Table 9.

Effect of marine phenolics in human gut microbiota.

Compounds/Marine Source	Test Model	Outcome	Ref.
Food supplement from Kappaphycus alvarezii	In vivo: rats fed for 8 weeks on high-carbohydrate, high-fat diet, alone or supplemented with 5% (w/w) algae	Improved the cardiovascular, liver and metabolic biomarkers in obese rats Modulated the balance between Firmicutes and Bacteroidetes in the gut	[226]
Polyphenol-rich extracts from brown macroalgae L. trabeculate	In vivo: high-fat diet and STZ-induced diabetic rats (200 mg/kg/day bw of phenol for 4 weeks by gavage)	Attenuated the hyperglycemia in diabetic rats Increased the short-chain fatty acid contents in fecal samples Enhanced the abundance of Bacteroidetes, Odoribacter and Muribaculum Decreased the abundance of Proteobacteria as well as Firmicutes/Bacteroidetes ratio	[103]
Water-ethanolic extract of green macroalgae Enteromorpha prolifera rich in flavonoids	In vivo: STZ-induced diabetic rats (150 mg/kg/day bw of phenol for 4 weeks by gavage)	Showed the antidiabetic activity on diabetic mice Modulated the balance between Firmicutes and Bacteroidetes in the gut and increased the abundance of the Lachnospiraceae and Alisties bacteria involved in the prevention of T2DM	[191]
Water-soluble compounds from Nitzschia laevis extract	In vivo: high-fat diet obese mice (50 mg/kg/day bw of extract for 8 weeks by gavage)	Prevented obesity in mice Protected the gut epithelium and positively reshaped the gut microbiota	[274]