Neurodegenerative disorders, including Alzheimer’s, Parkinson’s, Huntington’s disease, and amyotrophic lateral sclerosis, are marked by the gradual degeneration of neurons, ultimately resulting in significant impairments in cognition and motor function. Despite growing knowledge of their molecular mechanisms, including oxidative stress, mitochondrial dysfunction, and protein aggregation, available treatments are largely symptomatic and fail to halt disease progression. Emerging evidence highlights the critical role of lifestyle factors in modulating neurodegeneration through the gut–brain axis linking gut microbiota, immune system, and central nervous system. Diet strongly influences gut microbial composition, producing metabolites like short-chain fatty acids and neurotransmitter precursors that affect brain function. Disruption of this axis due to poor nutrition, inactivity, or stress contributes to neuroinflammation and cognitive decline. This chapter explores how dietary patterns such as the Mediterranean diet support neuroprotection by enhancing GABAergic signaling, reducing oxidative stress, and promoting neurotrophic factors. It also discusses the promise of bioactive phytochemicals, functional foods, and microbiota-targeted therapies. Integrating diet, exercise, and microbial modulation offers a holistic, non-pharmacological strategy to delay onset, alleviate symptoms, and improve quality of life in aging populations at risk for neurodegenerative disorders.