InfoSynergy
Probiotics
PHGG can act as a fermentable substrate for beneficial bacteria and may complement probiotic use.
Recommendation: Combine gradually to avoid gas; start one product first in sensitive IBS.
Partially Hydrolyzed Guar Gum (Sunfiber)
Other ·Moderate evidence ·Reviewed May 2026
Partially hydrolyzed guar gum (PHGG) is a low-viscosity soluble fiber produced from guar gum and commonly sold as Sunfiber. It is fermented by colonic bacteria to short-chain fatty acids and has human evidence for stool normalization and IBS symptom support. It is generally well tolerated when titrated slowly, but bloating and medication or mineral spacing issues still matter.
What it's good for
The bottom line
Evidence rating moderate. Most-documented uses: supports stool regularity in constipation or diarrhea tendency, may reduce ibs bloating and abdominal discomfort, acts as a prebiotic fiber supporting beneficial bacteria. 3 sources indexed (2015–2023), with 3 interaction records on file.
The science
How it works, mechanistically.
Core mechanism
PHGG resists upper-GI digestion and is fermented in the colon, supporting short-chain fatty acid production and beneficial shifts in gut microbiota. Hydrolysis lowers viscosity compared with intact guar gum, improving mixability and tolerability. It can normalize stool form by increasing water-holding capacity and fermentation products, but rapid dose escalation can increase gas and bloating.1,2
Class
Low-viscosity soluble prebiotic fiber
Found in food
Guar bean-derived fiber, Not naturally present as PHGG in ordinary foods
Low-status signs
No PHGG-specific deficiency; low soluble or prebiotic fiber intake may contribute to irregular stool patterns and lower short-chain fatty acid production.
Absorption
Water-soluble; take with food
Dosing
Dosing & protocol.
Common range
3-6 g daily, titrated slowly; some studies use 5-10 g/day
Recommended form
Unflavored PHGG powder such as Sunfiber mixed into water or food
This fiber is fermented or acts locally rather than being absorbed intact. Titrate gradually, take with adequate fluid, and separate from medications or minerals when absorption timing matters.
Forms
Forms & what to buy.
Ranked by evidence and value.
PHGG Powder Recommended
Low-viscosity powder dissolves well and is easy to titrate. Mix with water or food; take with adequate fluid.
PHGG Stick Packs
Premeasured servings improve adherence and dose consistency. Can be mixed into noncarbonated drinks.
PHGG Capsules
Convenient but requires many capsules for clinical fiber doses. Take with a full glass of water.
Cost
What it actually costs.
Real-world pricing across three quality tiers. Assumes PHGG powder.
BudgetBest value
$6 /mo
$0.20 per dose
Mid
$14 /mo
$0.45 per dose
Premium
$26 /mo
$0.85 per dose
Bulk powder is most economical; branded stick packs cost more but improve convenience. Updated 2026-06-04.
Goals
Goal-based dosing.
Bowel Regularity
Timing: With a meal or beverage
Increase by 1-2 g every several days to reduce bloating.
IBS Support
Dose: 5-6 g daily
Timing: With breakfast or dinner
Often better tolerated than rapidly fermented fibers, but individual FODMAP sensitivity varies.
Microbiome Support
Dose: 3-10 g daily3
Timing: Any consistent time with fluid
Benefits require consistent use over weeks.
Why people use it
Symptoms it's matched to.
Where this appears in the symptom-to-supplement map, ranked by relevance.
Irregular bowel habits
70% relevance
PHGG can normalize stool form in both loose and hard stool patterns.1,3
DigestiveModerate evidenceSunfiber-type powder
Alarm symptoms require evaluation.
Constipation
66% relevance
Soluble fiber increases stool water-holding and supports regular bowel movements.2
DigestiveModerate evidencePHGG powder with fluid
Adequate hydration is essential.
Safety
Full safety detail.
Side effects
- Gas, bloating, or abdominal cramping during titration
- Loose stools at high doses
- Constipation if taken with inadequate fluid
- Possible reduced medication or mineral absorption if taken together
Contraindications
Interactions
Interaction records.
ModerateTiming Sensitive
Iron
Soluble fiber can reduce or delay mineral supplement absorption when taken at the same time.
Recommendation: Separate iron from PHGG by at least 2 hours when treating iron deficiency.
InfoCaution
Magnesium Glycinate
Both can affect bowel habits; magnesium may loosen stools while PHGG changes stool water and fermentation.
Recommendation: Adjust doses if loose stools, cramping, or urgency occur.
Search all 3 interaction records for Partially Hydrolyzed Guar Gum (Sunfiber) →
Sources
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Randomized controlled trials
1- 1Randomized clinical study: Partially hydrolyzed guar gum (PHGG) versus placebo in the treatment of patients with irritable bowel syndromeNeeds reviewNo linkParisi GC et al. · Turkish Journal of Gastroenterology · 2016
PHGG improved IBS symptom measures over placebo with generally good tolerability.
Reviews & position papers
1- 2Partially hydrolyzed guar gum: clinical nutrition usesNeeds reviewNo linkYoon SJ et al. · Nutrition in Clinical Practice · 2015
Review summarized PHGG use across constipation, diarrhea, IBS, and enteral nutrition contexts.
Reference material
1- 3Role of Baseline Gut Microbiota in the Response to Partially Hydrolyzed Guar Gum in Irritable Bowel SyndromeNeeds reviewNo linkZhou SY et al. · Nutrients · 2023
Microbiome features helped explain variability in IBS response to PHGG.
Keep exploring
Deep dives & adjacent profiles.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Partially Hydrolyzed Guar Gum (Sunfiber) in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.