Table 2.

Summary of the putative biomarkers of seaweed intake, including reasons for inclusion or exclusion from the final list of candidate biomarkers

Food item	Metabolites	Biofluid locations	Reason for inclusion and exclusion	Selected for further systematic validation as BFIs
Brown seaweed	Hydroxytrifuhalol A	Hydrolyzed urine	Specificity and suitable post-prandial kinetics	Yes
Brown seaweed	7-Hydroxyeckol	Hydrolyzed urine	Specificity and suitable post-prandial kinetics	Yes
Brown seaweed	C-O-C dimer of phloroglucinol	Hydrolyzed urine	Specificity and suitable post-prandial kinetics	Yes
Brown seaweed	Dioxinodehydroeckol glucuronide	Urine	Specificity and suitable post-prandial kinetics	Yes
Brown seaweed	Diphlorethol sulfate	Urine	Specificity and suitable post-prandial kinetics	Yes
Brown seaweed	Fucophloroethol glucuronide	Urine	Specificity and suitable postprandial kinetics	Yes
Brown seaweed	Fucoxanthinol	Plasma	Quite specific, existing in many other marine foods but much lower than that in brown seaweeds	Yes
Brown seaweed	Pyrogallol sulfate	Urine	Unspecific, also a metabolite found after intake of tea, mango, berry fruits, nuts and red wine.	No
Brown seaweed	Phloroglucinol sulfate	Urine	Unspecific, also a metabolite found after intake of grape. Phloroglucinol is also a drug.	No
Brown seaweed	Fucoxanthin	None	Only reported in seaweed and at low levels in some crustaceans, not yet detected in human plasma	No
Green seaweed	Astaxanthin	Serum	Unspecific, existing in many other marine foods	No
Green seaweed	Astaxanthin	Plasma	Unspecific, existing in many other marine foods	No
Red seaweed	β-carotene	Serum	Unspecific, existing in many fruits and vegetables	No