Gut Reaction

Last Updated (Tuesday, 18 May 2010 09:23) Written by Raymond Nakamura

You've probably heard that we are what we eat. A recent study shows that at least our gut microbes are what we eat. Bacteria in the guts of people in Japan included ones that could breakdown seaweed, unlike those found in North Americans.

New Kids in the Gut

The idea is that Japanese people eat more seaweed. Some of this seaweed naturally includes microbes that break down seaweed for a living. They passed some of their genes on to gut microbes in Japanese people. Bacteria are sneaky that way.

Raw Deals

Nowadays, in Vancouver, you can't swing a tuna without hitting a sushi shop. I wondered if our population has increased seaweed consuming bacteria. I emailed the lead investigator, Dr. Jan-Hendrik Hehemann about this. He is now at the University of Victoria. He emailed that it was "a very interesting question that needs to be tested." But the nori now is usually roasted first. As food becomes more efficiently processed, and people become more obsessed with cleanliness, maybe fewer bacteria survive to be ingested. 

What About Me?

My chances of having these gut bacteria may be higher than the average North American or even Vancouverite. If people in Japan have genes for a more hospitable gut, I might also have them. Also, my grandparents came from Japan. Maybe they had these gut bacteria in them and somehow passed them on to my parents and then I got them. Dr Hehemann told me that gut microbiota are transmitted from mother to child. "So," he emailed, "depending on the history of eating behaviour in your family you may have kept these nori degrading bacteria when there was enough nori in your diet." 

Before sushi became so popular, I ate it only when someone else was paying. But as a kid growing up in Toronto, I liked adding seaweed condiments to my rice. As an adult, I lived in Japan for three years by the seashore. I remember seeing women in their sun bonnets and white rubber boots gathering seaweed off the rocks to eat. Maybe I was inoculated that way. According to Dr. Hehemann, "One could imagine that contact with persons that have other species may lead to transmission of species with new traits from one person to the other. When the recipient eats the right food he may b diet select this new species."

Live Long and Prosper

Scientists don't know yet if these critters provide any benefits to their gracious hosts. But the Japanese do have the longest life expectancy in the world, so it couldn't be too bad. Perhaps one day I'll share my gut biota for science, if it's not too uncomfortable.