The Interaction of Polyphenols and the Gut Microbiota in Neurodegenerative Diseases

Abstract

Polyphenols are secondary metabolites of plants and play a potential role in the prevention and treatment of neurodegenerative diseases (NND) such as Alzheimer’s disease (AD) and Parkinson’s disease (PD) due to their unique physiological functions such as acting as antioxidants, being anti-inflammatory, being neuroprotective, and promoting intestinal health. Since dietary polyphenols exist in plant foods in the form of glycosylation or esterification or are combined with polymers, they need to undergo extensive metabolism through phase I and phase II biotransformations by various intestinal enzymes, as well as metabolism by the intestinal microbiota before they can be fully absorbed. Polyphenols improve intestinal microbiota disorders by influencing the structure and function of intestinal microbiota, inducing beneficial bacteria to produce a variety of metabolites such as short-chain fatty acids (SCFAs), promoting the secretion of hormones and neurotransmitters, and playing an important role in the prevention and treatment of NND by affecting the microbe–gut–brain axis. We review the ways in which some polyphenols can change the composition of the intestinal microbiota and their metabolites in AD or PD animal models to exert the role of slowing down the progression of NND, aiming to provide evidence for the role of polyphenols in slowing the progression of NND via the microbiota–gut–brain (MGB) axis.

Determination of Flavonoids and Phenolic Acids in the Liver of Wistar Rats after a Dietary Enrichment with Corinthian Currant (Vitis vinifera L., var. Apyrena): A Liquid Chromatography-Tandem Mass Spectrometry Study

“…Furthermore, in all enzymatically hydrolyzed liver samples, benzoic acid derivatives (gallic acid and homovanillic acid) were detected and quantified. Several other phenolic acids, including vanillic acid, trans -cinnamic acid, and p -hydroxybenzoic, were also detected in liver samples that were not further evaluated due to their complex nature of origin. , …”

“…Several other phenolic acids, including vanillic acid, trans-cinnamic acid, and p-hydroxybenzoic, were also detected in liver samples that were not further evaluated due to their complex nature of origin. 48,49 3.3.2. Phenolic Compounds Detected in Liver of 10% w/w Corinthian Currant-Fed Rats.…”

Translational Research on Bee Pollen as a Source of Nutrients: A Scoping Review from Bench to Real World

“…Polyphenols are very well-known antioxidants and thousands of scientific works have verified this activity for these ubiquitous natural compounds. A countless number of them, including many of those encountered in BP, have been conducted either at experimental or clinical levels, and have concerned many types of human diseases [ 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 ]. The development of these studies being beyond the scope of our current paper, we will not develop these results here.…”

Dietary (Poly)phenols and the Gut–Brain Axis in Ageing

“…However, the different biological activities of various (poly)phenols will depend both on their bioavailability, itself influenced by factors such as age, sex and body composition, and on their secondary metabolites produced by the gut microbes [60,61], potentially explaining inter-individual variability in response to (poly)phenol intake [65]. Evidence that interactions exist between (poly)phenols and brain health, mediated via effects on the gut microbiome and inflammatory pathways, is compelling and widely reported [66], but whether products of polyphenol-mediated gut microbial metabolism are associated with brain activity is far less well-established [67].…”