Gut Transit Effect on Enterohepatic Circulation

The digestion of food by human body starts from oral cavity and continues until its excreted as faeces. There are different factors affecting this process. Important factors are movement through the GI Tract, breakdown of food material and absorption by the body to produce energy. The unabsorbed waste material is then excreted by the body.

Different enzymes are produced by human body which are responsible for digestion of food. One important chemical is bile which is produced in the gall bladder. It is important in digestion of fatty foods but affects the movement of food material as well. There are numerous bacteria present in human GI tract especially in mouth and large bowel which also play an important role in process of digestion of food.

Different conditions of health and disease can affect how food moves through the GI tract (known as intestinal transit). It also affects the activity of different digestive enzymes and chemicals in body. The bacterial population in the body is also affected by changes described above. The purpose of this study is to observe how these different processes especially the intestinal transit, bile salts and gut bacteria affect each other. This will help to identify mechanisms responsible for different disorders of human gut like irritable bowel syndrome. The study is part of an effort to identify new and future treatment of these conditions.

• Loperamide (Drug): Alters intestinal transit time.
• Senna (Drug): Alters intestinal transit time.

Primary outcomes

• The effect of intestinal transit on faecal bile acids [7 days]: Change in bile acid pool and activity from baseline with each intervention

Secondary outcomes

• Stool bacterial count [7 days]: Bacterial count
• 1. common stool test [7 days]: calprotectin
• 2. common stool test [7 days]: elastase
• 3. common stool test [7 days]: lactoferrin
• Volatile Organic Compounds [5 days]: VOC estimation in urine

Sex: All, ages: 18 Years to 65 Years, accepts healthy volunteers

Inclusion Criteria:

* • Healthy volunteers between the ages of 18 and 65

Exclusion Criteria:

* Unable to consent
* Pregnant or lactating
* Known diarrhoeal disorder
* Known constipation.
* Any gastrointestinal disease or previous gastric surgery
* An episode of gastroenteritis within the last month
* Taking any acid suppressing medication
* Any significant medical condition (e.g. diabetes, renal disease)
* Any antibiotic intake within the last one-month
* Any drug with known effects on GI motility
* Known allergy or intolerance to senna or loperamide

• Stephen Lewis, MD, Principal investigator, University Hospital Plymouth NHS Trust