It has been found that constipation more than doubles the risk of developing Alzheimer's disease. This finding, resulting from a study of big data from Korea and Japan, has identified a risk factor for Alzheimer's disease in East Asians.
The Gwangju Institute of Science and Technology (GIST) announced on the 22nd that a joint research team, led by Professor Tae Kim of the Department of Biomedical Science and Engineering and Professor Dong-geon Yeun of the Digital Health Center at Kyung Hee Medical Center, has confirmed a causal relationship between reduced bowel motility and Alzheimer's disease.
The research team confirmed that constipation increases the risk of Alzheimer's disease through big data research. They also established the causal relationship through basic research using animal models.
First, the team observed reduced gastrointestinal transit time, such as slow bowel movements or constipation, in an Alzheimer's mouse model. They then investigated how further slowing the mice's bowel movements would affect the pathology of Alzheimer's disease.
When an Alzheimer's mouse model was treated with ‘loperamide,’ a type of antidiarrheal drug, there was a significant increase in brain amyloid-beta protein and microglia, which are immune cells in the brain. Pathological phenomena, such as memory decline, were also observed.
RNA sequencing analysis of colon tissue revealed increased gene expression related to the hormone norepinephrine, as well as secretion and immune responses. Pathological changes in the gut tissue were observed, including decreased expression of genes responsible for defense against bacteria.
The team also analyzed big data from approximately 3.13 million Koreans and 4.38 million Japanese. They found that patients with constipation had a higher hazard ratio for Alzheimer's disease compared to those without: 2.04 times higher in the Korean cohort and 2.82 times higher in the Japanese cohort.
The research team concluded that a functional decline in bowel motility can exacerbate the pathophysiology of Alzheimer's disease.
Professor Tae Kim stated, “Since there is a high probability that intestinal dysfunction or constipation can worsen Alzheimer's disease, active management is necessary.” The study's findings were published online in the ‘Journal of Advanced Research’ on the 13th.
