Reviewer's report
Title:Tryptophan degradation in Irritable Bowel Syndrome: Evidence of
indoleamine 2,3-dioxygenase activation in a male cohort.
Version: 1Date:31 July 2008
Reviewer: John Potokar
Reviewer's report:
This is a fairly straightforward small study that compares levels of tryptophan
metabolites in 10 male IBS patients compared with 26 controls. It is an
“investigative” study rather than a clear hypothesis driven research study, but the
findings are nonetheless intriguing, and the discussion attempts to integrate and
synthesise the results with what is know re IBS together with stress induced 5-HT
metabolism.
The methods appear reasonable, but it is not clear why there were only 10 IBS
patients and 26 controls. Was the study powered for just 10 patients and what
was this sample size based on? The IBS group is much older [48 vs 32] and
neither groups are adequately described - this needs to be addressed before
publication. Were their any age associated confounders that might be relevant?
Were any of either group on serotonergic medication? Were their differences in
smoking between the 2 groups (IDO activity is reduced in smokers). Where were
the controls recruited from?
The manuscript is well written, with only the odd typo e.g. p9 last sentence
remove “there”. The discussion is reasonably clear although on p11 I am not
clear how this study clarifies that if the increased tryptophan degradation is IDO
dependent, the knock on consequences for serotonergic signalling are greater
than if it is TDO-mediated.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
Reviewer's report
Title:Tryptophan degradation in Irritable Bowel Syndrome: Evidence of
indoleamine 2,3-dioxygenase activation in a male cohort.
Version: 1Date:31 July 2008
Reviewer: John Potokar
Reviewer's report:
This is a fairly straightforward small study that compares levels of tryptophan
metabolites in 10 male IBS patients compared with 26 controls. It is an
“investigative” study rather than a clear hypothesis driven research study, but the
findings are nonetheless intriguing, and the discussion attempts to integrate and
synthesise the results with what is know re IBS together with stress induced 5-HT
metabolism.
The methods appear reasonable, but it is not clear why there were only 10 IBS
patients and 26 controls. Was the study powered for just 10 patients and what
was this sample size based on? The IBS group is much older [48 vs 32] and
neither groups are adequately described - this needs to be addressed before
publication. Were their any age associated confounders that might be relevant?
Were any of either group on serotonergic medication? Were their differences in
smoking between the 2 groups (IDO activity is reduced in smokers). Where were
the controls recruited from?
The manuscript is well written, with only the odd typo e.g. p9 last sentence
remove “there”. The discussion is reasonably clear although on p11 I am not
clear how this study clarifies that if the increased tryptophan degradation is IDO
dependent, the knock on consequences for serotonergic signalling are greater
than if it is TDO-mediated.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
Please review this paper.
user
Reviewer's report
Title:Tryptophan degradation in Irritable Bowel Syndrome: Evidence of
indoleamine 2,3-dioxygenase activation in a male cohort.
Version: 1Date:31 July 2008
Reviewer: John Potokar
Reviewer's report:
This is a fairly straightforward small study that compares levels of tryptophan
metabolites in 10 male IBS patients compared with 26 controls. It is an
“investigative” study rather than a clear hypothesis driven research study, but the
findings are nonetheless intriguing, and the discussion attempts to integrate and
synthesise the results with what is know re IBS together with stress induced 5-HT
metabolism.
The methods appear reasonable, but it is not clear why there were only 10 IBS
patients and 26 controls. Was the study powered for just 10 patients and what
was this sample size based on? The IBS group is much older [48 vs 32] and
neither groups are adequately described - this needs to be addressed before
publication. Were their any age associated confounders that might be relevant?
Were any of either group on serotonergic medication? Were their differences in
smoking between the 2 groups (IDO activity is reduced in smokers). Where were
the controls recruited from?
The manuscript is well written, with only the odd typo e.g. p9 last sentence
remove “there”. The discussion is reasonably clear although on p11 I am not
clear how this study clarifies that if the increased tryptophan degradation is IDO
dependent, the knock on consequences for serotonergic signalling are greater
than if it is TDO-mediated.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
assistant