Green kiwifruit for the relief of constipation in patients with functional constipation and IBS-C – meta-analysis of three international trials
Richard Gearry, Shin Fukudo, Barbara Kuhn-Sherlock, Juliet Ansell,
Lynley Drummond, Giovanni Barbara
Disclosures
• I have received the following from Zespri International
– Research funding
– Advisory board membership
– Support to attend conferences
Background
• Constipation affects ~17% of global population
• Conventional treatments may be poorly tolerated
• There is a strong demand for natural food interventions to address GI symptoms
• Studies support the use of Zespri® Green Kiwifruit (Actinidia deliciosa var. Hayward) to improve bowel function
Kiwifruit and IBS-C / FCWhat do we know so far?
Authors Country Participants Study Design N Findings
Rush et al NZ >60 yearsConstipated
Randomised, crossover, no control
38 stool frequency ease of passing BM bulkier, softer stool
Chang et al Taiwan Adult IBS -constipated
Randomised study with capsule control
41 stool frequency colonic transit time
Chan et al Hong Kong
Constipatedadults
Prospective observational study, no control
53 stool frequency bowel habit satisfaction laxative use
Hiele(unpublished)
Belgium Adult IBS -constipated
Prospective observational study, no control
38 stool frequency ease of passing BM abdominal bloating
Rush et al, APJCN, 2002, Chang et al, APJCN, 2010, Chan et al, WJG, 2007
Potential mechanisms of action of kiwifruit
Bayer, Gearry, Drummond, Critical Reviews in Food Science and Nutrition, 2017
More evidence required
Strong evidence
Permeability (actinidin)
Mucous production (actinidin)
Inflammation (kissper)
Pro-inflammatory cytokines
NO production
Protein digestion (actinidin)
Gastric emptying (actinidin)
Transit time
Water retention (fibre)
Faecal bulk (fibre)
Lactobacilli, Bifidobacteria (fibre)
SCFA (fibre)
Hypotheses
• That consumption of two Zespri green kiwifruit* daily improves bowel motion frequency in constipated individuals by >1.5 complete spontaneous bowel motions (CSBM) per week
• That consumption of two Zespri green kiwifruit* daily improves gastrointestinal discomfort in constipated individuals
• That two Zespri green kiwifruit* are well tolerated by constipated individuals and healthy controls
*Actinidia deliciosa var Hayward
Three independent studies (same methodology)
• Christchurch, New Zealand (Gearry)
• Bologna, Italy (Barbara)
• Sendai, Japan (Fukudo)
InterventionsTwo Zespri Green Kiwifruit 7.5g psyllium
Study design• Randomised single-blinded cross-over design
• Powered to show an increase of 1.5 CSBM per week 90% power, 5% significance
2-week lead in period
4-week kiwifruit
intervention
4-week psyllium
intervention
4-week washout period
2-week follow-up period
4-week kiwifruit
intervention4-week psyllium
intervention
Inclusion / exclusion criteria.
Inclusion
• 18-65 years of age• BMI 18-35• Functional constipation (20)• IBS-C (20)• Healthy (20)
Exclusion• GI alarm symptoms• Significant chronic medical
conditions• Fasting glucose >7.2mmol/L• Drugs affecting GI motility• Pregnant / breastfeeding women• Known kiwifruit or latex allergy• Not prepared to stop other
laxatives
Schedule of assessments.
GSRS
POMS
IBS- SSI
Rome III
Lead –in 2 weeks
Intervention 14 weeks
Washout 4 weeks
Follow-up2 weeks
Intervention 24 weeks
0Week 62 10 14 16
BASELINE
Daily Diary
IBS - QoL
Food Diary
Stool Sample
Blood Sample(Vitamin C)
SmartPills (Italy/NZ)Radiopaque markers (Japan) (sub-cohort)
START OF STUDY
Results
Participants (ITT)
Healthy controls (HC) 61
Functional constipation (FC) 57
Constipation-predominant IBS (IBS-C) 60
Total 178
Primary outcome – CSBM / week (ITT)*P<0.05, **P< 0.01; ***P<0.001
Change in CSBM frequency
0
2
4
6
8
10
12
Pre Wk1 Wk2 Wk3 Wk4
Nu
mb
er /
wee
kFC+IBS-C CSBM
Psyllium
Kiwifruit
*** *** *** ***
*** *** *** ***
**P< 0.01; ***P<0.001
Meta-analysis of the effect of kiwifruit on CSBM/week
Effect of kiwifruit on GSRS total score**P< 0.01; ***P<0.001
Change in stool consistency (Bristol)
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Pre Wk1 Wk2 Wk3 Wk4
Sco
re
FC+IBS-C BSFS
Psyllium
Kiwifruit
** *** ** ***
**P< 0.01; ***P<0.001
Meta-analysis of the effect of kiwifruit on GSRS score
Adverse events
• No adverse events were observed
Conclusions
• Two Zespri green kiwifruit / day are safe & effective in people with IBS-C or FC for:
– relief of constipation
– improvement in gastrointestinal discomfort
– improvement in overall gastrointestinal symptoms
• Results suggest non-inferiority with psyllium
Acknowledgements• Giovanni Barbara / Bologna research team
• Shin Fukudo / Sendai research team
• Plant and Food Research
• Lynley Drummond
• Juliet Ansell / Zespri international