Global prevalence of Helicobacter pylori and its effect on human health

Helicobacter pylori infection is non-hereditary disease caused by a bacteria H. pylori that possess gramnegative helical morphology. H. pylori infection can cause variety of gastrointestinal problems, including stomach ulcers, inflammation in stomach linings and cancer. The H. pylori bacterium has infected approximately 50% of the total populations. The frequency of H. pylori infection varies among countries, underdeveloped countries have high ratio of cases of H. pylori whereas its ratio is low in developed countries. Around 70% children of underdeveloped countries may be affected by H. pylori infection. Noncardia gastric patient have a high chances to be infected by H. pylori however, the risk of gastric cardia cancer is relatively low in the H. pylori infection. Patients with weak metabolic control and poor glycemic condition especially diabetes type 2 patients are more susceptible to H. pylori disease. The Gastroesophageal reflux syndrome and H. pylori infection share an inverse relationship particularly those with CagA-positive strains, are less likely to have risk of Gastroesophageal Reflux Disease (GERD). The association of Non-alcoholic fatty liver disease (NAFLD) with H. pylori infection reveals that Cytotoxicassociated gene A (cagA) negative strain is the leading cause of H. pylori infection in NAFLD. Diagnosis of H. pylori can be performed by upper endoscopy or EGD, Breath test and stool culture. Treating H. pylori medicine with natural ingredient such as probiotic, green tea, honey and olive oil can improve the efficiency of antibacterial drug. This review demonstrates that patients of non-cardia gastritis, diabetes type 2 and NAFLD are more prone to be infected by H. pylori disease the ratio of H. pylori infection in humans can be reduced by improving domestic hygienic and sanitary infrastructure.


Introduction
Good nutrition is an essential for leading a healthy lifestyle. Factors for staying healthy include the healthy genetics, diet, exercise, environment, relationships and education. All  H. pylori bacterium can be passed from one person to another simply by saliva, fecal material, vomiting and by contaminated food and water. The health problems which are related to a H. pylori disease includes (1) the ulcer caused by bacterium that impairs the stomach linings and form an open sore (ulcer). Many researches proof that 10 % of total patients of H. pylori have ulcer.
(2)Inflammation in stomach linings. (3) Cancer of stomach. Once H. pylori enters to stomach the acute symptoms such as nausea, bloating, burning pain in abdomen and loss of appetite are started but these symptoms become chronic infection if the bacteria succeed to survive [5]. H. pylori bacterium has infected approximately 50 percent of the total population. The occurrence of H. pylori transmission varies from age, race, ethnicity and geographic area. The rate of transmission of H. pylori in developing countries is comparatively high [6]. Moreover, the frequency of H. pylori diseases is reducing over the last decade in many countries but still its intensity is high in some under developed countries [7]. Doctors usually recommend a combination of an acid-reducing medication and two antibiotics for treating H. pylori infection and this mixture is known as the triple therapy. Treatment of H. pylori infection takes about 10 days to 2 weeks. The reason for using two antibiotics instead of just one because it reduces the risk of antibiotic resistance in patient. Some antibiotics like Tetracycline, Clarithromycin, Amoxicillin and Metronidazole are used in the treatment of H. pylori. Acid-reducing drugs help to heal the stomach lining. To heal stomach, acidreducing drugs like Proton pump inhibitors; pantoprazole and omeprazole are used. Furthermore histamine blockers; ranitidine ( Zantac) and cimetidine (Tagamet) that inhibits acid-triggering histamine, another acid-reducing medicine, bismuth subsalicylate (Pepto-Bismol) that protects and coats the stomach lining of patient. There are some natural treatments that increase the efficiency of conventional drugs, they are used in H. pylori treatment. Probiotic are the good bacteria that help in digestion, taking probiotics before or after standard H. pylori medicine may enhance their working rates. Drinking green tea and using honey, olive oil, broccoli and licorice root in diet have some antibacterial properties when taken against the H. pylori disease [28]. The rate of H. pylori attack can be decreased by improving household hygienic and sanitary infrastructure. There are several important steps for decreasing the prevalence of H. pylori infection i.e. washing hands thoroughly, eating food that is clean and properly cooked, by drinking clean water, by quitting smoking and reducing alcohol intake [29].

Classification of H. pylori
Helicobacter pylori possess gram-negative helical morphology as shown in figure 1 and the bacterium which is about 0-5 micrometer in the diameter and 3 micrometers long. H. pylori has micro aerophilic characteristic means it require oxygen for fermentation and respiration [30]. The bacterium have 5-7 flagella [31] and also contains hydrogenase enzyme that accelerates oxidation of hydrogen and let bacterium to use hydrogen in place of an energy source for their growth. Molecular structure of H. pylori has urease enzyme which helps it to penetrate into the mucosa of stomach. Moreover, it secretes the urease enzyme which exchanges urea into bicarbonate [HCO3] and ammonia [NH4]. Acidic environment of stomach kills the bacteria so its neutralization is important, after the discharge of ammonia, the ammonia plays its role by neutralizing the acidic environment of stomach.
Some other products of H. pylori, include protease, mucinase and phospholipases degrade gastric mucus. The lipopolysaccharide of bacterium when released in the circulation, has a powerful endotoxin activity which causes acute inflammation [30].     H. pylori treatment can be taken from both routes natural and conventional.

Conventional treatment
For the last two decades, triple therapy mechanism was used to eradicate H. pylori infection. In triple therapy, medications for neutralizing stomach acidity and decrease the secretion of stomach acid were used such medicines contains proton pump inhibitors (PPIs), clarithromycin, ranitidine bismuth citrate and amoxicillin. Due to high antibiotic resistance the efficiency rate of triple therapy decreased to 70% [41]. In recent years, plenty of studies suggested that eradication of H. pylori through second line therapies is still possible. The second line therapies include two methods i.e. sequential therapy and quadruple therapy [42]. In sequential therapy similar antibiotic such as PPI, amoxicillin and clarithromycin which were used in standard triple therapy. But the combination of the medicine has been changed i.e. firstly amoxicillin is given instead of PPI because it disturbs the cell wall of bacteria [43]. In quadruple therapy, PPI, amoxicillin and clarithromycin is given but without bismuth for ten days. This therapy is effective for those countries in which there is high resistances of H. pylori against clarithromycin [44]. Natural treatment Eradication of H. pylori is challenging because the clever bacterium is proficient to develop resistance to a common antibiotics. Along with the medication, H. pylori natural treatment can help to destroy infection and also reduces inflammation of the stomach lining as shown in figure 6. Some study suggested that bifid bacteria which are probiotics living microorganisms often have health benefits in treating gastrointestinal infection. A study on mice shows that green tea decreased both inflammation of H. pylori in mice as well as number of bacteria. According to an experiment based study, the gel inside the leaves of an aloe Vera plant has effective results on inhibiting growth and killing H. pylori strains. One other study demonstrates that honey has anti H. pylori property [29]. Recent study of fungal properties demonstrates that Antrodia camphorata a mushroom in China displays anti-inflammatory activity against H. pylori in human gastric mucosa [45].

Prevention of H. pylori
Approximately over three billion (50%) of the total inhabitants are identified to be infected H. pylori and likely no vaccine available that's why it is difficult for people to stay safe from bacterium. Currently, effective recommendations to prevent infections are to wash hands frequently, Drink clean water , Eat properly cooked food , Stop smoking and reduce intake of alcohol [29]. Conclusion Good nutrition plays a significant role in good mental and physical health. Extensive studies shows that there is a link between microbes and human health. There are trillion of microorganism, not all of them harm human but those who do can effect human as well as the food they intake. H. pylori possess gram-negative helical morphology that is found in stomach, cause chronic gastritis with long lasting stomach inflammation.