In a study from the National Center for Geriatrics and Gerontology in Obu, Japan, Dr. Naoki Saji and his associates reported that patients suffering from dementia have a composition of gut bacteria that differs from those without dementia, suggesting that gut bacteria may contribute to the neurodegeneration of brain cells that causes dementia.

The researchers obtained stool samples from 128 older volunteers and compared the composition of their gut microbiomes to those with and without dementia. (Microbiome refers to the trillions of bacteria in the digestive system.) Recent research has shown that such gut-dwelling bacteria not only assist in digestion, they also impact various bodily functions.

In addition, they produce vitamins and compounds that fight inflammation, as well as chemicals that send messages to brain cells.

The study did not prove that the microbiome causes dementia, but it could serve as a starting point for such research.