Adjunctive periotherapy shows potential in H. pylori treatment
Adding periodontal therapy (periotherapy) to standard triple antibiotic therapy targeting Helicobacter (H.) pylori may reduce the risk of recurrence of H. pylori infections, a new study shows, suggesting a promising approach for managing H. pylori infection.
“Chronic H. pylori infection has been found in approximately 50 percent of the global population and is aetiologically linked to gastric cancers, comprising 25 percent of cancers related to this aetiology of infection. Therefore, it constitutes a primary public health problem,” said the researchers.
A total of 689 individuals with H. pylori-associated gastritis were randomized 1:1 to receive 1-week triple therapy consisting of esomeprazole 20 mg twice daily, clarithromycin 500 mg twice daily or metronidazole 400 mg thrice daily (if clarithromycin-resistant), and amoxicillin 1,000 mg twice daily – either alone or in combination with periotherapy*. Follow-up ensued 4 weeks after completion of therapy. H. pylori-negative individuals underwent further evaluation a year after to determine recurrence rate. [J Int Med Res 2019;47:875-883]
Despite the lack of significant between-group difference in terms of eradication rate in the per-protocol analysis (odds ratio [OR], 0.77, 95 percent confidence interval [CI], 0.58–0.97; p=0.078), combination therapy yielded a significantly lower recurrence rate of H. pylori infection than standard therapy alone (OR, 0.69, 95 percent CI, 0.52–0.99; p=0.001).
The intention-to-treat analysis similarly revealed a nonsignificant difference in eradication rate (OR, 0.87, 95 percent CI, 0.68–0.98; p=0.076) but significant between-group difference in recurrence rate, favouring combination over standard therapy alone (OR, 0.67, 95 percent CI, 0.45–0.99; p=0.001).
Although standard therapy has been proven effective in eradicating gastric H. pylori, the recurrence rate is relatively high (13 percent). [World J Gastroenterol 2008;14:1477-1478; Aliment Pharmacol Ther 2017;48:773-779] The findings show that combining periotherapy with standard therapy stands a better chance of eradicating H. pylori, said the researchers. “[Therefore,] periodontal treatments may be useful adjuncts to triple therapy for H. pylori eradication.”
Targeting the source
Evaluation of gastric biopsy samples revealed the presence of major H. pylori virulence factors – cytotoxin-associated gene A (cagA; 87.8 percent) and vacuolating cytotoxin A (vacA; 77.2 percent), which supports evidence linking H. pylori cagA- and vacA-positive strains to severe gastroduodenal diseases. [Microb Pathog 2017;105:226-230; Gastroenterology 2016;150:64-78]
Saliva samples also revealed a high rate of H. pylori cagA- and vacA-producing virulent strains (42.0 percent and 41.0 percent, respectively). “[Oral] H. pylori strains that produce cagA and vacA may be considered highly virulent,” said the researchers. However, some authors underlined the absence of living H. pylori in the oral cavity and attributed the positive PCR** response to regurgitation, vomiting, or reflux, they pointed out.
Nonetheless, the current findings suggest that the oral cavity is a potential reservoir for H. pylori and may be the source of gastric infection/reinfection and bacterial transmission, which could account for failed gastric H. pylori eradication, said the researchers. “[As such,] bacterial eradication in the oral cavity should be considered an important aspect in the elimination of H. pylori-associated diseases.”
It remains unclear whether oral H. pylori strains are the same as those causing gastritis despite evidence showing similarities between strains found in these two sites [Arch Oral Biol 2009;54:684-688; Arch Oral Biol 2010;55:896-901]. “[G]enotyping of H. pylori strains isolated from the stomach and the oral cavity have demonstrated that strains from these two sites appear to be identical, although different strains are harboured by different individuals … Therefore, genotyping … should be prioritized in future research,” they said.
“[Overall, our] findings … may improve treatment efficacy and reduce the risk of H. pylori recurrence,” said the researchers. “[However, despite the] association between the presence of H. pylori in saliva and in the stomach, the complete genomes of H. pylori strains in both sites should be sequenced [as] this is the only method to assess genetic identity,” they added.