Here's how E. coli can be both good and bad for your health

Though E. coli is an important microorganism that regulates gut health, some strains can cause severe illness.
Christopher McFadden
Discover the good, the bad, and the ugly of E. coli.


  • Escherichia coli, E. coli for short, is a variety of bacteria in both human and animal intestines.
  • While most E. coli strains are helpful and harmless, some can be dangerous.
  • E. coli has recently gained attention due to outbreaks of the foodborne disease brought on by tainted food and water.

With sudden outbreaks of E. coli in the press from time to time, this tiny organism has, understandably, gotten something of a bad rap of late. But, while it is known to be a health risk, it also contributes significantly to scientific study and biotechnology.

Here we'll look at what E. coli is, how it impacts your health, and discuss ways to keep yourself and your family safe from getting infected.

What is E. coli?

E. coli (Escherichia coli) is a group of gram-negative bacteria and is a member of the Enterobacteriaceae family. Gram-negative bacteria are a subgroup of bacteria that have a different cell wall structure than gram-positive bacteria. They also tend to be the most common form of bacteria that are rapidly developing resistance to antibiotics. The term "gram-negative" comes from the fact that these bacteria do not retain the violet stain in the Gram stain test, a popular laboratory technique for classifying bacterial species.

Here's how E. coli can be both good and bad for your health
Some strains of E. coli can make you very sick.

Gram-negative bacteria have a lipopolysaccharide-containing outer membrane encasing a thin peptidoglycan coating in their cell walls. Gram-negative bacteria are typically more resistant to certain antibiotics and disinfectants than gram-positive bacteria because of this outer membrane, which acts as an extra barrier.

Theodor Escherich, a German pediatrician, isolated E. coli from the feces of healthy newborns and initially discovered the bacteria in 1885. E. coli has since undergone extensive study, becoming one of the most well-known microorganisms.

It has since been discovered that strains of E. coli are crucial for food digestion, gut health, and the ability to produce vitamin K and vitamin B12. Many strains of E. coli are safe and helpful for their host organisms, for example, by maintaining a friendly environment for other anaerobic gut microorganisms by consuming oxygen that enters the gut. However, some strains, like E. coli O157:H, can produce toxins that can lead to severe disease in humans and animals. These pathogenic strains frequently release toxins that can harm the intestinal lining and cause symptoms like diarrhea, vomiting, abdominal discomfort, and kidney failure.

But it is not all bad.

E. coli is also a crucial model organism in studying genetics and bioengineering. It is frequently used as a host organism to create recombinant proteins and other biotechnological applications because its genome has been completely sequenced. Additionally, it is commonly used in studies of gene regulation and other essential biological processes because it is simple to modify genetically.

Overall, E. coli is an important microorganism because it can regulate gut health and be used as a research instrument.

What is the leading cause of E. coli infection?

Ingestion of food or water tainted with the bacterium is the most frequent way E. coli infections are contracted. This can occur during food processing or handling when fecal matter carrying E. coli comes into contact with food or water or through contaminated water sources.

Eating undercooked ground beef is one of the most frequent causes of E. coli contamination. E. coli can live in the intestines of cattle and other animals and contaminate meat during processing. Ingesting unpasteurized milk, juice, raw produce, and tainted water are additional causes of E. coli contamination.

Also, E. coli can be transmitted from person to person, especially in unhygienic environments. For instance, a sick person who doesn't clean their hands after using the restroom can infect food or surfaces, contact others, or spread the bacteria by touching them.

Some E. coli strains are more virulent than others and can cause severe illness, particularly in young children, older adults, and people with weakened immune systems. Symptoms of E. coli infection can include fever, vomiting, diarrhea (which may be bloody), cramping, and discomfort in the abdomen. Hemolytic uremic syndrome (HUS), a dangerous condition resulting in kidney failure and other complications, can also develop due to severe E. coli infections.

Maintaining excellent hygiene is crucial to lowering the risk of E. coli infection, especially when handling food. This entails thoroughly washing hands with soap and water both before and after handling food, thoroughly cooking meat, avoiding unpasteurized products, and making sure that fruits and veggies are thoroughly cleaned before consumption.

How does E. coli affect the body?

E. coli can cause illness by producing toxins that damage the intestinal lining, leading to diarrhea, abdominal pain, and vomiting. The specific type of toxin produced by an E. coli strain and the mechanism by which it causes illness are interdependent.

Shiga toxin, produced by one of the most dangerous strains of E. coli, E. coli O157:H7, harms the intestinal lining and can cause hemorrhagic colitis, a serious form of diarrhea. A severe condition called hemolytic uremic syndrome (HUS), which can result in kidney failure and other complications, can be brought on by the toxin entering the bloodstream.

Different E. coli strains may generate toxins that cause comparable symptoms. For instance, some E. coli strains produce a heat-stable toxin that can cause diarrhea, while others have a heat-labile toxin that can cause diarrhea and vomiting. Heat-labile toxins (HLTs) are a type of toxin produced by certain strains of bacteria that are easily destroyed by heat (hence the importance of thoroughly cooking risky foods).

E. coli infections are usually contracted through ingestion of contaminated food or water, although they can also be spread from person to person in certain situations. E. coli infections can sometimes go unnoticed or only produce minor symptoms, while in other instances, they can result in severe sickness and even be life-threatening.

What are the main symptoms of E. coli infection?

The severity of an E. coli infection can range from mild to severe, and the symptoms can change based on the bacterial strain and infection. Although they can appear as quickly as 24 hours or up to 10 days after exposure, signs of an E. coli infection typically occur 2 to 5 days after exposure.

The most prevalent symptom of E. coli infection is diarrhea, which may be watery or bloody. Abdominal pain and cramping, which can be mild to intense, can occur along with diarrhea. With an E. coli infection, some individuals may also experience nausea and vomiting, though children are more likely to experience these symptoms.

E. coli infection can occasionally cause more severe symptoms and complications, such as dehydration and hemolytic uremic syndrome, especially in children and older people. Rare but severe HUS can result in renal failure, anemia, and low platelet counts. HUS symptoms include decreased urine production, exhaustion, and inexplicable bleeding or bruises.

Most E. coli infections abate in a few days or around a week without medical intervention. However, it's crucial to see a doctor if you have severe symptoms which don't go away after a few days or you're more likely to develop complications. Hospitalization might be necessary for some circumstances to address dehydration or other complications.

How is an E. coli infection treated?

As mentioned, E. coli infections typically clear within a few days or a week without medical attention. Medical attention, however, might be required in extreme instances or vulnerable populations like young children, elderly people, and those with compromised immune systems.

Supportive care for an E. coli infection usually entails taking in fluids and electrolytes to avoid dehydration. Hospitalization may be necessary to administer fluids and electrolytes intravenously when the infection produces severe diarrhea or vomiting.

Antibiotics are typically not advised for treating E. coli illnesses, especially when the infection is brought on by E. coli O157:H7 or another strain that produces the Shiga toxin. This is because antibiotics may worsen the symptoms by causing the bacteria to produce more toxins.

More severe infections that lead to Hemolytic uremic syndrome (HUS) are generally treated via hospitalization. Supportive care, such as renal replacement therapy and dialysis, is frequently used to treat this condition. If you think you might have an E. coli infection and are at a greater risk for complications, you should see a doctor immediately.

Can E. coli be good for you too?

As previously mentioned, E. coli is a bacterium that typically resides in the human stomach and is a component of the gut microbiota. For this reason, certain strains of the bacteria are beneficial to the hosts and play an important role in gut health.

These include, but are not limited to: -

  • E. coli aids in the breakdown and digestion of food in the intestines. It generates enzymes that assist in the body's inability to digest certain fibers and carbohydrates. This can enhance intestinal health and avoid digestive problems like bloating and constipation.
  • Some E. coli can produce vital vitamins, including vitamin K2, important for bone health, and vitamin B12, essential for nerve and brain health.
  • By interacting with the gut epithelium and inducing the creation of immune cells, E. coli can also stimulate the immune system. This can strengthen immunity generally and ward off illnesses.
  • E. coli competitively excludes pathogens from its niche in the gut.
  • E. coli consumes oxygen that enters the gut, maintaining a friendly environment for other anaerobic gut microbes.
  • In newborns, E. coli enters the gut during birth and changes the structure and function of the epithelial cells in ways that appear vital for healthy microbiome development. This includes helping to prevent gut colonization by Staphylococcus aureus, which is linked to an increased risk of developing asthma, obesity, and diabetes later in life.

It's crucial to remember that not all E. coli strains are helpful and that some can even be dangerous. Certain strains of E. coli infections can cause severe illness and even mortality. To avoid infections, it is vitally important that you follow good hygiene and food safety practices.

And that is your lot for today.

While some strains of E. coli are harmless or even beneficial, others can cause severe illness and even death. The ability of E. coli to produce a variety of toxins and adapt to diverse environments underscores the importance of continued research into this organism. By understanding the complex interactions between E. coli and its host, scientists and medical professionals can develop better strategies for preventing and treating E. coli infections.

Add Interesting Engineering to your Google News feed.
Add Interesting Engineering to your Google News feed.
message circleSHOW COMMENT (1)chevron
Job Board