When Good E. Coli Goes Bad

Is there a type of bacteria out there with worse press than Escherichia coli? There are strains of E. coli that are not only neutral toward their human hosts but beneficial, playing a key role in our microbiomes by producing crucial vitamins or preventing harmful bacteria from colonizing our digestive system.

But of course, the mainstream media can only ever report on the negative aspects of E. coli. Though to be fair, while the number of neutral or positive strains significantly outnumber the number of negative strains, those pathogenic strains can cause traveler's diarrhea (with nearly a billion cases around the world every year), urinary tract infections, sepsis, gastroenteritis, and Crohn's disease. And those are just the common diseases. Some strains can even produce Shiga toxin, which has been used as a bioterrorism agent. Maybe it's little wonder we have negative associations with a generally positive bacteria.

The big question then is why. Why are so many types of E. coli perfectly harmless while others will so prominently ruin your day? That's the question a group of researchers from Australia sought to answer, and the answer comes down to a single word: cellulose.

Yeah, cellulose isn't just for trees and belly fat. As it turns out, E. coli also produces cellulose, using it in the structure of its cell walls to anchor to our intestines. Pathogenic E. coli, on the other hand, possess a mutation that prevents them from producing cellulose. Without that compound, harmful E. coli are able to inflame and irritate the intestinal wall, eventually passing through and into the blood stream. From there, they're able to spread and multiply, causing the various maladies we've come to know and love from E. coli.

While the research is obviously important for the purposes of preventing future infections, the researchers noted that it's doubly important in the case of E. coli, which is actually the most common pathogen associated with antibiotic resistance. MRSA may get the attention, but of 5 million yearly deaths caused by antibiotic-resistant bacteria, 800,000 were caused by E. coli. Finding another way to bring wayward E. coli to heel would certainly benefit the world at large, though in the meantime, if you want to give your digestive system a little bit of a boost, why not munch on a piece of paper? It'll keep your microbiota in line, I promise. Totally not trying to go viral on TikTok. Nope. Not at all.