PONE-D-24-16781Gut microbial composition is altered in sarcopenia: A systematic review and meta-analysis of clinical studiesPLOS ONE

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Masoud Rahmati

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Dear Editor

This is a good manuscript reviewing “Gut microbial composition is altered in sarcopenia: A systematic review and metaanalysis of clinical studies”. The subject of the manuscript is fully consistent with the aims and scope of the journal « PLOS ONE». The research methodology is fully consistent with the aims declared by the authors. Their conclusions are also consistent with the set goals, however, some issues need to be reconsidered:

- Please explain all abbreviations in the abstract and manuscript.

Abstracts

- Abstract should be informative, did they have any language and publication preference?

- Keywords: are these keywords are Mesh terms? Word that serves as a keyword, as to the meaning of that condition must be a Mesh term

Introduction

-The authors suggest alpha diversity and they did not explain it, because it need to be explained in the context of gut microbiota; Alpha diversity is crucial in gut microbiota studies because it provides insights into the health and stability of the gut ecosystem. A diverse gut microbiome is often associated with better health outcomes, resilience to infections, and overall well-being, while low diversity can be linked to various diseases and conditions, such as inflammatory bowel disease, obesity, and metabolic disorders.

Methods

- What about other source of potential included articles such as grey literatures? Did the authors searched this references?

Results:

- The figure 1 (flowchart of literature search and review) should be presented as the most updated version of 2020

- Table 1 is not informative; it could summarize included studies data.

Discussion

Authors should also acknowledge some serious limitations of the study:

1. the vast majority of studies originated from Eestern countries; thus, extrapolation of these results to Wastern populations is questionable.

2. significant heterogeneity was encountered perhaps due to various regimens, doses, duration, center settings, populations enrolled etc. calling for cautious interpretation of the results. This is a serious limitation and should be included because it may significantly undermine the validity of results.

3. many of the studies suffer from significant sources of bias and this should be also taken into consideration

4. the effect in many occasions was assessed by very few studies; thus, the evidence to support it is low and should be mentioned.

Authors should also include an Appendix section according to the full PRISMA Guidelines checklist, where respective sections of the manuscript are presented.

-The quality of evidence should be evaluated following the GRADE approach.

Reviewer #2: Dear writers

The gut-muscle axis theory has attracted the attention of researchers in recent years, and conducting a meta-analysis study is necessary for general conclusions. Thank you for choosing this topic.

The manuscript is well written, but revise these points to improve it.

1. It is better to focus on the gut-muscle axis in the introduction of the abstract, instead of reporting the problem of increasing the number of studies in recent years. This is a more attractive start.

2. The abstract of each article should express the study. Your conclusion is very general and it is better to be in the context of the investigated variables in the study and related to the subject.

2. The relationship between intestinal microbiota and muscles, as well as its process in sarcopenia, is not well explained in the introduction. The necessity of this study should be properly reported.

3. The results are reported correctly, but the discussion and conclusions are weak and you could have pointed to more communication mechanisms.

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Reviewer #1: No

Reviewer #2: No

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Gut microbial composition is altered in sarcopenia: A systematic review and meta-analysis of clinical studies

PONE-D-24-16781R1

Dear Dr. Chen,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Masoud Rahmati

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: (No Response)

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

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