Role of Gastrointestinal Microbes on Digestion of Resistant Starch and Tryptophan Availability to Humans

May 1, 2017 updated by: Paul Burghardt, Wayne State University
There is currently a critical gap in knowledge of how intestinal bacterial communities alter metabolic substrates available to the host thereby influencing central and enteric nervous system (CNS/ENS) neurotransmitter levels involved in regulating carbohydrate consumption in humans. Understanding these relationships is essential for developing strategies to improve blood glucose control and to reduce the risk of transitioning from prediabetes to type-2 diabetes (T2D). The investigators' long-term goal is to determine the biological underpinnings of behaviors that impact food intake and blood glucose control that contribute to the development of T2D. The objective of this proposal, which is an essential next step in attaining the investigators' long-term goals, is to determine how bacterial populations in the digestive system impact circulating tryptophan (TRP) and large neutral amino acid (LNAA) levels that regulate production of monoamine 5-hydroxytryptamine (5-HT, serotonin) in the ENS and in gastrointestinal system and the brain. The central hypothesis is that a reduced ratio of TRP producing (TRPp) to TRP consuming (TRPc) bacteria (decreased TRPp:TRPc ratio) in the gut will decrease TRP availability following a carbohydrate meal lowering the plasma TRP:LNAA ratio and resulting in less TRP for ENS/CNS production of 5HT. Further, dietary interventions that promote TRPp bacterial abundance within the gut will increase TRP availability to the host. The investigators will test the central hypothesis and, thereby, accomplish the overall objective for this project by pursuing the following specific aims: 1) Assess impact of divergent microbiota on plasma TRP:LNAA ratio in response to acute carbohydrate consumption, and 2) Assess the impact of dietary supplementation with resistant starch (RS) on gut microbiota and circulating TRP:LNAA ratio. During Aim 1, stool samples will be collected from healthy participants. Participants will be stratified based on gut TRPp:TRPc ratio and the response to an acute meal will be assessed by determining plasma TRP:LNAA ratios. During Aim 2 the capacity for 4-weeks of pre-biotic RS (Potato Starch) supplementation to increase the TRPp:TRPc bacterial ratio in the gut will be determined from stool samples. Additionally, plasma TRP:LNAA ratio following acute carbohydrate consumption before and after supplementation will be determined. The scientific contribution will be to determine the impact of RS on TRPp and TRPc bacteria abundance in the gut, and how bacterial populations impact circulating TRP:LNAA levels, that can impact ENS and CNS 5HT production in humans. This contribution will be significant because it will have direct translational implications for human diseases with altered 5HT signaling.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Unknown

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Anticipated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 65 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Male and female
  2. Age 18 - 65 years old
  3. Non-Obese (BMI ≤ 30 kg/m2 and >17 kg/m2 )

Exclusion Criteria:

  1. Urine toxicology positive,
  2. Pregnant (female)
  3. Alcohol intake 48 hours prior to studies,
  4. Evidence of inherited disorders of lipid metabolism,
  5. History of Cancer within the last 5 years,
  6. Human immunodeficiency virus (HIV) antibody positive,
  7. Patients with solid organ transplants,
  8. Unstable angina or NY heart association class II failure or above,
  9. Gastrointestinal disease specifically GI motility disorders,
  10. Unstable neuropsychiatric disease including major depression/anxiety, eating disorder such as bulimia or anorexia,
  11. End stage renal or hepatic disease,
  12. Autoimmune disorders (e.g. SLE),
  13. Prior bariatric surgery,
  14. A history or current alcohol/substance abuse or nicotine containing products or illicit drugs of abuse during the preceding 6 months,
  15. Treatment within one month with sedative hypnotic medications (benzodiazepines, barbiturates), or over the counter sleeping aids

  16. Women: any selective estrogen receptor modulator or aromatase inhibitor Men:

    androgen ablation/deprivation hormonal therapies

  17. Any medical condition, which in the opinion of the investigator would make the patient unsuitable for recruitment, or could interfere with the patient participating in or completing the protocol
  18. Any previous adverse events or allergic reactions to acetaminophen
  19. Unwilling or unable to consent for the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: BASIC_SCIENCE
  • Allocation: NON_RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: SINGLE

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
EXPERIMENTAL: Potato Starch (Bob's Red Mill)
Daily dietary supplementation with Potato Starch (48g total/day) suspended in water. 24g will be consumed 2 times per day.
Dietary supplement: Potato Starch (Bob's Red Mill)
Subjects will be assigned to Potato Starch (active) following assessment of their gut microbiome.
PLACEBO_COMPARATOR: Resource ThickenUp Pregelatinized Starch
Daily dietary supplementation with Pregelatinized Starch (48g total/day) suspended in water. 24g will be consumed 2 times per day.
Dietary supplement: Pregelatinized Starch (Resource ThickenUp)
Subjects will be assigned to Pregelatinized Starch (placebo) following assessment of their gut microbiome.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Plasma Amino Acid Levels
Time Frame: Baseline
Baseline
Plasma Amino Acid Levels
Time Frame: Following 4 weeks of supplementation
Following 4 weeks of supplementation

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Plasma Amino Acid Levels
Time Frame: Baseline vs. 4-weeks
Difference in plasma amino acid levels between baseline and following 4-weeks of supplementation
Baseline vs. 4-weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Wayne State University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2017

Primary Completion (ANTICIPATED)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2017

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 21, 2016

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 22, 2016

First Posted (ESTIMATE)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 28, 2016

Study Record Updates

Last Update Posted (ACTUAL)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 4, 2017

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 1, 2017

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2017

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 110116M1F

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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