Effects of Inulin and Arabinoxylan on Satiety, Energy/Food Intake and Changes in the Human Gut Microbiota
Effects of Inulin and Arabinoxylan on Satiety, Energy/Food Intake and Changes in the Human Gut Microbiota
This proposed randomized, double blinded 12 week crossover human feeding study aims to
 investigate the effects of consuming a composite drink of inulin and arabinoxylan on satiety
 by measuring appetite biomarkers such as subjective satiety, energy/food intake and changes
 in the human gut microbiota in healthy weight males (22 to 24.9kg/m2)
Research that focuses on the mechanisms involved in appetite regulation is topical given the
 emergence of the worldwide obesity epidemic. Understanding the physiological processes
 associated with the onset of obesity is essential for the development of effective
 anti-obesity strategies. There is evidence that people who consume a diet high in non-starch
 polysaccharides (NSPs) have a lower body mass index (BMI) than those that do not.

 A 2009 review of fibre and satiety by Bridget Benelam, 2009 focused on different types of
 fibre and the significant impact they may have on satiety and/or energy intake, through
 fermentation of fibre such as non starch polysaccharides in the colon by gut bacterial groups
 such as Bifidobacterium. non starch polysaccharides and other fibre sources are poorly
 digested by human enzymes in the small intestine but are degraded by large groups of bacteria
 in the large bowel. One of the beneficial outcomes of this fermentation of fibre that gut
 bacteria produce of metabolites called short chain fatty acids (SCFA) thought to affect
 appetite regulation by stimulating production of satiety hormones that can help you feel
 full. Acetate and propionate are two of these metabolites highlighted as potential mediator
 of satiety.

 Some fibres are called prebiotics as they act as selective sources for beneficial gut
 bacteria. However Western populations do not consume natural prebiotics in high quantities in
 their diet and the overall intake of fibre is also low. Therefore, in this study, the
 investigators aim to utilise a mixture of prebiotics in order to increase the growth and/or
 activity of commensal gut bacteria and SCFA production in human volunteers and to assess the
 effects of consumption on satiety.

 Testing the impact of a composite mix of inulin and arabinoxylan in a human study will help
 determine the effect it has on appetite regulation, ad libitum food intake, SCFA production,
 anthropometric measurements, cognitive state (e.g. mood) and composition of the gut
 microbiota.

 The study design is a 12 week randomized, human feeding study, with a crossover design
 testing a composite mix of inulin and arabinoxylan against an equivalent energy matched
 (kcal) maltodextrin control drink in 33 healthy weight (22 to 24.9kg/m2) males aged between
 21-55. Volunteers will be enrolled to treatment or placebo for four weeks, with a four week
 wash out before the crossover. the primary endpoint, satiety following a test meal challenge
 will be measured on four occasions throughout the study. Anthropometry measures, dietary
 intake, body weight and blood pressure will be monitored throughout the study. Faecal and
 urine will be collected at baseline and at the end of each treatment period.
Inclusion Criteria:

 -  Males

 -  21-55 years old

 -  Body Mass Index (BMI) 19.5-24.5kg/m2

 -  Overall healthy

 -  Weight Stable (<3 kg change in the past 4 months, before the trial).

 Exclusion Criteria:

 -  Smokers

 -  drink more than 28 units of alcohol per week (i.e. not more than 14 pints of beer or
 28 small glasses of wine)

 -  Restricted diet such as weight loss, vegetarian/vegan or taking dietary supplements
 such as prebiotics (such as oligosaccharides ie Fructo-oligosaccharides (FOS),
 galacto-oligosaccharides (GOS) or probiotics (ie Actimel)), not eating breakfast and
 >25g/d dietary fibre consumption as well as those with food allergies

 -  Gastrointestinal procedure or surgery in the past three months.

 -  Gastrointestinal disorders: celiac disease, Intestinal Bowel Disease (IBD), irritable
 bowel syndrome (IBS), chronic constipation, diverticulitis or a history of chronic
 constipation, diarrhoea, or other chronic gastrointestinal complaints

 -  Disorders of swallowing, severe dysphagia to food or pills.

 -  Appetite modulator drugs: orlistat, sibutramine, rimonabant.

 -  Mood disorder medications: antidepressants, lithium.

 -  Chronic metabolic conditions: diabetes, hepatic disease, gout, kidney, thyroid or
 coagulation disease.

 -  Psychiatric disorder: severe depression, bulimia, anorexia, schizophrenia, bipolar
 disorder.

 -  Pregnancy

 -  Others: oral antidiabetics, insulin, digoxin, thyroid hormones, antibiotics, steroids
 or immunosuppressants, recreational substances.

 -  Use of implanted or portable electro-mechanical device such as cardiac peacemaker or
 infusion pump.

 -  Blood donor in the past 3 months.