Characterization of the Oral and Stomach Microbial Community Structure in Patients with Intestinal Metaplasia, Dysplasia, and Gastric Cancer Through High-Throughput Sequencing

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors, the study presents relevant results and a potential contribution to the understanding of the microbiota associated with gastric carcinogenesis. However, some points deserve revision:

 

INTRODUCTION

The introduction is well structured and adequately contextualizes the role of H. pylori and the microbiota in gastric carcinogenesis. However, further elaboration is suggested on the following aspects:

- More recent evidence on the role of oral microbiota as a non-invasive biomarker for gastric diseases;

- Greater emphasis on the gaps in the literature, especially regarding the integrated analysis of oral and gastric microbiota at different histological stages, which would reinforce the originality of the study.

 

MATERIALS AND METHODS

The laboratory and bioinformatics methodology is well described and follows recognized protocols. Some clinical and collection aspects deserve further detail:

- The clinical and dental criteria for participants are unclear, such as:

- presence of periodontal disease;

- general dental condition;

- oral hygiene habits.

- The absence of standardization prior to the collection of oral swabs (fasting, brushing, use of mouthwashes) may influence the composition of the oral microbiota;

- Additional information on medication use (antibiotics, antacids, proton pump inhibitors) would be important, considering the direct impact of these factors on the gastric microbiota.

- It is suggested to discuss whether and how these factors may have acted as variables in the results obtained.

 

RESULTS

The results are presented clearly, with good graphical representations and adequate statistical analyses. However:

- It would be interesting to further clarify the clinical relevance of the findings related to H. pylori-negative patients, since this subgroup represents a diagnostic challenge in clinical practice.

 

DISCUSSION

The discussion is consistent and well-founded, but could be strengthened by:

- Greater integration between microbiological findings and possible clinical implications, such as chronic inflammation, mucosal changes, and risk of neoplastic progression;

- Discussion of the fact that genera traditionally considered beneficial in the intestine (e.g., Faecalibacterium, Anaerostipes) appear to be associated with advanced stages of gastric cancer;

- Further exploration of the potential (and limitations) of the oral microbiota as a noninvasive screening tool, considering the results of oral-gastric correlation analyses;

 

CONCLUSION

The conclusion adequately summarizes the results, but could be improved by:

- Highlighting more clearly future applications, validation in different populations, and integration with clinical data;

- Emphasize that the findings suggest potential markers, but that they are not yet sufficient for direct clinical use.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Great work overall. To further strengthen the paper, please consider the following minor suggestions. A brief discussion on how the potential markers findings might translate into future diagnostic or risk-stratification strategies (particularly for non-invasive oral biomarkers) would enhance clinical relevance. The Discussion already notes the single country cohort and lack of healthy controls. Explicitly mentioning the cross sectional nature of the study and its implications for causal inference would further strengthen transparency. Some heatmaps (Figures 3–6) are information-dense. Slight increases in font size or clearer legends may improve accessibility for readers. Overall, the study is methodologically sound, the analyses are rigorous, and the interpretations are appropriately cautious. Only minor revisions are suggested.

Comments on the Quality of English Language

Overall great. Minor editing needed. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors, congratulations on your dedication to the creation and improvement of the manuscript.