Impact of Native Chicory Inulin on Change and Persistence of Gut Microbiota

The main aim of this study is to investigate differences in rate, extent of change and persistence of the gut microbiota in healthy adult volunteers in response to native chicory inulin. Along with investigating the impact of native chicory on bowl habits, mood and appetite. The two main questions this study aims to answer:

* To what extent do differences exist in rate of change over time between individuals in gut microbiota response (Bifidobacterium growth) to native chicory inulin supplementation.
* To what extent do differences exist between individuals in persistence of the gut microbiota upon stopping supplementation.

The effects of native chicory inulin on gut microbiota response will be compared to a maltodextrin placebo to sure changes in gut microbiota result directly from chicory inulin supplementation.

Participants will firstly complete a one-week run-in phase to establish baseline data and will then be allocated to either native chicory inulin or maltodextrin supplementation for 6 weeks. Inulin will be delivered at 12 g/day split into 2 x 6g portions. Maltodextrin will be calorie matched at 6 g/day split into 2 x 3g portions. This will then be followed by a 6 week post-supplementation phase. Fecal and blood samples will be collected regularly throughout all phases for analysis of gut microbiota and compounds of interest. Participants will also record any changes in gastrointestinal sensation, bowel habits and mood in a diary. Changes in appetite sensation will also measured.

The term prebiotic was established in 1995 and has since undergone several updates in definition. As of 2017, the International Scientific Association for Probiotics and Prebiotics (ISAPP) defines prebiotics as a substrates that is selectivity utilised by the host microorganism conferring a health benefit. Of all prebiotics the most highly researched prebiotics are inulin and fructo-oligosaccharides that belong to a group of non-digestible carbohydrates referred to as inulin-type fructans. The main concept behind prebiotics is to stimulate selective changes in microbiota - namely Bifidobacterium in regards to inulin-type fructans. The ability for inulin-type fructans to stimulate changes in bifidobacteria has been demonstrated across across a wide array of studies. Yet, while in vivo studies suggest that inulin-type fructans exert a bifidogenic effect, substantial differences in changes in bifidobacteria responses are often documented between individuals. More specifically, evidence is lacking regarding differences in the rate, extent of change and persistence of the gut microbiota upon the commencement and seizing of inulin supplementation. While, increasing pre-clinical data suggests that a wide variety of bacteria found within the gut can utilise inulin-type fructans in addition to just Bifidobacterium. The aims of this research study are to explore effects that supplementation with 12 g/day inulin-type fructans has on frequent changes in gut microbiota load, composition, gastrointestinal sensation (flatulence, intestinal bloating, abdominal pain and abdominal pressure), bowel habits (stool frequency and stool consistency) and mood with maltodextrin employed as a placebo ((control) 6 g/day). This study will also examine differences in appetite sensation and blood metabolites. The study will consist of 3 phases - a one-week run-in phase; a 6-week supplementation phase and a 6-week post-supplementation phase.

Eligibility Criteria:
Inclusion Criteria:

* adults aged 18-45
* BMI \>18.5 - \< 30 kg/m2
* Regular bowel movements (\> 4 days per week)

Exclusion Criteria:

* Self-reported sensitivity to FODMAPs and following a low FODMAP diet ((FODMAPS stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols).
* Self-reported food allergies and sensitivities including gluten, dairy, nuts, soya and lactose etc.
* Self-reported antibiotic treatment in the past 6 months.
* Self-reported history of gastrointestinal disease and/or heart disease, cardiovascular, liver, and respiratory disorders, cancer and/or clinically relevant (pre) diabetes.
* Self-reported to having undergone major surgery of the gastrointestinal tract, with the exception of cholecystectomy and appendectomy.
* Self-reported smoking and/or self-reported drug or alcohol abuse.
* Self-reported history of psychiatric and/or mood disorders including eating disorders.
* Self-reported to be following a restrictive diet (i.e. ketogenic, intermittent fasting).
* Pregnant and lactating women.