Review for 10.1186/s12876-021-01776-8 (2021)

Reviewer’s report
Title: 
Measurement of fasting breath hydrogen concentration as a simple
diagnostic method for pancreatic exocrine insufficiency
Version: 
0 
Date: 
18 Mar 2021
Reviewer's report:
1. The author's experimental design is reasonable, and the data are persuasive.
The author proposes a simple method for PEI diagnosis. But for this method I
have the following questions. In clinic, according to the patient's medical history,
for patients with suspected PEI, 
pancreatin replacement therapy can be used for
4-6 weeks experimentally. If the symptoms improved, it can be diagnosed the
PEI. Compared with the examination method proposed by the author, is this
more timely and convenient for patients? What does the author think about this?
2.At present, we commonly use Faecal Elastase 1 detection (FE-1). When its
content is less than 200ug/g, it indicates the presence of PEI. FE-1 is secreted by
the pancreas and is not decomposed in the intestine. It is completely excreted in
feces. The test results are not affected by exogenous pancreatin. The FE-1 test is
convenient and suitable for PEI screening and long-term follow-up of confirmed
patients. What are the advantages of the author's method and our commonly used
methods? Has the author compared the advantages of indirect experiments such
as FBHC and 13C-MTG-BT? The author should compare the advantages of
FBHC with other indirect tests in the discussion.
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons after the final decision on the manuscript has been made. If you have
already registered at Publons, they will notify you of the receipt of this review
and update your profile 
as per your settings and their policy. If you are not
registered with Publons, you will receive an email from them asking you to
register in order for them to be able to recognize your review on your new
profile page. Publons may use the Review Data to generate derivative metadata
for the benefit of Publons and you as a reviewer, carefully considering the
sensitivity of such information. For example, Publons may verify your record as
a reviewer by updating your profile published on its webservice if you have
registered for such service or help editors to identify candidate reviewers. Please
find the details of processing in Publons’ privacy policy
https://publons.com/about/terms
No
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, 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
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the
editorial office before completing the review.
If you wish, you can include your
name in your published report. Please note you must decide whether to include
your name at the start of the process and confirm this decision whenever
prompted. If you change your decision later, we will not be able to publish your
name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
Yes
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes