a gut's tale

12 ). That’s a lot. A large proportion of these bacteria are part of our gut, add an average of 2 kg to our adult weight and form what has been termed our gut microbiome. Why have they set up camp inside us? Because we need them… And vice versa. The human gut hosts bacteria that are able to break down all sorts of molecules we cannot. In exchange, we offer them an environment to thrive in. This mutual parasitism ha s evolved over time, and is a consequence of the vari ous surroundings humans have lived in, especially t he kinds of food we have eaten, and eat. Recently, sci entists discovered that a group of Japanese were ab le to digest polysaccharides westerners are unable to. It turned out that this was most probably the result of the long Japanese tradition of eating ‘nori’, an edible seaweed species of the red algae, and is due to sp ecific seaweed carbohydrate active enzymes which have become an integral part of their digestive system.