Composition of the Gut Microbiota Associated with the Response to Immunotherapy in Advanced Cancer Patients: A Chinese Real-World Pilot Study

Round 1

Reviewer 1 Report

The aim of the study was a very interesting issue of an analysis of a gut microbiota composition with respect to the response to immunotherapy in advanced cancer patients. I suppose a lot of effort went into the study. The authors demonstrated that the gut microbiome is associated with the clinical response to anti-PD-1 immunotherapy in a quite diverse group of cancer patients and that the taxonomic signatures enriched in responders are effective biomarkers to predict the clinical response. Their findings provide a new strategy to improve the efficiency of a response to immunotherapy among cancer patients. Novelty and a significant impact of the results are really interesting.

However, my major concerns are:

·         The credibility of the results would be higher for the study performed on a bigger group of patients with different types of cancers or, even better, one but more unified group of patients – focused on one particular cancer type or at least a group of cancers of the same origin. Therefore, I recommend an addition of “pilot study” into the title of the manuscript. Of course, if the authors are going to continue the research.

·         There is no information on antibiotics application during patients’ treatment or at least at the time directly before the samples collection.

·         Line 97 – units need correction.

·         Line 126 – are these optimal conditions to preserve stool samples?

My minor concerns are:

·         Keywords should be listed in alphabetical order, in my opinion.

·         Was there any mechanical homogenization step during sample processing to facilitate DNA extraction?

·         Tables 1 and 2 – suggest placing the data in consecutive order – starting each case from the most prevalent.

·         Tables 1 and 2 –  “Other cancer” definitely needs specification.

·         Figures are mostly eligible.

·         Lack of italics where it should be used.

All the points mentioned above do not decrease the total value of the research.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

·       All abbreviations must be defined when used for the first time.

·       All names of genus and species of microorganisms must be written in italics, e.g. lines 63-64.

·       Give detailed aim of the study.

·       Subtitles in Methods should be numbered.

·       There are some typos in the whole text.

·       How many patients did the experimental group have? How many test groups were there? What about a blind placebo group? It is not clearly presented in the methodology.

·       How stool samples were collected, transported and stored until analysis?

·       Authors should not use unused term “microflora” as there are no plants in the human body, but microbiota or microbiome in relation to human microorganisms.

·       Figures and tables captions are not informative.

·       Figures 3 and 4 are illegible.

·       I miss the Conclusions section. What is the general conclusion of the research conducted?

Author Response

Please see the attachment.

Author Response File: Author Response.docx