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Bacterial infections

Related Terms

  • Amebiasis, aminoglycosides, antibiotic resistant bacteria, antibiotics, bacteria, bacterium, cellulitis, cephalosporins, chlamydia, food poisoning, Fournier’s gangrene, gastrointestinal infection, intestinal flora, lung infection, macrolides, methicillin-resistant Staphylococcus aureus, MRSA, penicillin, pulmonary infection, quinolones, skin bacteria, tetracyclins, trachoma, tuberculosis.


  • Some microscopic organisms called bacteria can cause diseases in humans. When this occurs, it is called a bacterial infection.
  • There are thousands of different types of bacteria that live around the world. Only a few types of bacteria cause disease in humans.
  • Some bacteria are actually beneficial for humans. For examples, bacteria help humans digest certain types of food and keep infectious organisms at bay. Bacteria may be found in the environment, on the skin, in the airways, in the mouth, in the vagina, and in the digestive tract.
  • Disease-causing bacteria can cause an illness in humans when they enter the body. The bacteria may enter the body through the skin, nose, eyes, vagina, or mouth. Once the invading bacteria start to multiply and harm the body, it is called an infection. Infections can develop in any area of the body.
  • In some cases, the bacteria in the digestive tract, called the intestinal flora, can cause a severe infection if they move into the bloodstream. This process, called bacterial translocation, is most likely to occur during surgery on the digestive tract.
  • When the bacteria enter the body, they begin multiplying. If the infection is not treated, it may spread to other areas of the body. Bacteria cause different diseases depending on the specific type of bacteria and where they are in the body. Examples of bacterial infections include cellulitis, cholera, Fournier’s gangrene, methicillin-resistant Staphylococcus aureus (MRSA), trachoma, and tuberculosis.
  • If left untreated, some bacterial infections may lead to death. However, if diagnosed and treated quickly, most patients with bacterial infections experience a complete recovery. Bacterial infections are treated with medications called antibiotics. Depending on the type and severity of the infection, as well as the patient’s overall health, antibiotics may be taken by mouth, applied to the skin, or injected into the vein.


  • Bacteria can enter the body through the nose, mouth, eyes, or skin. Once the bacteria enter the body, they begin multiplying. Each bacterium divides into two. Under ideal conditions, a single bacterium can produce 72 billion bacteria in just 12 hours.
  • The bacteria release harmful toxins into the body, which cause symptoms of infection. Symptoms worsen as the number of bacteria increase.

Signs and Symptoms

  • General: Symptoms vary depending on the type and severity of the infection, as well as the parts of the body that are infected. In general, most infections cause swelling, redness, fever, and pain. Patients should visit their healthcare professionals if any of these symptoms develop.
  • Blood (sepsis): A bacterial infection from virtually any part of the body can potentially enter the bloodstream. When this happens, the condition is called sepsis. Symptoms typically include fever, severe shaking, low blood pressure, and coma. If the condition is not treated quickly, sepsis can lead to organ dysfunction and death.
  • Sepsis is a leading cause of death mostly in the elderly or chronically ill in the United States, killing an estimated 215,000 Americans each year.
  • Eyes: Bacteria can also infect the eyes. This condition is commonly called pinkeye or conjunctivitis. Common symptoms include redness, irritated and watery, itchy eyes, blurred vision, and discharge that forms a crust during sleep. Other less common symptoms may include pain and sensitivity to light.
  • Digestive tract: Bacterial infections, including those caused by Staphylococcus aureus or Escherichia coli (E. coli), can develop in the digestive tract if a patient consumes food or beverages that are contaminated with disease-causing bacteria. This type of infection is commonly known as food poisoning. Common symptoms of digestive tract infection include upset stomach, abdominal cramping, vomiting, and diarrhea.
  • Nervous system: Bacterial infections, such as bacterial meningitis, can affect the body’s nervous system, which includes the brain and spinal cord. Common symptoms of bacterial infections of the nervous system include severe headache or back pain, weakness, sensory loss, and a fever. An individual may report a stiff neck, nausea or vomiting, tiredness, and disorientation. In severe cases, patients may experience seizures, paralysis, coma, or death.
  • Respiratory tract: Bacterial infections can develop in the respiratory tract, which includes the nose, sinuses, throat, and lungs. Symptoms may include fever, chills, difficulty breathing, chest pain, stuffy nose, congestion, sore throat, increased heartbeat, fatigue, and general feeling of discomfort.
  • Skin: If bacteria causes an infection of the skin, common symptoms include reddening of the skin, swelling, pain, rash, blisters, and skin discoloration.
  • Urinary tract: Bacteria may infect the urinary tract, which includes the kidneys, the tubes that carry urine from the kidneys to the bladder (ureters) bladder, and tube that carries urine out of the body (urethra). Common symptoms of urinary tract infections include strong urge to urinate, burning sensation when urinating, frequently passing small amounts of urine, blood in the urine, or cloudy, strong-smelling urine.
  • Vagina: When bacteria cause an infection in the vagina, it is called bacterial vaginosis. The most obvious sign of the condition is an unpleasant odor. Other symptoms often include itching and/or burning sensation near the vagina.


  • Antibiotic resistance: Antibiotic resistance occurs when antibiotics are not effective against specific disease-causing bacteria. This is more likely to occur in individuals who receive antibiotics often than those who do not. If a patient becomes infected with antibiotic resistant bacteria, he/she may need to take different types of antibiotics that are less effective than the standard treatment.
  • Organ damage and death: If bacterial infections are not treated, they can spread to other areas of the body. In some cases, the bacteria can lead to organ damage and death. Infections in the blood are especially dangerous. Once the bacteria are in the bloodstream, the infection can spread to virtually any area of the body. In order to avoid complications of bacterial infections, patients should visit their healthcare providers if they develop any symptoms of an infection.


  • An infection is suspected if a patient has a fever, swelling, and/or pain. Some infections, such as cellulitis, can be diagnosed after the healthcare provider evaluates the patient’s signs and symptoms during a physical examination.
  • Most bacterial infections are diagnosed after the bacteria are identified in the patient’s blood or tissue. The healthcare provider will take a small sample of tissue from the affected area. The sample is then analyzed under a microscope for the presence of bacteria. For instance, if the patient’s symptoms involve the respiratory tract, a healthcare provider may use a swab on the back of the patient’s throat. The cells that are collected on the swab are then analyzed for bacteria.


  • General: Bacterial infections are treated with medications called antibiotics. Depending on the type and severity of the infection, as well as the patient’s overall health, antibiotics may be taken by mouth, applied to the skin, or injected into the vein. Antibiotics are also available as eye drops. If a patient is infected with a different type of microorganism, such as a virus or a fungus, antibiotics will not be effective. Antibiotics only work against bacteria.
  • Antibiotics are categorized into different drug classes including aminoglycosides, cephalosporins, macrolides, penicillins, quinolones, and tetracyclins. Each drug class destroys bacteria in a different way. For instance, some drugs kill bacteria by interrupting a stage of the bacteria’s life cycle. Other drugs may slow down or stop bacteria from multiplying, which then allows the body’s immune system to kill the bacteria.
  • Patients should tell their healthcare providers if they are taking any other drugs (prescription or over-the-counter), herbs, or supplements because they may interact with treatment. Patients should take medications exactly as prescribed. Even if symptoms appear to go away, patients should take all of their medication because there may still be bacteria in the body. Stopping medication early may allow the infection to return. Also, stopping medication early may lead to antibiotic resistance. The few remaining bacteria in the body that survive most of the antibiotic therapy are the most difficult to kill. If the bacteria become resistant to treatment, the medications will no longer be effective if taken in the future.
  • Aminoglycosides: Aminoglycosides are injected into the patient in order to prevent bacteria from growing inside the body. Examples of aminoglycosides include Amikacin sulfate (Amikacin®), gentamicin (Garamycin®), and netilmicin (Netromycin®). These drugs are commonly used to treat many types of bacterial infections that affect the lungs, skin, bones, joints, stomach, blood, and urinary tract. These drugs may cause serious side effects, such as hearing loss, decreased sense of balance, and kidney problems. Serious side effects are more likely to occur in young children and elderly patients.
  • Cephalosporins: Cephalosporins destroy the cell walls of bacteria, eventually causing them to die. Cephalosporins are used to treat a wide variety of infections, including urinary tract infections and respiratory infections. These drugs are usually taken by mouth as a pill or liquid solution. Examples include cephalexin (Keflex®), cefazolin (Ancef®, Kefzol®), cefmetazole (Zefazone®), cefuroxime (Zinacef®, Kefurox®), cefdinir (Omnicef®), and cefepime (Maxipime®).
  • Macrolides: Macrolides, such as erythromycin (e.g. Ery-Tab®, Eryc®, Ilosone®, EryPed®) and azithromycin (Zithromax®) are used to treat many different types of bacterial infections, including trachoma. These drugs prevent bacteria from growing inside the body. These drugs are usually taken by mouth in the form of pills or liquid. However, they may also be injected if the infection is severe. Side effects may include upset stomach, diarrhea, vomiting, stomach cramps, and stomach pain. Side effects are usually mild and they usually lessen over time.
  • Penicillins: Penicillins, such as penicillin V (such as Pen Vee K®) and amoxicillin (Amoxil®), are a group of antibiotics that are used to treat many different types of infections including respiratory infections and skin infections. These drugs are usually taken by mouth in the form of pills or liquid. They may also be injected if the infection is severe. Mild side effects may include mild stomach cramps or upset, nausea, vomiting, and diarrhea. Serious allergic reactions have been reported with use of penicillins. Patients should call their healthcare providers immediately if they develop a skin rash that is itchy or red or if they experience difficulty breathing, chest pain, or dizziness.
  • Quinolones: Quinolones, such as ciprofloxacin (Cipro®), moxifloxacin (Avelox®), levofloxacin (Levaquin®), and ofloxacin (Floxin®), are used to treatment many different types of bacterial infections, including urinary tract infections, skin infections, and respiratory infections such as sinusitis, pneumonia, and bronchitis. These drugs interfere with bacteria’s genetic makeup. As a result, the bacteria can no longer multiply in the body. Side effects may include mild stomach pain or upset, nausea, vomiting, diarrhea, dizziness, nervousness, trouble sleeping, a change in sense of taste, or increased sensitivity to sunlight. If patients develop symptoms of an allergic reaction, such as skin rash, difficulty breathing, chest pain, or dizziness, they should call their healthcare providers immediately. Quinolones may cause chest pain or irregular heart beat in some patients. Patients should tell their healthcare providers immediately if they experience these symptoms.
  • Tetracyclines: Tetracyclines (Helidac Therapy®, Sumycin®, Sumycin® Syrup) are used to treat infections of the respiratory tract, sinuses, middle ear, urinary tract, and intestines. These drugs are taken by mouth in the form of pills or liquid. Side effects may include upset stomach, diarrhea, itching of the rectum or vagina, sore mouth, redness of the skin (sunburn), or changes in skin color. Avoid if pregnant or breastfeeding.

Integrative Therapies

A Strong scientific evidence

  • Iodine : Iodine is commonly used in topical disinfectant preparations for cleaning wounds, sterilizing skin before surgical/invasive procedures, or sterilizing catheter entry sites. Betadine solution, for example, contains povidone-iodine. Other topical disinfectants include alcohol and antibiotics and iodine is sometimes used in combination with these as a skin disinfectant. Commercially prepared iodine products are recommended in order to assure appropriate concentrations.
  • There have been reports of severe and even fatal reactions to iodine. Avoid iodine-based products if allergic to iodine. Do not use for more than 14 days. Avoid lugol solution and the saturated solution of potassium iodide (SSKI, PIMA) with high amounts of potassium in the blood, fluid in the lungs, bronchitis, or tuberculosis. Use cautiously when applying to the skin because it may irritate or burn tissues. Use sodium iodide cautiously with kidney failure. Avoid sodium iodide with gastrointestinal obstruction. Iodine is considered to be safe in recommended doses for pregnant or breastfeeding women. Avoid povidone-iodine for perianal preparation during delivery or postpartum antisepsis.
  • Probiotics : Probiotics are beneficial bacteria and are sometimes called friendly germs. They help maintain a healthy intestine by keeping harmful bacteria and yeasts in the gut under control. Most probiotics come from food sources, especially cultured milk products. Probiotics can be taken as capsules, tablets, beverages, powders, yogurts, and other foods. An increasing number of studies support the use of probiotics as a supplement to antibiotic therapy. Probiotic supplementation during a course of antibiotics has been studied for reducing adverse effects of antibiotics in the intestinal environment. This includes reducing growth of Clostridium difficile bacteria, which can lead to colitis, a common complication of antibiotics, especially in the elderly. Some probiotics may also help prevent the development of antibiotic resistance. In acutely ill children, synbiotics have been linked to greater weight gain and fewer bacterial illnesses after antibiotics are ended. The evidence consistently supports supplementation of antibiotics with probiotics.
  • Probiotics are generally considered to be safe and well-tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose intolerant. Caution is advised when using probiotics in neonates born prematurely or with immune deficiency.

B Good scientific evidence

  • Probiotics : Limited evidence with day care children suggests supplementation with Lactobacillus GG may reduce number of sick days, frequency of respiratory tract infections, and frequency of related antibiotic treatments. Fermented milk (with yogurt cultures and L. casei DN-114001) may reduce the duration of gastrointestinal and respiratory infections in elderly people. More research is needed to make a firm conclusion.
  • Probiotics are generally considered to be safe and well-tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose intolerant. Caution is advised when using probiotics in neonates born prematurely or with immune deficiency.

C Unclear or conflicting scientific evidence

  • Astragalus : Limited available clinical study suggests the potential for benefit of astragalus in patients with tuberculosis. Further well-designed clinical trials are required before recommendations can be made.
  • Avoid if allergic to astragalus, peas, or any related plants or with a history of Quillaja bark-induced asthma. Avoid with aspirin or aspirin products or herbs or supplements with similar effects. Avoid with inflammation (swelling) or fever, stroke, transplant or autoimmune diseases (like HIV/AIDS). Stop use two weeks before surgery/dental/diagnostic procedures with a risk of bleeding and avoid use immediately after these procedures. Use cautiously with bleeding disorders, diabetes, high blood pressure, lipid disorders, or kidney disorders. Use cautiously with blood-thinners, blood sugar drugs, or diuretics or herbs and supplements with similar effects. Avoid if pregnant or breastfeeding.
  • Berberine : Berberine is a bitter-tasting, yellow, plant alkaloid with a long history of medicinal use in Chinese and Ayurvedic medicine. Berberine has been found to possess antimicrobial properties, and there is limited evidence of anti-inflammatory properties as well. Preliminary evidence suggests that berberine eye preparations may be beneficial for trachoma. However, the safety and efficacy of berberine for this indication remains unclear.
  • Avoid if allergic or hypersensitive to berberine, to plants that contain berberine (Hydrastis canadensis (goldenseal), Coptis chinensis (coptis or goldenthread), Berberis aquifolium (Oregon grape), Berberis vulgaris (barberry), and Berberis aristata (tree turmeric), or to members of the Berberidaceae family. Avoid in newborns due to the potential for an increase in free bilirubin, jaundice, and development of kernicterus. Use cautiously with cardiovascular disease, gastrointestinal disorders, hematologic disorders, leukopenia, kidney disease, liver disease, respiratory disorders, cancer, hypertyraminemia, diabetes, or low blood pressure. Use cautiously in children due to a lack of safety information. Use cautiously in individuals with high exposure to sunlight or artificial light. Use cautiously for longer than eight weeks due to theoretical changes in bacterial gut flora. Use cautiously if taking anticoagulants, antihypertensives, sedatives, anti-inflammatories, medications metabolized by CYP P450 3A4 including cyclosporin, or any prescription medications. Avoid if pregnant or breastfeeding.
  • Beta-glucan : Beta-glucan is a soluble fiber derived from the cell walls of algae, bacteria, fungi, yeast, and plants. PGG-glucan, an immunomodulator, has been studied in patients undergoing surgery, particularly abdominal surgery. Currently, PGG-glucan appears to have positive results in decreasing postoperative infections. More study is warranted to make a firm conclusion.
  • Avoid if allergic or hypersensitive to beta-glucan. When taken by mouth, beta-glucan is generally considered to be safe. Use cautiously with AIDS or AIDS-related complex (ARC). Avoid using particulate beta-glucan. Avoid if pregnant or breastfeeding.
  • Beta sitosterol : Beta-sitosterol is found in plant-based foods, such as fruits, vegetables, soybeans, breads, peanuts, and peanut products. It is also found in bourbon and oils (such as olive oil, flaxseed, and tuna). Due to data that suggest immune modulating effects of beta-sitosterol and beta-sitosterol glucoside, these sterols have been studied for the adjunct treatment of tuberculosis with antituberculosis regimens. Clinical study is currently limited in this area, and larger populations of patients with tuberculosis should be evaluated.
  • Avoid if allergic or hypersensitive to beta-sitosterol, beta-sitosterol glucoside, or pine. Use cautiously with asthma or breathing disorders, diabetes, primary biliary cirrhosis (destruction of the small bile duct in the liver), ileostomy, neurodegenerative disorders (like Parkinson’s disease or Alzheimer’s disease), diverticular disease (bulging of the colon), short bowel syndrome, celiac disease, and sitosterolemia. Use cautiously with a history of gallstones. Avoid if pregnant or breastfeeding.
  • Black tea : Black tea is made from the dried leaves of Camellia sinensis, a perennial evergreen shrub. In early study, inhaled tea catechin was reported as temporarily effective in the reduction of Methicillin-resistant Staphylococcus aureus (MRSA) infection and shortening of hospitalization in elderly patients with MRSA-infected sputum. Additional research is needed to further explore these results.
  • Avoid if allergic or hypersensitive to caffeine or tannins. Skin rash and hives have been reported after caffeine ingestion. Use cautiously with diabetes. Use cautiously if pregnant. Heavy caffeine intake during pregnancy may increase the risk of SIDS (sudden infant death syndrome). Very high doses of caffeine have been linked with birth defects. Caffeine is transferred into breast milk. If breastfeeding mothers consume black tea, it may lead to anemia, decreased iron metabolism, and irritability in their infants.
  • Blessed thistle : Human research of blessed thistle as a treatment for bacterial infections is currently lacking. Laboratory studies report that blessed thistle (and chemicals contained in blessed thistle, such as cnicin and polyacetylene) may have activity against several types of bacterial infections and no effects on some types. Early studies report no activity of blessed thistle against herpes viruses, influenza, or poliovirus. Further evidence is necessary in this area before a firm conclusion can be drawn.
  • Blessed thistle is generally considered to be safe when taken by mouth in recommended doses for short periods of time, with few reported side effects such as birth defects, bleeding, breathing problems, bruising, cancer of the nose or throat, increased production of stomach acid, itching, kidney disease, liver toxicity, skin rash, stomach discomfort, stomach ulcers, and vomiting. Allergic reactions to blessed thistle including rash may occur, as well as cross-sensitivity to mugwort and Echinacea. Cross-reactivity may also occur with bitter weed, blanket flower, Chrysanthemum, coltsfoot, daisy, dandelion, dwarf sunflower, goldenrod, marigold, prairie sage, ragweed or other plants in the Asteraceae/Compositae family. Avoid if pregnant or breastfeeding.
  • Chlorophyll : Preliminary evidence suggests that chlorophyll intake during chemotherapy treatment in patients with tuberculosis may improve immune parameters and free radical indices, such as malonic dialdehyde. Additional study is needed in this area.
  • Avoid if allergic or hypersensitive to chlorophyll or any of its metabolites. Use cautiously with photosensitivity, compromised liver function, diabetes, or gastrointestinal conditions or obstructions. Use cautiously if taking immunosuppressant agents or agents used to treat diabetes. Avoid if pregnant or breastfeeding.
  • Cranberry : Limited laboratory research has examined the antibacterial activity of cranberry. Further research is warranted in this area.
  • Avoid if allergic to cranberries, blueberries, or other plants of the Vaccinium species. Sweetened cranberry juice may affect blood sugar levels. Use cautiously with a history of kidney stones. Pregnant and breastfeeding women should avoid cranberry in higher amounts than what is typically found in foods.
  • Ginseng : In patients treated with Hochu-ekki-to, which contains ginseng and several other herbs, urinary Methicillin-resistant Staphylococcus aureus (MRSA) has been reported to decrease after 10 weeks. Further study of ginseng alone is necessary in order to draw firm conclusions.
  • Avoid with a known allergy to plants in the Araliaceae family. There has been a report of a serious life-threatening skin reaction, possibly caused by contaminants in ginseng formulations.
  • Goldenseal : The goldenseal component berberine has shown effects against bacteria and inflammation. Several poorly designed human studies report benefits of berberine used in the eye to treat trachoma (Chlamydia trachomatosis eye infection). Better research is needed before a strong recommendation can be made.
  • Avoid if allergic or hypersensitive to goldenseal or any of its constituents, like berberine and hydrastine. Use cautiously with bleeding disorders, diabetes, or low blood sugar. Avoid if pregnant or breastfeeding.
  • Honey : Currently, there is insufficient available evidence for the use of honey in the treatment of Fournier’s gangrene. Additional study is needed.
  • Avoid if allergic or hypersensitive to honey, pollen, celery or bees. Honey is generally considered to be safe in recommended doses. Avoid honey from the genus Rhododendron because it may cause a toxic reaction. Avoid in infants younger than 12 months of age. Use cautiously with antibiotics. Potentially harmful contaminants (like C. botulinum or grayanotoxins) can be found in some types of honey and should be used cautiously in pregnant or breastfeeding women.
  • Hydrotherapy : Hydrotherapy is broadly defined as the external application of water in any form or temperature (hot, cold, steam, liquid, ice) for healing purposes. It may include immersion in a bath or body of water (such as the ocean or a pool), use of water jets, douches, application of wet towels to the skin, or water birth. These approaches have been used for the relief of various diseases and injuries, or for general well being. There is preliminary evidence that some hydrotherapy techniques may reduce skin bacteria. There may be benefits in people with skin wounds or ulcers who are at risk of infection. Evidence that infection of the skin itself (cellulitis) is improved is currently lacking. More research is needed in this area.
  • Avoid sudden or prolonged exposure to extreme temperatures in baths, wraps, saunas, or other forms of hydrotherapy, particularly with heart disease, lung disease, or if pregnant. Avoid with implanted medical devices, such as pacemakers, defibrillators, or liver infusion pumps. Vigorous use of water jets should be avoided with fractures, known blood clots, bleeding disorders, severe osteoporosis, open wounds, or during pregnancy. Use cautiously with Raynaud’s disease, chilblains, acrocyanosis, erythrocyanosis, or impaired temperature sensitivity, such as neuropathy. Use cautiously if pregnant or breastfeeding. Hydrotherapy should not delay the time to diagnosis or treatment with more proven techniques or therapies, and it should not be used as the sole approach to illnesses. Patients with known illnesses should consult their physicians before starting hydrotherapy.
  • Lavender : Early laboratory studies suggest that lavender oils may have topical antibiotic activity. However, this has not been well tested in human studies.
  • Avoid if allergic or hypersensitive to lavender. Avoid with a history of seizures, bleeding disorders, eating disorders (such as anorexia or bulimia), or anemia (low levels of iron). Avoid if pregnant or breastfeeding.
  • L-carnitine : Preliminary study suggests antibacterial activity may be increased in patients with tuberculosis given acetyl-L-carnitine. Additional research is needed to confirm these findings.
  • Avoid with known allergy or hypersensitivity to carnitine. Use cautiously with peripheral vascular disease, hypertension (high blood pressure), alcohol-induced liver cirrhosis and diabetes. Use cautiously in low birth weight infants and individuals on hemodialysis. Use cautiously if taking anticoagulants (blood thinners), beta-blockers, or calcium channel blockers. Avoid if pregnant or breastfeeding.
  • Lime : Limited available study found that lime juice used in sauces may aid in cholera prevention. Another preliminary study suggested that using limes in the main meal may also have a protective effect; both studies were investigated by the same primary author. Additional study is needed before a firm conclusion can be made.
  • Lime is considered safe when used in amounts typically found in foods. Avoid if allergic or hypersensitive to lime or any members in the Rutaceae family. Use cautiously with drugs that are broken down by the liver. Use cautiously with drugs that cause sun sensitivity. Avoid if pregnant or breastfeeding.
  • Peppermint : There is currently not enough available scientific evidence to support the use of peppermint for tuberculosis. More research is needed in this area.
  • Peppermint oil may be safe in small doses, although multiple adverse effects are possible. When used on the skin, peppermint oil has been associated with allergic/hypersensitivity reactions, skin rash/hives/contact dermatitis, mouth ulcers/sores, chemical burn, and eye irritation. Lung injury has occurred following an injection of peppermint oil. Peppermint oil taken by mouth may cause headache, dizziness, heartburn, anal burning, slow heart rate, or muscle tremor. Very large doses of peppermint oil taken by mouth have resulted in muscle weakness, brain damage, and seizure. Peppermint oil should be used cautiously by people with G6PD deficiency or gallbladder disease. Use in infants or children is not recommended due to potential toxicity.
  • Prayer/distant healing : Prayer can be defined as a “reverent petition,” the act of asking for something while aiming to connect with God or another object of worship. Prayer may help reduce the length of hospital stay as well as the duration of fever in patients with infections. However, early study is controversial and additional study is needed before a conclusion can be drawn.
  • Prayer is not recommended as the sole treatment approach for potentially serious medical conditions, and it should not delay the time it takes to consult with a healthcare professional or receive established therapies. Sometimes religious beliefs come into conflict with standard medical approaches and require an open dialog between patients and caregivers.
  • Probiotics : There is limited evidence that probiotic supplementation may reduce the presence of bacterial infections in the upper respiratory tract. Results are mixed regarding the ability of probiotics to reduce infective complications of medical treatment. Reduced incidence of infection has been seen in patients treated for brain injury, abdominal surgery and liver transplantation. Other studies have shown no such reduction in elective abdominal surgery and critical care patients. More studies are needed to determine the effectiveness of probiotics for these indications.
  • Probiotics are generally considered to be safe and well-tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose intolerant. Caution is advised when using probiotics in neonates born prematurely or with immune deficiency.
  • Propolis : Propolis is a natural resin created by bees to make their hives. Propolis is made from the buds of conifer and poplar trees and combined with beeswax and other bee secretions. Animal and laboratory studies suggest that propolis may be a beneficial treatment for various types of bacterial infections. Additional research is needed to confirm these findings.
  • Avoid if allergic or hypersensitive to propolis, black poplar (Populas nigra), poplar bud, bee stings, bee products, honey, or Balsam of Peru. Severe allergic reactions have been reported. There has been one report of kidney failure with the ingestion of propolis that improved upon discontinuing therapy and deteriorated with re-exposure. Avoid if pregnant or breastfeeding because of the high alcohol content in some products.
  • Seaweed, kelp, bladderwrack : Bladderwrack (Fucus vesiculosus) is a brown seaweed found along the northern coasts of the Atlantic and Pacific oceans and North and Baltic seas. Another seaweed that grows alongside bladderwrack is Ascophyllum nodosum, and it is often combined with bladderwrack in kelp preparations. Laboratory research suggests that bladderwrack may have antibacterial activity. However, reliable human studies to support this use are currently lacking in the available literature.
  • Avoid if allergic or hypersensitive to Fucus vesiculosus or iodine. Avoid with a history of thyroid disease, bleeding, acne, kidney disease, blood clots, nerve disorders, high blood pressure, stroke, or diabetes. Avoid if pregnant or breastfeeding.
  • Selenium : Selenium is a mineral found in soil, water, and some foods. Preliminary research reports that selenium may be beneficial in the prevention of several types of infection, including recurrence of erysipelas (bacterial skin infection associated with lymphedema) or Mycoplasma pneumonia. Further research is needed to confirm the effects of selenium for infection prevention.
  • Avoid if allergic or hypersensitive to products containing selenium. Avoid with a history of non-melanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.
  • Sorrel : There is currently not enough evidence on the proposed antibacterial effects of sorrel. More research is needed.
  • Avoid large doses of sorrel because there have been reports of toxicity and death. This may be because of the oxalate found in sorrel. Many sorrel tinctures contain high levels of alcohol and should be avoided when driving or operating heavy machinery. These sorrel formulations may cause nausea or vomiting when taken with the prescription drugs metronidazole (Flagyl®) or disulfiram (Antabuse®). Avoid if pregnant or breastfeeding.
  • Soy : It has been suggested that soy may be beneficial for tuberculosis when taken with standard medications. According to early research, soy may improve the process of detoxification, have positive effects on the liver, reduce cell damage, and decrease inflammation. Therefore, soy supplements may allow patients to safely take higher doses of antimicrobial drugs that are used to treat tuberculosis.
  • Avoid if allergic to soy. Soy, as a part of the regular diet, is traditionally considered to be safe during pregnancy and breastfeeding, but there is limited scientific data. The effects of high doses of soy or soy isoflavones in humans are unclear, and therefore, not recommended. There has been a case report of vitamin D deficiency rickets in an infant nursed with soybean milk that was not specifically designed for infants. People who experience intestinal irritation from cow’s milk may experience intestinal damage or diarrhea from soy. It is unknown if soy or soy isoflavones share the same side effects as estrogens (e.g. increased risk of blood clots). The use of soy is often discouraged in patients with hormone-sensitive cancers, such as breast or prostate cancers. Other hormone-sensitive conditions, such as endometriosis, may also be worsened. Patients taking blood-thinning drugs (e.g. warfarin or aspirin) should check with their doctors before taking soy supplements.
  • Tea tree oil : Tea tree oil is purported to have antiseptic properties, and has been used traditionally to prevent and treat infections. Laboratory studies report that tea tree oil has activity against methicillin-resistant Staphylococcus aureus (MRSA) colonization. It has been proposed that using tea tree oil ointment in the nose and a tea tree wash on the body may treat colonization by these bacteria. However, there is currently not enough information from human studies to make recommendations for or against this use of tea tree oil.
  • Tea tree oil may be toxic when taken by mouth and therefore, should not be swallowed. Avoid if allergic to tea tree oil or plants of the Myrtle (Myrtaceae) family, Balsam of Peru, or benzoin. Use cautiously with a history of eczema. Avoid if pregnant or breastfeeding.
  • Thymus extract : Thymus extracts for nutritional supplements are usually derived from young calves. Although inconclusive, preliminary evidence suggests that thymus extract may improve effectiveness of antibacterial therapy in patients with tuberculosis. Well-designed clinical trials are required before recommendations can be made.
  • Avoid if allergic or hypersensitive to thymus extracts. Use bovine thymus extract supplements cautiously due to potential for exposure to the virus that causes “mad cow disease.” Avoid use with an organ transplant or other forms of allografts or xenografts. Avoid if receiving immunosuppressive therapy or hormone therapy. Avoid with thymic tumors, myasthenia gravis (neuromuscular disorder), or untreated hypothyroidism. Avoid if pregnant or breastfeeding.
  • Zinc : A few studies have examined the efficacy of zinc treatment in leprosy. Studies of zinc taken by mouth report positive results, while one study of topical zinc reports negative results. Further research is needed before a conclusion can be drawn.
  • Zinc (zinc sulfate, zinc acetate, zinc glycine, zinc oxide, zinc chelate, and zinc gluconate) is generally considered safe when taken in the recommended dosages. Avoid zinc chloride since studies have not been done on its safety or effectiveness. While zinc appears safe during pregnancy in amounts lower than the established upper intake level, caution should be used since studies cannot rule out the possibility of harm to the fetus.

D Fair negative scientific evidence

  • Macrobiotic diet : A macrobiotic diet has been advocated to preserve intestinal health. However, it apparently does not reduce the incidence of antibiotic resistant bacteria, nor infections caused by resistant strains in the gastrointestinal tract, compared to a diet with animal products.
  • Use cautiously with cancer or other medical conditions without expert planning or supplementation. Avoid in children or adolescents without professional guidance or appropriate supplementation. Avoid in pregnant or lactating women due to potential deficiencies, unless properly supplemented.
  • Probiotics : Bacterial infection translocation, the passage of bacteria from the gut to other areas of the body where they can cause disease, is of special concern in surgery. Limited evidence suggests that supplementation with probiotics may not reduce this problem.
  • Probiotics are generally considered to be safe and well-tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose intolerant. Caution is advised when using probiotics in neonates born prematurely or with immune deficiency.


  • Avoiding close contact with individuals who have contagious illnesses may help reduce the risk of acquiring infections.
  • Practicing good hygiene and regularly washing the hands with soap and water may help reduce the risk of acquiring infections.
  • Antibiotics should only be taken when needed. This helps reduce the risk of developing antibiotic-resistant bacterial infections in the future.

Author Information

  • This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (


Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to Selected references are listed below.

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  8. Natural Standard: The Authority on Integrative Medicine. . Copyright © 2010.
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