Hydrogen and Methane Breath Test in the Diagnosis of Lactose Intolerance

Round 1

Reviewer 1 Report

Considering the significant impact of this journal, I kindly suggest to add more detailed information about the sample:

• where the sample was collected;
• details about the clinical conditions of this sample (for example, celiac patients were excluded?)
• pre-test conditions according to the Rome consensus conference of 2009;
• documentation of clinical symptoms.
• you can add more details about the treatment of positive patients (for example, how long was the lactose-free diet treatment?)

Author Response

 

 

Reviewer 1

We thank the reviewer for the positive and constructive comments. All suggestions were considered in the revised version.

·         Where the sample was collected	Added
Details about the clinical conditions of this sample (for example, celiac patients were excluded?)	Information added
Pre-test conditions according to the Rome consensus conference of 2009;	Added
·         Documentation of clinical symptoms.	Information added
You can add more details about the treatment of positive patients (for example, how long was the lactose-free diet treatment?)	Information added

 

Reviewer 2 Report

The authors of the present work aimed to evaluate the interest of H2 and CH4 breath test in the diagnosis of lactose intolerance in the infant population.

The study design is well described and the number of participants could be enough to stablish some preliminary results. As the authors recognized, this is a pilot study and they have some limitations such as the lack of a blinded lactose challenge, giving to a possible placebo effect.

Statistical analysis is adequate and results are presented in a understandable way and discussion, except for a few paragraphs, is easy to follow.

Nevertheless, the major shortcoming of this research is the lack of originality.

Other works published, even in this journal, sought the same objective and already published the main similar conclusions. For examples, Houben et al (2015): Additional Value of CH₄ Measurement in a Combined (13)C/H₂ Lactose Malabsorption Breath Test: A Retrospective Analysis. Nutrients. 2015 Sep 7;7(9):7469-85. doi: 10.3390/nu7095348; Peron et al (2018)

Retrospective analysis of a lactose breath test in a gastrointestinal symptomatic population of Northeast Italy: use of (H 2+2CH 4) versus H 2 threshold. Clin Exp Gastroenterol.2018 Jun 18;11:243-248.  doi: 10.2147/CEG.S163962.

 

Discussion is well structured but there it is some points may be improved:

-Other reasons such as SIBO, Non-celiac gluten sensitivity (NCSG) could be responsible of CH4 and H2 production. Some explanation have been included about this issue but we don’t know if the authors have taking into account these other pathologies in the anamnesis.

- One cause of the transient lack of lactase is the inflammation caused by, e.g. celiac disease.  Have the authors discarded that the participating children had celiac disease?

 

Although the data obtained by the authors contribute to the idea of including the methane breath test as an indicator of lactose intolerance, to improve the novelty of the work they should provide something additional to what has already been published.

Author Response

 

Reviewer 2

 

We thank the reviewer for the constructive suggestions to further improve our manuscript. All suggestions were included in the revised manuscript.

Nevertheless, the major shortcoming of this research is the lack of originality. Other works published, even in this journal, sought the same objective and already published the main similar conclusions. For examples, Houben et al (2015): Additional Value of CH₄ Measurement in a Combined (13)C/H₂ Lactose Malabsorption Breath Test: A Retrospective Analysis. Nutrients. 2015 Sep 7;7(9):7469-85. doi: 10.3390/nu7095348; Peron et al (2018) Retrospective analysis of a lactose breath test in a gastrointestinal symptomatic population of Northeast Italy: use of (H 2+2CH 4) versus H 2 threshold. Clin Exp Gastroenterol.2018 Jun 18;11:243-248.  doi: 10.2147/CEG.S163962.	Both papers are added to the references and discussed.
Other reasons such as SIBO, Non-celiac gluten sensitivity (NCSG) could be responsible of CH4 and H2 production. Some explanation have been included about this issue but we don’t know if the authors have taking into account these other pathologies in the anamnesis.	We included additional information in the methods section.
- One cause of the transient lack of lactase is the inflammation caused by, e.g. celiac disease.  Have the authors discarded that the participating children had celiac disease?	Celiac disease and other conditions causing secondary hypolactasia were excluded; This information is added.
Although the data obtained by the authors contribute to the idea of including the methane breath test as an indicator of lactose intolerance, to improve the novelty of the work they should provide something additional to what has already been published	The determination of methane is still debated in literature, and is certainly not done in routine since many devices only measure H2. The fact that our study adds information to the existing literature that methane measurement is of additional value was added to the conclusion.

 

Round 2

Reviewer 2 Report

The authors have clarified many of the issues that have been questioned. The new test has improved but moderate English changes are required.