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: 0 Date: 15 Jan 2020  
 
Reviewer: Veronica Ojetti  
 
Reviewer's report:  
 
Amber Milan et al performed a very interesting paper on the Evaluation of breath, plasma, and 
urinary markers of lactose malabsorption to diagnose lactase non -persistence following lactose 
or mil k ingestion.  
This is a very good point even if other paper suggested that the use of lactose in better than milk.  
 
It would be interesting to know in which ambulatory you have recruited these patients.  
why did you select such a young population  
The number  of patients is very small and you compare 30 symptomatic with 10 
asyntomptomatic.  
 
it would be interesting to know how did you convinced asymptomatic patients to carry out non -
invasive and invasive tests (repeated blood samples)  
in clinical practice this is very difficult without a financial support  
 
Why did you use the dose of 50 gr of lactose (very high) and not the standard 25 gr.  
Ghoshal UC1, Kumar S, Misra A, Mittal B.J Gastroenterol Hepatol. 2013 Sep;28(9):1462 -8. 
Lactose malabsorption diagnosed by 50 -g dose is inferior to assess clinical intolerance and to 
predict response to milk withdrawal than 25 -g dose in an endemic area  
Di Rienzo T1, D'Angelo G, D'Aversa F, Campanale MC, Cesario V, Montalto M, Gasbarrini A, 
Ojetti V. Eur Rev Med Pharmacol Sci. 2013;17 Suppl 2:18 -25. 
Lactose intolerance: from diagnosis to correct management.  
 
The sample collected during the lactose breath tes t that does not follow the guidelines (air 
collection every 30 minutes for 4 hours, 3 hours in children)  
 
 
 
 
 
 
 
 
 
 
 
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.  
 
No 
 
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 recommend additional st atistical review  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
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  
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below.  If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests'  
 
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