Once the Helicobacter pylori is protected inside the mucous membranes, it is able to fight the stomach acid that reaches it by producing an enzyme known as urease. Urease helps break down urea and changes it to ammonia and bicarbonate. Bicarbonate and ammonia are strong bases (the opposite of acids), which make the film of the mucous membrane less acidic. By making the environment less acidic, the acid cannot destroy the Helicobacter pylori. More detailed description of urea, bicarbonate, and ammonia are provided below.

Urea is a waste product formed by the breakdown of extra amino acids in the liver. It is present in or around the mucous membrane of the stomach. Amino acids are a group of chemical substances that form proteins. The liver is the largest organ in the body and is responsible for filtering (removing) harmful chemical substances, producing important chemicals for the body, and other important functions. Bicarbonate is a substance in the blood that prevents it from becoming too acidic or too alkaline (non-acidic). Ammonia is a colorless gas that dissolves in water to form a liquid that is less acidic.

In addition to the defense tactics mentioned above, Helicobacter pylori also has another advantage. That is, the body's defenses cannot reach the bacteria in the mucous membrane of the stomach. This is because the white blood cells and other infection fighting agents cannot easily get through the lining of the stomach. The body's defense system continues to react, however, to the presence of Helicobacter pylori, which can reproduce inside the mucous membrane.

Helicobacter pylori is also found on epithelial cells in the stomach and in the first part of the intestine. Epithelial cells are cells that help absorb, move, and distribute some of the fluids and nutrients in the body. A gland is an organ in the body made of special cells that form and release materials such as fluid. There are glands in the stomach that produce stomach juices.

WHAT ARE SIGNS AND SYMPTOMS OF HELICOBACTER PYLORI INFECTION?

To begin with, most people infected with Helicobacter pylori do not have any signs or symptoms, or only have mild signs or symptoms. This may be because some types of Helicobacter pylori do not contain toxins (poisons) that are harmful to cells (although some do).

Signs of Helicobacter pylori include inflammation of the stomach lining (known as gastritis) and ulcers of the stomach, intestine, or any other part of the digestive system. An ulcer is an open sore on the skin or on a mucous membrane (see last section). The intestine is a tube shaped structure that is part of the digestive tract. It stretches from an opening in the stomach to the anus (the area that poop comes out of) and occupies most of the lower parts of the belly. The ulcers may be caused by the inflammation of the stomach rather than directly caused by the Helicobacter pylori.

Between 70 and 80% of people with stomach ulcers are infected with Helicobacter pylori. Approximately 90% of people with ulcers in the first part of the intestine (known as the duodenum) are infected with Helicobacter pylori. About 1% of people infected with Helicobacter pylori develop ulcers. The risk of developing ulcers in people with Helicobater pylori infections increases with smoking and longs term use of pain medications know as non-steroidal anti-inflammatory drugs (NSAIDs). An example of an NSAID is aspirin.

Symptoms of an ulcer in the stomach or first part of the small intestine include weight loss, poor appetite, nausea, vomiting, burping, and bloating. Another symptom is a dull, gnawing ache in the belly that comes and goes for several days or weeks. These symptoms generally occur 2 to 3 hours after eating a meal or in the middle of the night.

Serious symptoms that would warrant an immediate call to the doctor include bloody or black feces (poop), bloody vomit, vomit that looks like coffee grinds, or a sharp, sudden, and continuous stomach pain (that usually feels like a burning sensation). This pain can last from minutes to hours and is most common between meals.

In addition to other factors (such as diet), cancer of the stomach may also be caused by Helicobacter pylori. Cancer is any of a large group of malignant diseases characterized by an abnormal, uncontrolled growth of new cells in one of the body organs or tissues. Cancer in the stomach caused by Helicobacter pylori is usually found in the mucous membranes of the stomach.

One type of cancer that may be at least partially caused by Helicobacter pylori is gastric (stomach) lymphoma. Gastric lymphoma is a type of cancer of the lymphatic tissue in the stomach. Lymnphatic tissue is a type of tissue that makes up part of the lymphatic system. The lymphatic system is a system of vessels that drain lymph from all over the body back into the blood. Lymph is a milky fluid that contains proteins, fats, and white blood cells (which help the body fight off diseases).

Another type of cancer that may be at least partially caused by Helicobacter pylori is gastric (stomach) adenocarcinoma. An adenocarcinoma is a type of cancer that involves the epithelial cells of glands. Epithelia cells are cells that help absorb, move, and distribute some of the fluids and nutrients in the body. A gland is an organ in the body made of special cells that form and release materials such as fluid. There are glands in the stomach that produce stomach juices.

It should be noted that the link between Helicobacter pylori and cancer is speculative at this time and there is no conclusive proof that this bacteria causes cancer. It is known, however, that having Helicobacter pylori infection significantly increases the risk of developing the previously mentioned cancers. Then again, about 50% of people age 45 and over have Helicobacter pylori infections, with only 1% going on to develop stomach cancer.

Abnormal development of the mucous membrane cells that is not yet cancerous can also occur as a result of Helicobacter pylori. Helicobacter pylori can also cause normal mucous membrane cells to reverse into a more primitive (less developed) condition. Impaired production of stomach acids can occur, but this may only be short-lived.

Helicobacter pylori is thought to cause some cases of cholecystitis, which is inflammation of the gallbladder. The gallbladder is a small, pear shaped sac, located under the liver, which helps store and transport bile to the first part of the small intestine (known as the duodenum). Bile is a bitter, yellow-green substance released from the liver that carries away waste products.

Helicobacter pylori is thought to cause some cases of thyroiditis, which is inflammation of the thyroid. The thyroid gland is a butterfly-shaped organ located in the front of the neck that plays an important role in metabolism. Metabolism is the chemical actions in cells that release energy from nutrients or use energy to create other substances.

Some have suggested that Helicobacter pylori may be a factor in Sudden Infant Death syndrome (SIDS). SIDS is the sudden death of a healthy infant after all known causes have been ruled out.

HOW DOES HELICOBACTER PYLORI CAUSE PROBLEMS?

Some types (about 50%) of Helicobacter pylori contain substances that are toxic (poisonous) to cells. These substances are released when individual Helicobacter pylori bacteria die. The release of these substances onto healthy cells in the stomach (known as parietal cells) can lead these cells to be extensively damaged. Parietal cells are located on the side of the glands of the stomach that release stomach juices.

Helicobacter pylori weakens the mucous membrane of the stomach and the first part of the intestine. The weakening of the mucous membrane allows acid to get through to the sensitive lining beneath it. The acid and the Helicobacter pylori irritate the lining, which can cause ulcers. Destruction of tissue in the stomach causes the stomach to decrease in size.

There is also evidence that Helicobacter pylori decreases levels of vitamin C in the stomach. Vitamin C is one of a group of substances made up partly of carbon that are essential in small amounts for normal bodily functioning and chemical processes in the body to take place. Decreased levels of vitaminC in the stomach may lead to ulcer formation.

HOW COMMON IS HELICOBACTER PYLORI INFECTION?

Helicobacter pylori infection is common throughout the world. In fact, about 66% of the world's population is infected with Helicobacter pylori. In the United States, about 500,000 people become infected with Helicobacter pylori each year. Not everyone knows they are infected, however, because the infection does not cause symptoms in most people. People have a greater chance of being infected with Helicobacter pylori as they get older. Estimates are that 20% of people under age 40 and 50% of people under age 60 have Helicobacter pylori infections. It is estimated to be responsible for between 3 to 4 million visits to the doctor each year.

WHO GETS HELICOBACTER PYLORI INFECTIONS?

As mentioned in the previous section, older people have a great chance of developing Helicobacter pylori infections. Family members of a person who has a Helicobacter pylori infection are also more likely to develop it. Black people, Hispanic people, and poor people have greater chances of developing Helicobacter pylori infections. Higher rates of Helicobacter pylori infections among black people, Hispanic people, and poor people have been attributed to social rather than biological causes.

HOW IS HELICOBACTER PYLORI SPREAD?

Helicobacter pylori is spread when someone's mouth comes in contact with feces (poop) that are contaminated with this bacteria. In such a case, the feces that leaves the body has Helicobacter pylori in it. If the feces wind up contaminating food or water, it can be eaten by accident and the bacteria spreads.

Another possible method of spreading is stomach to mouth contact. This means that someone with a Helicobacter pylori infection may burp and have some of the stomach juices travel up to the mouth. If the Helicobacter pylori are in the mouth and the infected person, say, kisses someone else, the infection may spread to the person being kissed. Helicobacter pylori has been found in the mouths of some infected people, so this explanation seems plausible.

Another cause of spread can be through the fault of health care providers. As you can read below, an endoscope is sometimes used in the diagnosis of Helicobacter pylori. An endoscope is a flexible viewing tube (known as an endoscope) that is inserted into the body to get a close look at a particular body part. If an endoscope is used on a patient with a Helicobacter pylori infection and is not properly cleaned afterwards, it can contaminate other patients in whom the endoscope is used on afterwards.

CAN HELICOBACTER PYLORI BE PREVENTED?

Since the source of Helicobacter pylori is not yet known, specific prevention recommendations have not yet been made. However, it is always helpful to eat foods that have been cooked thoroughly, drink water from a clean source, and to wash your hands thoroughly throughout the day.

HOW IS HELICOBACTER PYLORI DIAGNOSED?

There are many different ways to diagnose Helicobacter pylori. One method is known as the urea breath test. Remember that urea is a waste product formed by the breakdown of protein and other substances in urine (pee). Helicobacter pylori breaks down urea. In the urea breath test, the patient swallows a capsule that contains urea and which is labeled with a small, non-harmful amount of radioactive carbon (known as C-14 or C-13). Carbon is a common type of element. Radioactivity is a property of nuclei (the center parts of atoms) that breaks up and sends out rays or particles known as radiation (a form of energy). Atoms are the smallest part of an element that can exist alone or in combination with something else.

If Helicobacter pylori is present in the stomach, it will break down the urea and form ammonia (see earlier section) and carbon dioxide gas. Carbon dioxide is a colorless and odorless gas that is present in small amounts in the air and is produced as a result of metabolism in the body. Metabolism is the chemical actions in cells that release energy from nutrients or use energy to create other substances.

The carbon dioxide gas is quickly absorbed through the lining of the stomach and brought into the blood, eventually being expelled into the breath. Samples of exhaled breath are collected at various points (such as 6, 12, and 20 minutes after swallowing the urea pill) and the level of carbon dioxide is measured. The carbon dioxide level is easily measured because it is labeled with radioactivity (as a result of swallowing the capsule that contained radioactivity).

If the carbon dioxide level raises above a set amount, Helicobacter pylori is determined to be present. The sample is compared to a breathing sample taken before the test was performed. The urea breath test is about 96 to 98% accurate. The problem is that not many centers have this test available.

Doctors may also look for specific antigens formed by the body in response to Helicobacter pylori. Antigens are substances in the body, such as those present on the surface of bacteria, that can produce a defensive reaction by the body. The person's feces (poop) can be tested for antigens to Helicobacter pylori. This test is called the Helicobacter pylori stool antigen (HpSA) test and it is considered accurate.

Another technique is to look for specific antibodies in the blood that are formed by the body in response to Helicobacter pylori. This can be done through a blood test in which a blood sample is collected after a finger stick. This is a common way that doctors test for Helicobacter pylori. This test can also be done by testing a sample of the person's saliva. This blood or saliva test is cheap and results can be determined within minutes.

Analyzing the blood for antibodies as a way to diagnose Helicobacter pylori infection is considered the best method in a previously untreated patient. Antibodies are types of proteins produced by lymphocytes in response to bacteria, viruses, and other substances interpreted as a threat to the body. Lymphocytes are types of white blood cells present in the blood that help protect the body against diseases and fight infections.

As a last resort for diagnosis, tissue samples (usually four) from different parts of the mucous membrane of the stomach are taken. This is considered a last resort because it is more invasive than the other methods discussed. The tissue sample is taken during an endoscopy. An endoscopy is a procedure that uses a flexible viewing tube (known as an endoscope) inserted into the body to get a close look at a particular body part.

The type of endoscopy used in diagnosing Helicobacter pylori is called an upper esophagogastroduodenal endoscopy. In this type of endoscopy, the endoscope is placed down the esophagus, into the stomach, and into the duodenum (first part of the intestine). The esophagus is a tube-shaped structure that takes food down into the stomach after it is swallowed.

The collected tissue sample from the stomach and/or duodenum is exposed to a chemical stain and examined under a microscope. This helps doctors to identify the specific type of bacteria in the tissue sample. This is the most accepted way to diagnose Helicobacter pylori once a tissue sample is collected. The tissue sample may also be taken and placed in a special dish at increased temperature for seven days to see if Helicobacter pylori grow inside. This test requires an experienced laboratory, however, and it is expensive

Another test that can be performed when the tissue sample is collected is known as the rapid urease test. The rapid urease test involves taking the tissue sample and placing it in a container of liquid that contains urea. The goal is to look for increased urease activity, which is reflected by the liquid turning from yellow to red. This test takes about one hour for results to be known. Remember from above that urease is a substance released by Helicobacter pylori. Thus, if increased levels of urease are found, Helicobacter pylori is considered to be present.

HOW IS HELICOBACTER PYLORI TREATED?

Helicobacter pylori is treated with antibiotics, which are types of medications that fight against bacteria infections. As the Helicobacter pylori goes away, so do the symptoms of infection, such as ulcers. Two antibiotics are typically used to treat Helicobacter pylori. Names of some of the most common antibiotics used to treat Helicobacter pylori are metronidazole, clarithomycin, tetracycline, and amoxicillin.

A problem that is occurring with greater frequency, however, is that Helicobacter pylori is developing a resistance to some antibiotics. For example, about 30% of the types of Helicobacter pylori are thought to be resistant to the antibiotic, metronidazole. Resistance is especially likely to occur if the first course of treatment failed.

In addition to the antibiotics, bismuth subsalicylate (known to many as Pepto-Bismol) is also used. Pepto-Bismol helps control upset stomach, stomach cramps, nausea, and other common stomach problems by protecting the stomach lining. Antacids, such as Tums or Rolaids can relive symptoms of ulcers.

There are two types of medications used to treat ulcers caused by Helicobacter pylori that work to decrease the level of acid. These are called H2 blockers and proton pump inhibitors. H2 blockers work by blocking histamine. Histamine is a natural substance in the body that is released during allergic reactions and leads to many allergic symptoms. Histamine increases the release of acids. Examples of H2 blockers used to treat Helicobacter pylori are cimetidine (Tagament), ranitidine (Zantac), famotidine (Pepcid AC), and nizatidine (Axid). They help decrease pain from ulcers in a few weeks.

Proton pump inhibitors decrease the production of acid by stopping the pump that releases acid into the stomach. Examples of proton pump inhibitors used to treat Helicobacter pylori are omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (AcipHex), esomeprazole (Nexium), and pantoprazole (Protonix). Used alone, H2 blockers and proton pump inhibitors will not get rid of Helicobacter pylori. To do that, antibiotics are needed as well.

The most effective treatment for Helicobacter pylori is known as triple therapy because it uses three drugs: 2 antibiotics (usually tetracycline and metronidazole) and either an acid suppressor (usually Zantac) or a stomach lining protector (Pepto Bismol). There are a number of different triple therapy combinations used by doctors. The most acceptable or effective combination has yet to emerge. Triple therapy usually lasts for 10 days to 2 weeks.

In 10 days to 2 weeks, triple therapy decreases symptoms of ulcers, kills Helicobacter pylori, and prevents ulcers from returning in more than 90% of patients. The down side of triple therapy is that it requires taking about 14 to 20 pills a day. Dual therapy, which involves taking one antibiotic and one acid suppressor is not as effective as triple therapy. Dual therapy is usually used with people who are allergic to certain antibiotics.

To determine the effectiveness of treatment, the urea breath test (see previous section) is more effective than blood tests. The reason for this is that antibodies may remain at increased levels in the blood for up to one year after the Helicobacter pylori infection is gone. A repeat endoscopy can also be performed in which tissue samples are taken and analyzed. This is not preferred, however, since it is an invasive procedure. Since reinfection or regrowth of Helicobacter pylori can happen within six months, many doctors wait 6months before retesting the patient.

WHAT IS THE PROGNOSIS FOR PEOPLE WITH HELICOBACTER PYLORI?

Helicobacter pylori will generally go away in two weeks, if treated with antibiotics. If not treated, Helicobacter pylori infections will last throughout the infected person's life. Helicobacter pylori is dangerous, as represented by the fact that it causes approximately 16,000 deaths every year.

WHO DISCOVERED HELICOBACTER PYLORI?

Helicobacter pylori was first in 1982 by Robin Warren and Barry J. Marshall at Royal Perth Hospital in Western Australia. They discovered the bacteria by taking and analyzing samples of stomach tissue from 11 patients with chronic (long-term) stomach inflammation. You can visit Dr. Marshall's website by going to the Helicobacter Foundation

HOW IS HELICOBACTER PYLORI ABBREVIATED?

Helicobacter pylori is commonly abbreviated in medical charts as H. pylori.

WHAT ELSE IS HELICOBACTER PYLORI KNOWN AS?

Helicobacter pylori used to be known as Campylobacter pylori. This is because the bacteria was originally thought to be a species of Campylobacter, a different family of bacteria. After further study, the bacteria was appropriately classified as a species of Helicobacter in 1989.

WHAT IS THE ORIGIN OF THE TERM, HELICOBACTER PYLORI?

Helicobacter pylori comes from the Greek word "helix" meaning "coil," the Greek word "bakterion" meaning "small staff," the Greek word "pyle" meaning "gate," and the Greek word "ourus" meaning "guard." Put the words together and you have "coil(ed) small staff gate guard."