Contents

**Preface XI**


#### **Section 3 Helicobacter Pylori and Eradication Therapies 89**

Chapter 7 **Gastric Microbiota and Resistance to Antibiotics 91** Agnes Tving Stauning, Rie Louise Møller Nordestgaard, Tove Havnhøj Frandsen and Leif Percival Andersen

#### Chapter 8 **Nonantibiotic-Based Therapeutics Targeting Helicobacter pylori: From Nature to the Lab 109** Paula Parreira, Catarina Leal Seabra, Daniela Lopes-de-Campos and Maria Cristina L. Martins

Preface

therapy".

*pylori* infection in liver diseases".

*Helicobacter pylori* (*H. pylori*) remains one of the most common worldwide human infections and, although its colonization is not a disease in itself, it is a condition that affects the relative risk of developing various clinical disorders of the upper gastrointestinal tract, such as chron‐ ic gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma and gastric adenocarcinoma. Besides, in the last decades, the infection and its consequences pro‐ duced by this microorganism has been associated with the development of various extradi‐ gestive disorders, such as hepatobiliary, cardiovascular and pancreatic diseases, iron deficiency anemia, idiopathic thrombocytopenic purpura, skin diseases, among others.

Despite the bacteria infects half of the world population, most patients are asymptomatic for life, while only some will come to develop a digestive disease. Nevertheless, gastric cancer remains one of the principal causes of cancer death worldwide and *H. pylori* is consider as a class I carcinogen (International Agency for Research on Cancer – World Health Organization). Transmission of *H. pylori* is still not entirely clarified, but human-to-human spread through oral-oral or fecal-oral route is thought to be most plausible. The infection is typically ac‐ quired during childhood and usually becomes a lifelong infection, if left untreated. The host certainly mounts an immune response, but it fails to clear the infection, allowing *H. pylori* to

In this book, compounded by eight chapters, important aspects of *H. pylori* were reported and the book divided into three following sections: "General aspects of *Helicobacter pylori* infection", "Virulence factors of *Helicobacter pylori"*, and "*Helicobacter pylori* and eradication

The first section comprehends four chapters, "*Helicobacter pylori*: an overview of an old hu‐ man microorganism", "Clinical manifestations of the *Epsilonproteobacter, Helicobacter pylori*", "Endoscopical aspects of *Helicobacter pylori* gastritis in children", and "The importance of *H.*

In the second section some important aspects regarding virulence factors of *H. pylori* were reported in two chapters, "VacA genotype" and "*Helicobacter pylori* genes jhp0940, jhp0945,

Finally, in the third section, two chapters explore aspects concerning the eradication treat‐ ment of *H. pylori* infection and possible resistance mechanisms to the antibiotics commonly used for this purpose, besides the use of natural medicines for eradication of this microor‐ ganism: "Gastric microbiota and resistance to antibiotics" and "Non-antibiotic based thera‐

establish a persistent infection and a chronic inflammation.

jhp0947 and jhp0949 associated to gastroduodenal disease".

peutics targeting *Helicobacter pylori*: from Nature to the lab".
