GutGard® - Clinical Research Data Summary

GutGard® Deglycyrrhizinated Licorice Root Extract

GutGard® is a clinically studied ingredient used in the following Silver Fern™ Brand products:

Introduction

GutGard® is a standardized, flavonoid-rich extract of deglycyrrhizinated licorice root (Glycyrrhiza glabra) that has been evaluated in multiple randomized, double-blind, placebo-controlled human clinical studies. These studies have investigated its effects on upper digestive comfort, digestive quality of life, and markers associated with gastric microbial balance. Across the trials, participants taking approximately 150 mg per day of GutGard® experienced significant improvements in digestive symptom scores, reflux-related discomfort, and measures of digestive well-being compared with placebo. Benefits were observed within as little as one to two weeks in some studies, and the ingredient was reported to be well tolerated throughout the study periods.*

These are the studies for GutGard®. Below, we provided a summary of each key data for each study, along with a link to the complete clinical research.

  1. Summary of Study 1 – Full Study: https://pubmed.ncbi.nlm.nih.gov/21747893/
  2. Summary of Study 2 – Full Study: https://pubmed.ncbi.nlm.nih.gov/23606875/
  3. Summary of Study 3 – Full Study: https://pubmed.ncbi.nlm.nih.gov/39929150/

Ingredient Manufacturer Link: https://ingredients.aidp.com/#gutgard



Study 1 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/21747893/

An Extract of Glycyrrhiza glabra (GutGard®) Alleviates Symptoms of Functional Dyspepsia: A Randomized, Double-Blind, Placebo-Controlled Study
Evidence-Based Complementary and Alternative Medicine. 2012:216970.

A randomized, double-blind, placebo-controlled clinical study evaluated the effects of GutGard®, a flavonoid-rich extract of licorice root (Glycyrrhiza glabra), on digestive comfort in individuals experiencing functional dyspepsia symptoms. Participants took either GutGard® (75 mg twice daily) or a placebo for 30 days. Researchers assessed changes in upper digestive symptoms using a validated Likert symptom scale, overall treatment satisfaction, and quality of life using the Nepean Dyspepsia Index.

Study Design Highlights

  • Study design: Randomized, double-blind, placebo-controlled clinical study
  • Population: Adults experiencing upper digestive discomfort associated with functional dyspepsia symptoms
  • Dose: 75 mg GutGard® twice daily (150 mg total daily intake)
  • Duration: 30 days
  • Measured outcomes: Upper digestive symptom scores, global assessment of efficacy, quality of life (Nepean Dyspepsia Index)

Key Findings (What the Study Showed)

  • Statistically significant improvements in digestive symptom scores compared with placebo
  • Meaningful improvements in quality-of-life measures (Nepean Dyspepsia Index)
  • Improvements observed as early as day 15
  • Continued improvement through day 30
  • Well tolerated with no significant safety concerns reported

Benefits of GutGard® Demonstrated by This Study

Based directly on the clinical outcomes, GutGard® was shown to:
✓ Support upper digestive comfort in individuals with functional dyspepsia symptoms
✓ Support improvements in post-meal digestive comfort including fullness and bloating
✓ Support daily digestive well-being (Nepean Dyspepsia Index quality-of-life scores)
✓ Produce improvements within approximately two weeks
✓ Be safe and well tolerated at 150 mg/day

Why This Study Matters

The results of this randomized controlled study suggest that GutGard® may help support digestive comfort and quality of life in individuals experiencing upper digestive discomfort associated with functional dyspepsia symptoms when taken daily for 30 days. The relatively rapid onset of improvements — detectable by day 15 — makes this evidence particularly relevant for individuals seeking support for everyday upper digestive comfort.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/21747893/



Study 2 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/23606875/

Effect of GutGard® in the Management of Helicobacter pylori: A Randomized Double-Blind Placebo-Controlled Study
Evidence-Based Complementary and Alternative Medicine. 2013, Article ID 263805.

This randomized, double-blind, placebo-controlled clinical study evaluated the effects of GutGard®, a standardized flavonoid-rich extract of licorice root (Glycyrrhiza glabra), on gastric microbial balance in individuals with confirmed H. pylori colonization. A total of 107 participants were randomly assigned to receive either 150 mg of GutGard® once daily or a placebo for 60 days. Researchers assessed gastric microbial markers using both the ¹³C-urea breath test and stool antigen testing at baseline, 30 days, and 60 days.

Study Design Highlights

  • Study design: Randomized, double-blind, placebo-controlled clinical trial
  • Participants: 107 adults with confirmed H. pylori colonization
  • Dose: 150 mg GutGard® once daily
  • Duration: 60 days
  • Measured outcomes: ¹³C-urea breath test (¹³C-UBT) and stool antigen test (HpSA) at Day 0, Day 30, and Day 60

Key Findings (What the Study Showed)

  • Stool antigen improvement: 56% of GutGard® participants showed negative stool antigen results vs. 4% in placebo group
  • Breath test improvement: 48% of GutGard® participants showed negative breath test results
  • Improvements measured at both 30 and 60 days, with strongest results at day 60
  • Substantially greater improvements in gastric microbial markers in the GutGard® group compared with placebo
  • Well tolerated throughout the 60-day study period

Benefits of GutGard® Demonstrated by This Study

Based directly on the clinical outcomes, GutGard® was shown to:
✓ Support a healthy gastric microbial environment based on validated breath and stool markers
✓ Produce meaningful improvements in stool antigen markers (56% vs. 4% placebo)
✓ Produce meaningful improvements in breath test markers (48% of participants)
✓ Demonstrate a once-daily, well-tolerated dose over 60 days
✓ Show progressive improvement from day 30 to day 60

Why This Study Matters

The results of this randomized controlled trial suggest that daily supplementation with GutGard® may help support a balanced gastric microbial environment and healthy stomach function, as demonstrated by significant improvements in markers associated with H. pylori colonization over a 60-day period. Gastric microbial balance plays a role in upper digestive well-being, and supporting this balance may contribute to greater digestive comfort.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/23606875/



Study 3 Summary

Complete Study Information: https://pubmed.ncbi.nlm.nih.gov/39929150/

Efficacy and Safety of GutGard® (Deglycyrrhizinated Glycyrrhiza glabra Extract) in Managing Gastroesophageal Reflux–Related Symptoms: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

This randomized, double-blind, placebo-controlled clinical study evaluated the effects of GutGard®, a flavonoid-rich, deglycyrrhizinated licorice root extract, on upper digestive comfort in 200 individuals experiencing reflux-related symptoms. Participants were randomly assigned to receive either GutGard® or a placebo for 28 days. Researchers evaluated symptom changes using validated questionnaires including the Gastroesophageal Reflux Disease Symptom Assessment Scale and the GERD-Health-Related Quality of Life questionnaire.

Study Design Highlights

  • Study design: Randomized, double-blind, placebo-controlled, parallel-group clinical trial
  • Participants: 200 adults with reflux-related digestive symptoms
  • Duration: 28 days
  • Follow-up assessments: Day 7, Day 14, Day 21 (phone follow-up), Day 28, Day 35
  • Measured outcomes: GERD-Health-Related Quality of Life (GERD-HRQL) questionnaire and GERD Symptom Assessment Scale

Key Findings (What the Study Showed)

  • Significant improvements in reflux-related symptom scores vs. placebo
  • Heartburn improvement: significant by day 14, with further improvement by day 28
  • Regurgitation improvement: significant as early as day 7
  • Significant improvement in GERD-related quality-of-life scores vs. placebo
  • Well tolerated throughout the 28-day study period

Benefits of GutGard® Demonstrated by This Study

Based directly on the clinical outcomes, GutGard® was shown to:
✓ Support significant improvements in reflux-related symptom scores within 28 days
✓ Support improvements in heartburn discomfort measurable by day 14
✓ Support improvements in regurgitation as early as day 7
✓ Support improved GERD-related quality-of-life scores
✓ Demonstrate benefits across a large study population of 200 participants
✓ Be well tolerated throughout the intervention period

Why This Study Matters

The results of this randomized controlled trial suggest that daily supplementation with GutGard® may help support upper digestive comfort and quality of life in individuals experiencing occasional reflux-related digestive symptoms, with improvements observed within the first few weeks of use. The early onset of regurgitation improvements at day 7 and heartburn improvements at day 14 is notable for individuals seeking relatively rapid upper digestive support.*

Reference Link: https://pubmed.ncbi.nlm.nih.gov/39929150/

Big-Picture Integration with Other Studies

  • Study 1: In a randomized double-blind clinical trial, 75 mg GutGard® twice daily for 30 days significantly improved digestive comfort scores and quality-of-life measures compared to placebo, with benefits observed by day 15.
  • Study 2: In a randomized, double-blind clinical study, 150 mg of GutGard® taken daily for 60 days significantly improved markers associated with gastric microbial balance compared with placebo, with 56% of participants showing improvements in stool antigen markers vs. 4% in the placebo group.
  • Study 3: In a randomized, double-blind clinical study of 200 adults, daily supplementation with GutGard® for 28 days significantly improved reflux-related symptom scores and digestive quality-of-life measures compared with placebo, with improvements in regurgitation observed as early as day 7.

GutGard® Ingredient Summary & Real-World Relevance

GutGard® is a clinically studied, flavonoid-rich extract of deglycyrrhizinated licorice root (Glycyrrhiza glabra) designed to support upper digestive health and comfort. It is standardized to key bioactive compounds such as glabridin and total flavonoids while minimizing glycyrrhizin, a compound that can cause electrolyte imbalance and fluid retention when consumed in high amounts. This specialized formulation allows GutGard® to deliver the beneficial digestive properties of licorice with a favorable safety profile.

GutGard® has been evaluated in multiple randomized, double-blind, placebo-controlled clinical trials examining its effects on digestive comfort, reflux-related symptoms, and markers associated with gastric microbial balance. Across these studies, participants typically consumed approximately 150 mg per day of GutGard® for 28–60 days, and the ingredient was reported to be well tolerated.

Clinical research suggests that GutGard® may help support digestive comfort and overall digestive well-being. In one study involving individuals experiencing upper digestive discomfort, participants taking GutGard® experienced significant improvements in digestive symptom scores and quality-of-life measures within 30 days. Another clinical trial evaluating markers associated with gastric microbial balance found that 56% of participants showed improvements in stool antigen markers and 48% showed improvements in breath test markers after 60 days, compared with minimal improvement in the placebo group. A separate randomized study in individuals experiencing reflux-related symptoms reported significant improvements in digestive quality-of-life scores, with improvements in symptoms such as heartburn and regurgitation beginning within 1–2 weeks of supplementation. Together, these findings suggest GutGard® may help support upper digestive comfort, promote a balanced gastric environment, and improve daily digestive well-being when taken consistently.*

Ingredient Manufacturer Link: https://ingredients.aidp.com/#gutgard

GutGard® is a clinically studied ingredient used in the following Silver Fern™ Brand products:

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

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