Resistant Starch
Research reviewed: Up until 03/2026
Resistant Starch (Resistant starch (RS2, RS3 types)) is a dietary supplement with 11 published peer-reviewed studies involving 1,226 participants, researched for Gut Microbiome & SCFA Production, Blood Sugar & Insulin Sensitivity, Satiety & Weight Management and 2 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Gut Microbiome & SCFA Production
ModerateBlood Sugar & Insulin Sensitivity
ModerateSatiety & Weight Management
WeakColon Health
ModerateGut Health & Metabolic Function
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Gut Microbiome & SCFA Production
To evaluate resistant starch on gut microbiome composition and SCFA production.
Study Type
Randomised, double-blind, crossover
Purpose
To evaluate resistant starch on gut microbiome composition and SCFA production.
Dose
30 g/day resistant starch type 2 (from high-amylose maize)
Participants
46 healthy adults
Duration
3 weeks per arm, crossover
Results
RS2 significantly increased fecal Ruminococcus bromii and butyrate-producing bacteria. Fecal butyrate increased by 76%. Microbiome effects were highly individual-specific.
How They Measured It
Fecal microbiome (16S rRNA), fecal SCFA concentrations
To assess resistant starch type 3 effects on colonic fermentation and microbiome in overweight adults.
Study Type
Randomised controlled trial
Purpose
To assess resistant starch type 3 effects on colonic fermentation and microbiome in overweight adults.
Dose
25 g/day RS3
Participants
34 overweight adults
Duration
4 weeks
Results
RS3 significantly increased fecal butyrate concentrations and lowered fecal pH, indicating enhanced colonic fermentation. Bifidobacterium counts also increased.
How They Measured It
Fecal SCFA (butyrate, propionate, acetate), fecal pH, 16S sequencing
Blood Sugar & Insulin Sensitivity
To evaluate resistant starch on insulin sensitivity in metabolic syndrome.
Study Type
Randomised, double-blind, crossover
Purpose
To evaluate resistant starch on insulin sensitivity in metabolic syndrome.
Dose
40 g/day high-amylose maize resistant starch (HAM-RS2)
Participants
20 patients with metabolic syndrome
Duration
12 weeks per arm
Results
HAM-RS2 significantly improved insulin sensitivity (27% increase in first-phase insulin response) compared to placebo starch. No effect on body weight.
How They Measured It
Insulin sensitivity (euglycemic clamp), fasting glucose, HbA1c
To evaluate the effect of resistant starch on glycemic control.
Study Type
Systematic review and meta-analysis
Purpose
To evaluate the effect of resistant starch on glycemic control.
Dose
Various (10-40 g/day)
Participants
Meta-analysis of 18 RCTs, 982 participants
Duration
2-12 weeks
Results
RS supplementation significantly reduced fasting glucose (WMD −3.16 mg/dL) and fasting insulin (WMD −0.82 μU/mL). Greatest benefits in type 2 diabetes patients.
How They Measured It
Pooled fasting glucose, fasting insulin, HOMA-IR, HbA1c
Satiety & Weight Management
To evaluate resistant starch on satiety and energy intake.
Study Type
Randomised, crossover
Purpose
To evaluate resistant starch on satiety and energy intake.
Dose
30 g/day resistant starch
Participants
20 healthy adults
Duration
2 × 24 hours crossover
Results
RS significantly increased postprandial satiety and reduced energy intake at subsequent meal by ~10%. Breath hydrogen confirmed colonic fermentation.
How They Measured It
Satiety VAS, ad libitum energy intake, breath hydrogen
To evaluate resistant starch on body composition and metabolic markers in overweight adults.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate resistant starch on body composition and metabolic markers in overweight adults.
Dose
30 g/day HAM-RS2
Participants
86 overweight adults
Duration
12 weeks
Results
RS supplementation did not significantly reduce body weight but modestly reduced body fat percentage and waist circumference compared to placebo.
How They Measured It
Body weight, body fat (DXA), waist circumference, lipid profile
Colon Health
To evaluate resistant starch on colorectal cancer biomarkers.
Study Type
Randomised, placebo-controlled
Purpose
To evaluate resistant starch on colorectal cancer biomarkers.
Dose
30 g/day RS2
Participants
65 participants at increased CRC risk
Duration
4 weeks
Results
RS significantly reduced rectal mucosal proliferation and altered gene expression patterns consistent with reduced cancer risk. Butyrate levels correlated with effects.
How They Measured It
Rectal mucosal proliferation (Ki67), gene expression of cell cycle regulators
To evaluate resistant starch on colorectal cancer incidence in Lynch syndrome patients.
Study Type
Randomised, controlled (CAPP2 trial)
Purpose
To evaluate resistant starch on colorectal cancer incidence in Lynch syndrome patients.
Dose
30 g/day resistant starch (Novelose)
Participants
937 Lynch syndrome carriers
Duration
Up to 4 years intervention, 10-year follow-up
Results
RS did not reduce overall CRC risk during treatment period, but long-term follow-up showed 60% reduction in non-colorectal Lynch syndrome cancers (HR 0.37, p=0.002).
How They Measured It
Colorectal adenoma and cancer incidence
Gut Health & Metabolic Function
To evaluate the effects of resistant starch on metabolic markers and gut microbiota in women with metabolic syndrome risk factors.
Study Type
Randomized, Double-Blind Pilot Study
Purpose
To evaluate the effects of resistant starch on metabolic markers and gut microbiota in women with metabolic syndrome risk factors.
Dose
Resistant starch supplement 20 g/day
Participants
Women with metabolic syndrome risk factors
Duration
8 weeks
Results
Resistant starch supplementation improved metabolic markers and favorably modulated gut microbiota composition in women at risk for metabolic syndrome.
How They Measured It
Metabolic markers (glucose, insulin, lipids), gut microbiota composition
To evaluate the efficacy of resistant starch in patients with metabolic-associated steatotic liver disease (MASLD).
Study Type
Randomized Controlled Trial (Multicenter)
Purpose
To evaluate the efficacy of resistant starch in patients with metabolic-associated steatotic liver disease (MASLD).
Dose
Resistant starch supplement 40 g/day
Participants
Adults with metabolic-associated steatotic liver disease
Duration
16 weeks
Results
Resistant starch supplementation significantly reduced liver fat and improved metabolic parameters in MASLD patients, with effects mediated through gut microbiome changes.
How They Measured It
Liver fat content (MRI), ALT, AST, lipid profile, gut microbiota
To evaluate whether resistant starch improves Parkinson's disease symptoms through gut microbiome restructuring.
Study Type
Randomized Controlled Trial
Purpose
To evaluate whether resistant starch improves Parkinson's disease symptoms through gut microbiome restructuring.
Dose
Resistant starch supplement 40 g/day
Participants
Parkinson's disease patients
Duration
12 weeks
Results
Resistant starch supplementation improved motor symptoms in Parkinson's disease patients, associated with gut microbiome restructuring and reduced inflammation.
How They Measured It
UPDRS motor scores, gut microbiome composition, inflammatory markers, SCFAs
Frequently Asked Questions
Common questions about Resistant Starch research
There are currently 11 peer-reviewed studies on Resistant Starch (Resistant starch (RS2, RS3 types)), involving 1,226 total participants. Research covers Gut microbiome support, Blood sugar management, Satiety & weight and 1 more areas. The overall evidence strength is rated as Strong.
The evidence is currently rated as "Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (10 human studies), and reported outcomes.
Resistant Starch has been researched for: Gut microbiome support, Blood sugar management, Satiety & weight, Colon health. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 10 out of 11 studies are human trials. Human trials carry more weight in our evidence scoring system.
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