Effects of combined Mediterranean diet and physical activity intervention on the gut microbiome and disease progression in individuals with Parkinson's disease: study protocol for a multicenter, randomized controlled pilot study (PRIME study). - Fognani A; Rotondo R; Savo Sardaro ML; de Iure A; Gaglione M; Casali M; Leonardi L; Radicati FG; Vacca L; Guescini M; Zeppa SD; Gatta L; et al. (Frontiers in aging neuroscience, 2026)