Professor Lindsay Brown from the University of Southern Queensland and his research group came to the conclusion in 2017 that there was potential of Kappaphycus species as a functional food with application in the prevention of metabolic syndrome. They demonstrated that Kappaphycus may reverse metabolic syndrome through selective inhibition of obesogenic gut bacteria and promotion of health-promoting gut bacteria. There were no negative effects of Kappaphycus on any of the measured variables. More recent studies on another red seaweed Sarconema further confirm this.
A functional food is just food, but it also can provide a function. That function is just like a drug. E.g. Reduce inflammation, reduce blood pressure, be an appetite suppressant. Reduce fatty liver. Improve glucose tolerance.
Do not confuse a typical description of a functional food that is cheap simple food product, with additives. (such as margarine with added plant sterols). Functional foods are good whole natural foods. They just have additional functionality.
The group has been working for many years on a range of active plants including skins from mangostem, linseeds, achachairú (from South America), purple carrots, curcumin, Davidsons Plums, Queen Garnet plus and green coffee.
All these have the same outcomes. Rats that have metabolic syndrome, when fed a small amount of active products, reverse the effect of the obesity, hypertension, and impaired liver function.
Pacific Sea Moss is one of these natural products. Just food.
Wanyonyi S du Preez R Brown L Paul N Panchal S (2017) Kappaphycus alvarezii as a Food Supplement Prevents Diet-Induced Metabolic Syndrome in Rats. Nutrients 2017, 9, 1261; doi:10.3390/nu9111261 (see https://www.ncbi.nlm.nih.gov/pubmed/29149029)
du Preez R, Paul N, Mouatt P, Majzoub ME, Thomas T, Panchal SK, Brown L. 2020 Carrageenans from the Red Seaweed Sarconema filiforme Attenuate Symptoms of Diet-Induced Metabolic Syndrome in Rats. Mar Drugs. 2020 Jan 31;18(2). pii: E97. doi: 10.3390/md18020097.