What makes a bad bacteria bad?
The worst bacteria (the ugly) either directly destroy tissue by feeding upon it or produce a toxin that destroys tissue. Other bacteria (the bad) react negatively to food, or are poor fermenters of food, creating IBS symptoms like gas and diarrhea. And some species of yeast and bacteria are bad simply because they take up space, thereby crowding out the good bacteria and depriving your body of all the health-giving benefits that friendly bacteria provide, resulting in the poor digestion of food and the poor absorption of nutrients.
The ugly bacteria are never regarded as normal flora within the body. They are not usually considered to be causes of IBS, but they do cause severe, often life-threatening, conditions. Ugly bacteria include Salmonella, Shigella, Yersinia, Vibrio cholerae, Campylobacter, and certain strains of E. coli. Just a tiny amount of the most virulent strains of bacteria in a person’s body is enough to begin the process of infestation. The symptoms of these bacterial infections usually include severe watery diarrhea, which is often bloody. Some cause vomiting, muscular cramps, dehydration, and permanent intestinal damage. If untreated, they may even cause death. In short, they are nothing to fool around with. Luckily, the medical community is generally good at identifying and treating these kinds of bacterial infestations.
Less dangerous, but still unwelcome, are the bad bacteria, which include the Enterobacteriaceae family of Citrobacter, Enterobacter, Klebsiella, Proteus, and Serratia, as well as Clostridium difficile and Pseudomonas. At very low populations, these bacteria may be considered normal flora in the intestinal tract. However, being normal doesn’t make them good. Each has been documented as causing IBS-type symptoms, and they often need to be eliminated. Unfortunately most doctors rarely test for them, since the symptoms they cause are usually not immediately dangerous. But, if a bad bacteria has managed to increase its population and gain territory in your intestinal tract, you may experience gas, bloating, abdominal pain, or loose stools. You’re probably not dying, but you are very uncomfortable.
You may be surprised to learn that another bacteria considered normal flora is one strain of E. coli. Due to some recent well-publicized cases of E. coli infestation, the name itself now seems scary. Some types of E. coli are scary, but the strain of E. coli normally found in the intestines is not the toxic strain that causes bloody diarrhea and other symptoms. In fact, we all have E. coli living in our intestines.
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Dr. Wangen is the founder and medical director of the IBS Treatment Center, the award winning author of two books, and a nationally recognized speaker on digestive disorders. He has been on ABC, NBC, and Fox as well as public radio, and was named one of Seattle’s Top Doctors by Seattle Magazine.