When the term "E. coli" hits the headlines, it usually inspires angst. The bacteria's greatest claim to fame is causing foodborne illness — and few people enjoy vomiting and diarrhea, not to mention potential kidney failure or even death.

But when it comes to the bacteria that everyone loves to hate, it turns out to be a case of a few bad apples spoiling the bunch. For while a handful of pathogenic strains are to blame for some wicked gastrointestinal havoc, there are many strains of Escherichia coli that are harmless and actually serve us in beneficial ways.

Consider the following: 

1. It makes for a happy belly

E. coli normally resides in the intestines of people and mammals, where it plays an important role in the ecosystem of microorganisms that comprise our gut flora. And while pathogenic strains can make us sick as a dog, the normal E. coli in our intestines works hard to keep us healthy; it helps break down food and aids in digestion, and like a troop of microscopic soldiers, it does a bang-up job of preventing other pathogenic bacteria from establishing themselves in the region.

2. It helps prevent nutrient deficiencies

Non-pathogenic E. coli and the human body have a balanced relationship; the bacteria feeds on nutrition passing through the alimentary canal, and in turn, synthesizes some important vitamins for us along the way. It helps us get our B vitamins and vitamin K; deficiencies in these important vitamins can lead to diseases like beri beri, hemolytic anemia, hemorrhage and other irregularities. 

3. It is a workhorse in the lab

"What is true for E. coli is true for the elephant,” said French scientist Jacques Monod. And while that may sound like a poetic abstraction, it simply means that many of the genetic properties that E. coli exhibits hold true for mammals (including humans) as well. Because of this, scientists across the globe depend on E. coli for research where they can work with these single-cell bacteria in ways that they can’t work with more complicated organisms. E. coli is easy to grow and doesn’t demand much in terms of energy or living conditions.

4. It helps us understand DNA

Believe it or not, E. coli was one of the first organisms to have its genetic code sequenced, which has led to a better understanding of how DNA – and thus humans – function.

5. It can be turned into medicine

After insulin was discovered in the early 20th century, scientists at Eli Lilly found a way to obtain it from the pancreases of animals such as cows and pigs, and then mass produce it. But it wasn’t perfect; it was not easy to produce and animal insulin caused allergic reactions in some people. In the 1970s, researchers inserted the genes responsible for coding human insulin into E. coli and were able to cheaply and quickly produce vast quantities of the hormone to treat diabetes. It is one of the first commercial applications of biotechnology.

6. It can be turned into fuel

The world is hungrily looking for alternative energy sources, and researchers at the University of California, Los Angeles have developed an efficient way to produce butanol using E. coli. Butanol has been shown to work well with existing fuel systems, including use in vehicles designed for gasoline, without modifications that other biofuels require. The team is currently working on making the process more robust to suit commercial requirements.

7. It can detect arsenic

Scientists at the University of Edinburgh have found a way to use E. coli to test for arsenic in water, which could save millions of lives in underdeveloped countries. E. coli has a natural detoxification response that comes into play when subjected to arsenic. This is indicated by changing pH levels, which can be seen in simple field tests similar to a pregnancy test.

8. It helps ensure water purity

While most forms of E. coli are not a threat, their levels are looked at when testing water because they are a good indication of whether other potentially harmful bacteria may be present. If fecal coliform and E. coli are present in water, it signals that the water may be contaminated with human or animal wastes that pose a human health risk.

9. It has mad math skills

OK, here’s where things start getting weird. According to Dr. Karmella Haynes of Harvard Medical School, there are a number of scientists who are trying to take advantage of the digital nature of DNA in E. coli. "It has a very strict genetic code — it is almost like hardware," she says. Her team used the bacteria to help solve problems akin to classical mathematical puzzles. Based on their design, each E. coli bacterium worked as a micro-computer and certain bacteria were able to quickly solve the problems, reports the BBC. Meanwhile, students at the University of Tokyo have genetically engineered a strain of E. coli that can solve sudoku puzzles. Next stop, world domination.

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