Published online Nov 7, 2021. doi: 10.3748/wjg.v27.i41.7100
Peer-review started: March 20, 2021
First decision: July 3, 2021
Revised: July 11, 2021
Accepted: September 19, 2021
Article in press: September 19, 2021
Published online: November 7, 2021
Core Tip: Polymerase chain reaction (PCR) is not endorsed for Helicobacter pylori (H. pylori) diagnostics due to nonspecific primers and the threat of false-positives. However, a nested PCR that is as specific and equally sensitive in biopsy samples as the 13C-urea breath test was developed. Due to the threshold of H. pylori abundance and the ability to survive in the oral cavity, it is not suitable for saliva samples. Despite DNA degradation in stool samples, nested PCR for a shorter 148 bp amplicon identified twice the number of positive samples as stool antigen test, indicating that many patients are misdiagnosed, not treated by antibiotics, explaining why their problems are interpreted as chronic.