Effects of resistant starch on behaviour, satiety-related hormones and metabolites in growing pigs.
Resistant starch (RS) has been suggested to prolong satiety in adult pigs. The present study investigated RS-induced changes in behaviour, satiety-related hormones and metabolites in catheterized growing pigs to explore possible underlying mechanisms for RS-induced satiety. In a cross-over design with two 14-day periods, 10 pigs (initial BW: 58 kg) were assigned to two treatments comprising diets containing either 35% pregelatinized starch (PS) or 34% retrograded starch (RS). Diets were isoenergetic on gross energy. Pigs were fed at 2.8× maintenance. Postprandial plasma response of satiety-related hormones and metabolites was measured at the end of each period using frequent blood sampling. Faecal and urinary energy losses were measured at the end of each period. Behaviour was scored 24 h from video recordings using scan sampling. Energy digestibility and metabolizability were ~6% lower in RS compared with PS diet (P<0.001), and metabolizable energy (ME) intake was ~3% lower in RS-fed than in PS-fed pigs (P<0.001). RS-fed pigs showed less feeder-directed (P=0.001) and drinking (P=0.10) behaviours than PS-fed pigs throughout the day. Postprandial peripheral short-chain fatty acid (SCFA) levels were higher in RS-fed than in PS-fed pigs (P<0.001). Postprandial glucose and insulin responses were lower in RS-fed than in PS-fed pigs (P<0.001). Triglyceride levels were higher in RS-fed than in PS-fed pigs (P<0.01), and non-esterified fatty acid levels did not differ between diets (P=0.90). Glucagon-like peptide-1 (GLP-1) levels were lower in RS-fed than in PS-fed pigs (P<0.001), and peptide tyrosine tyrosine (PYY) levels did not differ between diets (P=0.90). Blood serotonin levels were lower (P<0.001), whereas monoamine oxidase activity (P<0.05) and tryptophan (P<0.01) levels were higher in RS-fed than in PS-fed pigs. Despite a lower ME intake, RS seemed to prolong satiety, based on behavioural observations. Possible underlying mechanisms for RS-induced satiety include increased 24 h plasma SCFA levels, and decreased postprandial glucose and insulin responses. GLP-1 and PYY seemed not to play a role in RS-induced satiety. Low blood serotonin levels in RS-fed pigs suggested a difference in intestinal serotonin release between treatments. Increased postprandial plasma triglyceride levels corresponded with increased SCFA levels, but it is unclear whether triglycerides may have signalled satiety in RS-fed pigs.
1Adaptation Physiology Group,Wageningen University,P.O. Box 338,6700 AH,Wageningen,The Netherlands.
C
C
Souza da Silva
3Nutrition,Metabolism and Genomics Group,Division of Human Nutrition,Wageningen University,Bomenweg 2,6703 HD,Wageningen,The Netherlands.
D
D
Haenen
1Adaptation Physiology Group,Wageningen University,P.O. Box 338,6700 AH,Wageningen,The Netherlands.
S J
SJ
Koopmans
3Nutrition,Metabolism and Genomics Group,Division of Human Nutrition,Wageningen University,Bomenweg 2,6703 HD,Wageningen,The Netherlands.
G J E J
GJ
Hooiveld
2Animal Nutrition Group,Wageningen University,P.O. Box 338,6700 AH,Wageningen,The Netherlands.
G
G
Bosch
1Adaptation Physiology Group,Wageningen University,P.O. Box 338,6700 AH,Wageningen,The Netherlands.
J E
JE
Bolhuis
1Adaptation Physiology Group,Wageningen University,P.O. Box 338,6700 AH,Wageningen,The Netherlands.
B
B
Kemp
3Nutrition,Metabolism and Genomics Group,Division of Human Nutrition,Wageningen University,Bomenweg 2,6703 HD,Wageningen,The Netherlands.
M
M
Müller
2Animal Nutrition Group,Wageningen University,P.O. Box 338,6700 AH,Wageningen,The Netherlands.
W J J
WJ
Gerrits
D000821:Animal Feed; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D018592:Cross-Over Studies; D004032:Diet; D004043:Dietary Fiber / Q000378:metabolism / Q000494:pharmacology; D002149:Energy Intake / Q000187:drug effects; D005232:Fatty Acids, Volatile / Q000378:metabolism; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism; D006728:Hormones / Q000502:physiology*; D006815:Hunger / Q000187:drug effects; D007328:Insulin / Q000097:blood; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D019518:Postprandial Period / Q000187:drug effects; D012528:Satiety Response / Q000187:drug effects*; D013213:Starch / Q000378:metabolism / Q000494:pharmacology*; D013552:Swine / Q000502:physiology*; D013997:Time Factors; D014280:Triglycerides / Q000378:metabolism
D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; D006728:Hormones; D007328:Insulin; D014280:Triglycerides; D052216:Glucagon-Like Peptide 1; D013213:Starch