Helicobacter pylori (H. pylori) is a type of bacteria that lives in the stomach and upper part of the small intestine. It is estimated that approximately half of the world’s population is infected with this bacterium. H. pylori is transmitted through oral-oral or fecal-oral routes and is commonly acquired during childhood. The infection is usually asymptomatic but can cause various gastrointestinal disorders, such as gastritis and peptic ulcer disease, and in rare cases, it can lead to stomach cancer.
The significance of H. pylori infection lies in its association with chronic gastritis, peptic ulcer disease, and gastric cancer, which are leading causes of morbidity and mortality worldwide. In this article, we will discuss the causes, symptoms, diagnosis, treatment, complications, and prevention of H. pylori infection. Understanding these aspects of H. pylori infection can help in reducing the burden of related gastrointestinal disorders.
A. What is Helicobacter pylori (H. pylori)?
Helicobacter pylori (H. pylori) is a gram-negative bacterium that has a helical shape and is considered a microaerophile, which means it requires oxygen to survive, but not in high concentrations. It has multiple flagella that allow it to move and swim in the viscous mucus layer of the stomach lining, where it colonizes and persists for a long time. H. pylori is well-adapted to survive in the acidic environment of the stomach, thanks to its ability to produce urease, which converts urea into ammonia, thus neutralizing the acidity of the surroundings.
B. Prevalence of H. pylori in the world
Helicobacter pylori (H. pylori) infection is one of the most common bacterial infections worldwide, affecting an estimated 50% of the world’s population. Its prevalence varies widely between regions and countries, with higher rates reported in developing countries, particularly in Africa, Latin America, and Asia, compared to developed countries.
According to the World Health Organization (WHO), the prevalence of H. pylori infection ranges from 30% to over 80% in some countries. In the United States, the overall prevalence of H. pylori infection is around 30%, but it is higher in certain populations, such as African Americans, Hispanics, and older individuals. In Europe, the prevalence ranges from less than 20% in northern and western countries to over 70% in some eastern and southern European countries. In Japan and Korea, the prevalence is over 50%, while in some parts of Africa, it is close to 90%.
The higher prevalence of H. pylori infection in developing countries is thought to be due to poor sanitation and hygiene, crowded living conditions, and a lack of access to clean drinking water. In contrast, the declining prevalence of H. pylori infection in developed countries is attributed to improved sanitation, better hygiene, and the widespread use of antibiotics.
C. The significance of H. pylori infection
Helicobacter pylori (H. pylori) infection is significant due to its association with a wide range of gastrointestinal disorders, including chronic gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric adenocarcinoma. The International Agency for Research on Cancer (IARC), a division of the World Health Organization (WHO), classified Helicobacter pylori (H. pylori) as a definite class I carcinogen in 1994.
The mechanisms by which H. pylori causes these disorders are not fully understood, but it is believed to be related to the bacterium’s ability to persistently colonize and damage the gastric mucosa.
Chronic gastritis is a common condition characterized by inflammation of the stomach lining, which can lead to abdominal pain, nausea, vomiting, and loss of appetite. H. pylori is a major cause of chronic gastritis, and its eradication can lead to resolution of the condition in many cases.
Peptic ulcer disease is a condition characterized by ulcers in the stomach or duodenum, which can cause abdominal pain, bloating, nausea, and vomiting. H. pylori infection is the leading cause of peptic ulcer disease, and its eradication is the mainstay of treatment for the condition.
Gastric MALT lymphoma is a type of cancer that develops in the lymphoid tissue of the stomach. It is associated with chronic H. pylori infection, and its treatment involves eradicating the bacterium.
Gastric adenocarcinoma, also known as stomach cancer, is a leading cause of cancer-related deaths worldwide. It is strongly associated with chronic H. pylori infection, particularly in populations with high rates of infection.
The significance of H. pylori infection lies in its potential to cause serious and sometimes life-threatening gastrointestinal disorders. Timely diagnosis and treatment of the infection can prevent or resolve these disorders, reducing the burden of disease and improving patient outcomes.
II. Causes of H. pylori infection
Helicobacter pylori (H. pylori) infection is caused by the bacterium H. pylori, which is transmitted from person to person through oral-oral or fecal-oral routes. The exact mode of transmission is not fully understood, but it is believed to occur through close contact with an infected individual or through ingestion of contaminated food or water.
The infection is most commonly acquired during childhood, and its prevalence increases with age. Factors that increase the risk of H. pylori infection include living in crowded or unsanitary conditions, poor hygiene, and a lack of access to clean drinking water. Other risk factors include a family history of H. pylori infection, and smoking.
The bacterium is well-adapted to survive in the acidic environment of the stomach, where it colonizes and persists for a long time. H. pylori produces urease, an enzyme that converts urea into ammonia, which neutralizes the acidity of the surroundings and allows the bacterium to survive. H. pylori also has a unique ability to penetrate and adhere to the gastric mucosa, where it can cause chronic inflammation and damage to the stomach lining, leading to the development of various gastrointestinal disorders.
A. Transmission of H. pylori
Helicobacter pylori (H. pylori) infection is primarily transmitted from person to person through oral-oral or fecal-oral routes. The exact mode of transmission is not fully understood, but several routes of transmission have been proposed.
Oral-oral transmission is believed to occur through close contact with an infected individual, such as kissing, sharing utensils, or using contaminated dental instruments. This route of transmission is thought to be particularly important in childhood, when children are more likely to engage in behaviors that increase the risk of infection.
Fecal-oral transmission is another route of transmission, and it is believed to occur through ingestion of contaminated food or water. This can happen when food or water is contaminated with fecal matter containing H. pylori. Poor sanitation and hygiene practices, such as improper handwashing after using the bathroom, can increase the risk of fecal-oral transmission.
Vertical transmission from mother to child during childbirth or through breast milk has also been proposed as a possible route of transmission, although its role in H. pylori infection is not well established.
In addition to person-to-person transmission, certain environmental factors may also play a role in the transmission of H. pylori. Overall, the transmission of H. pylori is complex, and several factors, including environmental and host-related factors, may contribute to the spread of the infection.
B. Factors that increase the risk of H. pylori infection
Several factors can increase the risk of Helicobacter pylori (H. pylori) infection. These include:
- Age: The prevalence of H. pylori infection increases with age, and it is most commonly acquired during childhood.
- Living conditions: Living in crowded or unsanitary conditions, such as in developing countries or institutions, can increase the risk of infection.
- Poor hygiene: Poor hygiene practices, such as improper handwashing after using the bathroom or before eating, can increase the risk of infection.
- Lack of access to clean drinking water: Drinking contaminated water can increase the risk of infection.
- Family history: Individuals with a family history of H. pylori infection are at an increased risk of infection.
- Smoking: Smoking has been associated with an increased risk of H. pylori infection.
Overall, the risk of H. pylori infection is influenced by a complex interplay of factors, including environmental, genetic, and host-related factors.
III. Symptoms of H. pylori infection
Many people with Helicobacter pylori (H. pylori) infection do not experience any symptoms, and the infection can remain asymptomatic for many years. However, in some cases, H. pylori infection can cause acute symptoms, particularly if the infection leads to peptic ulcer disease or gastritis.
Peptic ulcer disease is a condition that occurs when the lining of the stomach or duodenum is damaged, allowing stomach acid to come into contact with the underlying tissue. Symptoms of peptic ulcer disease may include:
- Abdominal pain, which may be dull or sharp and is typically located in the upper abdomen
- Nausea and vomiting
- Loss of appetite and weight loss
- Bloating and belching
- Heartburn or acid reflux
- Dark or tarry stools
Gastritis is a condition that occurs when the lining of the stomach becomes inflamed. Symptoms of gastritis may include:
- Abdominal pain or discomfort, which may be dull or burning in nature and is typically located in the upper abdomen
- Nausea and vomiting
- Loss of appetite and weight loss
- Bloating and belching
- Feeling full after eating small amounts of food
In some cases, H. pylori infection can also lead to the development of stomach cancer, although this is rare. Symptoms of stomach cancer may include:
- Abdominal pain or discomfort
- Nausea and vomiting
- Loss of appetite and weight loss
- Feeling full after eating small amounts of food
- Blood in the stool or vomit
- Fatigue and weakness
Many of these symptoms can also be caused by other conditions, and individuals experiencing these symptoms should seek medical evaluation to determine the underlying cause.
IV. Diagnosis of H. pylori infection
Several methods can be used to diagnose Helicobacter pylori (H. pylori) infection, including:
- Blood test: A blood test can detect the presence of antibodies to H. pylori in the blood. However, this serological test cannot distinguish between a current or past infection.
- Stool test: A stool test can detect the presence of H. pylori antigens in the stool. Like the blood test, this test cannot distinguish between a current or past infection.
- Breath test: A breath test involves drinking a solution containing a substance that is metabolized by H. pylori, and then breathing into a bag to detect the presence of H. pylori in the breath.
- Esophagogastroduodenoscopy: An endoscopy involves inserting a thin, flexible tube with a camera into the mouth and down into the stomach to visualize the lining of the stomach and take a biopsy sample for testing. The biopsy sample can be examined for the presence of H. pylori.
- Urea breath test: The urea breath test involves drinking a solution containing urea and then measuring the amount of carbon dioxide in the breath. H. pylori metabolizes the urea, which produces carbon dioxide that can be detected in the breath.
V. Treatment of H. pylori infection
The treatment of Helicobacter pylori (H. pylori) infection typically involves a combination of antibiotics, bismuth, and acid-suppressing medications. The goal of treatment is to eradicate the bacteria, heal any damage to the stomach lining, and prevent the development of complications such as peptic ulcers and stomach cancer.
The antibiotics commonly used to treat H. pylori infection include:
Bismuth is a chemical element that has been used for many years as part of the treatment for Helicobacter pylori (H. pylori) infection. Bismuth compounds, such as bismuth subsalicylate and bismuth subcitrate, have been shown to have antibacterial activity against H. pylori and can help reduce the severity of the symptoms of infection.
Bismuth-containing therapies are often used in combination with antibiotics and proton pump inhibitors (PPIs) to help eradicate H. pylori and promote healing of the gastrointestinal tract. The antibiotics work to kill the bacteria, while the PPIs help to reduce the amount of acid in the stomach, allowing the antibiotics to work more effectively. The bismuth compounds help to further reduce inflammation and promote healing.
Bismuth-containing therapies can be effective in treating H. pylori infection, with eradication rates of around 92-95%. However, there are some potential side effects of bismuth therapy, including blackening of the tongue and stool, constipation, and rare cases of neurological symptoms. Therefore, bismuth-containing therapies are generally used for short-term treatment and only under the supervision of a gastroenterologist.
In recent years, there has been some concern about the potential toxicity of bismuth and its impact on the environment. As a result, alternative treatments for H. pylori infection, such as probiotics and phage therapy, are being explored. However, bismuth-containing therapies remain an important part of the current treatment options for H. pylori infection.
The acid-suppressing medications used in combination with antibiotics include:
- Proton pump inhibitors (PPIs), such as omeprazole, esomeprazole, lansoprazole, pantoprazole, or rabeprazole.
- Potassium-competitive acid blocker (PCAB), such as vonoprazan.
The specific combination of antibiotics and acid-suppressing medications used may depend on the individual’s medical history, the severity of the infection, and local antibiotic resistance patterns.
Treatment typically lasts for 10-14 days, and it is important to complete the full course of antibiotics and acid-suppressing medications to ensure that the infection is fully eradicated. Follow-up testing is recommended after treatment to confirm that the bacteria have been successfully eliminated.
In some cases, H. pylori infection may be resistant to antibiotics, which can make treatment more challenging. If antibiotic resistance is suspected, the gastroenterologist may recommend alternative antibiotics or a longer course of treatment.
VI. Complications of H. pylori infection
Helicobacter pylori (H. pylori) infection can lead to several complications, including:
- Peptic ulcer disease: H. pylori infection is a common cause of peptic ulcer disease, which occurs when the lining of the stomach or duodenum is damaged, allowing stomach acid to come into contact with the underlying tissue. Peptic ulcer disease can cause symptoms such as abdominal pain, nausea, vomiting, and bloating.
- Gastritis: H. pylori infection can cause inflammation of the stomach lining, leading to a condition called gastritis. Gastritis can cause symptoms such as abdominal pain, nausea, vomiting, and loss of appetite.
- Stomach cancer: Although rare, long-term infection with H. pylori can increase the risk of developing stomach cancer. Stomach cancer may cause symptoms such as abdominal pain, nausea, vomiting, weight loss, and anemia.
- MALT lymphoma: H. pylori infection can cause a type of non-Hodgkin’s lymphoma called mucosa-associated lymphoid tissue (MALT) lymphoma. MALT lymphoma is a slow-growing cancer that typically affects the stomach or intestines.
- Iron-deficiency anemia: Chronic H. pylori infection can lead to iron-deficiency anemia, a condition in which the body does not have enough iron to produce red blood cells.
In addition to the complications mentioned earlier, H. pylori infection may also be associated with other conditions, although the evidence for these associations is not yet clear:
- Cardiovascular disease: Some studies have suggested a possible link between H. pylori infection and an increased risk of cardiovascular disease, such as heart attacks and strokes. However, more research is needed to confirm this association.
- Rosacea: Rosacea is a common skin condition that causes redness, bumps, and pimples on the face. Some studies have suggested that H. pylori infection may be a risk factor for rosacea, although the evidence is not yet conclusive.
- Autoimmune disorders: H. pylori infection has been associated with several autoimmune disorders, including autoimmune thyroiditis and Sjogren’s syndrome. However, more research is needed to better understand these associations.
VII. Prevention of H. pylori infection
Prevention of Helicobacter pylori (H. pylori) infection can be challenging, as the exact mechanisms of transmission are not well understood. However, there are some strategies that may help reduce the risk of infection, including:
- Good hygiene practices: Washing your hands regularly with soap and water can help reduce the risk of acquiring H. pylori infection.
- Avoiding contaminated food and water: Drinking clean, safe water and avoiding food that may be contaminated with H. pylori, such as undercooked meat and unwashed fruits and vegetables, can help reduce the risk of infection.
- Using caution when taking non-steroidal anti-inflammatory drugs (NSAIDs): Long-term use of NSAIDs such as aspirin and ibuprofen can increase the risk of peptic ulcer disease, which may be caused by H. pylori infection. If you need to take NSAIDs regularly, talk to your healthcare provider about ways to reduce your risk of peptic ulcer disease.
- Consider testing and treatment if you are at high risk: If you have a family history of H. pylori infection or have a medical condition that puts you at high risk for infection, such as peptic ulcer disease or gastric cancer, talk to your gastroenterologist about whether testing and treatment for H. pylori infection may be appropriate for you.
VIII. Concluding remarks and future perspectives
Helicobacter pylori (H. pylori) infection remains a significant public health issue, with a high prevalence worldwide and the potential to cause several gastrointestinal and other complications. However, with the availability of effective treatments, the long-term outlook for individuals with H. pylori infection is generally good.
In recent years, there has been a growing interest in the role of the microbiome, the collection of microorganisms that live in and on the human body, in health and disease. Researchers are exploring the complex relationship between H. pylori and the gut microbiome and how this relationship may impact health outcomes. Additionally, studies are being conducted to develop new diagnostic tests and more targeted treatments for H. pylori infection.
Overall, continued research into H. pylori and its interactions with the microbiome and other factors will be important for improving our understanding of this common infection and developing more effective strategies for prevention and treatment. With ongoing efforts, we can hope to reduce the burden of H. pylori infection and its associated complications for individuals and populations worldwide.
You can download and read the latest 6th edition of the Maastricht/Florence 2021 Consensus Report on the management of Helicobacter pylori infection here.
How can I contact gastroenterologist Dr. Zavos for an appointment?
Dr. Chris Zavos is a board-certified gastroenterologist and hepatologist, located in Thessaloniki Greece, and specifically in Kalamaria suburb, about 7 kilometres (4 miles) southeast of downtown Thessaloniki. His private office is at: Fanariou 8 street (near Aigaiou and Adrianoupoleos avenues), Kalamaria (Thessaloniki), Greece.
Thessaloniki International Airport is only 10 km away from his private office in Kalamaria and can be reached by taxi within 13 minutes from the airport.
Dr. Chris Zavos performs endoscopies at Bioclinic private hospital in downtown Thessaloniki (Mitropoleos 86 street).
You can contact Dr. Zavos at phone numbers: (+30)-6976596988 and (+30)-2311283833, or you can email him at firstname.lastname@example.org. Dr. Zavos responds to Greek and English languages.