How Does the Body Fight Food Poisoning?

Food poisoning affects as many as 76 million Americans each year, according to the University of Maryland Medical Center, sending 350,000 to the hospital and killing 5,000 2. A number of different bacteria and toxins can cause food poisoning 2. While food poisoning causes a number of unpleasant symptoms, many actually benefit you 2. Trying to get rid of symptoms can prevent your body from fighting off the invaders, so let the symptoms do their job, within reason.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


The type of food poisoning you have determines the types of symptoms that occur and the way that your body fights off the intruder 2. Many food-borne illnesses primarily affect the intestines, while some, like botulism, mushroom poisoning and fish poisoning, attack the nerves 2. Poisons that attack the nerves can have more serious consequences than those that affect only the stomach; your body will have a harder time fighting these effects before they cause serious damage, such as paralysis.

Intestinal Symptoms

Nausea, vomiting, diarrhea and abdominal pain are the most common group of symptoms in people with salmonella, shigella, campylobacter or E. Coli, bacteria that enter through the intestines. Bacteria infect the lining of the intestines, producing toxins that cause the symptoms. Your body pulls fluid into the intestine to wash the bacteria out more quickly, causing diarrhea, or tries to expel the bacteria through vomiting. Although these symptoms cause discomfort, they’re your body’s way of ridding itself of the toxins, so don’t try to stop them with anti-emetics or anti-diarrheal medications unless you have symptoms so severe that you become dehydrated. Most food-borne infections stay confined to the gut, but can also spread via the bloodstream to other parts of the body.

Internal Actions

Stomach symptoms are the part of your body’s infection-fighting procedures that you notice, but much more goes on inside your body to fight the infection. Stomach acids can inactivate bacteria, so don’t take antacids to treat symptoms, since you may reduce the stomach’s effectiveness to control infection. Your body produces antibodies to attack the invading bacteria and mobilizes white blood cells to surround and destroy bacteria.

Extra Help

Taking calcium supplements or probiotics or eating yogurt with live cultures can help your body fight back against food poisoning by increasing the numbers of “good” bacteria in your gut, so they crowd out the “bad” bacteria 2. Activated charcoal binds to the bacteria and expels it in the feces, which may appear black.


While dehydration is the most frequent complication of food poisoning, other serious effects, harder for the body to fight off on its own, can also occur 2. If you have a fever over 101 F, if diarrhea continues for more than two to three days and you become lightheaded, dizzy or if your pulse is racing, your body may not be keeping up with infection and you may need intravenous fluids or antibiotics.