Genetic Link between Gut Health and Alzheimer’s Disease confirmed
Friday, October 14th, 2022
The same genes that send people to the bathroom with gut issues, may be involved in brain health.
Previous observational studies have suggested a relationship between Alzheimer’s Disease and gastrointestinal tract disorders. However, it has been unclear what underpins these relationships. According to new data from Australia’s Edith Cowan University, it could be genetic[1]. Researchers evaluated genetic data from between 34,650 – 456,000 people who had previously participated in cohort studies. They discovered a distinct genetic overlap between Alzheimer’s disease and gastroesophageal reflux disease, peptic ulcer disease, gastritis-duodenitis, diverticulosis, and irritable bowel syndrome.
People with gut disorders may be at greater risk of developing Alzheimer’s Disease
The team found that many disease-specific genes shared the same loci, or chromosomal location. Many of these genes are involved in the brain’s inflammatory response and are also associated with cholesterol levels. The gene CD46 is involved in killing bacteria linked to peptic ulcers.
The same overlap was not seen among those with inflammatory bowel disease. This could be due to the small number of inflammatory bowel disease genome-wide association studies available.
The Gut-Brain Connection
Despite the link, there is no proof of causation. In other words, it is not safe to assume that gastrointestinal disorders cause Alzheimer’s, or vice versa. At minimum, the study provides further evidence to support the concept of the ‘gut-brain’ axis – a two-way link between the brain’s cognitive and emotional centres, and the functioning of the intestines. The findings could lead to new interventions for dementia, such as cholesterol-lowering statins or a healthy diet. Screening people with gastrointestinal disorders for cognitive decline might also be a way of identifying people with Alzheimer’s disease early.
[1] https://www.nature.com/articles/s42003-022-03607-2
