Title: Plasma and fecal zonulin are not altered by a high green leafy vegetable dietary
intervention: secondary analysis of a randomized control crossover trial.
Version: 2 Date: 31 Oct 2021
Reviewer's report:
This is an interesting sub-analysis of a randomized controlled trial that measured the response
to high green leafy vegetables on several biological domains. However, this study's statistical
analysis, results, and conclusions need to be substantially revised. Furthermore, I don't think that
it is possible to infer on sex differences in this specific design. Due to the small sample size and
talking account, this was not the pre-defined analysis and/or outcome of this study.
Headline: Sex is written in the headline while gender is being used along the ms.
Introduction:
P2L46-49 It is essential to mention the implication that has been suggested in the mentioned
medical conditions and or disease.
P3L72-76 Several diets have been shown to reduce zonulin levels. It is important to review those
entities and to explain why the current intervention was selected.
Methods:
The methodical part of the intervention is written clearly and allows for replication.
I didn't see any sample size or power calculation (if this is a secondary analysis).
In my opinion, the outline of the intervention (M3G protocol) should move to the main ms.
Statistical analysis:
Accounting for the small size, it is more appropriate to use non-parametric tests instead of t-tests.
It is not clear where Bonferroni correction was used.
Results:
P7L162-169 – Analysis of correlations by sex is inappropriate in this small sample size.
I did not see any description of changes in anthropometric measurement. However, weight loss
has been shown to induce changes in inflammatory markers and microbiome.
Table 1 and 2:
Again, some of the variables are not normally distributed, and it would be better to present them
as medians and IQR.
Figure 2:
Were these correlations corrected for multiple testing? If so, how many comparisons?
Table 3 – same comment as in table 1 and 2.
Discussion:
P11L239-241 – Changes in anthropometric measurements within subjects should be added to
the results.
P11L234-241 – These are strengths and limitations of this study and should be moved to the
relevant section accordingly.
Conclusion:
I think it is not possible to conclude on sex differences in this experimental design
Title: Plasma and fecal zonulin are not altered by a high green leafy vegetable dietary
intervention: secondary analysis of a randomized control crossover trial.
Version: 2 Date: 31 Oct 2021
Reviewer's report:
This is an interesting sub-analysis of a randomized controlled trial that measured the response
to high green leafy vegetables on several biological domains. However, this study's statistical
analysis, results, and conclusions need to be substantially revised. Furthermore, I don't think that
it is possible to infer on sex differences in this specific design. Due to the small sample size and
talking account, this was not the pre-defined analysis and/or outcome of this study.
Headline: Sex is written in the headline while gender is being used along the ms.
Introduction:
P2L46-49 It is essential to mention the implication that has been suggested in the mentioned
medical conditions and or disease.
P3L72-76 Several diets have been shown to reduce zonulin levels. It is important to review those
entities and to explain why the current intervention was selected.
Methods:
The methodical part of the intervention is written clearly and allows for replication.
I didn't see any sample size or power calculation (if this is a secondary analysis).
In my opinion, the outline of the intervention (M3G protocol) should move to the main ms.
Statistical analysis:
Accounting for the small size, it is more appropriate to use non-parametric tests instead of t-tests.
It is not clear where Bonferroni correction was used.
Results:
P7L162-169 – Analysis of correlations by sex is inappropriate in this small sample size.
I did not see any description of changes in anthropometric measurement. However, weight loss
has been shown to induce changes in inflammatory markers and microbiome.
Table 1 and 2:
Again, some of the variables are not normally distributed, and it would be better to present them
as medians and IQR.
Figure 2:
Were these correlations corrected for multiple testing? If so, how many comparisons?
Table 3 – same comment as in table 1 and 2.
Discussion:
P11L239-241 – Changes in anthropometric measurements within subjects should be added to
the results.
P11L234-241 – These are strengths and limitations of this study and should be moved to the
relevant section accordingly.
Conclusion:
I think it is not possible to conclude on sex differences in this experimental design
Please review this paper.
user
Title: Plasma and fecal zonulin are not altered by a high green leafy vegetable dietary
intervention: secondary analysis of a randomized control crossover trial.
Version: 2 Date: 31 Oct 2021
Reviewer's report:
This is an interesting sub-analysis of a randomized controlled trial that measured the response
to high green leafy vegetables on several biological domains. However, this study's statistical
analysis, results, and conclusions need to be substantially revised. Furthermore, I don't think that
it is possible to infer on sex differences in this specific design. Due to the small sample size and
talking account, this was not the pre-defined analysis and/or outcome of this study.
Headline: Sex is written in the headline while gender is being used along the ms.
Introduction:
P2L46-49 It is essential to mention the implication that has been suggested in the mentioned
medical conditions and or disease.
P3L72-76 Several diets have been shown to reduce zonulin levels. It is important to review those
entities and to explain why the current intervention was selected.
Methods:
The methodical part of the intervention is written clearly and allows for replication.
I didn't see any sample size or power calculation (if this is a secondary analysis).
In my opinion, the outline of the intervention (M3G protocol) should move to the main ms.
Statistical analysis:
Accounting for the small size, it is more appropriate to use non-parametric tests instead of t-tests.
It is not clear where Bonferroni correction was used.
Results:
P7L162-169 – Analysis of correlations by sex is inappropriate in this small sample size.
I did not see any description of changes in anthropometric measurement. However, weight loss
has been shown to induce changes in inflammatory markers and microbiome.
Table 1 and 2:
Again, some of the variables are not normally distributed, and it would be better to present them
as medians and IQR.
Figure 2:
Were these correlations corrected for multiple testing? If so, how many comparisons?
Table 3 – same comment as in table 1 and 2.
Discussion:
P11L239-241 – Changes in anthropometric measurements within subjects should be added to
the results.
P11L234-241 – These are strengths and limitations of this study and should be moved to the
relevant section accordingly.
Conclusion:
I think it is not possible to conclude on sex differences in this experimental design
assistant