A study by King's College London has found that daily protein and prebiotic supplements can improve memory test scores in people over age 60. The findings were published in 2024, as the same visual memory and learning test is used to detect early signs of Alzheimer's disease. The study tested two plant-fiber prebiotics, inulin and FOS, which are often used as a natural low-calorie sweetener. The supplements were found to be linked to subtle changes in the gut microbiome, with beneficial Bifidobacterium being found in those taking inulin or FOS. While the study did not identify significant physical benefits, it suggested that consuming certain 'brain foods' could be a promising way to treat cognitive decline. The research supports the emerging idea that cognitive decline is always a disease, but may also involve external factors.