Dietary flavonoids and gut microbiota interaction: A focus on animal and human studies to maximize their health benefits

Abstract

Flavonoids are phytochemicals that widely exist in plants, fruits, and vegetables and have a variety of activities. However, due to their complex structure, it is often rarely absorbed into the blood. Intestinal bacteria regarded as the third kind of human organ have attracted extensive attention in recent years. Complex structural flavonoids can be catabolized into low molecular weight phenolic acids under the action of intestinal bacteria and then absorbed into the blood, showing several protective effects on the body. In addition, the intake of flavonoids can also regulate the composition and function of intestinal flora. This paper comprehensively summarizes the interaction between flavonoids and intestinal flora, as well as the impact on human health, in order to provide some insights on how to combine intestinal microorganisms to select and ingest dietary polyphenols for future applications in medicine.

Association of dietary flavonoid intakes with prevalence of chronic respiratory diseases in adults

“…In examining the relationship between dietary flavonoids and CRDs, it is necessary to consider the role of the gut microbiome [ 57 – 61 ]. Flavonoids, a diverse group of polyphenolic compounds, are metabolized by gut microbiota, resulting in the production of various biologically active metabolites [ 57 , 60 ]. These metabolites can exert systemic effects, potentially influencing respiratory health through several mechanisms.…”

A View on the Chemical and Biological Attributes of Five Edible Fruits after Finishing Their Shelf Life: Studies on Caco-2 Cells

“…Also, apart from their notorious antioxidant anti-inflammatory activities, the dietary flavonoids are renowned in promoting metabolic and cardiovascular health, in promoting cognitive and vascular endothelial functions, as well as in sustaining the glycemic response in type 2 diabetes mellitus, and they are proved to decrease the risk of breast cancer in postmenopausal women too [69]. Above these, the literature data in recent years [70][71][72][73][74][75][76][77][78][79][80][81] point out the existence of a microbiota-flavonoid bidirectional interaction meaning that the gut microbiota influence the fate of the flavonoids regarding their metabolic mechanism, biotransformation, bioavailability and bioactivity in humans, but also flavonoids influence the human microbiome's homeostasis as well. Furthermore, flavonoids can regulate the human microbiota by promoting the growth of beneficial bacteria (prebiotic effect) and by inhibiting opportunistic and pathogenic bacteria [72,73].…”

“…Above these, the literature data in recent years [70][71][72][73][74][75][76][77][78][79][80][81] point out the existence of a microbiota-flavonoid bidirectional interaction meaning that the gut microbiota influence the fate of the flavonoids regarding their metabolic mechanism, biotransformation, bioavailability and bioactivity in humans, but also flavonoids influence the human microbiome's homeostasis as well. Furthermore, flavonoids can regulate the human microbiota by promoting the growth of beneficial bacteria (prebiotic effect) and by inhibiting opportunistic and pathogenic bacteria [72,73]. It has been established that the microbial metabolism of the dietary flavonoids follows a general model by which the bacterial enzymes carry out the -O-deglycosylation of the flavonoids glycosides to release their active aglycones, and at the same time, the gut bacteria perform many other transformations, including oxidation and demethylation reactions, which result in smaller molecules in the series of phenolic acids [70,[82][83][84].…”

Formation mechanism of polycyclic aromatic hydrocarbons in grilled beef and the mitigative effect of flavonoids

“…Flavonoids can be catabolized into low molecular weight compounds, showing several protective effects on the body (Yang et al, 2023). Besides, appropriate consumption of flavonoid-rich food may contribute to preventing or delaying hyperuricemia and its complications (Xue et al, 2023).…”