Highland Barley‐Derived Polyphenols: A Category of Bioactive Phytochemicals Beneficial for Intestinal Health

ABSTRACT Currently, dietary polyphenols have been widely demonstrated to promote human health, and reasonable direct or indirect intake of dietary polyphenols and foods rich in dietary polyphenols is crucial for maintaining the homeostatic metabolic system of the human body. Highland barley (HB, Hordeum vulgare var. coeleste ), known as Qingke in Chinese, has attracted increasing scientific attention due to its health‐promoting properties and exceptional composition of bioactive compounds, notably polyphenols, flavonoids, and β‐glucans. HB is a type of pigmented cereal grain, which is primarily classified into white, blue, black, and purple varieties based on the variations in the color of its pericarp color. Generally, the polyphenol content and diversity in HB are related to the intensity of its pericarp pigmentation. Pigmented HB serves as an excellent source of dietary polyphenols and has become a research hotspot as a functional food ingredient. Understanding the variety, distribution, and intestinal health promoting effect of polyphenols derived from HB is crucial for their utilization in different fields. This minireview emphasizes on the regulatory effects of highland barley polyphenols (HBPPs) on intestinal microbiota and the mechanisms promoting intestinal homeostasis. Furthermore, future research priorities concerning the relationship between HBPPs and gut health were proposed.