Review for 10.1186/s12876-024-03384-8 (2024)

Title: The associations between modifiable risk factors and constipation: A comprehensive
Mendelian randomization study
Version: 0 Date: 23 Jun 2024
Reviewer's report:
PEER REVIEWER ASSESSMENTS:
OBJECTIVE - Full research articles: is there a clear objective that addresses a testable research
question(s) (brief or other article types: is there a clear objective)?
Yes - there is a clear objective
DESIGN - Is the current approach (including controls and analysis protocols) appropriate for
the objective?
No - there are minor issues
EXECUTION - Are the experiments and analyses performed with technical rigor to allow
confidence in the results?
No - there are minor issues
STATISTICS - Is the use of statistics in the manuscript appropriate?
Yes - appropriate statistical analyses have been used in the study
INTERPRETATION - Is the current interpretation/discussion of the results reasonable and not
overstated?
No - there are major issues
OVERALL MANUSCRIPT POTENTIAL - Is the current version of this work technically
sound? If not, can revisions be made to make the work technically sound?
Maybe - with major revisions
PEER REVIEWER COMMENTS:
GENERAL COMMENTS: This is the review of the manuscript "The associations between
modifiable risk factors and constipation: A comprehensive Mendelian randomization study". In
this study, authors have used MR analytic framework to dissect causality of the effects of the
genetic predisposition to various modifiable factors on constipation.
As a results, after Bonferroni correction, only predisposition to GERD was shown as causal.
All other factors have demonstrated non-significant trends only. Notably, some of the factors
typically seen as predisposing to constipation did show as tentatively protective, with chief
example being the consumption of beef, while opposite trend was seen for fish. While i had no
opportunity to check original data file, I urge authors to double check if the sign in the respective
tab-delimited file' column was reversed (that inadvertent error did happened to me once).
While i have no problem with statistical analysis presented in this paper, authors should do
the following: 1) BioBank and FinnGEN datasets should be mentioned in M&M section of
the paper, and any other datasets if used. 2) all bacterial species names should be italicized;
3) please check the phrase "However, after adjusting for HDL, low-density lipoprotein (LDL),
and triglycerides, there was no evidence of an association between HDL and constipation."
HDL cannot be adjusted for HDL. 4) authors do not discuss atorvastatin in Results, but
dedicate a lot of Discussion to that. In fact, atorvastatin finding begs the question, why
other statins were not profiles, and whether "any use of statins" should be used as better
characteristic. 5) Finally, authors are correct in saying that nobody simultaneously studied
effects of multiple factors on constipation, but there are many published works showing (or
not showing) effects of separated factors (i.e. depression, blood pressure) on constipation.
Discussion should start with these findings, and whether current study supports or contradicts
recent literature (please see the following as examples PMID: 38806066; PMID: 38701266;
https://pubmed.ncbi.nlm.nih.gov/38046045/)
REQUESTED REVISIONS:
Please see my comments above. This is a good paper that should be improved before publishing.
Please also take good care of the text by subjecting it to professional editing, and reference
verification. use of LLM for text generation is noticeable.
ADDITIONAL REQUESTS/SUGGESTIONS:
please see noticed above