Role of dietary fiber and short-chain fatty acids in preventing neurodegenerative diseases through the gut-brain axis

As global life expectancy rises, maintaining physical and mental health is increasingly vital, particularly for aging populations. Neurodegenerative diseases like Alzheimer's, Parkinson's, amyotrophic lateral sclerosis, and multiple sclerosis significantly affect quality of life and pose public health challenges. Emerging evidence highlights dietary fiber and its metabolites, short-chain fatty acids (SCFAs), as crucial in promoting gut health and preventing these diseases. This review explores current mechanistic insights into how SCFAs influence gut-brain communication and provides an integrative perspective by comparing fiber-based and non-fiber-based dietary interventions, such as Mediterranean-DASH intervention for neurodegenerative delay (MIND) and ketogenic diets. It also highlights emerging synergistic approaches that combine dietary fiber with functional foods like polyphenols, offering novel opportunities for dietary modulation of neurodegenerative disease risk. These findings support the development of fiber-focused dietary interventions to promote the production of SCFAs and potentially delay neurodegenerative disease progression in elderly populations. • Rising life expectancy increases the importance of mental and physical health. • SCFAs from dietary fiber help regulate inflammation and oxidative stress. • SCFAs strengthen gut and brain barriers, reducing neurodegenerative risks. • Promoting dietary fiber intake aids in cognitive resilience for aging populations.