Comparison of an Alginate Containing Enteral Feed and an Alginate Free Enteral Feed.

When patients cannot eat and drink enough a tube can be placed through their nostril, down the back of their throat into their stomach and used to give their nutrition as a liquid feed. One of the commonest problems when using this tube is regurgitation of feed up from the stomach (gastro- oesophageal reflux (GOR)), or liquid stools (diarrhoea). This can cause the patient discomfort, a higher risk of getting a skin or chest infection, and increase the risk that the feed is stopped.

The investigators intend to investigate, in twelve healthy young men, whether adding a form of dietary fibre (alginate) to the feed could reduce these symptoms (diarrhoea and GOR), hence ensuring patients are properly nourished and recover as quickly as possible from their illness, Each volunteer will come to the lab twice and will have a tube inserted into the stomach via the nose so that they can be given both feeds. Each time, the investigators will take repeated pictures of how the feed is passing through their gut using a non invasive technique called 'magnetic resonance imaging' (MRI), take blood samples to see how quickly the nutrition is absorbed into the blood, and measure how hungry they feel

TRIAL / STUDY DESIGN Each participant will be required to attend a screening visit, a brief education visit re collecting dietary information, adhering to a standardised diet and faecal sample collection; two, approximately five hour, study visits with 7- 10 days between each visit; and a brief visit after each intervention day to return diet information and the faecal samples. Prior to the study visits they will be required to consume a standardised diet for four days, based on their usual intake with similar macronutrient composition to the feed. On each study visit they will be fed, via a nasogastric enteral tube, 300mls/ hour of one of two enteral feeds (total feed delivered 300mls). The gastric response will be measured using MRI scanning, the biochemical and endocrine response will be measured using arterialised venous blood samples, and the appetitive response will be measured using visual analogue scales, and direct measurement of food intake at an ad libitum test meal. Participants will continue to consume a standardised diet for 3 days after the delivery of the enteral feed. Faecal samples will be collected before and after the visit day, for pH measurement.

Ethical approval has been obtained from the Faculty of Medicine and Health Sciences Ethics Committee, University of Nottingham. All participants will provided informed, written consent.

Eligibility Criteria:
Inclusion Criteria:

* Non- smoking (non- vaping) males
* aged 18- 45 years
* body mass index (BMI) of 18.5-24.5kg/ m2 or a BMI of 24.5- 26kg/ m2
* a waist circumference of less than 94 cm.
* ability to give informed consent

Exclusion Criteria:

* A history of an acute illness, lasting more than a week, in the last six weeks;
* taking any medications for gastrointestinal disorders, including acid suppressants or anti-spasmodics,
* taking anti-depressants or symptoms of clinical depression (defined by a score \>10 on the Beck Depression Inventory)
* taking medication for diabetes or having diabetes
* a history of substance abuse in the last six months;
* having any factors that preclude safe MRI;
* a history of gastrointestinal disorders, including Gastro Oesophgeal Reflux Disease, Irritable Bowel Syndrome, active peptic ulcer disease; having diabetes;
* previous surgery to the gastrointestinal or biliary systems;
* having characteristics of those with an eating disorders (defined by a score of more than 20 on the Eating Attitudes Test (EAT-26));
* having an allergy or intolerance to the ingredients in the enteral feeds, or the cheese and tomato pasta meal