A Comprehensive Review of Plant and Microbial Natural Compounds as Sources of Potential Helicobacter pylori-Inhibiting Agents

<i>Helicobacter pylori</i>, the gastric pathogen which colonizes the gastric mucosa of more than half of the world's population, is considered a risk factor for peptic ulcers and is epidemiologically associated with gastric cancer. Antimicrobial eradication of this pathogen has now become a central concern because of its growing resistance to frontline antibiotics such as clarithromycin and metronidazole. Moreover, these antibiotics can have adverse effects on the normal human gut flora and can lead to several health complications. Most times, the antibiotic doses become intolerable to the elderly population and they reject the therapy. This has impelled us to think about alternate effective and safe antimicrobials which can replace antibiotic usage or may reduce their dosage when used together with the antibiotics. Plant and microbial natural products, in view of this, offer an excellent source of novel and potential antimicrobial agents. Herein, we review anti-<i>H. pylori</i> natural compounds from diverse plant and microbial sources and highlight their role in the management of <i>H. pylori</i> infection.