TABLE 1.

The response of gut microbiome to the dietary interventions.

Dietary interventions	Duration	Study design	Sample size (population)	Population types	Analysis platform	Outcomes	References
No fiber, polydextrose (21 g/day); soluble corn fiber (21 g/day)	21 days	A randomized double-blind, placebo-controlled crossover trial	20	Normal weight (males)	Pyrosequencing 16S rRNA gene	A shift in the gut microbial community with fiber interventions	Hooda et al. (2012)
Whole grain 150 g/day) verses refined grain	14 days	Longitudinal crossover study	17	Normal weight individuals	FISH for bacterial species enumeration	An increase in the Clostridium leptum group with the whole grain diet	Ross et al. (2011)
130 g of pinto bean (dried and cooked) chicken-noodle soup	12 weeks	Factorial design	80 (40 each in 2 groups)	Normal weight pre-metabolic syndrome and control	FISH for bacterial species enumeration	Eubacterium limosum levels were decreased by 50% in the beans group	Finley et al. (2007)
Controlled basal diet fortified with either High resistant Starch (amylomaize starch) or Low resistant Starch (cornstarch)	04 weeks	Randomized controlled crossover	12	Normal weight individuals		Differences in breath hydrogen levels. Changes in the fecal parameters (pH, β-glucosidase, certain SCFAs, secondary bile acids) associated with bacterial activity	Hylla et al. (1998)
Fructo-oligosaccharides (20 g) and 10 g partially hydrolyzed guar gum (10 g) per day vs. placebo	21 days	Human volunteer study	31	Normal weight	FISH for bacterial species enumeration	Increase in Bifidobacterium species No change in fecal pH	Tuohy et al. (2001)
A high-fiber diet containing LKFiber compared to a control diet	01 month	A single-blind, randomized, crossover study	38	Normal weight males	Short chain fatty acids and bacterial enzymatic activity in feces	Higher fiber altered the parameters of bowel function, decreased fecal pH., Increased fecal SCFA and decreased β-glucuronidase activity	Johnson et al. (2006)
48 g breakfast cereals, (whole grain or wheat bran)	03 weeks periods (Twice)	A double-blind, placebo-controlled, crossover study	31	Normal weight individuals	FISH for the enumeration of bacterial groups	The numbers of fecal Bifidobacteria and lactobacilli were substantially higher in the whole-grain group. Significant increase in serum ferulic acid levels	Costabile et al. (2008)
LKFiber diet containing additional 17–30-g fiber per day compared with a control diet	28 days	Single-blind, randomized, crossover	18	Healthy males	Quantitative FISH analysis	Significantly higher levels of Bifidobacterium species and lower clostridial species in the LKFibre diet group	Smith et al. (2006)
Reduced-fat diet or reduced-carbohydrate diet	01 year	Clinical trial	12	Obese individuals	Pyrosequencing of 16S rRNA gene	The relative abundance of Bacteroidetes increased while the Firmicutes were decreased over time but were not associated with the diet type	Ley et al. (2006)
High protein and medium carbohydrate (164 g/day) compared with high protein and low carbohydrate (24 g/day)	04 weeks	Randomized controlled crossover	19	Obese individuals	FISH for major bacterial groups enumeration	Certain groups of bacteria varied with the diet type. The short-chain fatty acids differed by the diet type	Duncan et al. (2007)
Maintenance diet (360 g carbohydrate, 116 g fat, and 85 g protein per day). High-protein (139 g protein and moderate-carbohydrate (181 g carbohydrate) diet, and 82 g fat/day) and a high-protein (137 g protein, low-carbohydrate (22 g carbohydrate) and 143 g fat/day diet	07 days maintenance diet followed by 04 weeks intervention	Randomized controlled crossover	17	Obese males	FISH for bacterial 16S rRNA genes	The high protein and low carbohydrate diet decreased the population of Eubacterium rectale and Roseburia genus	Russell et al. (2011)
High (43 g/day) cereal fiber, or control (14 g/day) cereal fiber, or high-protein (28% of energy-intake) along with 14 g/day cereal-fiber, or moderately high cereal fiber (26 g/day) with protein (23% of energy-intake)	18 weeks	Randomized controlled crossover	69	overweight Individuals	FISH for bacterial groups enumeration	No effect of diet on the population of gut bacteria	Weickert et al. (2011)