Impact of Soluble Arabinoxylan and Rice Bran Fiber on the Gut Microbiome in Healthy Adults

NCT06873204 | Not Yet Recruiting

• 1 other identifier: IRB-2024-881
• Study Type: interventional
• Target: 25
• Locations: 1 country
• Sites: 1

Brief Summary

The importance of the gut microbiota for general health has been recently elucidated, but little is known about the impact of different types of nutrients on the gut microbiota. The soluble fiber in cereal by-products, arabinoxylan (AX), is known to be beneficial for generally promoting gut health. However, it is unclear whether consuming rice bran (RB), the source of AX, is equally helpful or better than consuming the extracted form of AX. This study aims to reveal the potential benefit of insoluble cereal bran fiber ingredients by comparing the effect of soluble arabinoxylan fiber alone and the mostly insoluble rice bran fiber, containing arabinoxylan, on intestinal health and gut microbiota. A placebo (maltodextrin) will be used as a control, with no significant changes expected in this group for the evaluated outcomes. Participants will:

• Consume two different fiber supplements (soluble arabinoxylan or stabilized rice bran) as well as a placebo (maltodextrin) for 3 weeks each, separated by a 2-week washout period.
• Provide blood and stool samples at six different time points.
• Complete a food and gastrointestinal symptom diary during the intervention periods.

Conditions

Healthy

Keywords

Gut microbiota; Dietary fiber; Soluble arabinoxylan; Rice bran fiber; Intestinal health; Butyrate-producing bacteria; Clostridium cluster IVa; Short-Chain Fatty Acids

Outcome Measures

Primary Outcomes (1)

• Comparison of two test fibers (insoluble cereal bran and soluble arabinoxylan) and a control (maltodextrin) on gut beneficial bacteria

  The primary outcome of the study is change in butyrogenic Clostridium cluster XIVa gut bacteria.

  From enrollment to the end of treatment at 13 weeks.

Secondary Outcomes (1)

• Comparison of two tests (insoluble cereal bran and soluble arabinoxylan) and a control (maltodextrin) on fecal butyrate and intestinal barrier function

  From enrollment to the end of treatment at 13 weeks.

Study Arms (3)

Soluble Arabinoxylan

EXPERIMENTAL

Participants in this arm will receive soluble arabinoxylan for 3 consecutive weeks.

Dietary Supplement: Soluble Arabinoxylan

Rice Bran

EXPERIMENTAL

Participants in this arm will consume rice bran fiber for 3 consecutive weeks.

Dietary Supplement: Rice Bran

Maltodextrin

PLACEBO COMPARATOR

Participants in this arm will consume maltodextrin for 3 consecutive weeks.

Dietary Supplement: Maltodextrin (Placebo)

Interventions

Soluble Arabinoxylan DIETARY_SUPPLEMENT

10 grams of soluble arabinoxylan diluted in 200 mL of water, twice daily for 3 consecutive weeks.

Soluble Arabinoxylan

Rice Bran DIETARY_SUPPLEMENT

10 grams of rice bran fiber diluted in 200 mL of water, twice daily for 3 consecutive weeks.

Rice Bran

Maltodextrin (Placebo) DIETARY_SUPPLEMENT

10 grams of maltodextrin diluted in 200 mL of water, twice daily for 3 consecutive weeks.

Maltodextrin

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Men or women.
• Aged between 18-45 years.
• Body mass index between 18.5 and 25 kg/m².
• Able to read/speak English.

You may not qualify if:

• Gastrointestinal disorders (inflammatory bowel disease, irritable bowel syndrome, gluten sensitivity/intolerance, etc.).
• Those who took antibiotics 3 months before the study.
• Individuals taking regular medication or supplements that might affect the gut microbiota.
• Individuals undertaking weight-loss diets.
• Unstable body weight (±3 kg in the past 3 months), and individuals below 110 lb.
• Heavy drinkers (for men, consuming more than 4 drinks on any day or more than 14 drinks per week; for women, consuming more than 3 drinks on any day or more than 7 drinks per week).
• Smokers (those who have smoked 100 cigarettes in their lifetime and who currently smoke cigarettes, even every day or occasionally).
• Breastfeeding or pregnant women.

Sponsors & Collaborators

• Purdue University: lead
• Rural Development Administration (RDA) of the Republic of Korea: collaborator

Study Sites (1)

Clinical Research Center at Purdue University

West Lafayette, Indiana, 47907, United States

Location

MeSH Terms

Interventions

maltodextrin

Central Study Contacts

Bruce R Hamaker, Ph.D.

CONTACT

765-494-5668; hamakerb@purdue.edu

Mirian A de Campos Costa, Ph.D.

CONTACT

765-496-3802; decampos@purdue.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: Randomized, crossover, double-blind, clinical trial (RCT).

Study Record Dates

• First Submitted: March 6, 2025
• First Posted: March 12, 2025
• Study Start: July 1, 2025
• Primary Completion: October 1, 2025
• Study Completion: October 1, 2025
• Last Updated: June 29, 2025

Record last verified: 2025-06

Locations

US (1)