Kiwifruit and Kiwifruit Extracts for Treatment of Constipation: A Systematic Review and Meta-Analysis

Table 2

Study characteristics.

Population					Intervention	Outcomes
Study/Design/Population	Age years (SD)	Baseline weekly frequency of spontaneous bowel movements (standard deviation)	Intervention/dose/duration	Control	Study follow-up period in days
	Weight mean (standard deviation) kg
	Sex (%)
	Definition of constipation
Weir 2018; Adults ≥18 yrs.; Parallel-group double-blind RCT; N = 58	Age range: 23 to 65	2.2 (0.8)	Zyactinase capsules 2160 mg/day given as 720 mg tid	Placebo capsules containing the same color isomalt given at the same frequency as an intervention	14	(i) SBM^†; (ii) Modified BSS^§ (score 1–3); (iii) Abdominal pain; (iv) Adverse events (nonreported)
	Not reported
	Not reported
	FC^# defined by the author
Kindleysides 2015; Adults ≥18 yrs.; Crossover double-blind RCT; N = 40	Age: 40.8 (13.2)	2.4 (0.1)	Encapsulated kiwifruit extracts containing skin, flesh, and seeds, 1000 mg/day given as 500 mg bid	Placebo was encapsulated magnesium stearate matched for weight, color, and size given at the same frequency as intervention	21	(i) SBM^†; (ii) BSS^§; (iii) GSRS; (iv) Adverse events
	Weight 68 (14.7)
	Female (93%)
	FC defined by author
Ansell 2015; Adults ≥18 yrs.; Crossover double-blind RCT; N = 9	Age: 44 (6)	Not reported	Encapsulated kiwifruit extracts containing high dose Actazin 2400 mg/day given as 600 mg qid	Placebo capsules containing isomalt given at the same frequency as intervention	28	(i) SBM^†; (ii) BSS^§; (iii) frequency of SBM^† with straining; (iv) incomplete evacuation; (v) bloating; (vi) flatulence; (vii) laxatives; (viii) abdominal pain
	Weight: 67 (8)
	Female (89%)
	Rome III FC criteria
Udani 2013; Adults ≥18 yrs.; Parallel-group double-blind placebo-controlled RCT; N = 87	Age: 39.3 (13.8)	2.1 (0.6)	Kivia powder containing zyactinase 5500 mg/day given once daily in a sachet	Placebo was powder containing inactive compounds in identical sachet to kivia given same frequency as intervention	28	(i) CSBM^◊; (ii) BSS^§; (iii) abdominal pain; (iv) bloating; (v) flatulence; (vi) satisfaction with bowel habits; (vii) use of rescue laxatives; (viii) adverse events
	Weight: 73.5 (14.1)
	Female (64%)
	Rome III FC criteria
Barbara 2018; Adults ≥18 yrs.; Crossover, single-blind 3-centre RCT; N = 117	Not reported	3.5 (2.2)	Kiwifruit, 2 fruits/day	Psyllium 7.5 grams/day	14	(i) CSBM^◊; (ii) BSS^§; (iii) GSRS; IBS-C^‡ QoL questionnaire
Eady 2019; Adults ≥18 yrs.; Crossover, single-blind, RCT; N = 35	Age: 47 (12.9)	3.0 (1.6)	Kiwifruit, 3 fruits daily	Metamucil 2.5 teaspoons (5 g of fibre total) daily	45	(i) CSBM^◊; (ii) BSS^§; (iii) GSRS; (iv) Rome III classification
	Weight 67.5 (14.4)
	Female (100%)
	Rome III: (i) FC (29%); (ii) IBS-c‡ (71%)
Chey 2021; Adults ≥18 yrs.; Parallel-group nonblinded partial RCT; N = 79	Age 44.9 (16.8)	1.2 (1.5)	2 green kiwifruit daily (Actinidia deliciosa var. Hayward, fibre 6 g/day)	12 g of psyllium daily	28	(i) CSBM^◊ responder rate defined as ≥1 CSBM^◊/week; (ii) CSBM^◊ and SBM frequency; (iii) BSS; (iv) frequency of straining; (v) abdominal pain; (vi) bloating; (vii) adverse events
	Weight: NR
	Female (87%)
	Rome III: (i) FC (71%); (ii) IBS-C (33%)

^◊CSBM = complete spontaneous bowel movement, GSRS = gastrointestinal symptom rating scale for abdominal pain, RCT = randomized controlled trial, ^†SBM = spontaneous bowel movement, ^#FC = functional constipation, ^‡IBS-C = irritable bowel syndrome with constipation, ^§BSS = Bristol Stool Chart.