Gastric versus distal to the ligament of Treitz feeding in healthy volunteers

Enteral feeding is the preferred method of nutritional support in patients who
have a functioning gastrointestinal (GI) tract but cannot maintain an adequate
oral intake. Enteral nutrition (EN) preserves the intestinal integrity and
prevents mucosal atrophy, and is therefore preferred over parenteral nutrition.
There are various ways of administrating EN. In general, the preferred route is
gastric feeding. It is considered to be more physiological and the tube is
easier to place. Disadvantages of gastric enteral feeding are encountered in
patients with delayed gastric emptying and those at risk for aspiration.
According to the Guidelines for the Provision and Assessment of Nutritional
Support in Therapy in the Adult Critically Ill Patient, gastric residual
volumes in the range of 250-400 ml should raise concern and lead to the
implementation to reduce the risk of aspiration. Jejunal feeding reduces the
aspiration risk, and is therefore the appropriate nutrition for patients at
risk of aspiration. Peristaltic transport between the duodenum and jejunum
behaves as if the *Ligament of Treitz* were the site of a one-way valve.
Jejunal peristalsis is very resistant to spontaneous reversal with reflux of
its contents. This phenomenon is considered to protect against aspiration.

What the consequences are of gastric or jejunal feeding with respect to changes
in levels of amino acids (AA) and serving the nutritional requirements of the
patient is currently unknown. The first proteolyses step of pepsin and gastric
acid is skipped when EN is administered in the jejunum. That is why it is
hypothesised that digestion and absorption of AA will be lower when the stomach
is bypassed. Still, it is taken into account that casein coagulates in the
stomach, and may therefore cause less absorption in the gastrointestinal tract.
Therefore, it is proposed that the differences in the responses to gastric and
jejunal feeding with a main focus on digestion and absorption of AA will be
determined.

Changes in GI response occur after gastric bariatric bypass surgery. Roux-en-Y
Gastric Bypass surgery (RYGB) involves anatomical changes, physiology is hence
altered. The interplay between food intake and gut function of the altered GI
system apparently results in clinical improvement. It has been postulated that
this improvement in glycemic control, reduction in appetite, and subsequent
weight loss following bypass surgery may be due to changes in circulating gut
hormones. By administrating enteral nutrition to the jejunum RYGB is more or
less mimicked. For better understanding of hormonal involvement in gastric
bariatric bypass surgery, the physiology of GI hormones will be studied in
extensive detail. Insight into the relationship of GI hormone response, plasma
glucose and pancreatic islet after administration of EN may give us insight in
an optimal metabolic support.

Primary objective: To evaluate the differences in digestion and absorption on
the administration of enteral nutrition either gastric or distal to the
ligament of Treitz in the jejunum.

Secondary objective: To evaluate the differences in endocrine responses on the
administration of enteral nutrition either gastic or distal to the ligament of
Treitz in the jejunum.

The GuTz study is a randomized, single-blind, single center, cross-over study.
The influence of confounding covariates is reduced because each crossover
subject serves as his own control. In this study it is not needed to add a
control group, because all parameters are influenced by the nutritional
intervention, and baseline sampling before the start of the administration of
EN is done. Also, a crossover design is statistically efficient and so requires
fewer subjects.
To see if there is an order effect the route of administering EN is randomised.
This way an order effect will be detected in retrospect. To be sure there is no
carry-over effect of the previous visit there will be a sufficiently long
wash-out period of four-weeks between the visits.

Administration enteral nutrition on the stomach is compared to administrating
enterl nutrition distal of de ligament of Treitz in the jejunum.
The intervention is gastric feeding and jejunal feeding with Nutrison Standard
Advanced Multi Fiber (Danone Research). Nutricia has developed and marketed a
tube feed for patients who cannot maintain an adequate oral intake. It is a
complete nutrition, with a specific protein blend opmitised on aminoacid
profile, enriched with EPA/DHA, fibres, vitamins and minerals, the levels are
based on the guidelines for Food for Special Medical Purposes (FSMP). Nutrison
Standard Multi Fibre is a product which is commercially available and has
proven to be safe, well tolerated and can be given as a sole nutrition. A multi
fibre blend is added several years ago to reduce gastrointestinal intolerance
like diarrhea.

Blood sampling: subjects may experience pain at the needle puncture site;
light-headedness, haematoma; fainting; infection (a slight risk any time the
skin is broken).

NGT/NJT: placement of the naso-gastric and naso-jejunal tube can be very
unpleasant; retching is a common phenomenon during placement; sore throat;
hoarse voice; nosebleeds (in case of multiple nosebleeds the naso-tube will be
replaced by an oral-tube); placement of the NGT or NJT will be monitored with
X-rays as insertion in the trachea will lead to a severe adverse event when
enteral nutrition is started. This is a very rare complication.

Possible adverse effects with enteral nutrition include: belching; nausea;
change in stool consistency; diarrhea; abdominal cramps;
There are no other known adverse effects with Nutrison Standard Multi Fibre.