Eating seaweed can genetically modify the bacteria in our guts

By Michael Le Page

Seaweed contains fibres we normally can’t digest

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Eating seaweed can genetically alter the bacteria in your gut as they can acquire genes from marine bacteria for digesting substances unique to seaweeds. It isn’t known if this affects people’s health, but having gut bacteria that can digest carrageenan, a common food additive derived from seaweed, might be harmful.

“Our microbes are naturally genetically engineering themselves,” says Eric Martens at the University of Michigan.

Seaweeds contain unique dietary fibres – large carbohydrate molecules – that neither we nor the bacteria in our guts can normally digest. For instance, the …