The effects of ethanol on gut wall integrity as measured by I-FABP and LBP

A common finding in trauma patients admitted to the ER with serious injuries is
the presence of alcohol abuse. Alcohol is involved in up to 40% of deaths from
motor vehicle crashes, 60% of deaths from intentional injuries, and 50% of
hospital admissions for injuries.
Chronic alcohol consumption leads to a decrease in gut wall integrity in
actively drinking alcoholics and patients with alcohol induced liver disease.
Animal studies show that the mucosal damage caused by alcohol consumption
increases the permeability of the gut to macromolecules. This facilitates the
translocation of endotoxin and other bacterial toxins from the gut lumen to the
portal circulation. In addition to increased endotoxemia other studies show
that the initial event in response to alcohol is an increased influx of
leukocytes leading to an enhanced release of noxious mediators, such as
reactive oxygen species, leukotrienes and histamine by mast cells. Alcohol
consumption thus leads to a decrease in gut wall integrity with increased
endotoxemia and as a result induces an inflammatory response. Data on the
effects of acute alcohol consumption on gut wall integrity in non-alcoholics is
still scarce.
In patients exposed to severe trauma, loss of gut wall integrity has been
implicated as an important contributor to the development of excessive
inflammation. Intestinal mucosal damage develops early after trauma leading to
loss of gut wall integrity and resulting in translocation of luminal bacteria
and toxins into the gut wall. This has been associated with the development of
an inflammatory response. This excessive inflammation can in turn lead to the
systemic inflammatory response syndrome (SIRS) which can ultimately lead to
multiple organ failure (MOF) and death. Up to 20% of the deaths in trauma
patients are due to the consequences of SIRS and MOF.
When assessing the effects of alcohol and severe trauma on gut wall integrity
combined with the fact that the two co-exist frequently one can hypothesize
that the outcome for trauma patients under the influence of alcohol is
detrimental. Literature regarding this issue is unequivocal, consisting only of
relatively small retrospective series.

The aim of this study is to determine the immediate effects of oral alcohol
consumption in healthy volunteers on gut wall integrity as measured by
Intestinal Fatty Acid Binding Protein (I-FABP) and Lipopolysaccharide Binding
Protein (LBP) These proteins enter the systemic circulation within minutes of
mucosal damage to the gut resp translocation.
Furthermore, the effect of alcohol on gut wall integrity markers per se is
assessed by artificially adding alcohol to blood and comparing it to
non-alcoholised blood.

Randomized crossover design. After informed consent fifteen healthy adult male
volunteers, aged 18-60, will be randomized into two groups. One will drink
alcohol, the other group will drink water according to the protocol. The next
week, groups will be switched.

Volunteers with a medical history of alcohol abuse or bowel disease or subjects
using any medication will be excluded from the study. Volunteers will be
fasting for 6 hours before sampling to obtain a reproducible alcohol uptake. To
avoid dehydration or hypoglycaemia, volunteers will be allowed to drink tea,
water or clear fruit juices until 2 hours before sampling.
Blood sampling: from each volunteer two samples of blood will be collected
without additives after discarding the first 3 ml of blood to avoid sample
contamination. The first sample (S1) of 19 ml blood will be divided in two
halves: 8 ml blood for analyzing the gut wall integrity without addition of
ethanol, the other 8 ml will be analyzed after addition of 10 µl of 96% pure
ethanol to obtain a blood concentration of 1* ethanol. After the first sample
15 volunteers will drink 1 g/kg ethanol in wine (Pinot noir 12%, 12 gr/100 ml)
to obtain a blood alcohol level of 1 * and 2 volunteers will drink three 200 ml
glasses of water. The beverages will be consumed in maximal 45 minutes. Thirty
minutes after the last glass of beverage is consumed, the second sample (S2) of
11 ml blood will be collected. The next 4 samples are taken with one hour
intervals (S3, S4, S5 and S6 respectively). The last sample is taken in a
second visit at 17:00 the day after.
In each sample I-FABP, L-FABP and LBP will be measured as well as the alcohol
promillage.
The first 19 ml blood sample (S1) drawn from the sober participants is divided
in two halves:
The first 8 ml for analyzing native blood and the second 8 ml for analyzing
artificially alcoholised blood.
After ingestion of water or wine 5 samples are drawn with one hour intervals.
From the 11 ml drawn blood: 3 ml is used for blood alcohol concentration
5 ml is used for I-FABP, L-FABP and LBP
Artificially alcoholised sample:
10 µl 96 % pure ethanol is added to 8 ml blood to obtain an alcohol blood level
of 1 *
Naturally alcoholised:
8 volunteers drink 1 g/kg ethanol in wine (12%) = 8.3 ml wine/kg (average 600
ml per person)
Non alcoholised:
7 volunteers drink 600ml of water

Healthy male volunteers (ASA I) will be included between 18 and 60 years old
after they have given their informed consent. Exclusion criteria are the use of
medicine as well as a medical history of alcohol abuse or bowel disease.

Subjects consume 1g of alcohol per kg bodyweight. One blood sample of 19 ml
followed by 5 samples of 11 ml and one of 8ml will be drawn between 16.45 hours
and 17:00 hours the day after. The first 6 observations take place in a single
visit followed by one observation in short visit the next day. It is unlikely
that subjects will experience any physical or psychological discomfort from the
withdrawal of a total of 82 ml of blood in 24 hours or the consumption of the
amounts alcohol or water mentioned above.