Hydrocolloid

Hydrocolloids: A Comprehensive Reference on Natural Dietary Polysaccharides and Proteins as Supplement and Food Ingredients

1. Identity and Definition

The term "hydrocolloid" is used to describe the range of polymers that perform gelling, thickening, and stabilising functions in a variety of industrial sectors, including food. More specifically, hydrocolloids are a diverse group of ingredients, predominantly high-molecular-weight carbohydrate polymers, along with some proteins (like gelatin), that are water-soluble or partially water-soluble. They are commonly used as stabilizers, thickening agents, or gelling agents.

Hydrocolloids are water-soluble macromolecules — mostly polysaccharides or proteins — used primarily to control texture and stability in foods, often at usage levels below 2%. The effectiveness and versatility of these compounds stems from their unique molecular structures and their powerful interactions with water.

Hydrocolloids can be synthetic, plant-based, or animal-based. They may be naturally present in foods (such as fruits, vegetables, seeds, and cereals), or they may be added as functional ingredients such as thickening agents, gelling agents, or stabilizers.

1.1 Major Natural Sources and Types

Natural hydrocolloids are derived from a wide range of plant, marine, and microbial origins. The major categories include:

• Seaweed-derived hydrocolloids: Algae-derived hydrocolloids such as carrageenan, agar, and alginate are widely used in the food industry as thickening, gelling, and emulsifying agents. Carrageenans are sulfated polysaccharides with diverse structural specificities.
• Seed gums: Guar gum is plant-derived from Cyamopsis tetragonoloba and produces a strong thickening effect at low concentrations. Locust bean gum (also known as carob gum or carob bean gum) is a natural hydrocolloid derived from the seeds of the carob tree (Ceratonia siliqua).
• Exudate gums: Gum Arabic (also known as acacia gum) is harvested from the sap of Acacia senegal and Acacia seyal trees. The sap is exuded naturally from the tree and solidifies into gum after drying. Gum Arabic is a versatile gum with excellent emulsifying and stabilizing properties.
• Microbial fermentation gums: Xanthan gum is a microbial exopolysaccharide produced by fermentation; it is an excellent stabiliser and shear-thinning thickener used in dressings, sauces, and pharmaceutical gels. Newer hydrocolloid ingredients produced by fermentation include gellan, bacterial celluloses, curdlan, and dextran.
• Fruit- and crop-derived hydrocolloids: Pectin is derived from citrus peels and apple pomace. Cereal β-glucans, arabinoxylans, and xyloglucans are being extracted and modified from hemicellulose, and additional examples include agricultural by-products such as flaxseed gum, yellow mustard gum, psyllium, tara gum, fenugreek, and corn fiber gum.
• Konjac glucomannan: Konjac gum is an excellent thickener, gelling agent, and stabilizer. It forms heat-stable and transparent gels and is commonly used in vegan and vegetarian food products, such as noodles, jelly candies, and dietary supplements. It is low in calories and high in fiber, making it suitable for health-conscious consumers.
• Psyllium: Psyllium, also known as ispaghula, is a dietary fiber obtained from the shells of Plantago ovata seeds. The most abundant monosaccharides in its composition are xylose and arabinose.
• Modified celluloses (semi-synthetic): Examples include carboxymethyl cellulose (CMC), methylcellulose, and polyvinyl alcohol (PVA), which are produced by chemical modification of naturally occurring cellulose.

1.2 Common Forms and Preparations

Hydrocolloids are used in foods for two main reasons: either for the physical functionality they add or for their nutritional benefits. Physical functionality is usually either to add viscosity or gelation to a food system.

In the dietary supplement context, hydrocolloids are commonly encountered as powders for dissolution in water, capsules or tablets containing specific gums (e.g., psyllium husk powder, partially hydrolyzed guar gum), fiber-enriched food products, and encapsulation matrices for nutraceutical delivery systems. Many hydrocolloids are also dietary fibers, prebiotic substrates, or suitable for drug encapsulation, enabling label claims (source of fibre, digestive tolerance) and advanced drug delivery (alginate beads, controlled-release films).

2. Chemical Composition and Key Constituents

Molecular weight, chain shape (linear vs. branched), and the distribution of hydrophilic/hydrophobic groups determine core functional properties like viscosity and gelling potential. Longer, more extended polymer chains (higher molecular weight) increase viscosity significantly by trapping and restricting water movement.

The primary structural classes are:

• Polysaccharides — including galactomannans (guar gum, locust bean gum), glucomannans (konjac), sulfated galactans (carrageenan, agar), uronic acid-containing polymers (pectin, alginate), and β-glucans (oat, barley). These are the dominant chemical class among hydrocolloids.
• Proteins — gelatin (derived from animal collagen) and some glycoprotein complexes such as gum arabic, which contains both arabinogalactan polysaccharide chains and a protein backbone. Gum acacia (GA), a hydrocolloid exudate from acacia trees, is a polysaccharide carbonate and protein complex, which has been used for decades in food formulations for its interfacial properties.

2.1 Gelling and Thickening Mechanisms

Thickening occurs due to a random entanglement of polymers. When the polymer is at a low concentration it is able to move freely in solution, retaining its Newtonian flow. However, when the concentration exceeds the overlap concentration (C*), it becomes entangled with itself and is less mobile.

In ionotropic gelation, hydrocolloids cross-link with ions. For example, negative charges on the sodium alginate polymer interact with cations, mainly calcium, causing the polymers to associate while trapping water in the process. Gelatin melts at low temperatures because the junction zones are only bound by relatively weak hydrogen bonds. On the other hand, it is possible to make alginate gels that do not melt on heating because of the strength of calcium bridges in the junction zones.

Hydrocolloids stabilize emulsions and suspensions either by thickening the aqueous phase (enhancing viscosity) or by acting as a surface-active emulsifier/stabilizer.

3. Traditional and Historical Use

Hydrocolloids are a diverse group of naturally occurring and synthetic substances that form gels when combined with water. Historically, they have been valued not only for their thickening and stabilizing properties in food, but also for their medicinal uses, dating back centuries across various cultures.

Early civilizations, such as the Egyptians and Chinese, utilized plant-derived hydrocolloids like gum arabic, guar gum, and agar for wound healing, soothing digestive complaints, and as carriers for herbal remedies. These substances were often incorporated into poultices and balms, taking advantage of their moisture-retaining and protective qualities.

Their use in food preparation dates back centuries, particularly in traditional Asian and European cuisines, where they were valued for their ability to modify texture and preserve freshness.

Gum arabic, in particular, has an especially long recorded history. It was used in ancient Egypt as a binding agent in pigments and in medicinal preparations, and in traditional Arabic medicine as a demulcent for soothing the gut and urinary tract. Agar — derived from red algae — has been used in East Asian cookery and pharmacy since at least the 17th century in Japan, where it was discovered and named kanten. Carrageenan (from Irish moss, Chondrus crispus) was used in Irish folk medicine from at least the 19th century as a digestive and respiratory remedy, prepared as a hot aqueous extract of the dried seaweed.

Psyllium husk has a long history in Ayurvedic medicine, where it was used as a laxative and for soothing gastrointestinal mucosa. Guar gum, from the cluster bean grown widely in the Indian subcontinent, has similarly been a component of traditional South Asian cuisine and folk medicine for centuries, serving as a food thickener and a remedy for constipation and dyspepsia.

In traditional herbal medicine, hydrocolloids were frequently combined with healing herbs to enhance delivery and prolong contact with mucosal surfaces, taking advantage of their mucoadhesive properties.

4. Mechanisms of Action and Active Compounds

The physiological effects of dietary hydrocolloids arise from several intersecting mechanisms, all rooted in their physical chemistry in the gastrointestinal tract:

4.1 Viscosity Enhancement and Gastric Slowing

Dietary fiber, especially viscous dietary fiber, can contribute to a reduction in the glycemic response resulting from the consumption of carbohydrate-rich foods. Evidence has shown that soluble dietary fibre slows gastric emptying, increases perceived satiety and plays a significant role in appetite regulation. By increasing the viscosity of the intestinal contents, soluble hydrocolloids reduce the rate of nutrient absorption and delay the contact of digestive enzymes with their substrates.

4.2 Short-Chain Fatty Acid Production and Prebiotic Effects

Some mechanisms described for soluble dietary fiber action include the increase in chyme viscosity and the production of short-chain fatty acids resulting from fermentation, which stimulates gastrointestinal motility and the release of GLP-1 and PYY hormones. Prebiotic dietary fibers are complex, indigestible carbohydrates that are fermented into SCFAs by gut microbiota, including Actinobacteria and Bifidobacterium. The increase in these microbiota could lead to a higher production of SCFAs like butyrate and propionate, which in turn could stimulate the release of hormones such as satiety-promoting peptide YY (PYY) and glucagon-like peptide-1 (GLP-1), leading on the long run to reduced adiposity and overall weight gain.

Partially hydrolyzed guar gum also has a prebiotic effect due to its properties, including the production of high SCFA levels.

4.3 Bile Acid Binding and Cholesterol Reduction

β-glucans, mainly found in yeast, oats, and barley, can lower cholesterol by increasing bile acid excretion and by reducing intestinal cholesterol absorption. Soluble hydrocolloids such as pectin and alginate bind bile acids in the intestinal lumen, sequestering them for fecal excretion. This prevents their enterohepatic recirculation, compelling the liver to synthesize new bile acids from circulating cholesterol, thereby reducing serum LDL-cholesterol levels.

4.4 Lipid Digestion Modulation

One of the most popular research areas in food hydrocolloids over the past decade has been their application as functional ingredients to modulate the gastrointestinal fate of foods. In particular, they are being utilized to control the hydrolysis of macronutrients (such as fat, protein, and starch) in the gastrointestinal tract, as well as to alter the pharmacokinetics and bioavailability of hydrophobic bioactive agents, including oil-soluble vitamins (e.g., vitamin A, D, E, and K), nutraceuticals (e.g., carotenoids, phytosterols, curcumin, resveratrol, and quercetin), and healthy lipids (e.g., omega-3 fatty acids and conjugated linoleic acids).

4.5 Mucoadhesion and Mucosal Protection

When ingested, gel-forming hydrocolloids can coat gastrointestinal mucosal surfaces. The result is a layer of hydrocolloid over the mucous membrane. This hydrocolloid layer serves as a demulcent protecting the mucous membrane against chemical and physical irritants. This mechanism underlies their traditional use as soothing remedies for gastrointestinal inflammation.

4.6 Nutraceutical Delivery and Controlled Release

Based on prevailing literature, hydrocolloids offer significant opportunities in tailoring nutritional value along with providing health benefits via controlling gastric emptying and the ileal brake mechanism, lowering plasma cholesterol levels, glycemic response, postprandial glucose and insulin levels, and prevention of colon cancer, and improving the bioavailability of specific bioactive compounds and drugs through their controlled and targeted delivery along the gastrointestinal tract.

5. Scientific Evidence by Area of Use

5.1 Glycemic Response and Blood Glucose Control

Soluble dietary fibers that can contribute to glycemic control include gums, β-glucan, psyllium, arabinoxylan, soluble corn fiber, resistant maltodextrin, glucomannan, and edible fungi, which can be added alone or together in different products.

A systematic review with 14 studies evaluated interventions with either xanthan gum, pullulan, or dextran, with a wide variation in the amount of hydrocolloid supplementation provided and methods of preparation. Higher intake levels and longer-chain hydrocolloids promoted reduced postprandial blood glucose responses in half of the studies. A significant reduction in postprandial blood glucose was observed when xanthan gum was added to the cooking process of muffins and rice.

Pullulan reduced blood glucose excursions depending on its chain length and digestibility, the effect being stronger for longer-chain, lower digestibility pullulan. This was shown for a 15 g acute supplementation. The positive effect on reducing glycemic excursion was confirmed for pullulan that is hydrolyzed slowly over time.

Ten studies meeting inclusion criteria evaluated various types of dietary fiber, including soluble, insoluble, viscous fiber, and resistant starch. The findings demonstrated significant improvements in key glycemic markers such as fasting plasma glucose, glycated hemoglobin (HbA1c), and postprandial glucose levels.

Evidence strength: Moderate to strong for viscous soluble hydrocolloids (particularly β-glucan, psyllium, and guar gum) on postprandial glycemia; evidence is more preliminary and mixed for individual bacterial-origin hydrocolloids such as xanthan and pullulan.

5.2 Lipid-Lowering and Cardiovascular Risk

The reduction of cholesterol obtained by soluble fibers described in the literature is variable and dependent on the type of fiber, doses, subjects treated, study size, and different diets. The effective range of reduction of total cholesterol varies from 0 to 18% for oat-based fibers, 3–17% for psyllium, 5–16% for pectin, and 4–17% for guar gum.

A meta-analysis of 17 RCTs with 916 patients showed that β-glucan consumption in a hypercholesterolemic population significantly reduced LDL-C by −0.21 mmol/L (95% CI: −0.27; −0.14), p < 0.00001. However, there were no significant differences in HDL-C and triglycerides. No adverse effects were reported among the eligible trials. In 2010 the European Food Safety Authority (EFSA) confirmed that oat β-glucan is able to reduce plasma cholesterol levels; however, at least 3 g/day of β-glucan is necessary.

According to the American and European guidelines for the management of dyslipidemia, the consumption of 5–15 g/day (European guidelines) or 10–25 g/day (US guidelines) of soluble fibers derived from oat rich in β-glucan can essentially reduce the levels of cholesterol in the blood.

Clinical trials in hypercholesterolemic patients have shown that β-glucans reduce fasting concentrations of cholesterol, LDL cholesterol, apolipoprotein B, triglycerides, and LDL particle size, leading to a reduction in CVD risk.

Evidence strength: Strong for oat β-glucan and psyllium on LDL cholesterol reduction, supported by multiple RCTs and endorsed by EFSA and FDA health claims. Evidence for pectin and guar gum is moderate and consistent in direction.

5.3 Digestive Health: Constipation, Bowel Function, and IBS

Soluble fiber absorbs body water to become a gelatinous, viscous gel-like substance and is fermented by bacteria in the digestive tract. Studies focused on soluble fibers (oat, psyllium, pectin, and partially hydrolyzed guar gum) suggest that these fibers ingested with water help increase stool bulk and stool frequency.

Addition of partially hydrolyzed guar gum (PHGG) to the diet reduced laxative dependence in a nursing home population. PHGG also reduced the incidence of diarrhea in septic patients receiving total enteral nutrition and reduced symptoms of irritable bowel syndrome.

In a randomized, parallel, double-blind, placebo-controlled study, healthy men and women volunteers took either 3 g/day or 5 g/day of PHGG dietary fiber for eight consecutive weeks compared to placebo. The results revealed a significant suppression in fecal potent harmful mucolytic bacteria in the treated groups compared to the placebo group.

Psyllium may have therapeutic effects on various diseases. In recent years, its potential in the management of conditions such as hypertension, diabetes, and liver disease has been emphasized and multifaceted therapeutic applications have been described.

Evidence strength: Moderate to strong for psyllium and PHGG in constipation and IBS symptom improvement, supported by systematic reviews and multiple RCTs. Evidence for other hydrocolloids in these conditions is generally preliminary.

5.4 Satiety, Energy Intake, and Weight Management

The risk of bias was assessed as high for most individual studies. Meta-analysis of statistically pooled data for guar gum showed a sizeable effect on post-meal energy intake, followed by β-glucan, alginate, polydextrose, and pectin, with pooled effect sizes of −0.90, −0.44, −0.42, −0.36, and −0.26, respectively.

Guar gum (5 g) effectively reduced energy intake when prepared in milk beverages compared with control milk (p < 0.001). Alginate, when prepared in liquid (5 g) or solid (9 g) meals, effectively reduced energy intake compared with control (p < 0.001). A high dose of polydextrose (25 g) prepared in liquid meal form significantly reduced energy intake (p = 0.01).

This evidence suggests that soluble fibers are not all created equal. Further interventional studies are needed to determine whether combinations of these soluble fibres might have greater effects than individual fibres per se.

Evidence strength: Moderate. Effect sizes are significant but heterogeneity among trials is high, and study quality is variable. Guar gum and alginate show the most consistent satiety effects in RCTs to date.

5.5 Prebiotic Effects and Gut Microbiota

A 2024 review in Nutrients examined the gut microbiome effects of common food hydrocolloids including xanthan gum and guar gum. Both act as prebiotics at food-level doses — fermented selectively by beneficial bacteria including Bifidobacterium and Lactobacillus species. The authors concluded that regular dietary exposure at food concentrations is unlikely to be harmful and may support microbiome diversity in healthy adults.

The International Scientific Association for Probiotics and Prebiotics (ISAPP) proposed that a prebiotic is "a substrate that is selectively utilised by host microorganisms conferring a health benefit." Prebiotics fulfil three criteria: (a) resistance to gastric acidity, hydrolysis by mammalian enzymes, and gastrointestinal absorption; (b) fermentation by intestinal microflora; and (c) selective stimulation of the growth and/or activity of intestinal bacteria associated with health and well-being.

SCFAs can directly influence several different functions such as satiety and host metabolism. One of the underlying mechanisms by which SCFAs regulate food intake and satiety is via modulation of intestinal enteroendocrine L-cell-derived peptides, mainly GLP-1 and peptide YY (PYY).

Evidence strength: Preliminary to moderate. Prebiotic effects of guar gum and psyllium are well-supported in short-term human studies. Long-term clinical implications for overall metabolic health require further robust RCTs.

5.6 Lipid Digestion Control and Nutraceutical Bioavailability Enhancement

Hydrocolloids are being utilized to control the hydrolysis of macronutrients in the gastrointestinal tract, as well as to alter the pharmacokinetics and bioavailability of hydrophobic bioactive agents, including oil-soluble vitamins (e.g., vitamin A, D, E, and K), nutraceuticals (e.g., carotenoids, phytosterols, curcumin, resveratrol, and quercetin), and healthy lipids (e.g., omega-3 fatty acids and conjugated linoleic acids).

Food hydrocolloids may be used to construct colloidal delivery systems, such as emulsions, biopolymer nanoparticles, or microgels to protect and enhance absorption of co-formulated bioactives.

Evidence strength: Largely in vitro and animal model data. Human clinical trials specifically isolating the bioavailability-enhancing effect of hydrocolloid matrices on named nutraceuticals are limited; this is a rapidly growing but still preliminary area of research.

5.7 Colorectal Cancer — Preliminary Evidence

In an animal study, the combination of psyllium husk, guar gum, and wheat bran was found to increase hydrated feces mass and may reduce constipation, indirectly lowering the risk of colorectal cancer. Psyllium capecitabine-loaded core-shell nanoparticles have shown high cytotoxicity against the HCT-15 colon cancer cell line and may exert significant anticancer activities.

Evidence strength: Predominantly preclinical (animal and cell-line studies). No concluded human RCTs confirm anticancer effects of dietary hydrocolloids; this area remains speculative and is not the basis for current clinical recommendations.

6. Body Systems and Health Areas

• Gastrointestinal system: Bowel regularity, stool bulk and consistency, transit time, intestinal motility, IBS symptom management, mucosal protection.
• Metabolic system: Postprandial glycemia, insulin response, fasting plasma glucose, HbA1c, diabetes prevention and management.
• Cardiovascular system: LDL-cholesterol reduction, total cholesterol, apolipoprotein B modulation, cardiovascular risk reduction.
• Gut microbiome: Prebiotic substrate for fermentation, selective enrichment of Bifidobacterium and Lactobacillus, SCFA production.
• Appetite and body weight regulation: Satiety hormone modulation (GLP-1, PYY), slowing of gastric emptying, reduction of post-meal energy intake.
• Nutraceutical absorption: Carrier and delivery matrix for fat-soluble vitamins, polyphenols, and omega-3 fatty acids.

7. Dosage Forms and Doses Reported in Studies

Hydrocolloids are currently being found to have many increasing applications in the health realm: they provide low-calorie dietary fiber, among many other uses. Specific doses reported in clinical studies include:

• Oat β-glucan (cholesterol lowering): EFSA confirmed that at least 3 g/day of β-glucan is necessary to reduce plasma cholesterol levels. European guidelines recommend 5–15 g/day and US guidelines recommend 10–25 g/day of β-glucan-rich oat soluble fibers for cholesterol management.
• Guar gum (satiety/energy intake): Guar gum at 5 g effectively reduced energy intake when prepared in milk beverages compared with control (p < 0.001).
• Alginate (satiety/energy intake): Alginate at 5 g (liquid) or 9 g (solid meal form) effectively reduced energy intake compared with control (p < 0.001).
• Polydextrose (satiety): A high dose of polydextrose at 25 g prepared in liquid meal form significantly reduced energy intake (p = 0.01).
• Partially hydrolyzed guar gum (PHGG, constipation/gut health): In a randomized, parallel, double-blind, placebo-controlled study, volunteers took either 3 g/day or 5 g/day of PHGG dietary fiber for eight consecutive weeks.
• Pullulan (glycemic response): The positive effect on reducing glycemic excursion for pullulan was shown for 15 g acute supplementation.
• β-glucan/chitin-chitosan (lipid profile): In a prospective two-arm clinical trial, 58 overweight and obese individuals were randomized to receive either 3 g/day of the β-glucan/chitin-chitosan compound or a placebo for 12 weeks.

Overconsumption can lead to undesirable gastrointestinal side effects, further widening the gap between actual and suggested fiber intake levels.

8. Safety Considerations and Notable Interactions

8.1 Regulatory Status

Most hydrocolloids are classed as food additives, but some starches and gelatin are classed as ingredients, and therefore have labelling benefits as they do not have an E number. Carrageenan is widely regarded as safe. Its use as a food additive has been approved by the European Food Safety Authority (EFSA), the Joint FAO/WHO Expert Committee on Food Additives (JECFA), as well as the Food and Drug Administration (FDA).

For most adults, xanthan gum is safe at food-use levels. It is FDA GRAS and EFSA-authorized.

8.2 Gastrointestinal Adverse Effects

Guidance on tolerable intake levels of different hydrocolloids is needed because overconsumption can lead to undesirable gastrointestinal side effects. The FDA accepts as dietary fibers: β-glucan, pectin, arabinoxylan, guar gum, alginate, psyllium husk, inulin, fructooligosaccharides and oligofructose, galactooligosaccharides, polydextrose, cellulose, soy fiber, and resistant maltodextrin/dextrin.

Flatulence, bloating, and loose stools are the most commonly reported adverse effects with higher doses of soluble hydrocolloid fibers. These effects are dose-dependent and are typically self-limiting.

8.3 Risk of Esophageal Obstruction

The EFSA Panel noted that there have been human cases of severe adverse effects, such as oesophageal obstruction or asphyxiation, after oral intake of guar gum or other gums/hydrocolloids with similar physicochemical properties as guar gum in the form of granules or pills without enough liquid, or in the form of jelly mini-cups (konjac gum/glucomannan). These incidents led to the recall of certain weight-loss products containing high-dose guar gum in tablet or granule form.

8.4 Carrageenan: Ongoing Debate

The National Organic Standards Board (NOSB) in 2016 withdrew carrageenan from the list of substances permitted for use in organic foods. The report listed environmental contamination during the production of carrageenan, mentioning the fact that the function of carrageenan can be achieved using other additives such as xanthan gum, gellan gum, or guar gum.

The EFSA Panel emphasised that degraded carrageenan (e.g., poligeenan or C16) has not been authorised as a food additive in the EU. Information available from the US indicated that poligeenan is not used in any food applications. The ongoing controversy primarily concerns whether food-grade carrageenan is metabolically inert or whether it contributes to intestinal inflammation at higher doses — an area still under investigation.

8.5 Infants and Special Populations

The main documented concern for xanthan gum is a 2011 FDA warning about NEC (necrotizing enterocolitis) risk in premature infants exposed to xanthan gum-thickened feeds — this does not apply to trace amounts in packaged food or to older children and adults.

8.6 Partially Hydrolyzed Guar Gum — Emerging Animal Safety Signal

A study assessing the impact of purified PHGG on intestinal inflammation and colitis-associated colon carcinogenesis (CAC) found that wild-type mice fed PHGG exhibited more severe DSS-induced colitis than the control group. Additionally, PHGG feeding led to increased colonic expression of genes promoting cell proliferation. Accordingly, extensive colon tumorigenesis was observed in PHGG-fed mice in the AOM/DSS model, whereas the control group exhibited no visible tumors. This finding was observed in a murine model and has not been replicated in humans; its translational significance is uncertain and requires further investigation.

8.7 Drug and Nutrient Interactions

The gel-forming and viscosity-increasing properties of dietary hydrocolloids have the potential to delay or reduce the absorption of simultaneously ingested medications and nutrients. Psyllium has been documented to reduce the absorption of certain oral medications when co-administered. The general principle applies across viscous fiber hydrocolloids: combinations of hydrocolloids (e.g., xanthan + locust bean gum, pectin + starch, guar as a starch modifier) reliably control viscosity, gel strength, and syneresis in foods and excipient behavior in pharmaceuticals. This same viscosity modulation can transiently alter drug absorption kinetics if high doses of hydrocolloids are taken at the same time as medications.

8.8 Allergenicity

Guar gum has been documented to cause occupational asthma and sensitization in workers exposed to high concentrations of guar dust, though this is an inhalation hazard rather than an adverse effect at dietary intake levels. Sensitization through dietary intake is rare but has been reported.

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