplementation on Cognitive Function and Metabolic Status in Alzheimer’s Disease: A Randomized, Double-Blind and Controlled Trial. Frontiers in Aging Neuroscience, 2016; 8 DOI: 10.3389/fnagi.2016.00256

[ii] From

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