**The E** ff**ects and Mechanisms of Cyanidin-3-Glucoside and Its Phenolic Metabolites in Maintaining Intestinal Integrity**

#### **Jijun Tan 1, Yanli Li 1, De-Xing Hou 2 and Shusong Wu 1,\***


Received: 10 September 2019; Accepted: 8 October 2019; Published: 12 October 2019

**Abstract:** Cyanidin-3-glucoside (C3G) is a well-known natural anthocyanin and possesses antioxidant and anti-inflammatory properties. The catabolism of C3G in the gastrointestinal tract could produce bioactive phenolic metabolites, such as protocatechuic acid, phloroglucinaldehyde, vanillic acid, and ferulic acid, which enhance C3G bioavailability and contribute to both mucosal barrier and microbiota. To ge<sup>t</sup> an overview of the function and mechanisms of C3G and its phenolic metabolites, we review the accumulated data of the absorption and catabolism of C3G in the gastrointestine, and attempt to give crosstalk between the phenolic metabolites, gu<sup>t</sup> microbiota, and mucosal innate immune signaling pathways.

**Keywords:** cyanidin-3-glucoside; phenolic metabolites; gu<sup>t</sup> microbiota; signaling pathways; intestinal injury
