title: The metabolizable energy of dietary resistant maltodextrin is variable and alters fecal microbiota composition in adult men.
abstract: Resistant maltodextrin (RM) is a novel soluble, nonviscous dietary fiber. Its metabolizable energy (ME) and net energy (NE) values derived from nutrient balance studies are unknown, as is the effect of RM on fecal microbiota. A randomized, placebo-controlled, double-blind crossover study was conducted (n = 14 men) to determine the ME and NE of RM and its influence on fecal excretion of macronutrients and microbiota. Participants were assigned to a sequence consisting of 3 treatment periods [24 d each: 0 g/d RM + 50 g/d maltodextrin and 2 amounts of dietary RM (25 g/d RM + 25 g of maltodextrin/d and 50 g/d RM + 0 g/d maltodextrin)] and were provided all the foods they were to consume to maintain their body weight. After an adaptation period, excreta were collected during a 7-d period. After the collection period, 24-h energy expenditure was measured. Fluorescence in situ hybridization, quantitative polymerase chain reaction, and 454 titanium technology-based 16S rRNA sequencing were used to analyze fecal microbiota composition. Fecal amounts of energy (544, 662, 737 kJ/d), nitrogen (1.5, 1.8, 2.1 g/d), RM (0.3, 0.6, 1.2 g/d), and total carbohydrate (11.1, 14.2, 16.2 g/d) increased with increasing dose (0, 25, 50 g) of RM (P < 0.0001). Fat excretion did not differ among treatments. The ME value of RM was 8.2 and 10.4 kJ/g, and the NE value of RM was -8.2 and 2.0 kJ/g for the 25 and 50 g/d RM doses, respectively. Both doses of RM increased fecal wet weight (118, 148, 161 g/d; P < 0.0001) and fecal dry weight (26.5, 32.0, 35.8 g/d; P < 0.0001) compared with the maltodextrin placebo. Total counts of fecal bacteria increased by 12% for the 25 g/d RM dose (P = 0.17) and 18% for the 50 g/d RM dose (P = 0.019). RM intake was associated with statistically significant increases (P < 0.001) in various operational taxonomic units matching closest to ruminococcus, eubacterium, lachnospiraceae, bacteroides, holdemania, and faecalibacterium, implicating RM in their growth in the gut. Our findings provide empirical data important for food labeling regulations related to the energy value of RM and suggest that RM increases fecal bulk by enhancing the excretion of nitrogen and carbohydrate and the growth of specific microbial populations.
authors.affiliation: USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD David.Baer@ars.usda.gov.
authors.forename: David J
authors.initials: DJ
authors.lastname: Baer
authors.affiliation: USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD.
authors.forename: Kim S
authors.initials: KS
authors.lastname: Stote
authors.affiliation: USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD.
authors.forename: Theresa
authors.initials: T
authors.lastname: Henderson
authors.affiliation: USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD.
authors.forename: David R
authors.initials: DR
authors.lastname: Paul
authors.affiliation: Matsutani Chemical Industry, Itami City, Hyogo, Japan; and.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Okuma
authors.affiliation: Matsutani Chemical Industry, Itami City, Hyogo, Japan; and.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tagami
authors.affiliation: Matsutani Chemical Industry, Itami City, Hyogo, Japan; and.
authors.forename: Sumiko
authors.initials: S
authors.lastname: Kanahori
authors.affiliation: Matsutani Chemical Industry, Itami City, Hyogo, Japan; and.
authors.forename: Dennis T
authors.initials: DT
authors.lastname: Gordon
authors.affiliation: USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD.
authors.forename: William V
authors.initials: WV
authors.lastname: Rumpler
authors.affiliation: Department of Epidemiology, College of Public Health and Health Professions and College of Medicine, Emerging Pathogen Institute, University of Florida, Gainesville, FL.
authors.forename: Maria
authors.initials: M
authors.lastname: Ukhanova
authors.affiliation: Department of Epidemiology, College of Public Health and Health Professions and College of Medicine, Emerging Pathogen Institute, University of Florida, Gainesville, FL.
authors.forename: Tyler
authors.initials: T
authors.lastname: Culpepper
authors.affiliation: Department of Epidemiology, College of Public Health and Health Professions and College of Medicine, Emerging Pathogen Institute, University of Florida, Gainesville, FL.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, College of Public Health and Health Professions and College of Medicine, Emerging Pathogen Institute, University of Florida, Gainesville, FL.
authors.forename: Volker
authors.initials: V
authors.lastname: Mai
mesh_terms: D000328:Adult; D058491:Bacterial Load; D001439:Bacteroides / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D001644:Bifidobacterium / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D003013:Clostridium / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D018592:Cross-Over Studies; D004063:Digestion; D004311:Double-Blind Method; D004734:Energy Metabolism; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005285:Fermentation; D006090:Gram-Negative Bacteria / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology*; D008297:Male; D008396:Maryland; D008875:Middle Aged; D011134:Polysaccharides / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D056692:Prebiotics / Q000032:analysis; D012995:Solubility; D014783:Viscosity
chemical_list: D011134:Polysaccharides; D056692:Prebiotics; C008315:maltodextrin