Prevention of Helicobacter pylori infection

Alternative therapies for Helicobacter pylori: probiotics and phytomedicine

Helicobacter pylori is a common human pathogen infecting about 30% of children and 60% of adults worldwide and is responsible for diseases such as gastritis, peptic ulcer and gastric cancer. Treatment against H. pylori is based on the use of antibiotics, but therapy failure can be higher than 20% and is essentially due to an increase in the prevalence of antibiotic-resistant bacteria, which has led to the search for alternative therapies. In this review, we discuss alternative therapies for H. pylori, mainly phytotherapy and probiotics. Probiotics are live organisms or produced substances that are orally administrated, usually in addition to conventional antibiotic therapy. They may modulate the human microbiota and promote health, prevent antibiotic side effects, stimulate the immune response and directly compete with pathogenic bacteria. Phytomedicine consists of the use of plant extracts as medicines or health-promoting agents, but in most cases the molecular mode of action of the active ingredients of these herbal extracts is unknown. Possible mechanisms include inhibition of H. pylori urease enzyme, disruption of bacterial cell membrane, and modulation of the host immune system. Other alternative therapies are also reviewed.

Recent developments in Helicobacter pylori vaccination

This reviews discusses the recent progress in the development of a vaccine against Helicobacter pylori. To date, this gram-negative, spiral-shaped bacterium is one of the most common infections of mankind. Infection usually occurs during childhood, and when left untreated results in lifelong colonization of the stomach. Helicobacter pylori infection is a chronic gastritis that can lead to peptic ulcer disease, gastric adenocarcinoma and gastric B-cell lymphoma. Antimicrobial therapy is currently the method of choice for curing H. pylori infection, but complex dosing, inconsistent efficiency, development of antibiotic resistance, costs and various side effects compromise widespread use. As a consequence, new strategies for the prevention and eradication of H. pylori infections are being explored. Vaccines are an attractive option, because they are both effective and economic in use. Natural infection with H. pylori usually results in a strong inflammatory Th1-type CD4(+)T-cell response that does not seem to have any protective effects. Successful vaccination studies indicate that a Th2-type response is required for protection, but the exact mechanisms involved in protective immunization are still poorly understood. Although commercial development of products for clinical trial is underway, many important issues, such as lack of a suitable mucosal adjuvant, and prevention of potential side effects, such as postimmunization gastritis, need to be resolved.

Growth in infancy, infant feeding, childhood living conditions, and Helicobacter pylori infection at age 70

AIM

To examine childhood correlates of Helicobacter pylori infection in adults.

DESIGN

Follow up study of men and women whose birth weight, weight at age 1 year, and feeding in infancy were recorded by health visitors. Data on childhood housing conditions were obtained by recall.

SUBJECTS

631 men and 389 women born in Hertfordshire during 1920-30 and still living in the east or northwest districts of the county.

MAIN OUTCOME MEASURES

Serum H pylori IgG antibodies measured by enzyme linked immunosorbent assay.

RESULTS

Independent of their current social class, subjects were more likely to be H pylori seropositive if they had large numbers of siblings (p < 0.0001), and if they had lived in a crowded house (p = 0.001), or shared a bedroom or bed in childhood (p = 0.02). Low weight at 1 year was associated with increased seropositivity rates in men (p = 0.0002), but not women (p = 0.8). Men and women who were breast fed in infancy were less likely to be seropositive than those who were bottle fed (p = 0.08).

CONCLUSIONS

The findings support the current view that H pylori infection is often acquired in childhood by close person to person contact, and persists into adult life. H pylori infection may be a cause of failure to thrive in infancy, especially in boys. Alternatively, small infants may be more susceptible to infection. Breast feeding may prevent early infection.