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Digestibility of Selected Resistant Starches in Humans

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT01939600
First Posted: September 11, 2013
Last Update Posted: November 18, 2014
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Collaborators:
Ingredion Incorporated
University of Toronto
Glycemic Index Laboratories, Inc
Iowa State University
Information provided by (Responsible Party):
Thomas Wolever, St. Michael's Hospital, Toronto
  Purpose
Dietary fiber is a type of carbohydrate which is not digested in the human small intestine. Whole grains are a source of dietary fiber that are used to promote health; however, using whole grains in commercial products results in a different taste and/or texture than the usual products made from refined grains. Thus, other types of high-fiber ingredients have been developed which can be incorporated into food products with less effect on their taste and/or texture. An example of this is resistant starch, defined as starch which is not digested in the human small intestine. The digestibility of starch is usually determined in-vitro; however, there is evidence that such methods may overestimate the amount of resistant starch by as much as 100%. The measurement of the amount of carbohydrate in the ileal effluent, digestive waste, of subjects with an ileostomy is considered to be the best in-vivo method of starch digestibility. The subjects collect ileal effluent during the day during which time they consume a polysaccharide-free diet. There is evidence that resistant starch consumed at breakfast is completely recovered in ileal effluent 8-10hr after consumption. The purpose of this study will be to compare the carbohydrate content recovered in ileal effluent of 10 subjects with a conventional ileostomy.

Condition Intervention
Malabsorption; Carbohydrate Ileostomy - Stoma Other: Starch-free breakfast Other: Hi-Maize 260 Other: Hylon VII Other: Amioca

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: None (Open Label)
Official Title: Digestibility of Selected Resistant Starches in Humans

Further study details as provided by Thomas Wolever, St. Michael's Hospital, Toronto:

Primary Outcome Measures:
  • Amount of carbohydrate in ileostomy effluent [ Time Frame: Up to 10 hours after starting to consume breakfast ]
    Carbohydrate in ileal effluent will be measured using by proximate analysis and expressed in grams.


Secondary Outcome Measures:
  • Amount of fiber in ileostomy effluent [ Time Frame: Up to 10 hours after starting to consume breakfast ]
    Fiber is measured using the Englyst method and expressed in grams.

  • Amount of starch in ileostomy effluent [ Time Frame: Up to 10 hours after starting to consume breakfast ]
    Starch will be measured using the Megazyme assay and expressed in grams.


Other Outcome Measures:
  • Amount of fiber in ileostomy effluent [ Time Frame: Up to 10 hours after starting to consume breakfast ]
    Fiber will be measured using fiber assay 2009.01 and expressed in grams.

  • Amount of fiber in ileostomy effluent [ Time Frame: Up to 10 hours after starting to consume breakfast ]
    Fiber will be measured using fiber assay 991.43 and expressed in grams.

  • Amount of starch in ileostomy effluent [ Time Frame: Up to 10 hours after starting to consume breakfast ]
    Starch will be measured by acid hydrolysis and expressed in grams.


Enrollment: 3
Study Start Date: September 2013
Study Completion Date: August 2014
Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: All subjects
All subjects will undergo all 4 treatments, starch-free breakfast, Hi-Maize 260, Hylon VII and Amioca in randomized order
Other: Starch-free breakfast
Starch-free breakfast alone
Other: Hi-Maize 260
Starch-free breakfast plus 55.3g Hi-Maize 260
Other: Hylon VII
Starch-free breakfast plus 56.9g Hylon VII
Other: Amioca
Starch-free breakfast plus 56.4g amioca starch

Detailed Description:

Dietary fiber consists mainly of carbohydrates which are not digested in the human small intestine. A high intake of dietary fiber is associated with many health benefits including, but not limited to, improved bowel function and reduced risk of weight gain, cardiovascular disease and diabetes. Therefore, there is great interest in the food industry to produce products enriched with dietary fiber to promote health. One way to achieve this is to use more whole grains (wheat, rice, oats, barley) as ingredients in products such as breakfast cereals, breads and food bars. However, the use of whole grains results in products which have a different taste and/or texture than the usual products made from refined grains. Thus, other types of high-fiber ingredients have been developed which can be incorporated into food products with less effect on their taste and/or texture. Examples of such ingredients are inulin (an oligosaccharide containing fructose) and resistant starch. Resistant starch, defined as starch which is not digested in the human small intestine, is present in small amounts (2-5% of total starch) in many normal foods.

Starch is the most abundant energy containing nutrient in the human diet; it consists of 2 types of polysaccharides: amylose, is a linear polymer consisting of long chains of glucose molecules joined by 1-4 linkages; and amylopectin, a highly branched polymer consisting of long chains of glucose molecules joined by 1-4 linkages with numerous 1-6 linkage branch points. Most (70-80%) of the starch in normal starchy foods (eg. cereals and potatoes) is amylopectin. Amylopectin is highly digestible because its branched structure makes it readily able to gelatinize, the process whereby adjacent starch molecules swell and separate from each other under the influence of moist heat (ie. cooking). By contrast amylose is less digestible because its linear structure allows adjacent molecules to associate by hydrogen bonding which reduces their ability to gelatinize. Some types of commercially available resistant starch come from strains of corn which produce starch containing 70 to 100% amylose.

The digestibility of starch is usually determined in-vitro using methods involving digestion of the starch with α-amylase under pH and temperature conditions thought to mimick digestion in the human small intestine. However, there is evidence that such methods may overestimate the amount of resistant starch by as much as 100%. Methods used to estimate starch digestibility in-vivo include the breath hydrogen method and the measurement of the amount of carbohydrate in the ileal effluent of subjects with an ileostomy. The latter is considered to be the best in-vivo method which involves preparation of subjects with a polysaccharide-free diet the day before then consumption of the test carbohydrate with breakfast. Subjects collect ileal effluent during the day during which time they consume a polysaccharide-free diet. There is evidence that resistant starch consumed at breakfast is completely recovered in ileal effluent 8-10hr after consumption. The objective of this study is to determine the amount of carbohydrates in 3 commercially available starches (Hi-Maize® 260, Hylon® VII and Amioca corn starch) which escape digestion in the human small intestine.

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • males or non-pregnant females with a conventional ileostomy
  • clinically stable with no clinical evidence of malabsorption

Exclusion Criteria:

  • short bowel syndrome
  • acute exacerbation of inflammatory bowel disease
  • prone to high output with change in diet
  • ileostomy created less than 6 months from the first study visit
  • subjects using medications which influence gastrointestinal motility or absorption
  • any condition which might, in the opinion of Dr. Wolever or Dr. Kim either: 1) make participation dangerous to the subject or to others, or 2) affect the results
  • subjects who cannot or will not comply with the experimental procedures
  • food allergies of any kind
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01939600


Locations
Canada, Ontario
Glycemic Index Laboratories, Inc.
Toronto, Ontario, Canada, M5C 2N8
Sponsors and Collaborators
St. Michael's Hospital, Toronto
Ingredion Incorporated
University of Toronto
Glycemic Index Laboratories, Inc
Iowa State University
Investigators
Principal Investigator: Thomas M. Wolever, MD, PhD St. Michael's Hospital, Toronto
  More Information

Responsible Party: Thomas Wolever, Scientist at Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto
ClinicalTrials.gov Identifier: NCT01939600     History of Changes
Other Study ID Numbers: GIL-1322
First Submitted: August 29, 2013
First Posted: September 11, 2013
Last Update Posted: November 18, 2014
Last Verified: November 2014

Keywords provided by Thomas Wolever, St. Michael's Hospital, Toronto:
Resistant starch
Ileostomy
In vivo
Carbohydrate digestibility

Additional relevant MeSH terms:
Malabsorption Syndromes
Intestinal Diseases
Gastrointestinal Diseases
Digestive System Diseases
Metabolic Diseases