Ancient Japanese staple and supposed superfood, Natto gets a lot of hype for something that looks like beans swimming in slimy pond scum.

Fermenting soybeans using bacteria creates something slimy and sticky, but also funky and savory -- and, some people believe, based on a growing body of evidence, pretty good for you.

Natto is often eaten in Japan as a high-protein breakfast food.

Just add some soy sauce, maybe a little mustard, green onions or raw egg yolk and serve over rice -- like we did here.

It's pungent, by which I do mean stinky, and is often compared to washed rind cheese in terms of its complex funkiness and in-your-face-ness.

When I tried it, I got strong notes of both cheese and coffee -- which don't seem like they'd go well together.

It's an acquired taste, but I can see how you'd go about acquiring it -- it's actually really interesting!

In fermentation, you use microbes that grow and actually kind of pre-digest your food to create new and interesting changes in the flavor, the smell, the mouthfeel and even nutritional content.

But you only want specific, friendly microbes setting up camp.

You don't want others in there that could cause the food to spoil.

To transform soybeans into natto, makers use a particular strain of the bacterium B. subtilis, a common soil-dwelling bacterium with some neat tricks up its sleeve.

When B. subtilis are facing stress from their environment, they have an escape plan- they can start forming dormant cells housed in super-tough armor called spores.

Spores aren't really alive; they're kind of like seeds of a plant but they're practically indestructible.

They're resistant to extreme temperatures, corrosive chemicals, and even radiation.

And they don't need food or water.

So you can cook your soybeans at temperatures and pressures that would kill most other microbes that might be around.

Then you introduce B. subtilis spores while the soy beans are still hot, and those Bacillus spores are the only thing that can stand to be in there.

After that, your natto-to-be is held in hot, humid conditions for about a day or so to allow the bacteria to settle in and get to work.

Since no one else is home, B. subtilis spores wake up and have no absolutely competition to eat the lovely beans.

And the effect of its munching is to transform the bland unfermented soybeans into...THIS.

But why do the bacteria produce these gooey strings?

Turns out this slippery substance is what microbiologists called a biofilm - a protective environment for the bacteria to live in, something lots of bacteria make for themselves.

This particular biofilm is made primarily of polyglutamate.

The amino acid glutamate is responsible for the flavor of savoriness -- these strings shed glutamate molecules, which our tongues perceive as umami.

More umami flavor emerges in the Natto over time as the biofilm produces more glutamate molecules.

Protected by this biofilm, the bacteria go to town chowing down on the carbs & proteins of the beans.

The fermentation of natto takes place above pH 7 -- it's an alkaline-fermented food.

A lot of other fermented foods are actually acidic, which makes them taste sour.

That's probably why I went in expecting the natto to taste like yogurt or something, but instead it had a more earthy, slightly bitter flavor that reminded me of coffee or truffles.. Like a lot of fermented foods, natto was likely "discovered" by accident and turned out to be a good way to preserve soybeans.

But it's still best fresh, as opposed to frozen.

And since it will slowly keep fermenting in your fridge, after a while, it can get pretty strong.

There's also a lot of buzz surrounding the health benefits of natto.

The label "superfood" is usually more hype than substance, but scientists have taken an interest in natto and what it might do for us.

For example, natto is the most potent food source of vitamin K2, a micronutrient that helps build bone by transporting calcium from your bloodstream to your bones.

And B. subtilis is found in healthy human guts, so eating natto might have probiotic effects.

Natto also contains nattokinase, an enzyme made by B. subtilis, that's been shown both in the lab and in humans to have potentially useful effects as a blood thinner and therefore in fighting heart disease.

It supposedly works by breaking down blood clots, so they can't get stuck in your arteries and cause a heart attack or stroke.

Human trials are still ongoing into the effects of nattokinase, in heart disease as well as things like Alzheimer's.

We definitely don't know everything about nattokinase yet, like how or whether it's actually absorbed by the body, and whether it might interfere with other drugs.

But doctors are keeping an eye on this one.

That said, natto doesn't have to be a health food to be worth eating.

You can just enjoy the slimy funkiness.

Which I sort a did.

Let's be real.

I'll give it another shot sometime.