Review for 10.1186/s12876-020-01435-4 (2020)

Reviewer ’s report  
 
Title: The association between inflammatory potential of diet and d isease activity: results from a 
cross -sectional study in patients with inflammatory bowel disease  
 
Version: 0 Date: 16 Jun 2020  
 
Reviewer's report:  
 
Thank you for the opportunity to review this manuscrip t. I have a few comments that the authors 
should consider addressing and would be of interest to the wider reader. Ideally the manuscript 
should provide new data. Other than have a larger sample size the authors have not been able to 
use a larger DII group  of food parameters to others studies nor provide new evidence in this area. 
Not answering questions set out  
 
1. Introduction needs to describe to the reader more about the DII, where it originated 
from, what are the score values - this is not discussed i n the paper other to state a lower score 
reflects anti -inflammatory and higher pro inflammatory.  What are the score ranges, what range 
is considered anti -inflammatory, what is pro -inflammatory etc?  
 
2. The article tries to tie in multiple conclusions that  do not appear to form part of the 
aims of this study. The aims need to be reviewed to reflect the discussion of the paper - eg are 
you comparing between UC and CD as this is not clearly stated in the aims however regularly 
used in the discussion. The role  of supplements forms a part of the discussion however is not 
mentioned as an aim of this study.  
 
3. In regards to the aim it is specified that participant's self -perceived impact of diet on 
disease activity would be investigated. It is not clear how this was measured. There are results 
saying that patients tended to avoid lactose and spicy foods but no discussion in relation to how 
this impacted their perceived disease activity.  
 
4. Methods: please specify the dates over which the data was collected  
 
5. Line 100:  It is not stated which validated questionnaires were provided and what data 
was collected. Please specify and reference these  
 
6. Why was an implausible energy intake an exclusion criteria? Is this due to presumed 
error data collection or entry? Co uld you be potentially excluding patients with IBD who are on 
either intentionally or unintentionally on a low calorie diet and the effect on their DII score and 
potentially their disease activity? Likewise could you be eliminating patients who over consum e 
and the effect of their food intake on disease activity? Is it worth including these 8 patients as a 
subset to review their data and see if there were any correlations noted?  
 
7. Line 115 - how has impact of diet on disease course been validated?  
 
8.  Have the authors considered using other measures of disease inflammation eg. FCP in 
UC, CRP? This would have made an interesting comparison whereby the DII of a diet could 
have been compared to inflammatory markers of IBD.  
 
9. Line 129 -131 requires a referen ce at the end of this sentence  
 
10. Line 133 -136 needs a reference at the end of this sentence  
 
11. How valid are the results when 28 of the 45 parameters are used? Discuss validity of 
the DII when 28/45 parameters used.  List some of the ones not included   line 144 -145  
 
12. Section Dietary intake and inflammatory potential regular repetition of the same 
information for example line 171, 173 and 180 all say the same thing. Line 176 and 182 say the 
same thing in different ways.  
 
13. Line 183 -184 which directi on were the difference noted?  
 
14. Line 189 change has to had  
 
15. Patient reported impact and adaptation of diet:  how has this been assessed/measured? 
What data shows avoiding foods impacted on the course of their disease? Did they avoid because 
they rea d or were told to avoid foods or because they felt it did make a difference to their 
symptoms?  
 
16. Line 193 -196 was the patients reported reduced intake of foods actually reflected in 
their FFQ / dietary analysis. Was the change in diet they made reflecti ve of perceived 
improvements as per your aim? This is not well defined or discussed. What a patient perceives to 
be reduced intake may not be reflected in their actual intake  
 
17. Other than a larger sample size please discuss more clearly how your study ha s bought 
new knowledge to this area of DII, pro and anti -inflammatory diets.  
 
18. Section lines 227 to 232 - on supplements this does not fit the aims of this study and 
does not flow with the topic  
 
19. Line 232 to 234 requires a reference for this statemen t  
 
20. Line 234 to 235 requires a reference for this statement  
 
21. Line 243 : this statement is not supported by your data as your data showed there was 
no  
 
22. Line 274 : would it make sense to have a study designed around recruiting unhealthy 
diets? How  would this be defined and recruited for? I am not sure this is a valid recommendation 
for future research as a criterion for recruitment.  
 
23. It is difficult to use a FFQ of the past months intake and make a correlation to a 
person's disease activity at present, particularly given a large percentage of your patient group 
were in remission.  You would need to assess at different points in time someone's diet and 
disease activity along with other inflammatory markers what the correlation is.  
 
24. Line 292: these questionnaires have not been mentioned previously and it is unclear 
how you have made this correlation without discussing if you have used these measures in your 
study.   
 
25. Conclusion: There was no link of statistical significance found in your stu dy therefore 
you cannot correlate your findings to IBD as a generalised statement.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supporte d by the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
Are you able to assess any statistics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please spe cify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
 
 
 
 
 
 
 
 
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, f ees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publicati on of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation t hat 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 currentl y 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 y es to any, please give details below.  
 
I declare that I have no competing interests' below  
 
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