Plant-food components at the microbiota-neuroinflammation interface: human evidence, translational limits, and...

This narrative review evaluates how convincingly plant-food components and plant-rich dietary patterns influence neuroinflammation and whether those mechanisms translate into neurological benefit. Infection is treated as one possible initiating exposure, neuroinflammation as a context-dependent mechanism, and neurological complications as clinical outcomes. Targeted literature searches and reference verification prioritized original human trials, mechanistic studies and balanced evidence syntheses. The most coherent pathways are modulation of microglial inflammatory signaling, including NLRP3-related processes, by selected phytochemicals, and microbial production of short-chain fatty acids from fermentable fiber, with effects on intestinal barrier function, systemic immune tone and microglial homeostasis. Cell and animal evidence is substantial, but human findings are heterogeneous. Randomized studies of whole dietary patterns and selected foods report both favorable and null cognitive, vascular, inflammatory, and microbiome outcomes. Trials of formulated curcumin and resveratrol show selective signals rather than consistent disease-modifying efficacy, underscoring problems of dose, metabolism, formulation and target engagement. Direct human evidence that plant foods prevent or modify infection-specific neurological outcomes remains insufficient. Translation also depends on food-system conditions: affordability, cultural acceptability, local availability, processing, safety, environmental burden and the foods displaced by a plant-forward intervention. Plant foods should therefore be framed as components of nutritionally adequate and context-specific sustainable diets, not as universally low-impact products or substitutes for clinical care. Future studies should integrate defined food exposures, pharmacokinetics, microbial function, inflammatory and vascular measures, neurological outcomes, safety, cost and environmental indicators.