Fiber and prebiotic supplementation in enteral nutrition: A systematic review and meta-analysis

Table 1 Characteristics of included studies (1990-2013)

Ref.	Study design	Study population	Dose and type of fiber	Study duration	SIGN category	Jadad score
Dobb et al[24], 1990	Double-blind RCT	91 adult patients in ICU, The Royal Perth Hospital, Australia	Soy polysaccharide, 21 g/L	Max of 18 d/discharge ICU	High quality	4
Shankardass et al[25], 1990	Double-blind, cross-over RCT	28 long-term EN patients, Multicenter: Chedoke-McMaster Hospital, Queen Elizabeth Hospital, Riverdale Hospital, Sunnybrook Medical Centre, University of Toronto, Toronto, Ontario, Canada	Soy polysaccharide, 12.8 g/1000 kcal	12 wk	Acceptable	3
Guenter et al[26], 1991	Non-RCT	100 ICU patients, Graduate Hospital Pennsylvania, United States	Soy polysaccharide, 14.4 g/L	Not mentioned	Acceptable	0
de Kruif et al[27], 1993	RCT	60 surgical patients, University Hospital, Netherlands	Soy polysaccharide, 20 g/L	5 d	Acceptable	3
Collier et al[28], 1994	Pre-post observational study	57 surgical patients, Regional Medical Centre, Memphis Tennessee, United States	Soy polysaccharide, 21 g/L	Not mentioned	NA	0
Homann et al[29], 1994	Double-blind RCT	100 surgical and medical patients, Germany	Partially hydrolyzed guar gum, 20 g/L	10 d	Acceptable	2
Zarling et al[30], 1994	Cross-over RCT	10 recovering stroke patients, Extended Care facilities, Hines VA Hospital, Illinois, United States	Oat and soy fiber, 14.4 g/L	23 d	Acceptable	2
Reese et al[31], 1996	Double-blind RCT	80 surgical patients (head and neck cancer), University of Iowa Hospital, United States	Soy polysaccharide, 7 or 14 g/L	Until patient changed to oral/discharged	High quality	5
Heather et al[32], 1991	RCT	49 mixed wards patients, Portland Veterans Affairs Medical Centre, Portland, United States	Psyllium, 15 g/d	6 d	Acceptable	2
Belknap et al[33], 1997	RCT	60 medical, surgical, and ICU patients, Department of Veterans Affairs Medical Center, Oklahoma, United States	Psyllium hydrophilic mucilloids, 14 g/d	7 d	Acceptable	3
Sobotka et al[34], 1997	Single-blind, pre-post single group trial	9 patients, Charles University, Hradec Krdlove, Czech Republic	Inulin 15 g/L	2 wk	Acceptable	0
Emery et al[35], 1997	RCT	31 ICU patients, Pennsylvania Hospital, United States	Banana flakes, 1.5 g/d	7 d	Acceptable	0
Khalil et al[36], 1998	Single-blind RCT	16 surgical patients, National University Hospital, Singapore	Oat and soy polysaccharides, 14.4 g/L	10 d	Acceptable	2
Cockram et al[37], 1998	Single-blind RCT	79 hemodialysis patients from three outpatients hemodialysis clinics, United States	FOS, 15.4 g/L	3 wk	Acceptable	2
Schultz et al[38], 2000	Double-blind, 2 × 2 factorial RCT	44 critically ill patients, Maine Medical Center, Portland, United States	Mixed fiber1 and pectin, up to 17 g/d, inclusive of 10 g/L FOS	9 d	High quality	4
Spapen et al[39], 2001	Double-blind, RCT	25 critically ill patients, Academic Hospital, Vrije, Brussels, Belgium	Partially hydrolyzed guar gum, 22 g/L	21 d/withdrawal of EN	High quality	4
Nakao et al[40], 2002	Pre-post single group trial	20 geriatric patients, Nagoya University Hospital, Japan	Galactomannan, 7-28 g/d	6 wk	Acceptable	0
Rushdi et al[41], 2004	Double-blind RCT	20 critically ill patients, Teaching Hospital, Cairo University, Egypt	Guar gum, 22 g/L	4 d	High quality	5
Vandewoude et al[42], 2005	RCT	172 geriatric patients, Universitair Centrum Geriatrie, Belgium	Mixed fiber2, 30 g/d inclusive of inulin	Not mentioned, measured weekly	Acceptable	1
Schneider et al[18], 2006	Double-blind, cross-over, RCT	15 long-term EN patients, University Hospital, Nice, France	Mixed fiber3, 15 g/L inclusive of 3.45 g/L of FOS	5 wk	High quality	3
Shimoni et al[43], 2007	Non-RCT	148 elderly patients from general internal medicine wards, Gastroenterology Laniado Hospital, Natanyia, Ramat Aviv, Israel	Soy polysaccharides, 13.6 g/1000 kcal	5 d	Acceptable	1
Wierdsma et al[44], 2009	Double-blind RCT	19 patients, Outpatients Clinic of the VU University Medical Centre, Amsterdam, The Netherlands	Mixed fiber1, 17.6 g/L inclusive of 7 g of FOS	8 wk	Acceptable	3
Chittawatanarat et al[45], 2010	Double-blind RCT	34 septic patients in ICU, Maharaj Nakorn Chiang Mai Hospital, Thailand	Mixed fiber2, 15.1 g/L inclusive of 5.3 g of FOS	14 d, ≥ 5 d	High quality	4
Kato et al[46], 2012	Pre-post single group trial	15 patients from medical wards of Kameyama Kaisei Hospital, Japan	Psyllium, 5.2 g/d	4 wk	Acceptable	0
Bittencourt et al[47], 2012	Sequential and observational study	110 adult patients, São Joaquim Hospital of Beneficência Portuguesa, Brazil	Soluble and insoluble fiber3, 15 g/L	≥ 5 d	NA	0
Majid et al[17], 2013	Double-blind RCT	22 critically ill patients, Guy’s and St Thomas’ NHS Foundation Trust and King’s College Hospital NHS Foundation Trust, London, United Kingdom	Mixed fiber4, 15 g/L and additional 7 g/d oligofructose/inulin	7-14 d	High quality	5

¹Oat, soy polysaccharide, gum arabic, cellulose, and FOS;

²Cellulose, hemicellulose A, pectin, hemicellulose B, and inulin;

³Cellulose, lignin, hemicellulose, pectin, and FOS;

⁴Soy polysaccharide, alpha-cellulose, arabic gum, inulin, oligofructose, and resistant starch. EN: Enteral nutrition; FOS: Fructo-oligosaccharides; ICU: Intensive care unit; RCT: Randomized controlled trial; SIGN: Scottish Intercollegiate Guidelines Network; NA: Not available.

Table 2 Studies investigating the effect of fiber supplementation in enteral nutrition on fecal microbiota

Ref.	Total microbiota count	Dominant group	Bifidobacteria	Others
Nakao et al[40], 2002	No change	↓ in aerobic bacteria	Not measured	Not measured
Schneider et al[18], 2006	↑	No change in composition of aerobic and anaerobic, gram positive and gram negative bacteria	No change	↑ in the numbers of enterococci at the end of the fiber-free EN
				↑ in the numbers of bacteroides at the end of the mixed fiber EN
Wierdsma et al[44], 2009	Not measured	Not measured	↓ In patients compared to healthy controls	Not measured
			Concentration remained stable in the FOS group but ↓ in the non-FOS group during intervention
Majid et al[17], 2013	No change	No change	No change	↓Faecalibacterium prausnitzii and Bacteroides-Prevotella in the prebiotics group

EN: Enteral nutrition; FOS: Fructo-oligosaccharides.

Table 3 Studies investigating the effect of fiber supplementation in enteral nutrition towards short-chain fatty acids

Ref.	Total SCFA	Acetate	Propionate	Butyrate
Sobotka et al[34], 1997	No change	No change	No change	No change
Nakao et al[40], 2002	No change	↑	↑	No change
Schneider et al[18], 2006	↑	↑	No change	↑
Kato et al[46], 2012	↑	↑	No significant amount detected	No significant amount detected
Majid et al[17], 2013	No change	No change	No change	No change

EN: Enteral nutrition; SCFA: Short-chain fatty acid.