RESUMO
OBJECTIVE: Resistant maltodextrin has been shown to increase fecal bulk by resisting digestion and being partially fermented by colonic bacteria to short-chain fatty acids (SCFA). The objective of this experiment was to determine potential prebiotic effects, gastrointestinal tolerance, and fecal characteristics of free-living humans fed a novel resistant maltodextrin or a normal maltodextrin control. METHODS: Subjects (n = 38) were enrolled in a randomized, double-blind study where they were assigned to one of three daily treatments: 15 g maltodextrin; 7.5 g maltodextrin plus 7.5 g resistant maltodextrin (Fibersol-2; Matsutani Chemical Company, Hyogo, Japan); and 15 g resistant maltodextrin. The experiment lasted 7 wk and consisted of a 2 wk baseline period, a 3 wk treatment period, and a 2 wk washout period. During wk 3 to 5 (treatment period), subjects consumed their assigned treatments. RESULTS: Resistant maltodextrin supplementation tended to increase (p = 0.12) fecal Bifidobacterium populations during the treatment period, altered (p < 0.05) bacterial populations from baseline to treatment, and resulted in very minor effects in gastrointestinal tolerance. There was a shift (p < 0.05) in molar proportions of SCFA towards butyrate, the preferred energy substrate of colonocytes. CONCLUSION: Resistant maltodextrin supplementation was well tolerated, resulted in favorable fermentation characteristics in the large bowel, and also resulted in a change in bacterial populations.
Assuntos
Fezes/química , Trato Gastrointestinal/efeitos dos fármacos , Polissacarídeos/administração & dosagem , Adulto , Amônia/metabolismo , Bifidobacterium/genética , Bifidobacterium/crescimento & desenvolvimento , Clostridium perfringens/genética , Clostridium perfringens/crescimento & desenvolvimento , DNA Bacteriano/química , DNA Bacteriano/genética , Método Duplo-Cego , Eletroforese em Gel de Poliacrilamida , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Feminino , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/fisiologia , Humanos , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Masculino , Reação em Cadeia da Polimerase , Polissacarídeos/química , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genéticaRESUMO
This research examined variation in chemical composition and nutrient quality of soybeans (SBs) and soybean meals (SBMs) produced at seven commercial extruder/expeller plants in the United States (experiment 1), as well as differences in amino acid digestibilities when roosters were fed SBMs extruded at 121, 135, 150, or 160 degrees C at a U.S. pilot processing plant (experiment 2). In experiment 1, limited variation existed in the composition of SBs arriving at the plants, whereas substantial differences were noted in amino acid composition and protein quality of the resultant SBMs. In experiment 2, the SBMs extruded at 121 and 135 degrees C were underprocessed as noted by high urease activities and lower amino acid digestibilities. Soybean meals extruded at 150 and 160 degrees C resulted in higher amino acid digestibilities and lower urease activities, indicating adequate processing. Large variation exists in the nutritional quality of extruder/expeller SBMs currently in the marketplace. Optimal processing temperatures should be >135 degrees C, and temperatures as high as 165 degrees C do not result in overprocessing.
