The “goo” being referred to is, of course, natto, and just how appropriate a word that is. If you’ve ever been to Japan you will no doubt have tried some, probably pushed on you by a Japanese person, willing you to tell them how revolting it is so they can follow up by extolling the health benefits of eating the stinky sludge. Mainly eaten at breakfast time, it seems to be especially popular with kids, a fact that serves to put off even more gaijin who see the buggers shovelling it eagerly into their mouths, little strings of slime running from their chopsticks back into the bowl.
In Japan its health benefits have been known for a long time, but it seems some more experiments are being done here in the West, particularly to treat Alzheimer’s patients. Read all about it over at Wired.
[Edit: Just thought I’d add the video below, taken from the Wired article, showing the Japanese version of Iron Chef (an American cooking-battle show) with English subtitles. The ingredient is natto, and the chefs have to compete to create the best dish]