Microbes, they get a bad rap. But, as I’ve reported on before (for instance here), not all microbes are bad news. A couple new papers shed light on the latest good news on the microbial front.

Marine Plastic, What’s It Good For?

By now we all know about the huge patches of plasticthat are floating about the ocean (seehereandhere)— the nom de science for this stuff is marine plastic debris. Of all the different kinds of marine debris out there, plastic is the most abundant. And there’s no question that that plastic is bad news — it kills birds and puts toxins into the ocean food web, to name just two baddies. However, it turns out that there are little bitty critters out there that are quite happy with all that plastic, thank you very much.

In “Life in the ‘Plastisphere’: Microbial Communities on Plastic Marine Debris,“Erik Zettler of the Sea Education Association and co-authors report in the journal Environmental Science and Technology on finding a “diverse microbial community of heterotrophs, autotrophs, predators, and symbionts” living in and on marine plastic debris.

Analyzing plastic debris collected from various spots in the North Atlantic revealed a “diverse microbial community” the researchers dubbed the “Plastisphere.” These communities, the researchers write, “are distinct from surrounding surface water, implying that plastic serves as a novel ecological habitat in the open ocean.” (Photos courtesy of Erik Zettler of the Sea Education Association)

Good news, entrepreneurs! We’ve finally found a market for all the plastic s**t we toss into the ocean. It’s the plastisphere. As markets go it’s not the best — an investment in selling plastic to the plastisphere is not likely to yield a lot of money. But still, it’s something, isn’t it?

OK, not really. But wait, I’ve got another idea — marketing your fecal bacteria. Now before you flush this post down the you know what, hear me out.

Obesity and the Microbiome

Recently TheGreenGrok ran a post on our gut microbiome and its possible role in obesity. The piece focused on two recent papers that suggested that low diversity of bacteria in our gut microbiome is a factor in being overweight and obese. We took those findings a bit further by speculating that perhaps our growing use of antibiotics may be depleting the diversity of our gut bacteria and contributing to the obesity epidemic that increasingly plagues the globe. (The speculation was informed by related studies that found small doses of antibiotics given to mice made them fatter and antibiotic exposure in infants tended to increase their body fat.)

Now a new paper, published in the journal Science last week by Vanessa Ridaura of the Washington University School of Medicine and colleagues, provides further evidence of the connection between our gut microbiome and obesity. The authors took samples of the gut microbiota (i.e., fecal bacteria) from four sets of twins — one member of each set was obese and the other lean. They then introduced the human bacteria from each subject into mice.The mice with the fecal bacteria from the obese twins became obese while the ones with the bacteria from the thin twins did not. And then, in a fascinating presto chango, once the mice shared the same living quarters, the weight gain in the obese mice stopped.*

So the evidence continues to grow that our gut microbiome is playing a role in controlling (or not controlling) our waistlines. This is huge (forgive the pun) —it could lead to a treatment to halt or reverse weight gain. And there remains the possibility that there’s an antibiotic connection.

But there’s also a money angle. If you’re thin and need a little extra cash, I’ve got a business proposition for you: sell your fecal bacteria to obese mice. Who knows, there may even be a market with obese rats. And I know where you can find millions of them — the New York subway system. Trust me they’re fat and they’ll eat anything. Well, everything but plastic, but that’s where the microbes of the Plastisphere come in.

End Note

* The study also had a diet component. Obese mice fed a low-fat, high-fiber diet were the ones that stopped gaining weight while those fed a high-fat, low-fiber diet did not benefit.

Post updated 9/17/2013 with images of the “Plastisphere.”