Table 2.

Characteristics of Studies Investigating Effects of Dietary Fibers and Prebiotics on the Fecal Microbiota of Healthy Children and Adolescents

Country of Study, Age Range, Duration of Intervention	Study Design and Participants/Group	Nutrition Base and Fiber Type and Amount	Microbiota Assessment	Outcomes	Citation
Hungary (Pécs) 3-6 y 24 wk	Randomized, double-blind, placebo-controlled trial Prebiotic (n=110) Placebo (n=109)	Mixed with food or drink Inulin type fructans (6 g/d)	Baseline and week 24 qPCR	↑ relative abundances of Bifidobacterium and Lactobacillus ↔ numbers of total bacteria, relative abundances of C. perfringens, C. difficile and Enterobacteriaceae ↔ fecal pH and stool consistency	53
Belgium (Leuven) 8-12 y 3 wk	Randomized, double-blind, placebo-controlled crossover trial with 2 wk washout Wheat bran extract and control (n=29)	Soft drink Wheat bran extract containing arabinoxylan-oligosaccharides (5 g/d)	Baseline and d19 or 20 FISH	↑ Bifidobacterium level ↔ counts of Lactobacillus/Enterococcus, C. histolyticum/C. liteseburense, R. rectale/E. rectela groups, and F. prausnitzii ↔ fecal pH, each SCFA levels, percentage of moisture and stool frequency	54
U.S. (Indiana) 10-13 y 3 wk	Randomized, double-blind cross-over trial with 2 wk washout GOS 5g, GOS 10g and control (n=20)	Smoothie drinks GOS (5 or 10 g/d)	Baseline and the end of each treatment DGGE, qPCR	↔ numbers of DGGE bands Change in Bifidobacterium counts: GOS 5g > GOS 10g, control ↔ bowel movement frequency and stool consistency	55
U.S. (Indiana) 12-15 y 3 wk	Randomized double–blind cross-over trial with 7 d washout SCF and control (n=23)	Spaghetti, hamburgers, sandwiches and potato chips Soluble maize fiber (12 g/d)	Baseline and the end of each treatment V3-V5 16S rRNA gene by 454 pyrosequencing	↑ proportions of Parabacteroides, other Clostridiales and other Ruminococcaceae ↓ Enterococcus, Anaerofustis, Coprococcus and other Peptostreptococcaseae	56
U.S. (Indiana) 12-15 y 4 wk	Randomized double–blind cross-over trial with 3-4 wk washout SCF (10 g), SCF (20 g) and control (n=27)	Muffin and beverage	Before and after each intervention V3-V4 16S rRNA gene by 454 pyrosequencing	↑ Chao 1 and observed OTUs at species level Overall microbiota differed between samples with and without SCF SCF 10g ↑P arabacteroides and unclassified Lachnospiraceae, ↓ reclassified Ruminococcus SCF 20g ↑Parabacteroides and unclassified Lachnospiraceae, ↓ Bacteroides and Lachnospira Fecal pH: SCF 20g < control. SCF 10g ↔ SCFA concentrations	57

Abbreviations: DGGE, denaturing gradient gel electrophoresis; GOS, galactooligosaccharides; OTU, operational taxonomic unit; qPCR, quantitative PCR; SCF, soluble corn fiber; SCFA, short-chain fatty acids; ↑indicates significantly increased; ↓ indicated significantly decreased; ↔ indicates no effect