Pathology, research and practiceApr 25, 2026

Polyphenols and exercise may activate gut bacteria signals to help protect the brain from degeneration

Gut-Brain Axis Weekly Brief ↗PubMed ↗DOI ↗

Updated Apr 26, 2026

Abstract

Polyphenols and regular physical activity may influence the gut-brain axis and contribute to neuroprotection.

The gut microbiota plays a central role in converting dietary components into bioactive metabolites that can affect brain health.
Polyphenol-derived metabolites and exercise-induced changes in gut bacteria may modulate the Nrf2 signaling pathway, which is crucial for antioxidant defenses and anti-inflammatory responses.
Key metabolites, such as short-chain fatty acids and urolithins, are associated with regulating oxidative stress and neuroinflammation.
Preclinical models suggest that combining dietary polyphenols with physical activity could enhance neuroprotection through gut microbiota.
Challenges exist in translating these findings into personalized interventions that leverage microbiota-dependent Nrf2 activation.

Simplified

Polyphenols and regular physical activity are increasingly recognized as complementary lifestyle interventions that influence the gut-brain axis and contribute to neuroprotection. Emerging evidence highlights the central role of the gut microbiota in mediating these effects by transforming dietary and host-derived substrates into bioactive metabolites. These metabolites can activate the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, a key regulator of cellular antioxidant defenses, mitochondrial function, and anti-inflammatory responses processes that are critically impaired in neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This review synthesizes current mechanistic insights into how polyphenol-derived metabolites and exercise-induced alterations in gut microbial composition converge to modulate Nrf2 signaling. We discuss the roles of key microbiota-derived metabolites, including short-chain fatty acids, urolithins, and indole derivatives, in regulating oxidative stress, neuroinflammation, and synaptic function. Furthermore, we examine evidence from preclinical models supporting the synergistic effects of dietary polyphenols and physical activity on gut microbiota-mediated neuroprotection. Finally, we address translational challenges and highlight the potential of integrating dietary and exercise-based strategies to harness microbiota-dependent Nrf2 activation. This integrative framework provides a basis for developing personalized, microbiome-informed interventions aimed at delaying or mitigating neurodegeneration.

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Competing interests

Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

PubMed

Polyphenols and exercise may activate gut bacteria signals to help protect the brain from degeneration

Abstract

Full Text

Funding

Competing interests

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