Yogurt every day keeps Alzheimer’s away? Probiotics, strong gut health may be key to avoiding dementia

CORK, Ireland — As of 2021, a whopping 6.2 million Americans are living with Alzheimer’s disease and this number is projected to rise 22% by 2025. Globally, the number of people with dementia is predicted to triple to around 150 million by 2050 because of aging populations. While there’s no cure for the Alzheimer’s, new research indicates that the bacteria in our gut could stave off the disease.

In a recent study, memory problems were reversed after old mice were given “friendly” bacteria. This research suggests gut-boosting yogurts could help to ward off Alzheimer’s disease, which opens the door to the development of probiotics that treat or even prevent dementia. 

“It’s a potential game-changer. We’ve now established the microbiome can be harnessed to reverse age-related brain deterioration. We also see evidence of improved learning ability and cognitive function,” says corresponding author Professor John Cryan, of University College Cork in Ireland, per South West News Service.

A staggering 100 trillion microorganisms live in the human gut – both good and bad. The immune system is impacted by the balance. The research team from Ireland showed that lab rodents experienced increased memory and cognitive function by introducing specific species.

Aging-associated changes in the immune system were reversed with fecal transplants from younger mice, including quicker deciphering of maze patterns and better memory afterward. They were also less prone to anxiety, another common symptom of dementia. Scans later showed their brains had been rejuvenated, containing metabolites and patterns of gene regulation resembling those of adolescents. 

“It should be said we are not advocating fecal transplants for people who want to rejuvenate their brain. Instead, these studies point towards a future where there will be a focus on microbiota-targeted dietary or bacterial-based interventions. They will promote optimum gut health and immunity in order to keep the brain young and healthy,” explains Cryan.

The study suggests such therapies could combat cognitive decline. It adds to evidence that probiotics sold in supermarkets as diet supplements boost concentration, decision-making, and understanding.

“Microorganisms that live on and in the human body have an impact on health and vary with age. Friendly bacteria have beneficial effects on the metabolic and immune systems. They can be gradually replaced with bacteria that drive chronic inflammation, metabolic dysfunction, and disease,” notes Cryan. “Much work is needed to translate the findings for clinical use in humans. We know that microorganisms in the gut shape local immunity, but can also affect brain aging and increase the risk of neurodegenerative diseases. Now, there is a growing appreciation of the importance of the microbes in the gut on all aspects of physiology and medicine.”

Previous research has found that a daily dose of probiotics over 12 weeks can produce significant improvement in elderly patients.

“This research further demonstrates the importance of the gut microbiome in many aspects of health – and particularly across the brain/gut axis where brain functioning can be positively influenced. The study opens up possibilities in the future to modulate gut microbiota as a therapeutic target to influence brain health,” concludes Professor Paul Ross, director of APC Microbiome Ireland at the university.

This study is published in Nature Aging.

South West News Service writer Mark Waghorn contributed to this report.