Effects of resistant starch, a non-digestible fermentable fiber, on reducing body fat.
OBJECTIVE
To assess the effects of energy dilution with non-fermentable and fermentable fibers on abdominal fat and gut peptide YY (PYY) and glucagon-like peptide (GLP)-1 expressions, three rat studies were conducted to: determine the effects of energy dilution with a non-fermentable fiber, compare similar fiber levels of fermentable and non-fermentable fibers, and compare similar metabolizable energy dilutions with fermentable and non-fermentable fibers.


METHODS
In Study 1, rats were fed one of three diets with different metabolizable energy densities. In Study 2, rats were fed diets with similar fiber levels using high amylose-resistant cornstarch (RS) or methylcellulose. In Study 3, rats were fed diets with a similar dilution of metabolizable energy using cellulose or RS. Measurements included food intake, body weight, abdominal fat, plasma PYY and GLP-1, gastrointestinal tract weights, and gene transcription of PYY and proglucagon.


RESULTS
Energy dilution resulted in decreased abdominal fat in all studies. In Study 2, rats fed fermentable RS had increased cecal weights and plasma PYY and GLP-1, and increased gene transcription of PYY and proglucagon. In Study 3, RS-fed rats had increased short-chain fatty acids in cecal contents, plasma PYY (GLP-1 not measured), and gene transcription for PYY and proglucagon.


CONCLUSIONS
Inclusion of RS in the diet may affect energy balance through its effect as a fiber or a stimulator of PYY and GLP-1 expression. Increasing gut hormone signaling with a bioactive functional food such as RS may be an effective natural approach to the treatment of obesity.
Keenan
Michael J
MJ
Human Nutrition and Food Division, School of Human Ecology, Louisiana State University Agriculture Center, Baton Rouge, LA 70803, USA. mkeenan@agctr.lsu.edu
Zhou
Jun
J
McCutcheon
Kathleen L
KL
Raggio
Anne M
AM
Bateman
H Gale
HG
Todd
Emily
E
Jones
Christina K
CK
Tulley
Richard T
RT
Melton
Sheri
S
Martin
Roy J
RJ
Hegsted
Maren
M
D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002432:Cecum / Q000378:metabolism; D004043:Dietary Fiber / Q000008:administration & dosage* / Q000378:metabolism; D002149:Energy Intake / Q000502:physiology; D004734:Energy Metabolism / Q000187:drug effects* / Q000502:physiology; D005232:Fatty Acids, Volatile / Q000032:analysis; D005260:Female; D005285:Fermentation; D052216:Glucagon-Like Peptide 1 / Q000097:blood / Q000378:metabolism*; D006801:Humans; D009765:Obesity / Q000178:diet therapy; D009929:Organ Size; D019894:Peptide YY / Q000097:blood / Q000378:metabolism*; D052336:Proglucagon / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013213:Starch / Q000008:administration & dosage* / Q000378:metabolism
D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; D019894:Peptide YY; D052336:Proglucagon; D052216:Glucagon-Like Peptide 1; D013213:Starch