Reviewer’s report
Title: 
The effects of preoperative intestinal dysbacteriosis on postoperative
recovery in colorectal cancer surgery: a prospective cohort study
Version: 
0 
Date: 
21 May 2021
Reviewer's report:
The authors describe a single-centre prospective observational study of patients
undergoing operations for colorectal tumours. Microbiological profiles of patient
faecal samples were taken before and after the operation and classified according
to the distribution of organisms in the faecal samples, along with records of post-
operative complications. 
This could be an interesting observational report but requires some, reasonably
substantial, modifications. 
There are detailed notes below, but I believe the main priorities are:
- I would recommend using the STROBE framework to ensure that all the
relevant study details are reported clearly and transparently,
- The inclusion & exclusion criteria should be reported clearly and specifically,
- The statistical methods require attention to ensure analysis is properly justified
and related clearly to the intended investigation.
I would also suggest that this should be reviewed by someone with expertise in
colorectal surgery and/or clinical microbiology. 
There are also issues with the grammar throughout that occasionally impede
understanding.
Introduction
There are some examples of the grammar and structure issues in the first
paragraph. Infections could be some of the most common complications and yet
still not occur in many patients. 
Methods
The cohort definition could be tightened up to better clarify the included
population. For example, it would be preferable to see the specifics of
classification as "colorectal cancer surgery". Did this include specific procedures
(as opposed to those excluded)? Were patients required to have a recorded
cancer diagnosis prior to the surgery, and how was this identified (e.g. ICD
codes, referral to the study from specialist clinics)?
The stated endpoints should be more specific. Additionally, are these intended to
be outcomes or endpoints?
Was the upper age limit an inclusion criteria or is this just how the age of the
included patients was distributed?
The section detailing the dysbiosis score would be better presented as bullet
points or a table, it is quite hard to follow as it is now. Listing grade 0 as item 1
is confusing.
In general, it is unclear whether patient data has come from patient records or
was recorded specifically for the study.
Results
In the section "correlation of pre-operative dysbacteriosis and short term
outcomes", I'm not clear what statistical test the results presented are from.
Please do not report "P=0.00", this value will have been rounded by your
statistical software. 
I'm not sure I understand why other post-operative complications (diarrhoea,
hypoalbuminaemia, etc.) are included in the model of post-operative infectious
complications? If patients were followed for 30 days, these complications could
have occurred after the infectious complication (unless perhaps only those
occurring before infection were included, but this is not stated if so). They may
also be affected by dysbiosis themselves. Either way I am not sure that this is the
most appropriate way to build this model. 
I feel the reporting of the assessment of the stool examination should come
earlier on, as it is important context for the results section. 
A clinical reviewer may be able to advise better, but might the results for patients
with colon and rectal cancer be better assessed separately? The rate of
neoadjuvant therapy for example would be expected to differ by primary cancer
site. 
How were the co-morbidities reported in table 1 selected, and how were patients
classified?
Adding a "totals" column to table 1 would be useful, to report the distribution of
these key characteristics across the whole population. 
What are the ranges reported for the time using antibiotics and length of stay in
table 3?
Publons Reviewer Recognition
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review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
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profile page. Publons may use the Review Data to generate derivative metadata
for the benefit of Publons and you as a reviewer, carefully considering the
sensitivity of such information. For example, Publons may verify your record as
a reviewer by updating your profile published on its webservice if you have
registered for such service or help editors to identify candidate reviewers. Please
find the details of processing in Publons’ privacy policy
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Yes
Declaration of competing interests
Please complete a declaration of competing
interests, considering the following questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I declare that I have no competing interests.
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the
editorial office before completing the review.
If you wish, you can include your
name in your published report. Please note you must decide whether to include
your name at the start of the process and confirm this decision whenever
prompted. If you change your decision later, we will not be able to publish your
name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
No
Are the methods sufficiently described to allow the study to be repeated?
No
Is the use of statistics and treatment of uncertainties appropriate?
No
Is the presentation of the work clear?
No
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes
Reviewer’s report
Title: 
The effects of preoperative intestinal dysbacteriosis on postoperative
recovery in colorectal cancer surgery: a prospective cohort study
Version: 
0 
Date: 
21 May 2021
Reviewer's report:
The authors describe a single-centre prospective observational study of patients
undergoing operations for colorectal tumours. Microbiological profiles of patient
faecal samples were taken before and after the operation and classified according
to the distribution of organisms in the faecal samples, along with records of post-
operative complications. 
This could be an interesting observational report but requires some, reasonably
substantial, modifications. 
There are detailed notes below, but I believe the main priorities are:
- I would recommend using the STROBE framework to ensure that all the
relevant study details are reported clearly and transparently,
- The inclusion & exclusion criteria should be reported clearly and specifically,
- The statistical methods require attention to ensure analysis is properly justified
and related clearly to the intended investigation.
I would also suggest that this should be reviewed by someone with expertise in
colorectal surgery and/or clinical microbiology. 
There are also issues with the grammar throughout that occasionally impede
understanding.
Introduction
There are some examples of the grammar and structure issues in the first
paragraph. Infections could be some of the most common complications and yet
still not occur in many patients. 
Methods
The cohort definition could be tightened up to better clarify the included
population. For example, it would be preferable to see the specifics of
classification as "colorectal cancer surgery". Did this include specific procedures
(as opposed to those excluded)? Were patients required to have a recorded
cancer diagnosis prior to the surgery, and how was this identified (e.g. ICD
codes, referral to the study from specialist clinics)?
The stated endpoints should be more specific. Additionally, are these intended to
be outcomes or endpoints?
Was the upper age limit an inclusion criteria or is this just how the age of the
included patients was distributed?
The section detailing the dysbiosis score would be better presented as bullet
points or a table, it is quite hard to follow as it is now. Listing grade 0 as item 1
is confusing.
In general, it is unclear whether patient data has come from patient records or
was recorded specifically for the study.
Results
In the section "correlation of pre-operative dysbacteriosis and short term
outcomes", I'm not clear what statistical test the results presented are from.
Please do not report "P=0.00", this value will have been rounded by your
statistical software. 
I'm not sure I understand why other post-operative complications (diarrhoea,
hypoalbuminaemia, etc.) are included in the model of post-operative infectious
complications? If patients were followed for 30 days, these complications could
have occurred after the infectious complication (unless perhaps only those
occurring before infection were included, but this is not stated if so). They may
also be affected by dysbiosis themselves. Either way I am not sure that this is the
most appropriate way to build this model. 
I feel the reporting of the assessment of the stool examination should come
earlier on, as it is important context for the results section. 
A clinical reviewer may be able to advise better, but might the results for patients
with colon and rectal cancer be better assessed separately? The rate of
neoadjuvant therapy for example would be expected to differ by primary cancer
site. 
How were the co-morbidities reported in table 1 selected, and how were patients
classified?
Adding a "totals" column to table 1 would be useful, to report the distribution of
these key characteristics across the whole population. 
What are the ranges reported for the time using antibiotics and length of stay in
table 3?
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons after the final decision on the manuscript has been made. If you have
already registered at Publons, they will notify you of the receipt of this review
and update your profile 
as per your settings and their policy. If you are not
registered with Publons, you will receive an email from them asking you to
register in order for them to be able to recognize your review on your new
profile page. Publons may use the Review Data to generate derivative metadata
for the benefit of Publons and you as a reviewer, carefully considering the
sensitivity of such information. For example, Publons may verify your record as
a reviewer by updating your profile published on its webservice if you have
registered for such service or help editors to identify candidate reviewers. Please
find the details of processing in Publons’ privacy policy
https://publons.com/about/terms
Yes
Declaration of competing interests
Please complete a declaration of competing
interests, considering the following questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I declare that I have no competing interests.
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the
editorial office before completing the review.
If you wish, you can include your
name in your published report. Please note you must decide whether to include
your name at the start of the process and confirm this decision whenever
prompted. If you change your decision later, we will not be able to publish your
name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
No
Are the methods sufficiently described to allow the study to be repeated?
No
Is the use of statistics and treatment of uncertainties appropriate?
No
Is the presentation of the work clear?
No
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes
Please review this paper.
user
Reviewer’s report
Title: 
The effects of preoperative intestinal dysbacteriosis on postoperative
recovery in colorectal cancer surgery: a prospective cohort study
Version: 
0 
Date: 
21 May 2021
Reviewer's report:
The authors describe a single-centre prospective observational study of patients
undergoing operations for colorectal tumours. Microbiological profiles of patient
faecal samples were taken before and after the operation and classified according
to the distribution of organisms in the faecal samples, along with records of post-
operative complications. 
This could be an interesting observational report but requires some, reasonably
substantial, modifications. 
There are detailed notes below, but I believe the main priorities are:
- I would recommend using the STROBE framework to ensure that all the
relevant study details are reported clearly and transparently,
- The inclusion & exclusion criteria should be reported clearly and specifically,
- The statistical methods require attention to ensure analysis is properly justified
and related clearly to the intended investigation.
I would also suggest that this should be reviewed by someone with expertise in
colorectal surgery and/or clinical microbiology. 
There are also issues with the grammar throughout that occasionally impede
understanding.
Introduction
There are some examples of the grammar and structure issues in the first
paragraph. Infections could be some of the most common complications and yet
still not occur in many patients. 
Methods
The cohort definition could be tightened up to better clarify the included
population. For example, it would be preferable to see the specifics of
classification as "colorectal cancer surgery". Did this include specific procedures
(as opposed to those excluded)? Were patients required to have a recorded
cancer diagnosis prior to the surgery, and how was this identified (e.g. ICD
codes, referral to the study from specialist clinics)?
The stated endpoints should be more specific. Additionally, are these intended to
be outcomes or endpoints?
Was the upper age limit an inclusion criteria or is this just how the age of the
included patients was distributed?
The section detailing the dysbiosis score would be better presented as bullet
points or a table, it is quite hard to follow as it is now. Listing grade 0 as item 1
is confusing.
In general, it is unclear whether patient data has come from patient records or
was recorded specifically for the study.
Results
In the section "correlation of pre-operative dysbacteriosis and short term
outcomes", I'm not clear what statistical test the results presented are from.
Please do not report "P=0.00", this value will have been rounded by your
statistical software. 
I'm not sure I understand why other post-operative complications (diarrhoea,
hypoalbuminaemia, etc.) are included in the model of post-operative infectious
complications? If patients were followed for 30 days, these complications could
have occurred after the infectious complication (unless perhaps only those
occurring before infection were included, but this is not stated if so). They may
also be affected by dysbiosis themselves. Either way I am not sure that this is the
most appropriate way to build this model. 
I feel the reporting of the assessment of the stool examination should come
earlier on, as it is important context for the results section. 
A clinical reviewer may be able to advise better, but might the results for patients
with colon and rectal cancer be better assessed separately? The rate of
neoadjuvant therapy for example would be expected to differ by primary cancer
site. 
How were the co-morbidities reported in table 1 selected, and how were patients
classified?
Adding a "totals" column to table 1 would be useful, to report the distribution of
these key characteristics across the whole population. 
What are the ranges reported for the time using antibiotics and length of stay in
table 3?
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons after the final decision on the manuscript has been made. If you have
already registered at Publons, they will notify you of the receipt of this review
and update your profile 
as per your settings and their policy. If you are not
registered with Publons, you will receive an email from them asking you to
register in order for them to be able to recognize your review on your new
profile page. Publons may use the Review Data to generate derivative metadata
for the benefit of Publons and you as a reviewer, carefully considering the
sensitivity of such information. For example, Publons may verify your record as
a reviewer by updating your profile published on its webservice if you have
registered for such service or help editors to identify candidate reviewers. Please
find the details of processing in Publons’ privacy policy
https://publons.com/about/terms
Yes
Declaration of competing interests
Please complete a declaration of competing
interests, considering the following questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I declare that I have no competing interests.
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the
editorial office before completing the review.
If you wish, you can include your
name in your published report. Please note you must decide whether to include
your name at the start of the process and confirm this decision whenever
prompted. If you change your decision later, we will not be able to publish your
name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
No
Are the methods sufficiently described to allow the study to be repeated?
No
Is the use of statistics and treatment of uncertainties appropriate?
No
Is the presentation of the work clear?
No
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes
assistant