Gut microbiota can adapt to cultural differences in diet, such as metabolizing porphyrin in Southeast Asian populations that consume seaweed.

“So we know that most Americans, if you eat sushi, and there's nori there and you eat some of the seaweed, it has a dietary fiber in it known as porphyrin. That porphyrin will shoot through most of us untransformed. Inert substance. It'll do other things like retain water, and serve as kind of something like cellulose, not be fermented at a high level. If somebody from Southeast Asia that's always consumed seaweed, and is part of a culture that consumes seaweed, eats seaweed, they have a gut microbe that can now metabolize porphyrin.”