Marine algal polysaccharides and gut microorganisms

- Only Japanese have gut bacteria that can utilise marine algal polysaccharides ?

Abstract

In 2010, an interesting paper on Japanese-dish lovers and seaweed lovers was reported by Hehemann, et al., entitled “Transfer of carbohydrate-active enzymes from marine bacteria to Japanese gut microbiota,” and was published in Nature. This report showed that red algae polysaccharide-degradation enzyme (agarase and porphyranase) genes of some marine bacteria were transferred to Bacteroides prebeius, which has been detected in Japanese volunteers, but not in North Americans. This result is regarded compelling because it shows the first evidence of horizontal gene transfer in the gut, amidst the high concentration of various bacteria, as mentioned above. However, some Japanese media used phrases such as "Seaweed can only be used by Japanese gut." Is this correct? In traditional Japanese cuisine, various materials consisting of three types of macroalgae (brown, red, and green algae) have been used. The colours are caused by their important photosynthetic pigments, and brown and red algae also contain unique polysaccharides. For example, laminaran, alginate, and fucoidan are present in brown algal water-soluble polysaccharides. Two water soluble polysaccharides in brown algae alginates and laminaran can be fermented by gut microorganisms of human (not only Japanes) and laboratory animals. Alginate and laminaran increased the murine caecal B. acidifaciens and B. intestinalis, respectively. The isolated B. acidifaciens and B. intestinalis could ferment each polysaccharide and produced mainly succinate and lactate, respectively. The combination of algae and algal polysaccharide intake and its susceptible gut indigenous bacteria (SIB) cells and their metabolites is thought to contribute to host health.