Table 1.

Tea compounds and the gut microbiome.

Tea Compounds	Reference
Ellagitannins—Tea has been found to be a significant contributor of dietary ellagitannins, which the gut microbiota metabolites use to produce urolithins.	Yang et al. (2019) [17]
Oligomeric, oxidized black tea phenolic (BTP) and monomeric green tea catechin (GTC)—GTC gives a higher yield of bioactive phenolic metabolites upon colonic fermentation than BTP.	Liu et al. (2016) [22]
Tea polyphenols—The major classes are catechins, including epicatechin, epigallocatechin, epicatechin-3-gallate, and epigallocatechin-3-gallate. Flavanols, such as quercetin, kaempferol, myricetin and their glycosides, are also found which could interact with gut microbiota.	Etxeberria et al. (2013) [8]
Hippuric acid—Ingestion of green and black tea majorly increases the excretion of hippuric acid into urine, though less is known about microbial degradation.	Mulder et al. (2005) [23]