According to a French study published in the journal Nature , the Japanese have large amounts of enzymes, porphyrases , in their digestive systems, which digest a special type of carbohydrates called porphyrins, present in certain red algae . These algae, of the genus Porphyra , are what the Japanese call nori, and they have been used for several generations both to cook soups and salads and to wrap fish and rice in the specialty of sushi called maki .
Specifically, porphyrans are present in bacteria of the microbiota of the stomach and intestine of the Japanese, of the species Bacteroides plebeius . Possibly the bacteria incorporated the genes necessary to manufacture these enzymes through contact with marine bacteria, very present in the diet of the Japanese but absent in the diet of Europeans and North Americans, as the research concluded.
