# Detection of Salivary Helicobacter pylori in Pediatric Patients and Its Association With Gastrointestinal and Oral Health

## TL;DR

This study found that Helicobacter pylori can be detected in children's saliva and is linked to more dental caries.

## Contribution

The study is the first to show a strong association between H. pylori in saliva and dental caries in children.

## Key findings

- 61% of children tested positive for H. pylori in gastric biopsies, and 53% in saliva samples.
- Children with H. pylori-positive saliva had significantly more dental caries than those without.
- The cagA virulence gene was detected in 8% of saliva samples, but sabA was not found.

## Abstract

Background

Helicobacter pylori (H. pylori) infection is one of the most common bacterial infections worldwide and is recognized as a major cause of gastritis. The oral cavity has been suggested as a potential reservoir for this bacterium. Yet, the relationship between its presence in the mouth and stomach, as well as its possible role in dental caries, remains unclear. This study aimed to investigate the prevalence of H. pylori contamination in the saliva of patients aged four to 18 years undergoing endoscopy.

Materials and methods

This cross-sectional study included 100 children aged four to 18 years who underwent endoscopy due to gastrointestinal symptoms. Saliva samples were collected before endoscopy, and gastric biopsies were analyzed for H. pylori using standard histopathological methods, specifically the Giemsa stain. The presence of H. pylori was confirmed through pathology results. In addition, polymerase chain reaction (PCR) targeting the 23S rRNA gene was used to detect the H. pylori in saliva, and the virulence genes sabA and cagA were also examined. Dental status was assessed using the Decayed/decayed, Missing/missing, and Filled/filled Teeth/teeth (DMFT/dmft) score according to World Health Organization (WHO) criteria. Data were analyzed using descriptive and inferential statistics, including t-tests, correlation analyses, and logistic regression; p<0.05 was considered significant.

Results

Overall, 61 patients (61%) tested positive for H. pylori in gastric biopsy specimens. In saliva samples, 53 patients (53%) were positive for H. pylori. Notably, all saliva-positive patients were also positive in biopsy specimens, indicating complete overlap. Among the saliva-positive samples, the virulence gene cagA was detected in eight samples (8%). In contrast, the sabA gene wasn't detected in any sample. Notably, children with H. pylori-positive saliva had a significantly higher mean number of dental caries than saliva-negative children (4.10 vs. 2.05, p<0.001).

Conclusion

Saliva can serve as a reservoir for H. pylori in Iranian children and could be associated with dental caries severity. Saliva testing may provide a simple, non-invasive method for early detection of H. pylori, while promoting oral hygiene and regular dental care can help prevent recurrent gastric infections and improve overall health of the children.