In Vitro Fermentation Shows Polyphenol and Fiber Blends Have an Additive Beneficial Effect on Gut Microbiota States

Area of Science:

• Microbiology
• Nutrition Science
• Gastroenterology

Background:

• Polyphenols and fermentable fibers positively influence gut microbiota and metabolism.
• Limited research exists on the additive effects of combined polyphenols and fermentable fibers on gut microbial states.

Purpose of the Study:

• To investigate the additive effects of combined polyphenols (PP) and fermentable fibers (FB) on gut bacteria and metabolite changes.
• To determine the influence of individual and combined PP and FB supplementation on an in vitro human gut model.

Main Methods:

• Utilized an in vitro fermentation model with human fecal inoculum from 30 healthy volunteers.
• Supplemented the model with blends of polyphenols (PP), dietary fibers (FB), or a combination (PPFB).
• Analyzed gut bacteria growth dynamics and key metabolite changes (short-chain fatty acids, indole, ammonia).

Main Results:

• Both PP and FB blends independently increased beneficial bacteria like Ruminococcus bromii, Bifidobacterium, Lactobacillus, and Dorea.
• Combined PPFB and FB supplementation significantly increased short-chain fatty acid concentrations.
• FB and PPFB supplementation decreased indole and ammonia levels, while PPFB also increased antioxidant capacity.

Conclusions:

• Individual PP and FB blends show selective positive impacts on gut microbial composition and function.
• The combination of PP and FB provides additive benefits, eliciting a broader positive influence on the gut microbiome.
• Mixed substrate blends hold potential for enhancing gut microbial resilience against dysbiosis.