Effects of a Diet Based on Inulin-rich Vegetables on Gut Health and Nutritional Behaviour in Healthy Humans

Modification of the Gut Microbiota Following the Consumption of Inulin-rich Vegetables: Effect on Gut Tolerance, Transit, Behaviour and Digestion in Healthy Humans

Inulin-type fructans (ITF) are fermentable dietary fibres that can confer beneficial health effects through changes in the gut microbiota. However, their effect on gut sensitivity and nutritional behaviour is a matter of debate.

The investigators evaluated, in healthy individuals, the impact of shifting from their usual food habits towards a diet based on the daily consumption of ITF-rich vegetables on gut microbiota, gastro-intestinal symptoms and food-related behaviour.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: Diet based on inulin-rich vegetables

• Study Type: Interventional
• Enrollment (Actual): 26
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• BMI between 20 and 25 kg/m²
• Caucasian ethnicity
• Hydrogen producers (assessed by hydrogen breath test)

Exclusion Criteria:

• Smokers
• Laxative consumption (<4 weeks)
• Severe intestinal problems
• Psychiatric problems or use of antipsychotic
• Consumption of antibiotics, pro/prebiotics, fibre dietary supplement, or any molecules that modifies the intestinal transit (<6 weeks)
• Specific dietary practise (vegetarian, vegan,...)
• Specific dietary treatment (<6 weeks) (e.g. high protein diet)
• Excessive alcohol consumption (>3 glasses/day)
• Consumption of the following drugs: proton pump inhibitor, antidiabetic drugs, cholesterol lowering drugs
• Inconclusive acceptability test (regarding the protocol of the intervention and the vegetables used in the protocol)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dietary intervention	Other: Diet based on inulin-rich vegetables; During two weeks, healthy subjects were instructed to adhere to a controlled diet based on ITF-rich vegetables (±15 g ITF/day).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gut microbiota composition	Gut microbiota composition is assessed by 16S rRNA pyrosequencing. This analysis allows to obtain the relative abundance (%) of the different bacterial taxa and OTUs (operational taxonomic units).	33 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gut microbiota fermentation in vivo	Gut microbiota fermentation is assessed in vivo by an hydrogen breath test. After an oral load of purified inulin, the level of expired hydrogen (ppm) is measured.	33 days
Gut microbiota fermentation in vitro	Gut microbiota fermentation is assessed in vitro by the measurement of total gas (ml/g of dry matter) produced from subject feces incubated with inulin-rich substrates.	14 days
Gastrointestinal Symptoms	Gastrointestinal symptoms were assessed by Visual Analogue Scale (horizontal line of 100 mm). Each subject completed seven separate scales, one for each symptom (rumble, burp, bloating, discomfort, nausea, flatulence, cramp), ranging from "no sensation" (0 mm) to "very severe sensation" (100 mm).	33 days
Appetite-related feelings	Appetite-related feelings were assessed by Visual Analogue Scale (horizontal line of 100 mm). Each subject completed seven separate scales, one for each appetite-related feeling (satiety, intention to eat, fullness, sweet envy, very sweet envy, fat envy, salt envy), ranging from "no sensation" (0 mm or 100 mm depending on the feeling) , to "very strong sensation" (0 mm or 100 mm depending on the feeling).	33 days
Correlation of gastrointestinal symptoms with gut bacteria	The levels of gastrointestinal symptoms were correlated (Spearman correlations) with the relative abundance of bacterial taxa and OTUs (operational taxonomic units)	33 days
Short chain fatty acids production	Short chain fatty acids (SCFAs) production was assessed in vitro by the measurement of total SCFAs (mg/g of dry matter) produced from subject feces incubated with inulin-rich substrates.	14 days

Collaborators and Investigators

• Sponsor: Cliniques universitaires Saint-Luc- Université Catholique de Louvain

Publications and helpful links

General Publications

• Hiel S, Bindels LB, Pachikian BD, Kalala G, Broers V, Zamariola G, Chang BPI, Kambashi B, Rodriguez J, Cani PD, Neyrinck AM, Thissen JP, Luminet O, Bindelle J, Delzenne NM. Effects of a diet based on inulin-rich vegetables on gut health and nutritional behavior in healthy humans. Am J Clin Nutr. 2019 Jun 1;109(6):1683-1695. doi: 10.1093/ajcn/nqz001.

Study record dates

Study Major Dates

• Study Start (Actual): March 4, 2016
• Primary Completion (Actual): April 12, 2016
• Study Completion (Actual): April 12, 2016

Study Registration Dates

• First Submitted: May 8, 2018
• First Submitted That Met QC Criteria: May 28, 2018
• First Posted (Actual): May 30, 2018

Study Record Updates

• Last Update Posted (Actual): June 1, 2018
• Last Update Submitted That Met QC Criteria: May 30, 2018
• Last Verified: May 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: B403201627275

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No