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BRS5 — Gut-Brain Axis & Enteric Nervous System

BRS5(KC2) - Polyphenol & Plant-Diversity Inputs​

(Polyphenol exposure and plant-food variety are distinct dietary concepts; no shared limiting pool is established.)

1. Ambition​

No single biological resource state can be specified from the attached evidence: polyphenol exposure, microbial conversion capacity, dietary fibre exposure, fermented-food intake, and plant-food variety are not shown to constitute one interchangeable pool or bottleneck.

2. Core Nutritional Requirements​

3. Evidence Base​

Summary​

Polyphenol exposure and plant-food variety are distinct dietary concepts, and the attached human evidence does not establish them as one shared nutritionally constrained pool. Wastyk et al. compared high-fibre and high-fermented-food diets rather than isolating polyphenols or plant variety, while Singh et al. showed that urolithin A exposure depends on ellagitannin exposure and variable microbial conversion and can be bypassed by direct supplementation (Wastyk et al., 2021; Singh et al., 2022).

  • Constraint and membership boundary: Neither broad polyphenol exposure nor plant-food variety is established here as a constituent of one shared limiting resource; a dietary pattern, a compound class, and microbial conversion capacity are not interchangeable biological pools.
  • Evidence and measurement boundary: The cited studies establish diet-associated microbiome and immune responses, plus variable production and exposure to one microbial polyphenol metabolite; they do not measure a combined polyphenol-and-diversity pool or show that its insufficiency constrains the listed mechanisms (Wastyk et al., 2021; Singh et al., 2022).
  • Biological relevance and provision limitation: These exposures may remain relevant to particular microbial processes, but the available evidence does not justify a shared-resource requirement, an adequacy threshold, or a claim that increasing either exposure improves downstream function or clinical outcomes.

4. Emerging Biological Supports​

No Emerging Biological Supports are currently prioritised for this KC.

5. Connected Mechanisms​

Functional Mechanisms​

No Functional Mechanism connection is established through a shared polyphenol-and-plant-diversity resource.

Primary Mechanisms​

No Primary Mechanism connection is established through a shared polyphenol-and-plant-diversity resource.

6. Key References​

Evidence assessed for the proposed grouping

Emerging Biological Supports

  • None currently prioritised for this KC.