Hundreds of types of bacteria live in human intestines. The thought may be alarming, but it is important to remember that several types of bacteria are useful--indeed necessary--for human health. These bacteria, called probiotics, synthesize vitamins and have many other functions that promote intestinal and systemic health. On the other hand, there are several strains of bacteria that are not normally found in the intestines; if an individual becomes infected with one of these pathogenic bacteria, food poisoning can result. These harmful bacteria include Campylobacter, Salmonella, E. coli and Listeria.
Probiotics
Several hundred strains of probiotics normally colonize the gastrointestinal (GI) tract. The most commonly supplemented probiotics are lactobacillus and bifidobacteria strains; lactobacillus acidophilus, lactobacillus rhamnosus, bifidobacterium bifidum and bifidobacterium longum are just a few of these. Also among the types of beneficial bacteria are strains of E. coli, streptococcus and saccharomyces. These probiotics may perform some or all of several important functions: keep yeast and other intestinal residents in balance, reduce intestinal inflammation, promote regular bowel movements, reduce antibiotic-associated diarrhea and eradicate harmful bacteria such as H. pylori and C. difficile, among others.
Campylobacter
Likely the most common cause of food poisoning in the United States, Campylobacter often results from eating undercooked, contaminated poultry. Symptoms often start two to five days after infection and include fever, nausea, vomiting, cramping and diarrhea; some people may notice blood in the stool. While most infected individuals recover within a week, those with impaired immune systems may require antibiotic treatment.
Salmonella
Salmonella is another type of bacterium that can cause symptoms of food poisoning. The most commonly affected foods are animal products, but any food--including produce--may be contaminated. According to the Centers for Disease Control (CDC), "most persons infected with Salmonella develop diarrhea, fever, and abdominal cramps 12 to 72 hours after infection; the illness usually lasts 4 to 7 days, and most persons recover without treatment."
E. coli
E. coli is a normal inhabitant of the human GI tract. However, pathogenic strains of E. coli, and one in particular (0157:H7), can be deadly. Major sources of pathogenic E. coli include undercooked ground beef and unpasteurized milk; however, any food, including produce, can be contaminated with infected feces. Common symptoms of E. coli poisoning include cramps (sometimes extremely painful), diarrhea (sometimes bloody) and fever. Most cases resolve within 5 to 10 days; however, complications may develop in children, the elderly and those with compromised immune systems.
Listeria
Found in soil and water, Listeria is a type of bacterium that can contaminate all kinds of foods. Though cooking can kill Listeria, unpasteurized cheese (such as goat cheese) and deli meats and hot dogs (which may be exposed after cooking but before packaging) may be contaminated. Listeria infection can cause flu-like symptoms, including muscle aches, fever and diarrhea and can spread to the nervous system, resulting in headache, stiff neck or convulsions. Other possible symptoms include inflammation of the heart and enlargement of the liver and spleen. As with other food-borne infections, the populations at greatest risk for Listeria poisoning and complications are children, the elderly and the immune compromised. Pregnant women are also considered a population at risk for Listeriosis. Indeed, according to the CDC, pregnant women "are about 20 times more likely than other healthy adults to get listeriosis. About one-third of listeriosis cases happen during pregnancy." Because of the serious risks to the fetus, pregnant women should seek treatment immediately if they experience flu-like symptoms after eating undercooked or unpasteurized foods.
References
- "Smart Medicine for Healthier Living;" J. Zand, LAc, et al.; 1999
