Food Poisoning

Food poisoning is the result of eating microbes or toxins in contaminated food. Cases can affect one person or can occur as an outbreak in a group of people who all ate the same contaminated food. While many cases are the result of bacteria, some cases can be the result of poisonous components of plants and animals. Food poisoning affects between 60 and 80 million people worldwide each year, resulting in approximately 6 to 8 million deaths.

Signs and Symptoms

Food poisoning from bacteria causes nausea, vomiting, abdominal cramping, and diarrhea. Specific bacteria may cause these signs and symptoms: Mushroom poisoning causes red blood cell problems, stomach flu, delirium (confusion), vision difficulties, heart muscle problems, kidney failure, and death of liver tissue. It causes death in about half of the people affected unless treated right away.

Fish poisoning causes nausea, vomiting, diarrhea, abdominal pain, dizziness, and headache. Specific types of fish can cause other signs and symptoms, such as:

What Causes It?

Usually bacteria, protozoans (such as amoebas), and algae cause food poisoning. But sometimes poisonous parts of plants and animals are the cause.

Common bacterial toxins include: Common types of fish poisoning include the following: Mushroom poisoning occurs from eating wild poisonous mushrooms, especially Amanita phalloides.

Who's Most At Risk?

Infants and the elderly are at greater risk for food poisoning. A person is also at greater risk if any of the following is true: Listeriosis is most common in pregnant women, fetuses, and people with immune problems. When a fetus is infected with L. monocytogenes, the fetus may be born prematurely or die.

What to Expect at Your Provider's Office

Your healthcare provider will examine you for signs and symptoms of food poisoning, such as stomach problems, and of dehydration. Your provider may also ask about foods you have eaten recently. Tests of your vomit, blood, and stool, and tests of any leftover food can identify the cause.

Your healthcare provider may also use these tests:

Treatment Options


These steps can help prevent food poisoning: If others may also have eaten a food that made you sick, let them know. If you think the food was contaminated when you bought it from a store or restaurant, tell the staff and your local health department.

Treatment Plan

Treatment is meant to help support recovery and relieve symptoms. For instance, treatment may help replace fluids and electrolytes (such as sodium, potassium, magnesium, and chloride), help the person breathe, or stop vomiting or diarrhea. In most cases, healthcare providers do not prescribe antibiotics because they may prolong diarrhea. If the person has eaten certain toxins (such as from mushrooms or shellfish), the provider may take steps to empty and clean out his or her stomach (a process called lavage) and administer activated charcoal, which can absorb the remaining toxin.

Drug Therapies

Depending on the symptoms and the cause of food poisoning, a healthcare provider may prescribe drugs including these:

Complementary and Alternative Therapies

Animal studies have shown that certain vitamins and nutrients, such as vitamin A and calcium, may be particularly effectively in protecting against some food toxins while others, such as fish oil, may actually worsen the effects of toxins. Milk thistle is an herb commonly used in Europe as a primary treatment for mushroom poison. Homeopathy is particularly promising for the treatment of diarrhea in children (which is sometimes caused by food poisoning) in developing countries.

Nutrition The following general nutritional guidelines may be helpful in the case of food poisoning: Advice more specific to food poisoning includes: Many animal studies have investigated the use of vitamins, minerals, and supplements to treat food poisoning. The most promising include: Herbs
Use of the following for people with a specific food poisoning is well documented: Animal studies of Chinese and Japanese combination herbal remedies used for L. monocytogenes support the traditional use for this type of food poisoning. A few of the active ingredients include: When considering use of combination remedies, it is best to seek the advice of an appropriately trained, licensed, and certified herbalist or traditional Chinese doctor who will guide your individual treatment; the substances tend to complement one another and work in tandem, not separately.

Laboratory studies (those performed in test tubes) suggest that the following substances have activity against particular organisms that may cause food poisoning: While these lab results are interesting, they do not necessarily translate into treatment for people, particularly the tea tree oil and thyme trials because essential oils should generally not be ingested. Thyme is available in a dried herb and is used to help digestion and to treat symptoms of gastritis (inflammation of the stomach lining); however, it is not known whether the dried herb would have the same activity as the oil against the bacteria mentioned. Homeopathy
In a recent study of children with acute diarrhea, those who received an individualized homeopathic treatment for five days had a significantly shorter duration of diarrhea than children who received placebo. Before prescribing a remedy, homeopaths take into account a person's constitutional type. In homeopathic terms, a person's constitution is his or her physical, emotional, and intellectual makeup. An experienced homeopath assesses all of these factors when determining the most appropriate remedy for a particular individual.

Prognosis/Possible Complications

Most food poisoning clears up on its own with no aftereffects. However, with mushroom poisoning, as many as 50% of people die; with botulism, less than 10% die. Some people may need help breathing for months afterwards. More than half of poisonings from puffer fish are fatal. Death is rare in other fish poisonings, but nerve-related symptoms can continue for months.

The following are some possible aftereffects of food poisoning:

Following Up

For severe cases of food poisoning, the person may need to stay in the hospital to receive fluids and electrolytes, and so healthcare providers can monitor breathing. Providers may need to intubate the person (insert a tube down his or her throat) or connect him or her to a machine to help with breathing. Dialysis may be required. Cathartics (substances that help the body remove waste), enemas, and lavage may help eliminate toxins.


Antibiotics. NMIHI. Accessed at on May 4, 2018.

Ampicillin. NMIHI. Accessed at on May 14, 2018.

Amitriptyline. NMIHI. Accessed at on May 17, 2018.

Beers MH, et al. The Merck Manual: Diagnosis and Therapy. 17th ed. Whitehouse Station, NJ: Merck Research Laboratories; 1999:285-292.

Blumenthal M, Goldberg A, Brinckmann J, eds. Herbal Medicine: Expanded Commission E Monographs. Boston, Mass: Integrative Medicine Communications; 2000:257.

Bovee-Oudenhoven IM, Wissink ML, Wouters JT, Van der Meer R. Dietary calcium phosphate stimulates intestinal lactobacilli and decreases the severity of a salmonella infection in rats. J Nutr. 1999;129:607-612.

Ciprofloxacin. NMIHI. Accessed at on May 14, 2018.

Co-trimoxazole. NMIHI. Accessed at on May 16, 2018.

Duncan SH, Flint HJ, Stewart CS. Inhibitory activity of gut bacteria against Escherichia coli 0157 mediated by dietary plant metabolites. FEMS Microbiol Lett. 1998;164:238-288.

Facey PC, Pascoe KO, Porter RB, Jones AD. Investigation of plants used in Jamaican folk medicine for anti-bacterial activity. J Pharm Pharmacol. 1999;51:1455-1460.

Fauci AS, Braunwald E, Isselbacher KJ, et al., eds. Harrison's Principles of Internal Medicine. 14th ed. Vol. 1. New York, NY: McGraw-Hill; 1998:796-801, 876-880, 904-905.

Food Poisoning. NMIHI. Accessed at on May 1, 2018.

Foodborne Illness. MedlinePlus. Accessed at on May 24, 2018.

Food Poisoning (for Parents) The Nemours Foundation. Accessed at on May 14, 2018.

Fritsche KL, Shahbazian LM, Feng C, Berg JN. Dietary fish oil reduces survival and impairs bacterial clearance in C3H/Hen mice challenged with Listeria monocytogenes. Clin Sci. 1997;92:95-101.

Gabriel EP, Lindquist BL, Abud RL, Merrick JM, Lebenthal E. Effect of vitamin A deficiency on the adherence of fimbriated and nonfimbriated Salmonella typhimurium to isolated small intestinal enterocytes. J Ped Gastroenterol Nutr. 1990;10:530-535.

Gustafson JE, Liew YC, Chew S, Markham J, Bell HC, Wyllie SG, Warmington JR. Effects of tea tree oil on Escherichia coli. Letters in Applied Microbiology. 1998;26:194-198.

Hatchigian EA, Santon JE, Broitman SA, Vitale JJ. Vitamin A supplementation improves macrophage function and bacterial clearance during experimental Salmonella infection. PSEBM. 1989;191:47-54.

Minocycline. NMIHI. Accessed at on May 14, 2018.

Haubrich WS, et al. Bockus Gastroenterology. 5th ed. Philadelphia, Pa: W.B. Saunders; 1995:1195-1210.

Hruby K, Csomos G, Fuhrmann M, Thaler H. Chemotherapy of Amanita phalloides poisoning with intravenous silibinin. Hum Exp Toxicol. 1983;2(2):183-195.

Jacobs J, Jiménez M, Malthouse S, Chapman E, Crothers D, Masuk M, Jonas WB. Homeopathic treatment of acute childhood diarrhea: results from a clinical trial in Nepal. J Altern Complement Med. 2000;6(2):131-139.

Jonas WB, Jacobs J. Healing with Homeopathy: The Doctors' Guide. New York, NY: Warner Books; 1996: 218-220.

Juven BJ, Kanner J, Schved F, Weisslowicz H. Factors that interact with the antibacterial action of thyme essential oil and its active constituents. J Appl Bacteriol. 1994;78:626-631.

Mandell GL, et al. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 4th ed. New York, NY: Churchill Livingstone; 1995:1012-1020.

Murray PR, et al. Manual of Clinical Microbiology. 7th ed. Washington, DC: ASM Press; 1999:356-359.

Rabbani GH, Butler T, Knight J, Sanyal SC, Alam K. Randomized controlled trial of berberine sulfate therapy for diarrhea due to enterotoxigenic Escherichia coli and Vibrio cholerae. J Infect Dis. 1987 May;155(5):979-984.

Rosen P, et al. Emergency Medicine: Concepts and Clinical Practice. 4th ed. Vol. 3. St. Louis, Mo: Mosby;1998:1931-1938, 2513-2516, 2178-2179.

Sabeel AI, Kurkus J, Lindholm T. Intensive hemodialysis and hemoperfusion treatment of Amanita mushroom poisoning. Mycopathologia. 1995;131(2):107-114.

Symptoms and causes. MFMER. Accessed at on May 14, 2018.

Taylor RB, et al. Family Medicine: Principles and Practice. 5th ed. New York, NY: Springer-Verlag; 1998:812-815.

Ullman D. Homeopathic Medicine for Children and Infants. New York, NY: Penguin Putnam; 1992: 75-77.

Ullman D. The Consumer's Guide to Homeopathy. New York, NY: Penguin Putnam; 1995: 243-245.

Verma RJ, Shalini M. Ochratoxin A-induced cytotoxicity to human red blood cells and its prevention by certain vitamins. Med Sci Res. 1997;25(12):833-834.

Yonekura K, Kawakita T, Mitsuyama M, Miura O, Yumioka E, Suzuki A, Nomoto K. Induction of colony-stimulating factor(s) after administration of a traditional Chinese medicine, xiao-chai-hu-tang (Japanese name: shosaiko-to). Immunopharmacol Immunotoxicol. 1990;12(4):647-667.

Yonekura K, Kawakita T, Saito Y, Suzuki A, Nomoto K. Augmentation of host resistance to Listeria monocytogenes infection by a traditional Chinese medicine, ren-shen-yang-rong-tang (Japanese name: ninjin-youei-to). Immunopharmacol Immunotoxicol. 1992;14(1-2):165-190.

What causes food poisoning? American Academy of Family Physicians Accessed at on May 14, 2018.