Locust bean gum and guar gum (Ceratonia siliqua L.; Cyamopsis tetragonoloba (L.) Taub.; Fabaceae)

Hydrocolloid ingredients obtained from the endosperm of carob (locust bean) seeds (LBG, E410) and guar seeds (galactomannan, E412). Both are high–molecular-weight polysaccharides with strong thickening capacity; LBG develops full functionality after heating, while guar builds viscosity at cold temperatures. In combination they provide complementary rheology and useful synergies across many food systems and in cosmetics as structure modifiers.

Caloric value (per 100 g of product)

Predominantly dietary fiber: ~200 kcal/100 g (≈2 kcal/g). At typical use levels (0.05–1.0%) the energy contribution is negligible.

Key constituents

Galactomannans
– Locust bean gum (LBG, E410): mannose:galactose ≈ 4:1; requires heat for full hydration.
– Guar gum (E412): mannose:galactose ≈ 2:1; hydrates rapidly in cold water.
Minor components (in less-purified flours): proteins 3–7%, traces of insoluble fiber/minerals; moisture typically ≤12%.
Analytical markers: solution viscosity (e.g., 1% m/m, 20 °C; Brookfield), particle size (D90), dispersion pH, microbiology, and contaminants within limits.

Production process

Seed cleaning and dehulling → separation into endosperm “splits,” hulls and germ.
Milling/sieving of splits to obtain flour; optional wet/dry purification to raise gum assay.
For refined food grades (esp. guar E412): refining, viscosity standardization, microbiological control; for instant grades, agglomeration to improve wettability.

Sensory and technological properties

Hydration & temperature: LBG reaches full function on heating (≈80–90 °C); guar builds viscosity at cold (fast but prone to lumping).
Rheology: both are pseudoplastic (shear-thinning). LBG at heat gives a silky body; guar gives quick, round mouthfeel.
pH and salts: best stability around pH 5–7; strong acid/alkali and high electrolytes lower viscosity (hydrolysis/screening).
Synergies:
– LBG + xanthan → elastic network, improved suspension and freeze–thaw stability.
– LBG + κ/ι-carrageenan → stronger, more cohesive thermoreversible gels.
– Guar + xanthan → pronounced viscosity boost and cold-process stability.
Compatibility: sugars and soluble solids raise apparent viscosity; dairy proteins interact favorably for creaminess.

Food applications

Beverages/syrups: guar 0.05–0.30% for body and phase control (premix with sugars); LBG 0.05–0.20% when hot processing is available.
Dairy/ice cream: LBG 0.10–0.30% (meltdown/syneresis control), guar 0.10–0.30% (cold viscosity); blends 0.10–0.40% total.
Bakery: guar 0.20–0.80% (water retention, softness); LBG 0.10–0.50% (structure/freshness). In gluten-free: often combined with xanthan.
Sauces/dressings: either 0.15–0.50% for stability and sheen; LBG preferred in hot-fill processes.
Plant-based/restructured meats: 0.10–0.40% for water binding and yield.
Optimize dosage through pilot trials per process and sensory targets.

Nutrition and health

Both are soluble, fermentable fibers that can yield SCFA via colonic fermentation. Rapid increases may cause gas/bloating—titrate gradually and ensure hydration. In foods, health claims require prior authorization.

Quality and specifications (typical topics)

Viscosity at defined concentration/temperature, particle size, moisture, ash, dispersion pH.
Contaminants: pesticides/metals within limits; compliant mycotoxins and microbiology; absence of Salmonella/E. coli in 25 g.
Purity: LBG/guar gum assay; controlled protein/mineral residues in refined grades.
Sensory: uniform color, free from grassy or dusty off-notes.

Storage and shelf life

Protect from humidity and odors; use barrier packaging with desiccants.
Avoid temperature swings and prolonged compression (caking).
Apply FIFO rotation; reseal containers promptly.

Allergens and safety

Not major allergens; powders may irritate the respiratory tract and rarely cause occupational sensitization. Excess intake or ingestion without adequate water is inadvisable (GI discomfort). Additives E410 and E412 are permitted per applicable regulations.

INCI functions in cosmetics

Typical entries: Ceratonia Siliqua (Carob) Gum / Locust Bean Gum; Cyamopsis Tetragonoloba (Guar) Gum; cationic guar derivatives (e.g., Guar Hydroxypropyltrimonium Chloride).
Roles: rheology modifiers/film formers; cationic guar provides conditioning in haircare (combability, wet/dry feel).

Troubleshooting

Lumps (“fish eyes”): poor dispersion → premix with dry solids, add under high shear; heat to 80–90 °C for LBG; 40–60 °C water speeds guar hydration.
Excess viscosity: overdose/high-MW grade → lower dose; switch to low-viscosity or partially hydrolyzed grade.
Viscosity loss: extreme pH, high temperature, or galactomannanase enzymes → correct pH, control process heat/asepsis.
Phase instability in beverages: use synergistic blends (LBG+xanthan or guar+xanthan), increase soluble solids, optimize shear.

Sustainability and supply chain

Guar: nitrogen-fixing legume suited to arid/semi-arid climates (India, Pakistan); by-products (churi/korma) valorized as feed.
Carob: Mediterranean, drought-tolerant crop; seed and pulp side-streams can be valorized. In-plant: water/energy recovery, effluent management to BOD/COD targets, recyclable packaging.

Conclusion

Locust bean gum and guar gum form a complementary rheology toolkit: LBG delivers thermal structure and strong synergies with xanthan/carrageenans, while guar provides fast cold viscosity and stabilization. Performance hinges on purity and particle size, pH/salt/temperature conditions, proper dispersion, and tight viscosity standardization.

Mini-glossary

LBG — locust bean gum (carob gum), galactomannan with M:G ≈ 4:1; hot-hydrating.
E410 / E412 — EU additive codes for locust bean gum and guar gum.
Pseudoplastic — fluid whose viscosity decreases as shear rate increases.
SCFA — short-chain fatty acids from colonic fermentation.
D90 — 90th-percentile particle diameter (fineness index).
FIFO — first in, first out (stock rotation).
BOD/COD — biochemical/chemical oxygen demand (effluent load indicators).

References__________________________________________________________________________

Carob

Micheli L, Muraglia M, Corbo F, Venturi D, Clodoveo ML, Tardugno R, Santoro V, Piccinelli AL, Di Cesare Mannelli L, Nobili S, Ghelardini C. The Unripe Carob Extract (Ceratonia siliqua L.) as a Potential Therapeutic Strategy to Fight Oxaliplatin-Induced Neuropathy. Nutrients. 2024 Dec 30;17(1):121. doi: 10.3390/nu17010121. 

Abstract. Background: Oxaliplatin-induced neuropathy (OIN) is a severe painful condition that strongly affects the patient's quality of life and cannot be counteracted by the available drugs or adjuvants. Thus, several efforts are devoted to discovering substances that can revert or reduce OIN, including natural compounds. The carob tree, Ceratonia siliqua L., possesses several beneficial properties. However, its antalgic properties have not been substantially investigated and only a few investigations have been conducted on the unripe carob (up-CS) pods. Thus, the aims of this study were to evaluate for the first time the unripe variety of Apulian carob, chemically characterized and profiled as antioxidant potential of polyphenolic compounds as well as to investigate the ability of up-CS to reduce the neurotoxicity in a mouse model of oxaliplatin-induced neuropathic pain. Methods: By UHPLC-HRMS/MS analyses, 50 phenolic compounds, belonging mainly to n-galloylated glucoses and flavonoids were detected. Results: In a mouse model of oxaliplatin-induced neurotoxicity (2.4 mg/kg, 10 injections over two weeks), acute per os treatment with up-CS provoked a dose-dependent pain-relieving effect that completely counteracted oxaliplatin hypersensitivity at the dose of 200 mg/kg. Repeated oral administration of up-CS (100 mg/kg), concomitantly with oxaliplatin injection, exerted a protective effect against the development of thermal and mechanical allodynia. In addition, up-CS exerted a neuroprotective role against oxaliplatin-induced astrocytes activation in the spinal cord measured as GFAP-fluorescence intensity. Conclusions: Overall, our study contributes to the knowledge on up-CS properties by highlighting its protective activity in the painful condition related to the administration of oxaliplatin.

Micheletti C, Medori MC, Bonetti G, Iaconelli A, Aquilanti B, Matera G, Bertelli M. Effects of Carob Extract on the Intestinal Microbiome and Glucose Metabolism: A Systematic Review and Meta-Analysis. Clin Ter. 2023 Nov-Dec;174(Suppl 2(6)):169-172.

Abstract. The legume tree known as carob (Ceratonia siliqua L.) is indigenous to the Mediterranean area and over the centuries its pods had been traditionally used mostly as animal feed. However, it has gained great attention in human nutrition due to the molecular compounds it contains, which could offer many potential health benefits: for example, carob is renowned for its high content of fiber, vitamins, and minerals. Moreover, in traditional medicine it is credited with the ability to control glucose metabolism and gut microbiome. Modern science has also extensively acknowledged the numerous health advantages deriving from its consumption, including its anti-diabetic, anti-inflammatory, and antioxidant properties. Due to its abundant contents of pectin, gums, and polyphenols (such as pinitol), carob has garnered significant attention as a well-researched plant with remarkable therapeutic properties. Notably, carob is extensively used in the production of semi-finished pastry products, particularly in ice cream and other creams (especially as a substitute for cocoa/chocolate): these applications indeed facilitate the exploration of its positive effects on glucose metabolism. Our study aimed at examining the effects of carob extract on intestinal microbiota and glucose metabolism. In this review, we conducted a thorough examination, comprising in vitro, in vivo, and clinical trials to appraise the consequences on human health of polyphenols and pectin from different carob species, including recently discovered ones with high polyphenol contents. Our goal was to learn more about the mechanisms through which carob extract can support a balanced gut flora and improve one's glucose metabolism. These results could influence the creation of novel functional foods and dietary supplements, to help with the management and prevention of chronic illnesses like diabetes and obesity.

Fujita K, Norikura T, Matsui-Yuasa I, Kumazawa S, Honda S, Sonoda T, Kojima-Yuasa A. Carob pod polyphenols suppress the differentiation of adipocytes through posttranscriptional regulation of C/EBPβ. PLoS One. 2021 Mar 8;16(3):e0248073. doi: 10.1371/journal.pone.0248073. 

Abstract. Obesity is a major risk factor for various chronic diseases such as diabetes, cardiovascular disease, and cancer; hence, there is an urgent need for an effective strategy to prevent this disorder. Currently, the anti-obesity effects of food ingredients are drawing attention. Therefore, we focused on carob, which has high antioxidant capacity and various physiological effects, and examined its anti-obesity effect. Carob is cultivated in the Mediterranean region, and its roasted powder is used as a substitute for cocoa powder. We investigated the effect of carob pod polyphenols (CPPs) on suppressing increases in adipose tissue weight and adipocyte hypertrophy in high fat diet-induced obesity model mice, and the mechanism by which CPPs inhibit the differentiation of 3T3-L1 preadipocytes into adipocytes in vitro. In an in vivo experimental system, we revealed that CPPs significantly suppressed the increase in adipose tissue weight and adipocyte hypertrophy. Moreover, in an in vitro experimental system, CPPs acted at the early stage of differentiation of 3T3-L1 preadipocytes and suppressed cell proliferation because of differentiation induction. They also suppressed the expression of transcription factors involved in adipocyte differentiation, thereby reducing triacylglycerol synthesis ability and triglycerol (TG) accumulation. Notably, CPPs regulated CCAAT/enhancer binding protein (C/EBP)β, which is expressed at the early stage of differentiation, at the posttranscriptional level. These results demonstrate that CPPs suppress the differentiation of adipocytes through the posttranscriptional regulation of C/EBPβ and may serve as an effective anti-obesity compound.

van Rijs P , Fogliano V . Roasting carob flour decreases the capacity to bind glycoconjugates of bile acids. Food Funct. 2020 Jul 1;11(7):5924-5932. doi: 10.1039/d0fo01158d. 

Abstract. Carob is the fruit obtained from Ceratonia siliqua L. and it is a source of bioactive compounds that have been linked to several health promoting effects, including lowering blood cholesterol concentration. The objective of this study was to connect the physicochemical changes of carob flour occurring during roasting with its capacity to bind glycoconjugates of bile acids. Carob flour samples were roasted for different times at 150 °C and chemically characterized by measuring the concentrations of tannins and polyphenols. Data showed that carob flour binds high amounts of bile acids: 732.6 μmol of bound bile acid per g of carob flour which is comparable to the 836.2 μmol per g bound by cholestyramine, a known cholesterol lowering drug. The carob flour ability to bind cholesterol decreases up to 40% during roasting. Data suggested that tannins and insoluble components play a major role in binding bile salts, as a result of hydrophobic interactions.

Ioannou GD, Savva IK, Christou A, Stavrou IJ, Kapnissi-Christodoulou CP. Phenolic Profile, Antioxidant Activity, and Chemometric Classification of Carob Pulp and Products. Molecules. 2023 Feb 28;28(5):2269. doi: 10.3390/molecules28052269. 

Abstract. In recent years, carob and its derived products have gained wide attention due to their health-promoting effects, which are mainly attributed to their phenolic compounds. Carob samples (carob pulps, powders, and syrups) were analyzed to investigate their phenolic profile using high-performance liquid chromatography (HPLC), with gallic acid and rutin being the most abundant compounds. Moreover, the antioxidant capacity and total phenolic content of the samples were estimated through DPPH (IC50 98.83-488.47 mg extract/mL), FRAP (48.58-144.32 μmol TE/g product), and Folin-Ciocalteu (7.20-23.18 mg GAE/g product) spectrophotometric assays. The effect of thermal treatment and geographical origin of carobs and carob-derived products on their phenolic composition was assessed. Both factors significantly affect the concentrations of secondary metabolites and, therefore, samples' antioxidant activity (p-value < 10-7). The obtained results (antioxidant activity and phenolic profile) were evaluated via chemometrics, through a preliminary principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA). The OPLS-DA model performed satisfactorily, differentiating all samples according to their matrix. Our results indicate that polyphenols and antioxidant capacity can be chemical markers for the classification of carob and its derived products.

Villalva M, García-Díez E, López de Las Hazas MDC, Lo Iacono O, Vicente-Díez JI, García-Cabrera S, Alonso-Bernáldez M, Dávalos A, Martín MÁ, Ramos S, Pérez-Jiménez J. Cocoa-carob blend acute intake modifies miRNAs related to insulin sensitivity in type 2 diabetic subjects: a randomised controlled nutritional trial. Food Funct. 2025 Apr 14;16(8):3211-3226. doi: 10.1039/d4fo04498c. 

Abstract. Postprandial metabolic disturbances are exacerbated in type 2 diabetes (T2D). Cocoa and carob, despite showing promising effects on these alterations in preclinical studies, have not yet been jointly tested in a clinical trial. Therefore, this acute, randomised, controlled, crossover nutritional trial evaluated the postprandial effects of a cocoa-carob blend (CCB) in participants with T2D (n = 20) and overweight/obesity. The subjects followed three treatments: hypercaloric breakfast (high-sugar and high-saturated fat, 900 kcal) as the control (treatment C); the same breakfast together with 10 g of the CCB, with 5.6 g of dietary fibre and 1.6 g of total polyphenols (treatment A); and the same breakfast after consuming the CCB (10 g) the night before (treatment B). Various analyses were performed, including the determination of the clinical markers of T2D (fasting and postprandial glucose and insulin, GLP-1, and glycaemic profile), satiety evaluation, analysis of exosomal miRNA expression and ex vivo determination of inflammation modulation. No effect on glucose homeostasis (glucose, insulin, and GLP-1) was found in the study population. However, eight exosomal miRNAs were found to be significantly modified owing to CCB supplementation compared with treatment C, with three of them (miR-20A-5p, miR-23A-3p, and miR-17-5p) associated with an improvement in insulin sensitivity. Furthermore, the CCB caused a decrease in hunger feelings (0-120 min), as assessed by the visual analogue scale (VAS). Finally, treatment A caused a significant decrease in the glucose increment within 0-30 min of treatment in subjects with overweight. No significant modifications were found in the other assessed parameters. The acute intake of the CCB by subjects with T2D showed modest although significant results, which need to be validated in a long-term randomised controlled trial.

Guar

Wu C, Liu J, Tang Y, Li Y, Yan Q, Jiang Z. Hepatoprotective Potential of Partially Hydrolyzed Guar Gum against Acute Alcohol-Induced Liver Injury in Vitro and Vivo.   Nutrients. 2019 Apr 27;11(5). pii: E963. doi: 10.3390/nu11050963.

Abstract. Natural polysaccharides, particularly galactomannans, are potential candidates for treatment of alcoholic liver diseases (ALD). However, applications are restricted due to the physicochemical properties associated with the high molecular weight. In this work, guar gum galactomannans were partially hydrolyzed by β-mannanase, and the molecular mechanisms of hepatoprotective effects were elucidated both in vitro and in vivo. Release of lactate dehydrogenase and cytochrome C were attenuated by partially hydrolyzed guar gum (PHGG) in HepG2 cells, due to protected cell and mitochondrial membrane integrity. PHGG co-administration decreased serum amino transaminases and cholinesterase levels of acute alcohol intoxicated mice, while hepatic pathologic morphology was depleted. Activity of superoxide dismutase, catalase, and glutathione peroxidase was recovered to 198.2, 34.5, 236.0 U/mg protein, respectively, while malondialdehyde level was decreased by 76.3% (PHGG, 1000 mg/kg∙day). Co-administration of PHGG induced a 4.4-fold increment of p-AMPK expression, and lipid metabolism was mediated. PHGG alleviated toll-like-receptor-4-mediated inflammation via the signaling cascade of MyD88 and IκBα, decreasing cytokine production. Moreover, mediated expression of Bcl-2 and Bax was responsible for inhibited acute alcohol-induced apoptosis with suppressed cleavage of caspase 3 and PARP. Findings gained suggest that PHGG can be used as functional food supplement for the treatment of acute alcohol-induced liver injury.

Kumar B, Murali A, Bharath AB, Giri S. Guar gum modified upconversion nanocomposites for colorectal cancer treatment through enzyme-responsive drug release and NIR-triggered photodynamic therapy.    Nanotechnology. 2019 Mar 20;30(31):315102. doi: 10.1088/1361-6528/ab116e.

Abstract. Multimodal therapeutic approach towards colorectal cancer (CRC) holds great promise. There is, however, no convincing strategy reported to date that employs a multimodal strategy in CRC treatment. The present study reports an intense green-emitting core-shell photoluminescent upconversion (CSGU) nanocrystal engineered to synergistically perform photodynamic and enzyme-triggered delivery of the chemotherapeutic agent for an enhanced therapeutic outcome on HT-29 colon carcinoma cells in vitro. The photodynamic activity is achieved by the energy transfer between CSGU and the chemically conjugated Rose Bengal (RB) molecules that are further protected by a mesoporous silica (MS) layer. The chemical assay demonstrates a remarkable FRET mediated generation of 1O2 under NIR (980 nm) excitation. The outermost MS layer of the nanoplatform is utilized for the loading of the 5FU anticancer drug, which is further capped with a guar gum (GG) polysaccharide polymer. The release of the 5FU is specifically triggered by the degradation of the GG cap by specific enzymes secreted from colonic microflora, which otherwise showed 'zero-release behavior' in the absence of any enzymatic trigger in various simulated gastro-intestinal (GI) conditions. Furthermore, the enhanced therapeutic efficacy of the nanoplatform (CSGUR-MSGG/5FU) was evaluated through in vitro studies using HT-29 CRC cell lines by various biochemical and microscopic assays by the simultaneous triggering effect of colonic enzyme and 980 nm laser excitation. In addition, the strong visible emission from the nanoplatform has been utilized for NIR-induced cellular bioimaging.

Paudel D, Nair DVT, Tian S, Hao F, Goand UK, Joseph G, Prodes E, Chai Z, Robert CEM, Chassaing B, Patterson AD, Singh V. Dietary fiber guar gum-induced shift in gut microbiota metabolism and intestinal immune activity enhances susceptibility to colonic inflammation. Gut Microbes. 2024 Jan-Dec;16(1):2341457. doi: 10.1080/19490976.2024.2341457.

Abstract. With an increasing interest in dietary fibers (DFs) to promote intestinal health and the growth of beneficial gut bacteria, there is a continued rise in the incorporation of refined DFs in processed foods. It is still unclear how refined fibers, such as guar gum, affect the gut microbiota activity and pathogenesis of inflammatory bowel disease (IBD). Our study elucidated the effect and underlying mechanisms of guar gum, a fermentable DF (FDF) commonly present in a wide range of processed foods, on colitis development. We report that guar gum containing diet (GuD) increased the susceptibility to colonic inflammation. Specifically, GuD-fed group exhibited severe colitis upon dextran sulfate sodium (DSS) administration, as evidenced by reduced body weight, diarrhea, rectal bleeding, and shortening of colon length compared to cellulose-fed control mice. Elevated levels of pro-inflammatory markers in both serum [serum amyloid A (SAA), lipocalin 2 (Lcn2)] and colon (Lcn2) and extensive disruption of colonic architecture further affirmed that GuD-fed group exhibited more severe colitis than control group upon DSS intervention. Amelioration of colitis in GuD-fed group pre-treated with antibiotics suggest a vital role of intestinal microbiota in GuD-mediated exacerbation of intestinal inflammation. Gut microbiota composition and metabolite analysis in fecal and cecal contents, respectively, revealed that guar gum primarily enriches Actinobacteriota, specifically Bifidobacterium. Guar gum also altered multiple genera belonging to phyla Bacteroidota and Firmicutes. Such shift in gut microbiota composition favored luminal accumulation of intermediary metabolites succinate and lactate in the GuD-fed mice. Colonic IL-18 and tight junction markers were also decreased in the GuD-fed group. Importantly, GuD-fed mice pre-treated with recombinant IL-18 displayed attenuated colitis. Collectively, unfavorable changes in gut microbiota activity leading to luminal accumulation of lactate and succinate, reduced colonic IL-18, and compromised gut barrier function following guar gum feeding contributed to increased colitis susceptibility.

Todd PA, Benfield P, Goa KL. Guar gum. A review of its pharmacological properties, and use as a dietary adjunct in hypercholesterolaemia. Drugs. 1990 Jun;39(6):917-28. doi: 10.2165/00003495-199039060-00007. 

Abstract. Guar gum is a dietary fibre advocated for use in lowering serum total cholesterol levels in patients with hypercholesterolaemia. Its mechanism of action is proposed to be similar to that of the bile-sequestering resins. Although guar gum is also employed as an adjunct in non-insulin-dependent diabetic patients this review is restricted to its efficacy as a hypolipidaemic agent. Clinical trials indicate that, when used alone, guar gum may reduce serum total cholesterol by 10 to 15%, although some studies show no significant response. An attenuation of this effect during longer term treatment has been seen but evidence of this effect is equivocal. As an adjunct to established therapies (bezafibrate, lovastatin or gemfibrozil) guar gum has shown some promise: it may produce a further reduction in total cholesterol of about 10% in patients not responding adequately to these drugs alone. Gastrointestinal effects, notably flatulence, occur relatively frequently and may be considered unacceptable by some patients. Standardization of formulations and methods of administration of guar gum is required to clarify its pharmacological and clinical properties. Thus, on the basis of presently available evidence guar gum as monotherapy may be considered at most modestly effective in reducing serum cholesterol levels. Nonetheless, further investigation of guar gum is warranted, particularly its use as an adjunct to produce additional reductions in serum cholesterol in patients not responding optimally to other lipid-lowering agents.

Okamura T, Hamaguchi M, Mori J, Yamaguchi M, Mizushima K, Abe A, Ozeki M, Sasano R, Naito Y, Fukui M. Partially Hydrolyzed Guar Gum Suppresses the Development of Sarcopenic Obesity. Nutrients. 2022 Mar 9;14(6):1157. doi: 10.3390/nu14061157. PMID: 35334814; 

Abstract. Partially hydrolyzed guar gum (PHGG) is a soluble dietary fiber derived through controlled enzymatic hydrolysis of guar gum, a highly viscous galactomannan derived from the seeds of Cyamopsis tetragonoloba. Here, we examined the therapeutic potential of dietary supplementation with PHGG against sarcopenic obesity using Db/Db mice. Db/Db mice fed a normal diet alone or a fiber-free diet, or supplemented with a diet containing PHGG (5%), were examined. PHGG increased grip strength and the weight of skeletal muscles. PHGG increased the short-chain fatty acids (SCFAs) concentration in feces and sera. Concerning innate immunity, PHGG decreased the ratio of inflammatory cells, while increasing the ratio of anti-inflammatory cells in the small intestine. The present study demonstrated the preventive effect of PHGG on sarcopenic obesity. Changes in nutrient absorption might be involved through the promotion of an anti-inflammatory shift of innate immunity in the intestine accompanied by an increase in SCFA production by PHGG.