NCT04633369

Brief Summary

Dietary fibers are generally not degraded by the endogenous digestive enzymes, but rather by the complex ensemble of microorganisms that reside in the human gut \[1\]. This ensemble, collectively known as the human gut microbiome, plays a key role in breaking down, fermenting, and ultimately converting such dietary fibers into a variety of beneficial metabolites, including most notably, short chain fatty acids (SCFA). These end products of fibers' fermentation affect host metabolism, immunity, and physiology, and have been implicated in multiple diseases including obesity, metabolic syndrome, diabetes, and cardiovascular diseases. Intermediate fasting, and in particular circadian intermediate fasting (i.e. 16 hours of fasting followed by 8 hours of allowed eating), has been shown to have positive associations with multiple health conditions as obesity, diabetes mellitus, cardiovascular disease, cancers, and neurologic disorders In this study, we will try to answer open questions utilizing the long fasting period during the day to investigate the isolated effect of dietary fiber consumption, uncovering the degradation effect, but not the bulking effect, on the microbiome and the host physiology, and in particular its glucose response.

Trial Health

75
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
115

participants targeted

Target at P50-P75 for not_applicable

Timeline
8mo left

Started Apr 2021

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress89%
Apr 2021Jan 2027

First Submitted

Initial submission to the registry

November 12, 2020

Completed
6 days until next milestone

First Posted

Study publicly available on registry

November 18, 2020

Completed
5 months until next milestone

Study Start

First participant enrolled

April 21, 2021

Completed
5.3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 1, 2026

Expected
5 months until next milestone

Study Completion

Last participant's last visit for all outcomes

January 1, 2027

Last Updated

March 19, 2026

Status Verified

March 1, 2026

Enrollment Period

5.3 years

First QC Date

November 12, 2020

Last Update Submit

March 18, 2026

Conditions

Dietary FibersIntermediate Fasting

Outcome Measures

Primary Outcomes (2)

  • microbiome

    stool and oral samples

    1 year

  • glycemic response of different dietary fibers

    Continuous glucose monitoring (CGM)

    1 year

Study Arms (3)

Fructo-oligosaccharide

EXPERIMENTAL

Fructo-oligosaccharide 20g

Dietary Supplement: dietary fibers

Arabinogalactan

EXPERIMENTAL

Arabinogalactan 12g

Dietary Supplement: dietary fibers

Glucomannan

EXPERIMENTAL

Glucomannan 4g

Dietary Supplement: dietary fibers

Interventions

dietary fibersDIETARY_SUPPLEMENT

during days 13-22 the participants will consume the dietary fiber according to their randomization and continue fasting. Participants will be asked to collect stool and oral samples 4 times during this period.

ArabinogalactanFructo-oligosaccharideGlucomannan

Eligibility Criteria

Age18 Years - 70 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Male and Female BMI\<28 Age - 18-70

You may not qualify if:

  • Consumption of antibiotics 3 months prior to the first day of the experiment. Consumption of probiotic or dietary fibers supplements 1 month prior to the first day of the experiment.
  • Practiced in intermediate fasting 1 month prior to the first day of the experiment.
  • Diagnosis with type 1 or type 2 diabetes. Pregnancy, breastfeeding, or fertility treatments in the last 6 months. Chronic disease (e.g. AIDS, Cushing syndrome, CKD, acromegaly, hyperthyroidism hepatitis, fibromyalgia, etc.).
  • Cancer and recent anticancer treatment. Psychiatric disorders. Coagulation disorders. IBD (inflammatory bowel diseases). IBS (Irritable bowel syndrome). Alcohol abuse, more than 2 drinks per day for males, and more than one drink for females.
  • Substance abuse. BMI\>28. Daily dietary intake higher than 25 grams per day. History of abdominal surgeries (including Bariatric surgery). Mentally incompetent or lack of judgment

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Weizmann institute of science

Rehovot, Israel

Location

MeSH Terms

Interventions

Dietary Fiber

Intervention Hierarchy (Ancestors)

Dietary CarbohydratesCarbohydratesFoodDiet, Food, and NutritionPhysiological PhenomenaFood and Beverages

Study Officials

  • Eran Elinav, Prof

    Weizmann Institute of Science

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

November 12, 2020

First Posted

November 18, 2020

Study Start

April 21, 2021

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

January 1, 2027

Last Updated

March 19, 2026

Record last verified: 2026-03

Data Sharing

IPD Sharing
Will not share

Locations

IL(1)