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Completed

NCT Number: NCT03829189

High-fiber Diet on the Body and the Brain

The central research question aims to understand what drives individuals to make and maintain a vegan / vegetarian dietary decision, to investigate whether there are possible predictors that might influence such a decision and whether personality differences already exist or can only be measured after the change in diet. The investigators will examine the effects of a high-fiber diet on food wanting on a neural and on a behavioral level. The microbiome is suggested to mediate the expected changes in food wanting.

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Key information

Conditions

Diet Modification Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences

Leipzig, Saxony, 04103, Germany

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • body-mass-index 25-30kg/m^2
  • females on contraception only

Exclusion criteria

  • current neurological or psychiatric illness
  • daily consumption of more than 50 g of alcohol, more than 10 cigarettes or more than 6 cups of coffee
  • use of antidepressants or other centrally acting drugs
  • type 2 diabetes mellitus or other serious metabolic disorders
  • MRI contraindication (e.g. cardiac pacemaker, drug pump, shunts)
  • major untreated medical condition, including gastrointestinal organs, lungs, heart, cardiovascular system, liver and kidney)
  • diet-related restrictions (food allergies, food intolerances, known nutrient deficiencies or a recent history of dieting or restrictive eating behaviour, including vegan, vegetarian diet)
  • current pregnancy or lactation

Treatment and study plan

Inulin

Dietary Supplement

prebiotic supplement

Maltodextrin

Dietary Supplement

placebo supplement

Primary outcomes

  1. fMRI BOLD activity during food wanting

    Time frame: 14 days

  2. microbial alpha and beta diversity

    Time frame: 14 days

    The taxonomic structure of the microbial community will be determined using 16S rRNA gene sequencing. The reads from the sequencing data will be assigned to taxa by sequence similarity using puplic available data bases. Relative distribution of microbial taxa is then based on the number of reads assigned to each taxa. For the description of the the community the alpha diversity of each sample will be determined based on species richness, evenness of species distribution which is combined in the single value of the Shannon diversity index. Furthermore beta-diversity, how the microbial communities differ between sample, will be analysed by principal component analysis as well as non-metric multidimensional scaling. In addition, for each taxa significant difference between sample groups will be assessed by comparing the relative number of reads.

Secondary outcomes

  1. fMRI BOLD activity memory performance

    Time frame: 14 days

  2. positive and negative affect

    Time frame: 14 days

    PANAS (Positive and Negative Affect Schedule); scores can range from 10 - 50, with higher (lower) scores representing higher (lower) levels of positive (negative) affect

  3. mood

    Time frame: 14 days

    POMS (Profile of Mood States); four scales (Depression/Anxiety, Fatigue, Vigor, Anger), 35 items, 7 point scale, instruction "How you have been feeling during the past 24 hours?"

  4. emotional health

    Time frame: 14 days

    BDI-II (Beck Depression Inventory); score minimum 0 to maximum 21

  5. well-being

    Time frame: 14 days

    WHO-5 (World Health Organization Well-Being Index); measures life quality and life contentment; score minimum 0 to maximum 5 with higher score representing higher life quality and life contentment

  6. satiety

    Time frame: 14 days

    self-reported hunger scale; visual analogue scale; score minimum 0 to maximum 8

  7. serum lipid metabolism markers

    Time frame: 14 days

    total cholesterol, triglycerides, high density lipoprotein, low density lipoprotein

  8. serum glucose metabolism markers

    Time frame: 14 days

    glucose, insulin

  9. serum glucose metabolism markers

    Time frame: 14 days

    long-term glucose marker HbA1C

  10. serum inflammatory markers

    Time frame: 14 days

    high sensitivity C-reactive protein, interleukin-6

  11. hunger hormones

    Time frame: 14 days

    leptin, ghrelin, Glucagon-like peptide-1 (GLP-1), peptide YY

  12. serum microbial metabolic markers

    Time frame: 14 days

    short-chain fatty acids (SCFA), trimethylamine N-oxide (TMAO), bile acids

  13. personality traits

    Time frame: 14 days

    BFMM (BIG FIVE Mine Marker); measures the Big Five personality traits as states; 5 subscales (neuroticism, extraversion, openness, agreeableness, conscientiousness); higher scores means being more extreme for a certain state

  14. gastrointestinal health

    Time frame: 14 days

    GQLI-10 (Gastrointestinal Quality of Life Index); 10 items to measure quality of life regarding gastrointestinal symptoms; the higher the score the stronger the symptoms

Sponsors and collaborators

Lead sponsor

Max Planck Institute for Human Cognitive and Brain Sciences

Other

Registry information

Official study title

Interventional Study Comparing the Effect of a High-fiber Supplement Versus Placebo on the Body and the Brain

Important dates

Study start
2019
Primary completion
2020
Study completion
2020
First posted
Feb 4, 2019
Registry last updated
Nov 27, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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