Seaweed Components as Potential Modulators of the Gut Microbiota

Abstract

Macroalgae, or seaweeds, are a rich source of components which may exert beneficial effects on the mammalian gut microbiota through the enhancement of bacterial diversity and abundance. An imbalance of gut bacteria has been linked to the development of disorders such as inflammatory bowel disease, immunodeficiency, hypertension, type-2-diabetes, obesity, and cancer. This review outlines current knowledge from in vitro and in vivo studies concerning the potential therapeutic application of seaweed-derived polysaccharides, polyphenols and peptides to modulate the gut microbiota through diet. Polysaccharides such as fucoidan, laminarin, alginate, ulvan and porphyran are unique to seaweeds. Several studies have shown their potential to act as prebiotics and to positively modulate the gut microbiota. Prebiotics enhance bacterial populations and often their production of short chain fatty acids, which are the energy source for gastrointestinal epithelial cells, provide protection against pathogens, influence immunomodulation, and induce apoptosis of colon cancer cells. The oral bioaccessibility and bioavailability of seaweed components is also discussed, including the advantages and limitations of static and dynamic in vitro gastrointestinal models versus ex vivo and in vivo methods. Seaweed bioactives show potential for use in prevention and, in some instances, treatment of human disease. However, it is also necessary to confirm these potential, therapeutic effects in large-scale clinical trials. Where possible, we have cited information concerning these trials.

Marine Sulfated Polysaccharides: Preventive and Therapeutic Effects on Metabolic Syndrome: A Review

“…A number of studies have shown that carrageenan induces colitis and is related to the gut microbiota of the host [68,73]. Porphyran and ulvans also have some anti-metabolic syndrome function, but there are few studies on related mechanism and its effect on gut microbiota [69,74].…”

Low-Molecular-Weight Seaweed-Derived Polysaccharides Lead to Increased Faecal Bulk but Do Not Alter Human Gut Health Markers

“…Seaweeds are a rich source of components that may exert advantageous effects on the mammalian gut microbiota through the improvement of bacterial abundance and diversity. A recent comprehensive review of in vitro and in vivo studies by Shannon and colleagues [ 50 ] considered the potential therapeutic potential of seaweed-derived polysaccharides, peptides and polyphenols to modulate the gut microbiota through diet. They reported that, in several studies, these components could act as prebiotics and positively modulate the gut microbiota [ 50 ].…”

“…A recent comprehensive review of in vitro and in vivo studies by Shannon and colleagues [ 50 ] considered the potential therapeutic potential of seaweed-derived polysaccharides, peptides and polyphenols to modulate the gut microbiota through diet. They reported that, in several studies, these components could act as prebiotics and positively modulate the gut microbiota [ 50 ]. In the current work, we observed modest changes in the levels of quantified bacteria in stool samples (FISH analysis) following agar and alginate treatments, including a significant increase in Faecalibacterium prausnitzii in subjects consuming agar LMWP.…”

Applying Seaweed Compounds in Cosmetics, Cosmeceuticals and Nutricosmetics

“…with interesting therapeutic properties. These polysaccharides have uses as gelling agent, nutritional supplement, with antioxidants [109][110][111][112], and are antiallergic [32,113], show tyrosinase inhibitory activity [62], protection against ultraviolet B radiation [59], anti-inflammatory and antitumoral activity, and can promote the growth of beneficial bacteria in intestinal microbiota [76,113] without toxicity in mice models [114,115]. Agarooligosaccharides (AOS) and carrageenan-oligosaccharides (COS) present enhanced biological properties compared to native ones, in relation to prebiotic, antitumoral, and antioxidant actions, related to their chemical structure, molecular weight, degree of polymerization, and the flexibility of the glycosidic linkages [116].…”