Mixed
Consuming complex, whole plant foods containing diverse dietary fibers and phytonutrients increases gastrointestinal tract (GIT) microbiota diversity and stability more effectively than consuming purified fiber isolates or ultra-processed foods.
Prioritize whole plant foods (fruits, vegetables, whole grains) over isolated fiber supplements or highly processed foods. The physical structure and variety of fibers and phytonutrients in whole foods are essential for feeding a diverse and healthy gut microbiome, which in turn supports metabolic health and reduces inflammation.
There are strong indications that the more complex and varied the diet (and its ingredients), the more complex and varied the GIT microbiota is likely to be.
Why this rating
Review of multiple studies comparing whole foods vs. purified fibers; strong mechanistic plausibility but observational/epidemiological data for human health outcomes.
Source
Gut Fermentation of Dietary Fibres: Physico-Chemistry of Plant Cell Walls and Implications for Health
Barbara A. Williams et al. · International Journal of Molecular Sciences · 2017
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