Title: COLONIC BACTERIAL DIVERSITY AND DYSBIOSIS IN ACTIVE
MICROSCOPIC COLITIS AS COMPARED TO CHRONIC DIARRHOEA AND HEALTHY
CONTROLS: EFFECT OF POLYETHYLENE GLYCOL AFTER BOWEL LAVAGE FOR
COLONOSCOPY
Version: 2 Date: 06 May 2022
Reviewer's report:
The main objective of the authors in this work was to assess the effect of polyethylene glycol
colonic lavage on clinical remission, microbial diversity , dysbiosis and diversity in patient with
microscopic colitis (MC). The area of the work is interesting and of clinical  importance. The
manuscript is well written, includes important controls (non-MC) and statistical parameters. The
methodology used is relevant and is of state-of-the art. The authors have included 55 patients
of MC, along with relevant controls of other diarrheal diseases and healthy volunteer subjects.
However, the findings (the differences between MC and non-MC) are very subtle, and that
comes as a general weakness of this work. While the study reveals a few subtle differences
between MC and non-MC patients, in most cases there isn’t much change. For instance, there
were no differences between MC and non-MC subjects in case of the Baseline Shannon Index
of microbial diversity. In case of dysbiosis, no bacterial species showed a significantly different
relative abundance among the diarrheal groups. No PEG-induced changes were found in faecal
microbiome. Nevertheless, considering the overall importance of the field the work may be
considered for publication only if the following weaknesses are addressed:
1. The clinical remission data 53% in MC versus 32% of non-MC is interesting but the
confidence level is not remarkable, increasing the sample size may be helpful.
2. There is lack of clarity of the rationale behind choosing the sample size in this study. Clear
description of the sample size calculation and statistical justification would  be helpful.
3. Addition of PCA of Shannon index would have strengthened the importance of diversity  in
various diseases included in context dependent manner.
4. It is unclear if in all cases post colonoscopy the patients were free of drugs/therapeutics and
similar diet. This should be clearly defined and in case the enrolment excluded those undergoing
any therapy post endoscopy, the same should be part of the exclusion criterion
5. All the figure legend description requires more details along with a suitable caption.
6. The human ethical clearance protocol number, the biosafety clearance protocol number should
be provided
7. All taxonomic names (genus and species) provided in tables (1-3) should be italicized
Title: COLONIC BACTERIAL DIVERSITY AND DYSBIOSIS IN ACTIVE
MICROSCOPIC COLITIS AS COMPARED TO CHRONIC DIARRHOEA AND HEALTHY
CONTROLS: EFFECT OF POLYETHYLENE GLYCOL AFTER BOWEL LAVAGE FOR
COLONOSCOPY
Version: 2 Date: 06 May 2022
Reviewer's report:
The main objective of the authors in this work was to assess the effect of polyethylene glycol
colonic lavage on clinical remission, microbial diversity , dysbiosis and diversity in patient with
microscopic colitis (MC). The area of the work is interesting and of clinical  importance. The
manuscript is well written, includes important controls (non-MC) and statistical parameters. The
methodology used is relevant and is of state-of-the art. The authors have included 55 patients
of MC, along with relevant controls of other diarrheal diseases and healthy volunteer subjects.
However, the findings (the differences between MC and non-MC) are very subtle, and that
comes as a general weakness of this work. While the study reveals a few subtle differences
between MC and non-MC patients, in most cases there isn’t much change. For instance, there
were no differences between MC and non-MC subjects in case of the Baseline Shannon Index
of microbial diversity. In case of dysbiosis, no bacterial species showed a significantly different
relative abundance among the diarrheal groups. No PEG-induced changes were found in faecal
microbiome. Nevertheless, considering the overall importance of the field the work may be
considered for publication only if the following weaknesses are addressed:
1. The clinical remission data 53% in MC versus 32% of non-MC is interesting but the
confidence level is not remarkable, increasing the sample size may be helpful.
2. There is lack of clarity of the rationale behind choosing the sample size in this study. Clear
description of the sample size calculation and statistical justification would  be helpful.
3. Addition of PCA of Shannon index would have strengthened the importance of diversity  in
various diseases included in context dependent manner.
4. It is unclear if in all cases post colonoscopy the patients were free of drugs/therapeutics and
similar diet. This should be clearly defined and in case the enrolment excluded those undergoing
any therapy post endoscopy, the same should be part of the exclusion criterion
5. All the figure legend description requires more details along with a suitable caption.
6. The human ethical clearance protocol number, the biosafety clearance protocol number should
be provided
7. All taxonomic names (genus and species) provided in tables (1-3) should be italicized
Please review this paper.
user
Title: COLONIC BACTERIAL DIVERSITY AND DYSBIOSIS IN ACTIVE
MICROSCOPIC COLITIS AS COMPARED TO CHRONIC DIARRHOEA AND HEALTHY
CONTROLS: EFFECT OF POLYETHYLENE GLYCOL AFTER BOWEL LAVAGE FOR
COLONOSCOPY
Version: 2 Date: 06 May 2022
Reviewer's report:
The main objective of the authors in this work was to assess the effect of polyethylene glycol
colonic lavage on clinical remission, microbial diversity , dysbiosis and diversity in patient with
microscopic colitis (MC). The area of the work is interesting and of clinical  importance. The
manuscript is well written, includes important controls (non-MC) and statistical parameters. The
methodology used is relevant and is of state-of-the art. The authors have included 55 patients
of MC, along with relevant controls of other diarrheal diseases and healthy volunteer subjects.
However, the findings (the differences between MC and non-MC) are very subtle, and that
comes as a general weakness of this work. While the study reveals a few subtle differences
between MC and non-MC patients, in most cases there isn’t much change. For instance, there
were no differences between MC and non-MC subjects in case of the Baseline Shannon Index
of microbial diversity. In case of dysbiosis, no bacterial species showed a significantly different
relative abundance among the diarrheal groups. No PEG-induced changes were found in faecal
microbiome. Nevertheless, considering the overall importance of the field the work may be
considered for publication only if the following weaknesses are addressed:
1. The clinical remission data 53% in MC versus 32% of non-MC is interesting but the
confidence level is not remarkable, increasing the sample size may be helpful.
2. There is lack of clarity of the rationale behind choosing the sample size in this study. Clear
description of the sample size calculation and statistical justification would  be helpful.
3. Addition of PCA of Shannon index would have strengthened the importance of diversity  in
various diseases included in context dependent manner.
4. It is unclear if in all cases post colonoscopy the patients were free of drugs/therapeutics and
similar diet. This should be clearly defined and in case the enrolment excluded those undergoing
any therapy post endoscopy, the same should be part of the exclusion criterion
5. All the figure legend description requires more details along with a suitable caption.
6. The human ethical clearance protocol number, the biosafety clearance protocol number should
be provided
7. All taxonomic names (genus and species) provided in tables (1-3) should be italicized
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