Review for 10.1186/1471-230X-13-113 (2013)

Reviewer's report
Title:Duodenal microbiota composition and mucosal homeostasis in pediatric
celiac disease
Version: 1Date:29 May 2013
Reviewer: Pirjo Wacklin
Reviewer's report:
Research article “Duodenal microbiota composition and mucosal homeostasis in
pediatric celiac disease “ by Jing Cheng, Marko Kalliomäki, Hans Heilig, Airi
Palva, Hannu Lähteenoja, Willem de Vos, Jarkko Salojärvi and Reetta Satokari
describes differences on microbiota composition and expression of
mucosa-associated genes in pediatric celiac disease patients and controls. In
this well-written manuscript they present results that even major differences in
intestinal microbiota between children with celiac disease and control children
were not observed, CD children and treated CD adults showed altered
expression of proteins related to microbiota-host interaction, in comparison to
controls.
Reviewer's report
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- Major Compulsory Revisions
- Minor Essential Revisions
1. Were controls healthy? or just controls?
2. The controls had different gastrointestinal symptoms and diagnosed diseases,
as they usually have in studies of biopsies. However, the disease of controls may
have effect on duodenal microbiota composition, and further the observation of
the differences between controls and CD groups. Could authors discuss on that?
3. Celiac disease can be manifested by several ways. In addition to
gastrointestinal complaints, eg. dermititis herpetiformis is common symptom (for
other examples see reference 4 of the manuscript). Please, rephrase “Untreated
CD is manifested by…” (Introduction, paragraph1)
4. Is reference 3 correct in Introduction, paragraph1,( line 52) ?
5. Figure 5A and 6A and B shows outlier samples that I suppose were not
included in analysis of data (calculation of mean, SD and statistical tests). In ZO-I
chart, the value of outlier does not seem be very different from other values
(close to SD bar). In CXCR6 chart, TCD group with 6 samples had 2 outlier
samples (33%). Could authors add explanation why these samples were treated
as outliers? Would results change if these samples would not be treated as
outliers?
6. Same reference is used to claim that S. wadsworthensis is potential human
pathogen and that it is part of normal intestinal microbiota. Please, check the
references (Discussion, paragraph 1)
- Discretionary Revisions
1. Could authors explain why this set of mucosa associated genes was selected
for expression analysis?
2. Could qPCR results, published previously by the same authors, and array
based microbiota composition results of current manuscript be compared?
3. In addition to the abundance of Aquabacterium, information its prevalence in
both groups of children could be added (i.e. was it present in all the samples, or
just in few samples with high abundance)(Discussion, paragraph 1).
4. Could codes for samples not working in expression analysis and microbiota
composition analysis be added? Was the same sample failing in both analyses?
5. The expression data for TNF-#, Cx43, MUC2, REGIII# and CXCL16 could be
added on supplement, even the expression levels did not differed between the
study groups
Minor issues not for publication
7. Check the reference 41, should it be 40 or 39? (Line 302)
6. Please, check the legend of figure 2. The chart legend is so small that the
colors in the chart legend are difficult to differentiate.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing financial interests. I have collaborated with
authors in other project (not studies of celiac disease).