Health Network》Probiotics don’t just take care of the intestines! Study reveals Alzheimer's disease indicators dropped after 6 months of eating

Probiotics not only help gut health, they may also be good for the brain. Wayne, a food and agriculture expert, said that a double-blind trial in South Korea found that elderly people with early cognitive impairment were allowed to eat three strains of probiotics every day. After 24 weeks, pTau181, which is related to Alzheimer's disease, in their blood significantly decreased, and memory and visuospatial organization ability tests also improved. As for the group that took a placebo, there was no significant change. This research will be published in the "Journal of Alzheimer’s Disease" in August 2026.

Wayne posted on Facebook that a study was conducted by a team from the Gwangju Alzheimer's Disease and Related Dementia Generation Research Center and Chonnam National University Hospital in Korea, including 87 subjects from the GARD Generation Study in Gwangju, which tracks cognitive decline over a long period of time. The subjects were randomly divided into two groups, 40 taking probiotics and 47 taking placebo. Neither the subjects nor the researchers knew who took which. The probiotic code KL-P301 is composed of 3 strains of Bifidobacterium animalis, Lactobacillus fermentum and Lactobacillus brevis. The powder can be eaten directly or soaked in water to drink.

Wayne said that pTau181 is a tau protein that is phosphorylated at the 181st position. The tau protein in the brains of Alzheimer's disease patients folds abnormally, becomes tangled, and gets stuck in nerve cells. Before the symptoms of dementia appear, pTau181 in the blood often begins to increase, so it is used as a blood indicator to track the pathological changes of Alzheimer's disease.

In addition to pTau181, the other two nerve damage indicators GFAP and NfL remained stable in the probiotic group, but increased significantly in the placebo group. In terms of cognitive performance, the clinical dementia score sum (CDR-SB) of the probiotic group improved, mainly from memory items, and test scores that test the visual spatial organization ability such as copying geometric figures and complex figures also improved; the placebo group showed a significant decline in scores on the test of recalling and drawing previously seen figures.

Wayne said that the research team believes that the two results of decreased pTau181 and preserved visuospatial ability occur simultaneously, supporting that the interaction between gut bacteria, the immune system and the brain may be involved in the process of early neurodegeneration. However, this study measured blood indicators and did not use positron imaging to directly look at the tau protein in the brain. The research team also stated that the next step is to use a larger scale, longer trial, and use tau and amyloid positron imaging to confirm the effect.