Diet–gut microbiome interaction and ferulic acid bioavailability: implications on neurodegenerative disorders.

Purpose of the review Ferulic acid (FA), which occurs naturally as the feruloylated sugar ester in grains, fruits, and vegetables,
is critical for combating oxidative stress and alleviating neurodegenerative diseases resulting from free radical-generated
protein aggregates in brain cells. However, FA cannot be absorbed in conjugated form. Therefore, strategies to improve the
bioavailability of FA are gaining more importance. Ferulic acid esterases (FAE) of the gut microbiota are critical enzymes
that facilitate FA release from feruloylated sugar ester conjugates and influence systemic health. This review provides insight
into a nutrition-based approach to preventing neurodegenerative disorders such as Alzheimer’s and Parkinson’s by altering
the diversity of FAE-producing gut microbiota.
Recent findings The human gut is a niche for a highly dense microbial population. Nutrient components and the quality
of food shape the gut microbiota. Microbiota–diet–host interaction primarily involves an array of enzymes that hydrolyse
complex polysaccharides and release covalently attached moieties, thereby increasing their bio-accessibility. Moreover,
genes encoding polysaccharide degrading enzymes are substrate inducible, giving selective microorganisms a competitive
advantage in scavenging nutrients.
Summary Nutraceutical therapy using specific food components holds promise as a prophylactic agent and as an adjunctive
treatment strategy in neurotherapeutics, as it results in upregulation of polysaccharide utilisation loci containing fae genes
in the gut microbiota, thereby increasing the release of FA and other antioxidant molecules and combat neurodegenerative
processes.