Food Additives & Ingredients · Gums & Thickeners

Guar Gum: Benefits, PHGG, Side Effects & Is It Bad for You?

Q: What is guar gum made from?

Guar gum is made from the seeds of the guar plant, Cyamopsis tetragonoloba, a legume: the seeds are split, the germ and hull are removed, and the inner endosperm is milled into a powder that's about 80% galactomannan fiber.[1][14]

Q: Is guar gum a prebiotic?

PHGG is: in placebo-controlled trials it raised Bifidobacterium and stool butyrate, and 3 or 6 grams a day raised Akkermansia in 2 weeks. Regular guar gum feeds gut bacteria too: in an 18-day study of 12 healthy men with no comparison group, 8 grams a day changed the makeup and activity of their gut bacteria.[31][35][34][40][84]

What guar gum is, how its gentle form, partially hydrolyzed guar gum (PHGG), feeds the good bacteria in your gut, what human trials show for bloating, regularity, SIBO, blood sugar and cholesterol, and how to use it well.

By Dr. Josh Axe, DC, DNM, CNS·Medically reviewed by the DrAxe.com Medical Advisory Board·24-min read

Meet the Medical Advisory Board

Evidence-based91 sources citedUpdated October 23, 2026

Published Oct 23, 2026Last updated Oct 23, 2026Editorial policyMedical review policyFact-checking policy

Guar pods. The young pods are cooked as a vegetable, and the seeds inside are milled into guar gum.

The Dr. Axe Score™

7.0/10

Overall Dr. Axe Score · Guar Gum

Guar gum scores 7.0 as a fiber you take on purpose, mostly as PHGG: a gentle prebiotic with a defined role in three of my gut protocols and human trials behind it for bloating, regularity, diarrhea and SIBO, plus regular guar's long record on blood sugar and cholesterol.

Scientific Evidence

6.4/10

Dozens of human trials of both forms: pooled cholesterol trials, a placebo-controlled IBS trial of 108 adults, diarrhea trials in children and a SIBO trial; many are small, and several were funded by a PHGG maker.

Bioavailability & Absorption

6.8/10

It isn't absorbed by design: it reaches your colon intact, where gut bacteria ferment most of it, and PHGG dissolves clear in any drink.

Clinical Effectiveness

7.0/10

Our judgment: a gentle prebiotic in Dr. Axe's Healing Leaky Gut, SIBO and Candida Cleanse protocols, with human results for bloating, regularity, diarrhea and SIBO clearance.

Safety & Tolerability

8.0/10

Stirred into water at normal amounts, the main effect is mild gas or bloating in the first week; the reported blockages came from regular guar diet pills and granules taken with too little fluid, and allergy is rare.

Why this score?

Why Guar Gum scores 7.0 / 10

Our scores for gellan gum (2.2) and locust bean gum (3.2) rate texture additives; this one rates guar fiber as a supplement. Weighting: Evidence 30% · Bioavailability & Absorption 25% · Clinical Effectiveness 25% · Safety & Tolerability 20% (6.4×0.30 + 6.8×0.25 + 7.0×0.25 + 8.0×0.20 = 1.92 + 1.70 + 1.75 + 1.60 = 6.97, shown as 7.0). How we score

A transparent, weighted index built for foods. See how it’s calculated →

Interaction check: Moderate. At supplement doses, guar fiber can slow how some medicines are absorbed and can add to the effect of blood-sugar medicines; food amounts don't call for spacing. No interaction study of PHGG exists, so the same spacing applies to it.69 70 1

Diabetes medicines, such as metformin: guar taken with a meal slowed metformin's absorption in healthy volunteers. Take guar 2 hours apart from them and check your blood sugar more often for the first few weeks.69 71 1

Antibiotics and other timed medicines, such as penicillin: guar lowered penicillin's absorption in healthy volunteers. Take medicines at least 2 hours before or after guar or PHGG.70 1

Thyroid medicine, such as levothyroxine: fiber supplements as a group can lower its absorption, though no study has tested guar itself. Take levothyroxine at least 4 hours before guar or PHGG, as thyroid guidelines advise for fiber.72 73

Interactions are rated separately and don't change the score.

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Guar gum at a glance

Guar gum is a soluble fiber milled from the seeds of the guar bean, and its gentle, enzyme-trimmed form, partially hydrolyzed guar gum (PHGG), feeds the good bacteria in your gut at a pace a sensitive gut can handle.1 2 3

What it does for your gut: PHGG eased bloating in a placebo-controlled trial of 108 adults with IBS, made bowel movements more regular, and helped clear SIBO when added to treatment4 5 6
Blood sugar and cholesterol: regular guar gum eaten with a meal blunted the rise in blood sugar after it, and in pooled placebo-controlled trials it lowered total and LDL cholesterol 7 8
How much: 5 to 7 grams of PHGG a day, the amount in my Healing Leaky Gut Protocol, starting with 3 grams for the first week if your gut is sensitive9 4
How to use it: stir the powder into a full glass of water, tea or a smoothie, never take it dry; PHGG dissolves clear and has no real taste2 10 11

Split a guar bean and you'll find a pale core inside the seed coat. Mill that core and you have guar gum, an off-white powder that dissolves in cold water and thickens it.1 It comes from a drought-hardy legume grown mostly on the dry, rain-fed land of northwest India, where it's also known as the cluster bean.12

Most people meet guar gum on a label, where it keeps a can of coconut milk smooth or gives a sauce its body.13 14 The form I recommend for your gut is a different one. Trim guar gum's long fiber chains with an enzyme and you get partially hydrolyzed guar gum, or PHGG: a powder that dissolves clear in a glass of water, barely thickens it, and ferments slowly in your colon.2 15

That slow pace is the point. Bloating and stools that swing between loose and hard are signals, and one upstream driver is a gut whose bacteria aren't getting the fiber they need at a speed they can handle. Feed them a gentle, fermentable fiber and they make short-chain fatty acids, the main fuel for the cells lining your colon.16 17 That's why PHGG has a defined place in three of my gut protocols, for leaky gut, SIBO and Candida, at 5 to 7 grams a day.9 18 19

If you have a sensitive digestive tract, PHGG is your best option as a fiber source. It is less fermentable, and it's typically more friendly for people that have histamine-like reactions or sensitive digestive systems.Dr. Josh Axe, DC, DNM, CNSFrom Nature's Ozempic: Eat These Foods To Kill Cravings & Burn Fat!, The Dr. Josh Axe Show (2026), at 19:09

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Did you know?

India grows about 80% of the world's guar, mostly in the desert state of Rajasthan, and by 2014 oil drilling used more guar gum than food did.12
In a 1978 study in small groups of volunteers, the thicker a fiber made a glucose drink, the more it flattened the rise in blood sugar, and guar flattened it the most of the fibers tested.20
USDA's branded food database holds 33,963 product records that list guar gum as an ingredient, about 1 in 13 of all its records.21

What is guar gum?

Quick answer

Guar gum is a soluble fiber milled from the seeds of the guar bean (Cyamopsis tetragonoloba), a drought-hardy legume. Food makers use it as a thickener, listed as guar gum or E 412, and an enzyme-trimmed form, partially hydrolyzed guar gum (PHGG), is sold as a prebiotic fiber supplement.14 1 2

Guar is a bean plant built for dry ground, and after India, Pakistan is the second-largest grower.12 To make the gum, processors split the seeds, sift away the germ, loosen and remove the hull, and mill the pale endosperm into powder. Food-grade guar gum is about 80% galactomannan, the fiber that does the work.1

Galactomannan is a long chain of a sugar called mannose with a galactose sugar hanging off roughly every other link. The more of those side sugars a galactomannan carries, the more easily it dissolves, and guar carries plenty, so it dissolves in cold water.22 A 1% solution of a typical commercial guar gum reaches 2,700 to 3,500 mPa·s, thousands of times thicker than water.1 That's why food makers reach for it. U.S. rules allow guar gum as a thickener, stabilizer and emulsifier in foods from sauces, soups, cheese and baked goods to dairy-free milks and jams, at no more than 2% of any food and 0.5% of most.14 It also counts as dietary fiber on a U.S. Nutrition Facts label.23

The gum is mostly fiber. USDA's only nutrient record for it, which combines guar with locust bean gum, lists 77.3 grams of fiber per 100 grams and no sugar.24 At the 0.5% limit, a 200-gram serving of a packaged food holds at most 1 gram of the gum, about 0.77 grams of fiber,24 14 while a 5-gram scoop of PHGG, which is at least 75% fiber, supplies 3.75 grams or more.2

A short history of guar gum

Guar began as a farm crop. In Rajasthan it was traditionally grown on marginal land for food, animal feed and fodder, and its green pods were cooked as a vegetable; as processing technology developed, its seeds became a source of gum powder.12 U.S. regulators affirmed guar gum as generally recognized as safe in 1977,14 and through the 1980s researchers in Finland, Britain and the United States ran dozens of trials of it for cholesterol and blood sugar.8 25 Food scientists then learned to trim its chains with an enzyme. The result, PHGG, kept the fiber but lost the thickness, which made it easy to drink every day, and it's the form tested in the modern gut trials on this page.2

PHGG: the gentle, gut-friendly form of guar

Quick answer

PHGG is guar gum cut into shorter chains with an enzyme, about one-tenth of the original size, so it dissolves clear, barely thickens and ferments gently in your colon. It's the form in my gut protocols and in the modern gut trials, while regular guar gum is the thickener on food labels and the form tested in the older blood-sugar and cholesterol trials.2 9 1

	Regular guar gum	PHGG
How it's made	The seed's endosperm, milled1	Guar gum trimmed with an enzyme to about one-tenth of its chain length2
In water	A thick gel: a 1% solution reaches 2,700 to 3,500 mPa·s1	Dissolves clear: about 10 mPa·s even at 5%2
Where you'll find it	Food labels, as guar gum or E 41214	Fiber supplement powders2
What it's been studied for	Blood sugar after meals and cholesterol7 8	IBS, constipation, diarrhea, SIBO and the gut microbiome 4 5 26 6
Amounts studied	8 to 39 grams a day in the cholesterol trials8	5 to 6 grams a day, the most common amount in adult trials4 5

Regular guar's gel slows a meal down in your small intestine, which is where its blood-sugar and cholesterol effects come from; in a 1978 study in small groups of volunteers, a broken-down guar that no longer thickened lost its flattening effect on blood sugar.20 27 PHGG gives up that gel. In exchange it's easy to take every day and gentle on a sensitive gut, which makes it the form for feeding your gut bacteria.2 3

I match the fiber to the person. If constipation is your main problem, psyllium husk is one of the best fibers for it; if you're prone to bloating, have loose stools or need to build up your good bacteria, a gentler prebiotic such as PHGG works better.15 With SIBO, I use PHGG or acacia fiber and not the other types.15 I see this all the time: probiotic products that add fibers such as raw potato, which you don't want if you have leaky gut, bloating or gas.15

PHGG suits a sensitive gut because your gut bacteria ferment it more gently than inulin or FOS. In lab tests with human stool bacteria, inulin and FOS made gas fast, 60 milliliters per gram or more, while PHGG made mild gas, 30 to 60 milliliters per gram, and acacia gum made the least.28 In a second lab model, only inulin had made gas at 8 hours, and PHGG fermented at an intermediate rate.29 PHGG fiber powders have also been certified low FODMAP by Monash University's program.30 So in my Healing Leaky Gut Protocol, PHGG and acacia are the only prebiotics in the Reinoculate step, and inulin and FOS wait until the gut has healed.9

The same logic carries over to histamine intolerance. When histamine reactions come with gut trouble, I use PHGG as the main fiber, alongside soil-based probiotics, because it grows good bacteria without overfermenting.16 And the fiber is only one lever. Clinically, I've found that lowering stress is the single biggest needle mover for reducing histamine: not overworking, and going on more walks around your meals.16

What is guar gum good for?

Quick answer

Guar gum is good for your gut first: as PHGG, it feeds your good bacteria, eased bloating with IBS, made bowel movements more regular, shortened diarrhea in children's hospital trials and helped clear SIBO alongside treatment.31 4 5 26 6 Regular guar gum taken with meals blunts the rise in blood sugar after them and lowers total and LDL cholesterol.7 8

Where the research stands

Guar gum is among the most studied dietary fibers in people.32 PHGG has placebo-controlled trials in IBS, constipation and gut bacteria, hospital trials in children's diarrhea and a randomized SIBO trial of 77 adults; regular guar gum has 19 placebo-controlled cholesterol trials pooled in 2023 and a long run of blood-sugar studies.4 5 26 6 8

Guar gum benefits, graded by evidence (updated October 2026). Evidence labels are editorial judgments that compare these uses with each other; they aren't formal certainty ratings.
Use	Evidence	Product studied	What the research shows
Bloating with IBS	Moderate	PHGG, 6 grams a day	Bloating score fell 4.1 points vs. 1.2 on placebo over 12 weeks4
Regular bowel movements	Emerging	PHGG, 5 grams a day	1.15 more bowel movements a week, vs. a slight drop on placebo5
Diarrhea	Moderate	PHGG in rehydration solution	Diarrhea ended about 16 to 18 hours sooner26 33
SIBO	Emerging	PHGG, 5 grams a day, added to an antibiotic	More people cleared SIBO than with the antibiotic alone6
Good gut bacteria	Emerging	PHGG, 3 to 6 grams a day	More Bifidobacterium and Akkermansia, and more stool butyrate31 34 35
Blood sugar after meals	Moderate	Regular guar gum with a meal, 5 to 6.3 grams	A 40% smaller blood-sugar rise in adults with type 2 diabetes7 36
Cholesterol	Moderate	Regular guar gum, 8 to 39 grams a day	Lower total and LDL cholesterol; HDL unchanged8
Constipation	Traditional	Guar pods and leaves, brewed	Taken as a tea or decoction for constipation37

How guar gum works in your body

For a sensitive gut, what matters is what a fiber does once it's inside you, and how fast. Soluble fiber forms a gel, feeds your gut bacteria and acts as a prebiotic, and it also lowers cholesterol and blunts blood sugar, as I put it on my show.38 Guar does each of those jobs, step by step:

1It dissolves

PHGG is guar gum cut into short chains, so a 5-gram scoop stirs clear into a glass of water, while regular guar gum turns a 1% solution into a thick gel.2 1

2Regular guar slows a meal down

Its gel slows how fast sugar from a meal reaches your bloodstream, and gel-forming fibers carry bile acids out of the gut, so the liver draws cholesterol from the blood to make more.20 27 39

3It reaches your colon intact

Your own enzymes don't digest it, so it reaches your colon as food for your bacteria: in a 2-week study of 6 healthy people with no comparison group, 82% to 95% of the guar they ate was broken down in the gut.1 40

4Bacteria ferment PHGG gently

Your gut bacteria ferment it slowly, so it makes milder gas than inulin or FOS did in lab tests with human stool bacteria.28 29

5Good bacteria grow

At 12 weeks, Bifidobacterium made up 11.40% of gut bacteria on PHGG vs. 7.98% on placebo, and Akkermansia rose within 2 weeks.31 34

6They make butyrate

After 12 weeks on PHGG, stool butyrate was about 31% higher than on placebo (0.934 vs. 0.711).35

7Butyrate fuels your colon lining

Butyrate is the main fuel for the cells lining your colon, supplying 73% to 75% of their energy use in lab studies of human colon cells, and as I put it on my show, short-chain fatty acids seal your gut barrier.17 16

8Your gut settles

In people, that adds up to less bloating with IBS and more regular stools.4 5

Short-chain fatty acids are fuel for your colon and for your cells, and they calm inflammation.Dr. Josh Axe, DC, DNM, CNSFrom The Shocking Reason Your Anxiety, Brain Fog & Bloating May Start in Your Gut, The Dr. Josh Axe Show (2026), at 13:41

PHGG also changes the pace of your gut, in a helpful direction at each end. In a trial that enrolled 25 healthy adults, each of whom ate test meals with 20 grams of PHGG and with a placebo on different days, a scan showed slower transit through the small intestine (24.2% of the test meal had moved through vs. 41.2% on placebo), with no change in hunger.41 In the colon it does the opposite: in 39 adults with chronic constipation who finished a 4-week trial with no comparison group, 5 grams a day sped colon transit from 57.3 to 45.6 hours.42

Guar gum benefits for your gut, blood sugar and cholesterol

Guar's benefits start in the gut, where PHGG does its work, and extend to blood sugar and cholesterol, where the research used regular guar gum.

Less bloating with IBS

Moderate evidenceHuman studyPlacebo-controlled trial · 108 adults with IBS, 12 weeks; randomized trial · 188 adults, PHGG vs. wheat bran

PHGG eased bloating in adults with irritable bowel syndrome. In a trial in Tel Aviv, 121 adults with IBS were randomized and 108 started: 3 grams of PHGG a day for the first week and 6 grams after that, or a maltodextrin placebo, for 12 weeks, and neither the people nor the researchers knew who got what. Their bloating score, on a 0-to-70 scale, fell 4.1 points on PHGG vs. 1.2 on placebo (P = 0.03).

The gap opened early (−3.1 vs. −0.07 after a month), was widest at 2 months (−7 vs. +0.3), and was still there, though no longer significant, 4 weeks after people stopped. Pain, stool frequency and overall severity didn't differ between the groups, and far fewer people quit the PHGG group (22.45% vs. 49.15%).4

In a second trial, 188 adults with IBS took 5 grams of PHGG or 30 grams of wheat bran a day for 12 weeks, and people knew which fiber they got. Both fibers eased pain and bowel habits, but counting everyone who started, 60% succeeded on PHGG vs. 40% on bran, and when people were allowed to switch, 49.9% moved from bran to PHGG while 10.9% moved the other way.43

Study takeaway: a fiber people with IBS tolerate well and stick with.

IBS bloating over 12 weeks: PHGG vs. placebo

Source: Niv et al. · Nutrition & Metabolism, 2016 [4]Lower is better. The difference at 12 weeks was significant (P = 0.03).

More regular bowel movements

Emerging evidenceHuman studyPlacebo-controlled trial · 51 adults with mild constipation, 8 weeks; trial in 61 children vs. lactulose; traditional use

In traditional medicine in Pakistan's Punjab, guar pods and leaves are brewed into a tea or decoction for constipation,37 and PHGG, the modern form, brings more regular bowel movements in people. In a placebo-controlled trial of 60 Japanese adults with mild constipation (51 analyzed), 5 grams a day for 8 weeks raised bowel movements from 5.35 to 6.50 a week, a gain of 1.15 against a slight drop (−0.16) on placebo; 3 grams didn't make a significant difference.5 In 61 children with constipation, 3 to 5 grams a day worked about as well as the laxative lactulose over 4 weeks (the difference, 1 stool a week, wasn't significant), people knew which treatment they got, and parents reported lactulose's bad taste and large volumes.44 45

PHGG steadies stools in the other direction too. In a placebo-controlled trial of 44 healthy adults with loose stools, 5 grams a day moved stool form toward normal, better than placebo at weeks 7 and 11, though how often they went didn't change.31 In a placebo-controlled trial of 52 care-home residents averaging about 84, 5 grams a day in water for 4 weeks meant fewer laxatives in weeks 3 and 4, though stool form and frequency held steady, and in a 15-day trial of 64 hospitalized adults already eating about 30 grams of fiber a day, 10 grams more of PHGG brought no extra benefit.10 46 When bloating comes with constipation, PHGG is the gentler fit.15 Our guide to natural constipation relief has more steps.

Study takeaway: a gentle way to keep stools regular, in either direction.

Shorter bouts of diarrhea

Moderate evidenceHuman studyRandomized trials · 150 and 126 children with acute diarrhea, hospital care in Bangladesh; tube-feeding trials

Added to the rehydration solution children drink during diarrhea, PHGG helped it end sooner. In 150 boys aged 4 to 18 months, neither the families nor the researchers knew who got which solution, and diarrhea lasted 74 hours with PHGG vs. 90 hours without (P = 0.03).26 In a second trial run the same way in 126 severely malnourished children aged 6 to 36 months, it lasted 57 vs. 75 hours.33 In a randomized trial of 116 children with persistent diarrhea, the kind that lasts two weeks or more, a chicken-based diet with PHGG cleared it in 84% vs. 62% within 7 days.47

Results vary by setting: in a randomized trial of 195 adult men with severe cholera, PHGG didn't change stool output, and in a randomized trial of 631 adults after gut surgery, a PHGG formula did as well as a fiber-free one (diarrhea in 9.6% vs. 10.1%).48 49 In hospital tube feeding, two small trials with 55 patients, pooled, cut the risk of diarrhea about in half (risk ratio 0.47),50 and in a randomized trial of septic patients in intensive care (25 analyzed), in which neither the people nor the researchers knew who got which formula, diarrhea came on 8.8% of feeding days with PHGG vs. 32.0% on a fiber-free formula.51 For everyday upsets, see how to stop diarrhea.

Study takeaway: PHGG helped children's diarrhea end 16 to 18 hours sooner in hospital trials.

Children's diarrhea lasted 74 hours with PHGG vs. 90 hours without

Source: Alam et al. · Journal of Pediatric Gastroenterology and Nutrition, 2000 [26]Average time until the diarrhea stopped, in a hospital trial in Bangladesh.

Better SIBO clearance alongside treatment

Emerging evidenceHuman studyRandomized trial · 77 adults with SIBO, 10 days of treatment

Added to treatment, PHGG helped clear small intestinal bacterial overgrowth. In a randomized trial of 77 adults with SIBO, researchers gave the antibiotic rifaximin alone or with 5 grams of PHGG a day for 10 days. A month later, breath tests showed SIBO cleared in 85.0% of people with PHGG vs. 62.1% without, counting everyone who started. Among those who cleared, symptoms improved at similar rates (91.1% vs. 86.9%).6

The order I use with patients is prepare, clear, restore, then prevent, and PHGG belongs to the clearing step: in my SIBO Protocol, 5 grams a day goes alongside the herbal antimicrobials in the Clear phase, and it ranks fifth among my top eight SIBO remedies.18

Study takeaway: added to treatment, PHGG helped more people clear SIBO.

SIBO cleared: 85.0% with PHGG added vs. 62.1%

Source: Furnari et al. · Alimentary Pharmacology & Therapeutics, 2010 [6]Counting everyone who started.

Feeds your good gut bacteria

Emerging evidenceHuman studyPlacebo-controlled trials · 44 and 96 adults, 12 weeks; 33 adults, each tried two doses and a placebo

PHGG feeds the beneficial bacteria in your colon. In a placebo-controlled trial of 44 healthy adults, Bifidobacterium made up 11.40% of gut bacteria at 12 weeks on 5 grams a day vs. 7.98% on placebo.31 As I've said on my show, PHGG increases Akkermansia,15 and in 33 adults on a low-fiber diet who each tried 3 grams, 6 grams and a placebo for 2 weeks apiece, both doses raised it.34

Well-fed bacteria make butyric acid, the fuel your colon lining runs on: as I explain on my show, about 70% of your colon cells' energy comes from butyrate.16 17 In a 12-week placebo-controlled trial of 96 healthy adults, 5.2 grams of PHGG a day left stool butyrate about 31% higher than on placebo (0.934 vs. 0.711), along with total short-chain fatty acids; a shorter 8-week trial saw no change in stool acids.35 5

Study takeaway: more of the bacteria, and the butyrate, a healthy colon runs on.

A smaller blood-sugar rise after meals

Moderate evidenceHuman studyRandomized single-meal trials · 18 adults with type 2 diabetes; 10 healthy adults; longer trials mixed

Regular guar gum, eaten with a meal, blunts the rise in blood sugar that follows. In a 2025 trial, 18 adults with type 2 diabetes who weren't on insulin each ate six test meals, and neither they nor the researchers knew which was which: 5 grams of guar gum baked into a chapati made the rise in blood sugar over 3 hours 40% smaller, whatever protein came with it.7 In 10 healthy adults, a breakfast cereal carrying 6.3 grams of guar lowered the blood-sugar rise by 42% at 60 minutes and 47% at 2 hours, and insulin by 28% to 36%.36

Over weeks, the effect on average blood sugar varies by trial. In a placebo-controlled trial of 16 adults with type 2 diabetes who each tried both for 8 weeks, guar lowered HbA1c and fasting blood sugar, while placebo didn't.52 In 18 adults with type 2 diabetes who each tried both, 5 grams of guar granules sprinkled on each main meal for 4 weeks brought HbA1 to 8.70% vs. 9.09% on wheat bran,53 and in 44 adults with type 2 diabetes who knew which group they were in, those who added 10 grams of PHGG a day for 6 weeks saw HbA1c fall from 6.88% to 6.57% while the comparison group's didn't change.54 In a placebo-controlled trial of 29 adults with type 2 diabetes who each tried both, and a 3-month placebo-controlled trial of 39, long-term blood sugar didn't change.55 56 One pooled analysis of 14 randomized trials found lower HbA1c with guar; a second, of 8 studies, found no significant change.57 58 For type 2 diabetes, guar works best as one part of the diet, exercise and lifestyle changes that get at the root of high blood sugar.

Study takeaway: taken with meals, regular guar gum flattens the blood-sugar spike.

Lower total and LDL cholesterol

Moderate evidenceHuman studyMeta-analysis · 19 placebo-controlled trials, 525 people; placebo-controlled trial · 24 healthy adults

Regular guar gum lowers cholesterol by carrying it out of your body. As I explain on my show, a fiber supplement helps lower LDL cholesterol by increasing how much bile and cholesterol your body clears.39 When researchers pooled 19 placebo-controlled trials with 525 people, mostly of regular guar gum at about 8 to 39 grams a day for 3 to 26 weeks, guar lowered total cholesterol by 19.34 mg/dL and LDL by 16.19 mg/dL, with no change in HDL or triglycerides. LDL fell most in people without diabetes, by 25.43 mg/dL, while the drop in people with diabetes wasn't significant, and the authors rated the LDL result low certainty.8 In a placebo-controlled trial of 24 healthy adults, in which neither the people nor the researchers knew who got what, 9 grams a day for 4 weeks lowered LDL by 25.6%.59 In placebo-controlled trials of 14 men who each tried both and of 50 men, all with high cholesterol, the drop faded by 2 to 3 months.60 61

LDL is one number among several. On my show, I tell people to look past total cholesterol to the real drivers of heart disease, such as the triglyceride-to-HDL ratio,39 and ApoB and hs-CRP belong on that list too. Our guide to normal cholesterol levels explains the cholesterol ranges and how to read that ratio.

Study takeaway: pooled trials show regular guar gum lowers total and LDL cholesterol.

Is guar gum bad for you?

Quick answer

No. At the amounts in food, guar gum is a fiber that food-safety reviewers saw no need to limit with a numerical daily intake, and it isn't on my list of additives to avoid. On a packaged label it still counts as an ingredient, and my guideline is five ingredients or fewer.1 62 63

The additives I tell people to put back on the shelf, listed in The Biblio Diet, include the emulsifiers carboxymethylcellulose (CMC) and polysorbate 80, along with nitrites, phosphate additives and artificial flavors; guar gum isn't on that list.63 My guideline for packaged food is simple: buy food with at most five ingredients,63 and guar gum counts as one of the five. You'll see it in sauces, soups, dairy-free milks, ice cream and baked goods,14 and canned coconut milk, which is on my list of foods to eat, shows how much labels vary:63 64 13 65

Canned coconut milk label	Ingredients	Count
Coconut milk A	Organic coconut extract, water64	2, the shortest label
Coconut milk B	Organic coconut extract, water, organic guar gum13	3: guar gum counts as one of the five
Coconut milk C	Coconut extract, water, guar gum, distilled monoglyceride, polysorbate 60, sodium carboxymethylcellulose (CMC), xanthan gum, sodium metabisulfite65	8: over five, and CMC is on my avoid list

A large French study has tracked guar gum from packaged foods. In a cohort of 104,139 adults who logged what they ate brand by brand, those who ate more guar gum were somewhat more likely to develop type 2 diabetes over about 7 years (11% higher risk for every extra 500 milligrams a day, about three times the average intake), even after accounting for how much ultra-processed food they ate; the same cohort found no link between guar gum and heart disease, and the authors noted that one observational study can't show cause.66 67

With patients, with my own family and with myself, I don't spend much time on what not to eat; I focus on what to eat, and eat as much of it as possible.39 Fill your cart with foods that don't need a thickener, and the gums take care of themselves.

How to use guar gum powder and PHGG

Quick answer

For your gut, take 5 to 7 grams of PHGG a day, stirred into a full glass of water, tea, a smoothie or soup; with a sensitive gut, start with 3 grams and build up after the first week. In the kitchen, a little regular guar gum thickens cold dressings and sauces and binds gluten-free baking.15 9 4 1

How much. Food comes first: high-fiber foods such as beans, oatmeal and chia seeds give you soluble fiber, and with a sensitive gut, PHGG is the best way to add more.38 3 Our list of soluble fiber foods has more. I recommend 5 to 7 grams of PHGG a day, the amount in my Healing Leaky Gut Protocol, in line with the 5 to 6 grams most often used in adult trials.15 9 4 5 With bloating or IBS, start low and slow with fiber, because your microbiome needs time to adapt.68 The IBS trial started people at 3 grams for a week before moving to 6,4 and our IBS diet lays out the foods to build around it.

How to take it. PHGG dissolves clear and has no real taste, so it disappears into water, tea, coffee, a smoothie or soup.2 10 I also follow a principle from traditional Chinese medicine in my Healing Leaky Gut Protocol: a healing gut prefers warm, cooked, soft foods over raw, cold ones.9 PHGG holds up to heat and stays thin, so a warm mug of herbal tea or bone broth is an easy place to put it.2

In the kitchen. Regular guar gum dissolves in cold liquid, so a small pinch thickens a dressing or sauce without heat, and its solutions hold up across a wide range of acidity.1 Six easy ways to use both forms:

Stir 5 grams of PHGG into a morning glass of water; it dissolves clear.

Add PHGG to a warm cup of herbal tea or bone broth.

Blend PHGG into a smoothie made with berries and coconut milk.

Whisk a pinch of regular guar gum into a cold dressing or sauce to thicken it.

Use a little guar gum to keep homemade coconut-milk ice cream or yogurt smooth.

Bind gluten-free flours in breads and muffins with a small amount of regular guar gum.

Guar gum side effects and who should skip it

Never take it dry. Regular guar swells as it soaks up water, to 10 to 20 times its size, while PHGG barely thickens.74 2 In the late 1980s, a guar diet pill taken before meals blocked the esophagus or small intestine in at least 25 people reported to the FDA, and one died after surgery to repair a tear made while a blockage was removed. The FDA stopped the product in 1990 and in 1991 ruled guar gum out as an ingredient in over-the-counter weight-loss drugs; food uses weren't affected.74 75 76 Granules have done the same in a documented case, and the FDA's choking warning for fiber products covers powders and granules taken without enough fluid.77 11 Stir every dose into at least 8 ounces of water or another drink, and skip guar supplements if you have trouble swallowing or a narrowed esophagus. If a dose ever feels stuck or you can't swallow, see a doctor right away.

Gas and bloating at first. My protocol tells you to expect possibly mild gas or bloating in the first week as your microbiome shifts.9 At around 15 grams a day, some people get abdominal discomfort.1 Start at 3 grams for the first week, as the IBS trial did, then build up.4

Allergy. Guar is a legume. Reactions from eating it are rare, but two people had anaphylaxis after foods containing it, and most guar allergy comes from breathing the dust at work.78 79 If you have a legume allergy, skip guar supplements unless your allergist clears them.

Babies and children. Since August 2026, the EU no longer allows guar gum in infant formula, after its food-safety agency said the data couldn't show it was safe for babies.80 81 Keep guar supplements out of baby bottles; the children's constipation and belly-pain trials of PHGG used 3 to 5 grams a day in children aged 4 to 16.44 82

Crohn's or ulcerative colitis. PHGG hasn't been tested in a controlled trial in inflammatory bowel disease, and in mice with chemically induced colitis it made the colitis worse.83 Hold off during a flare, and start very low once things settle.

The bottom line

Is guar gum good for you?

On a food label, guar gum is a thickener that counts as one of the five ingredients I aim for, and at food amounts it's simply a fiber. Taken on purpose as PHGG, it's one of the gentlest ways to feed your gut: it eased bloating with IBS, made bowel movements more regular, helped children's diarrhea end sooner and helped clear SIBO alongside treatment, while regular guar gum with meals blunted blood sugar and lowered cholesterol.

Start with 3 grams of PHGG stirred into a full glass of water or a warm cup of tea, build to 5 to 7 grams a day, and keep eating the beans, oatmeal and chia that feed your gut from the plate. Feed the bacteria in your gut well, and you give a body designed to heal what it needs to do its work.

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Guar gum: frequently asked questions

What is guar gum made from?

Guar gum is made from the seeds of the guar plant, Cyamopsis tetragonoloba, a legume: the seeds are split, the germ and hull are removed, and the inner endosperm is milled into a powder that's about 80% galactomannan fiber.1 14

Is guar gum bad for you?

No. At the amounts in food, guar gum is a fiber that European and international food-safety reviewers saw no need to limit with a numerical daily intake, and it isn't on my list of additives to avoid; on a packaged label it still counts as one of the five ingredients I aim for.1 62 63

What is PHGG, and how is it different from guar gum?

PHGG, partially hydrolyzed guar gum, is guar gum cut into shorter chains with an enzyme, so it dissolves clear and barely thickens. It's the form used as a fiber supplement and in the modern gut trials, while regular guar gum is the thickener on food labels.2

Is guar gum a prebiotic?

PHGG is: in placebo-controlled trials it raised Bifidobacterium and stool butyrate, and 3 or 6 grams a day raised Akkermansia in 2 weeks. Regular guar gum feeds gut bacteria too: in an 18-day study of 12 healthy men with no comparison group, 8 grams a day changed the makeup and activity of their gut bacteria.31 35 34 40 84

How much PHGG should I take a day?

I recommend 5 to 7 grams of PHGG a day for gut support, stirred into a full glass of water or another drink. With a sensitive gut, start at 3 grams and build up after the first week.15 9 5 4

Does guar gum help with constipation?

PHGG can: in a placebo-controlled trial of 51 adults with mild constipation, 5 grams a day raised bowel movements from 5.35 to 6.50 a week over 8 weeks. It's also the gentler fit when bloating comes with constipation.5 15

Is PHGG good for SIBO?

Yes, as part of a plan to clear it: in a randomized trial of 77 adults, adding 5 grams of PHGG a day to an antibiotic cleared SIBO in 85.0% of people vs. 62.1% with the antibiotic alone. In my SIBO Protocol, it goes with herbal antimicrobials in the Clear phase.6 18

Is guar gum low FODMAP?

PHGG is: PHGG fiber powders have been certified low FODMAP by Monash University's program, and in lab tests PHGG made less gas than the high-FODMAP fibers inulin and FOS.30 28

What are the side effects of guar gum?

The most common is gas or bloating in the first week as your gut bacteria adjust. The serious one, reported with regular guar diet pills and granules, is choking or a blockage when it's taken dry or with too little fluid, so always stir it into a full glass of water.9 74 77 11

Can you be allergic to guar gum?

Yes, though it's rare from eating it: two people had anaphylaxis after foods containing guar gum, confirmed by allergy testing, and most guar allergy comes from breathing guar dust at work.78 79

Does guar gum help you feel full?

PHGG may: 2 grams of PHGG with breakfast lowered hunger ratings and snacking compared with dextrin in 24 adults who each tried both. Other trials of PHGG and regular guar found no change in hunger, fullness or how much people ate. Soluble fiber ranks second on my list of supplements for supporting your body's own GLP-1, and for a sensitive gut, PHGG is the fiber I point to.85 86 41 7 3

Does guar gum block iron or other minerals?

Not in people: over 6 months, about 32 grams a day of regular guar gum didn't change the balance of iron, zinc, copper, calcium, magnesium or manganese in adults with type 2 diabetes, and PHGG didn't interfere with absorbing glucose, protein or fat. In iron-deficient rats, PHGG about doubled iron absorption (67.5% vs. 31.3% on a fiber-free diet).87 88 89

Guar gum vs. xanthan gum: what's the difference?

Guar gum is a fiber milled from a bean's seeds, while xanthan gum is made by bacteria fermenting sugar. Both thicken liquids, guar dissolves readily in cold water, and European reviewers set no numerical daily limit for either one.1 90

Is guar gum the same as locust bean gum?

No, though they're close cousins: guar gum and locust bean gum are both galactomannan fibers from legume seeds, but guar carries more galactose along its chain, which makes it dissolve more easily in water, and both count as dietary fiber on a U.S. label.22 23

Is guar gum gluten-free?

Yes. Guar gum comes from a bean, not from wheat, barley or rye, so it contains no gluten. If you follow a celiac disease diet, check the whole product for a gluten-free label.1

Is there organic guar gum?

Yes. U.S. organic rules allow water-extracted guar gum in products labeled organic, and some canned coconut milks list organic guar gum on the label.91 13

Freshness & update log

October 23, 2026 — Rewrote the page in full under Dr. Josh Axe's byline. The previous version, "Guar Gum: Is This Food Additive Harmful or Helpful?", said guar gum is also called gellan gum (they're different gums); misspelled the plant's species name; said more than 70% of guar goes to food (USDA put it near 20% in 2014, with oil drilling the largest use); credited guar with holding eight times the water of cornstarch (no source found); described a weight-loss result as 5.5 pounds more than placebo (the change was within the guar group and wasn't significant against placebo); called one paper by a supplement maker's staff a review of three studies; borrowed glucomannan's results for guar; gave a 20% LDL drop in "diabetics" without saying it was a small trial in type 1 diabetes; presented a PHGG study with no comparison group as a guar gum constipation trial; listed a pulmonary embolism and esophageal tear as side effects of high doses (both were one patient's surgical complications after a diet-pill blockage); tied guar allergy to soy allergy (no source; the best-documented case tested negative for soy); called guar a better choice than other emulsifiers (no source); and named a brand. This version keeps the old page's uses for constipation, blood sugar and cholesterol, with the right products, populations and numbers; keeps gluten-free baking and keeping mixtures smooth as kitchen uses; keeps the allergy and swelling cautions, corrected and stated once; and frames guar on a label with Dr. Axe's five-ingredient guideline and his list of additives to avoid. It adds PHGG as its own form, with human trials for IBS bloating, regularity, diarrhea, SIBO and gut bacteria; the traditional use of guar pods and leaves for constipation; how guar works in your body, step by step; Dr. Axe's dose and the protocols that use PHGG; fullness and iron absorption as FAQ answers at their level of evidence; a Dr. Axe Score (7.0) with an interaction check (Moderate); three charts; a coconut milk label comparison; and the 1990 diet-pill history, drug spacing and the 2026 EU infant-formula change in one safety section. It cuts weight loss as a benefit (11 pooled placebo-controlled trials found no effect), the unsourced home lotion and toothpaste amounts, and the unsourced numbers above.

September 12, 2024 — Previous version updated.

References

Dr. Josh Axe, DC, DNM, CNS

Doctor of Natural Medicine · Founder, DrAxe.com

Dr. Axe is a certified doctor of natural medicine, clinical nutritionist, and multiple New York Times bestselling author. He has spent 20+ years in clinical practice helping people heal at the root cause and founded one of the most-visited natural-health platforms in the world.

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This article is for educational purposes. See our medical disclaimer.

On this page

What is it?
PHGG
What is it good for?
How it works
Benefits
Is it bad for you?
How to use it
Side effects
The bottom line
Is guar gum good for you?
FAQ

Quick facts

What it isA soluble fiber milled from the seeds of the guar bean, a legume grown mainly in India
Two formsRegular guar gum, a food thickener (E 412), and partially hydrolyzed guar gum (PHGG), a gentle prebiotic fiber
FiberAbout 77% fiber by weight for guar gum (USDA seed-gum record); PHGG is at least 75% fiber
Dr. Axe's dose5 to 7 grams of PHGG a day
How to take itStirred into a full glass of water, tea or another drink, starting with 3 grams
On a labelOne ingredient; aim for five or fewer in a packaged food
Interaction checkModerate (diabetes medicines, some antibiotics, levothyroxine); take most medicines 2 hours apart, levothyroxine 4 hours before

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