Review for 10.1186/s12876-023-03102-w (2024)

Title: The effect of an acute aspirin challenge on intestinal permeability in healthy adults
with and without prophylactic probiotic consumption: a double-blind, placebo- controlled,
randomized trial
Version: 1 Date: 02 Oct 2023
Reviewer's report:
I would like to first point out the importance of not blinding
author names. The first thing I do in reviewing any paper is to
check prior publications. The authors have a strong history in
this subject area with publications mostly in high quality
journals. Research in Gainesville in general is of high quality.
The present paper is well written and important. Permeability
studies are difficult undertakings. Among the hurdles are the
time allocating sampling material, explaining instructions,
fetching and processing urine samples and then numerous
technical challenges in properly performing LC-MS of sugars.
Beyond this is compliance for repeated tests as a result of
subject time and in some cases bloating and laxative effects
of lactulose. Despite such hurdles, the authors managed a
double-blinded, placebo controlled study. Inclusion and
exclusion criteria were well thought through. There is a
shortage of such studies and I welcome seeing this one
published. I politely request the authors go through my
comments and questions.
Comments/Questions
1. I am not exactly following the premise of this study,
as I am not familiar with any probiotic mitigating the
adverse effects of NSAIDs on gastro or intestinal
cyclooxygenase activity on mucosal epithelium. Does
that exist (some form of local COX regulation by
microflora)?
2. Power analysis states 40 mg sucrose as a cutoff, but
results are given in µmol. For readability, I suggest
using same units.
3. I believe lactulose can be replaced by sucralose for
small intestinal permeability. This would be helpful to
eliminate bloating and laxative effects. It would also
eliminate presence of lactose in the assay. Lactulose for
human consumption is typically prepared from lactose and
there is substantial amount of lactose in the final product:
the 39% that is not lactulose in your formulation?
Pure lactulose is typically much more expensive and not
intended for human consumption. Please insert text
on this detail about the lactulose formulation you used
and if lactose was present. I noticed milk intolerance
was an exclusion criteria, but perhaps lactose should be
specified? Was sucralose measured in the 5 hour upper GI
samples? If so, I suggest including that as an additional
measure. I envision in the future sucralose might replace
sucralose, so it might be good to include this data for
future reference.
4. Was there a fasting period with water consumption
prior to the permeability test? We have our subjects
cease food and medication consumption and drink 500 ml water
prior to the test. This was done after increasingly
finding permeability probes in baseline urine samples
we take prior to ingestion of probes. We are increasingly
finding them in medication formulations, bakery
products, food additives, etc. This also led to
absention from food during the firt 4 hours.
5. Lactulose ratios alone are not really analytically
complete. The second probe (rhamnose, mannitol, whatever
is used) is also effectively a measure of absorptive area.
I suggest tabulating the mg or mole values to give a
sense of absorptive area in contrast to permeability.
I think this would end up as a table of reference values
since these are healthy subjects. I wonder if you have
considered a reference cutoff, since you have an effect
of the medication for comparison?
6. Maybe more of an issue for another paper, but since you
have done tandem MS and the chloride isotopes are easy
to identify, there is interest in knowing if any
sucralose metabolites were detected. These have been
reported (PMID 23668410), but I have never detected
them myself (e.g., 4-chloro-4-deoxygalactose,
1,6-dichloro-1,6-dideoxyfructose and
6-chlorofructose-1-glutathione).