Reviewer's report
Title:Comparison of the Gut Microbiota Composition between Obese and
Non-obese Individuals in a Japanese Population, as Analyzed by Terminal
Restriction Fragment Length Polymorphism and Next-generation Sequencing
Version:3Date:7 April 2015
Reviewer: Rajesh Krishnamoorthi
Reviewer's report:
I commend the study authors for their effort. The study investigates a currently
relevant area – relationship between obesity and gut microbiota. My additional
comments are:
1. The study suffers from a small number of subjects in both obese and
non-obese groups. Hence, the reliability of study results may not be high. The
study 'n' drops further in next-generation sequencing groups.
2. The authors need to further clarify the inclusion and exclusion of subjects such
as 'no of patients who underwent colonoscopy between 2012 -2013', 'No of
patients below 65 years', 'no of patients who met each of the exclusion criteria'
etc. This becomes all the more important given the small study 'n'. Addition of a
flow diagram might help.
3. Authors need to clarify if baseline characteristics listed in table 1 were
available in all study subjects. Were there any missing values at all?
4. Authors mention that the difference in age between the obese and non-obese
groups did not influence the results (line 290). Authors should consider providing
that data as supplementary material. In addition, similar analysis need to be
performed for each of the baseline variable that was different between the 2
groups like HbA1c and other laboratory markers.
5. While the authors justify the selection of unconventional BMI cutoffs <20 for
non-obese group and >25 for obese group, generalizability of the current study
results to the western world and comparability with other studies becomes a
significant issue.
6. One of the primary study results is that obese subjects have more bacterial
diversity compared to non-obese group. This is in contrast to previous studies
that have reported lesser diversity in obese subjects. Though the authors
propose that the 'different' BMI cut offs used in the current study could explain
the discrepancy, the small study 'n' could also contribute significantly to the
discrepancy.
7. Parts of discussion are repetitive. References are needed in paragraph 1 of
discussion.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests
Reviewer's report
Title:Comparison of the Gut Microbiota Composition between Obese and
Non-obese Individuals in a Japanese Population, as Analyzed by Terminal
Restriction Fragment Length Polymorphism and Next-generation Sequencing
Version:3Date:7 April 2015
Reviewer: Rajesh Krishnamoorthi
Reviewer's report:
I commend the study authors for their effort. The study investigates a currently
relevant area – relationship between obesity and gut microbiota. My additional
comments are:
1. The study suffers from a small number of subjects in both obese and
non-obese groups. Hence, the reliability of study results may not be high. The
study 'n' drops further in next-generation sequencing groups.
2. The authors need to further clarify the inclusion and exclusion of subjects such
as 'no of patients who underwent colonoscopy between 2012 -2013', 'No of
patients below 65 years', 'no of patients who met each of the exclusion criteria'
etc. This becomes all the more important given the small study 'n'. Addition of a
flow diagram might help.
3. Authors need to clarify if baseline characteristics listed in table 1 were
available in all study subjects. Were there any missing values at all?
4. Authors mention that the difference in age between the obese and non-obese
groups did not influence the results (line 290). Authors should consider providing
that data as supplementary material. In addition, similar analysis need to be
performed for each of the baseline variable that was different between the 2
groups like HbA1c and other laboratory markers.
5. While the authors justify the selection of unconventional BMI cutoffs <20 for
non-obese group and >25 for obese group, generalizability of the current study
results to the western world and comparability with other studies becomes a
significant issue.
6. One of the primary study results is that obese subjects have more bacterial
diversity compared to non-obese group. This is in contrast to previous studies
that have reported lesser diversity in obese subjects. Though the authors
propose that the 'different' BMI cut offs used in the current study could explain
the discrepancy, the small study 'n' could also contribute significantly to the
discrepancy.
7. Parts of discussion are repetitive. References are needed in paragraph 1 of
discussion.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests
Please review this paper.
user
Reviewer's report
Title:Comparison of the Gut Microbiota Composition between Obese and
Non-obese Individuals in a Japanese Population, as Analyzed by Terminal
Restriction Fragment Length Polymorphism and Next-generation Sequencing
Version:3Date:7 April 2015
Reviewer: Rajesh Krishnamoorthi
Reviewer's report:
I commend the study authors for their effort. The study investigates a currently
relevant area – relationship between obesity and gut microbiota. My additional
comments are:
1. The study suffers from a small number of subjects in both obese and
non-obese groups. Hence, the reliability of study results may not be high. The
study 'n' drops further in next-generation sequencing groups.
2. The authors need to further clarify the inclusion and exclusion of subjects such
as 'no of patients who underwent colonoscopy between 2012 -2013', 'No of
patients below 65 years', 'no of patients who met each of the exclusion criteria'
etc. This becomes all the more important given the small study 'n'. Addition of a
flow diagram might help.
3. Authors need to clarify if baseline characteristics listed in table 1 were
available in all study subjects. Were there any missing values at all?
4. Authors mention that the difference in age between the obese and non-obese
groups did not influence the results (line 290). Authors should consider providing
that data as supplementary material. In addition, similar analysis need to be
performed for each of the baseline variable that was different between the 2
groups like HbA1c and other laboratory markers.
5. While the authors justify the selection of unconventional BMI cutoffs <20 for
non-obese group and >25 for obese group, generalizability of the current study
results to the western world and comparability with other studies becomes a
significant issue.
6. One of the primary study results is that obese subjects have more bacterial
diversity compared to non-obese group. This is in contrast to previous studies
that have reported lesser diversity in obese subjects. Though the authors
propose that the 'different' BMI cut offs used in the current study could explain
the discrepancy, the small study 'n' could also contribute significantly to the
discrepancy.
7. Parts of discussion are repetitive. References are needed in paragraph 1 of
discussion.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests
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