Review for 10.1186/s12876-020-01352-6 (2020)

Reviewer ’s report  
 
Title: Evaluation of breath, plasma, and urinary markers of lactose malabsorption to diagnose  
lactase non -persistence following lactose or milk ingestion  
 
Version: 1 Date: 22 Apr 2020  
 
Reviewer: Guy Vergères  
 
Reviewer's report:  
 
The author s have corrected and addressed all the points that were raised in the first critical 
review of the paper. I appreciate the thorough efforts of the authors in these revisions.  
I consider the article in its present form now suitable for publication.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
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 supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess  any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an additional statistical review is recommended, please specify 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:  
 
Acceptab le 
 
 
 
 
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in t he past five years received reimbursements, fees, funding, or salary from an  
organisation that may in any way gain or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you  hold any stocks or shares in an organisation that 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 currently 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 yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be included  
on my report to the authors and, if the manuscript is accepted for publication, my named report  
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which I do not wish to be included in my nam ed report can be included as confidential comments  
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal