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Boosting gut microbes helps protect mice against Alzheimer’s disease

The food we eat might boost beneficial gut bacteria and lower the risk of Alzheimer’s

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A supplement that nourishes “good” bacteria in the gut seems to protect against an Alzheimer’s-like disease in mice and will soon be tested in a clinical trial.

Growing evidence points to a link between Alzheimer’s disease and gut health. For example, studies have found that people with the condition tend to have more pro-inflammatory, or “bad”, bacteria and less anti-inflammatory, or “good”, bacteria in their guts. They also tend to have a less diverse mix of gut microbes overall.

Chun Chen at Emory University in the US and her colleagues have added to this evidence by showing that mice engineered to have an Alzheimer’s-like disease also have more pro-inflammatory bacteria and less anti-inflammatory bacteria in their guts.


In addition, they demonstrated that healthy mice housed with those with the Alzheimer’s-like disease were more likely to develop the condition themselves, possibly through exposure to their cagemates’ unhealthy gut microbes.

To explore whether improving gut health may reduce the risk of developing Alzheimer’s disease, Chen and her colleagues gave mice a prebiotic supplement called R13 that is designed to promote a healthy mix of gut microbes.

They found that mice treated with R13 were less likely to accumulate a protein called beta-amyloid in their guts. Beta-amyloid builds up in the brains of people with Alzheimer’s disease – forming sticky clumps that damage brain networks. Recent research in mice hints that this protein can travel from the gut to the brain and cause Alzheimer’s symptoms.

R13 has recently been granted approval to be tested in a small clinical trial to see if it helps to slow or prevent Alzheimer’s disease in people. “It sounds really interesting, but we know from the history of Alzheimer’s drug trials that many promising treatments fail,” says Bryce Vissel at the University of Technology Sydney in Australia.

In the meantime, Chen recommends eating a varied diet to help boost microbial diversity in the gut. “For example, the Mediterranean diet has been shown to slow the development of Alzheimer’s disease, which might be partially attributed to maintaining the diversity of gut microbiota,” she says.

Journal reference: Science Advances, DOI: 10.1126/sciadv.aba0466

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