New Scientist : Japanese gut bacteria gain special powers from sushi

Quote Originally Posted by New Scientist
Sushi arms the guts of the Japanese with new digestive powers. A seaweed-eating enzyme seems to have jumped from marine bacteria to the harmless bugs that call the intestines of sushi-eaters home.

This is the first evidence that food bacteria can transfer genes to our own gut bacteria, and could help us extract more energy from food, says Mirjam Czjzek at the National Centre for Scientific Research (CNRS) in Roscoff, France.

Czjzek's group uncovered the genetic swap while hunting the genes for certain enzymes produced by bacteria. These enzymes break down carbohydrates in the cell walls of the algae that the bacteria feed on.

One enzyme, porphyranase, breaks down a polysaccharide that makes up around 40 per cent of the cell walls of Porphyra, a red alga used to make the nori sheets that wrap around sushi. The carbohydrate is rare in most other marine plants, however.
You can only acquire the new porphyranase enzyme by eating fresh seaweed, not the roasted nori used in maki. I suppose that means eating home-made miso soup with fresh seaweed like wakame or konbu. The article doesn't say if the enzyme is specific to one species of alga or is found in all Japanese algae.