From:  Mechanisms of action and health benefits of probiotics: a comprehensive review

 Some materials are used for the encapsulation of probiotics.

ComponentAdvantageDisadvantageProbioticTherapeutic effect of strain(s)Reference
Proteins
Milk proteins (whey protein and/or casein)Acid-stable; pepsin-resistant; bile salt-resistant; enzyme-activated controlled release in intestine; exceptional film-forming propertiesPotential allergenLactobacillus rhamnosus GG, Bifidobacterium longum 1941, Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilusPreventing diarrhoea, primary rotavirus infection, and atopic dermatitis[4042]
Plant proteins [zein (corn protein) and/or soy protein]Enhanced protection due to forming a hydrophobic shell; pH and thermal stabilityMight aggregate and compromise stabilityBacillus subtilis 168Increasing abundance of beneficial gut bacteria[43, 44]
GelatinImproved antioxidant property; mucoadhesion can potentially enhance probiotic deliveryDenatures at high temperaturesLactobacillus rhamnosus GG
Bifidobacterium bifidum
Lactobacillus acidophilus
Bacillus coagulans
Saccharomyces boulardii
Gut disease prevention, such as IBS, IBD, diarrhea prevention.
Improving immune modulation, such as allergy, inflammation.
Vaginal or urinary tract infection improved by Lactobacillus strain
[45]
Albumin (egg white protein)Gelling and cross-linking ability; specific site-targeting propertiesPotential allergen; pH sensitiveLactobacillus acidophilus TISTR 1338Preventing diarrhoea, treating Helicobacter pylori, improving respiratory tract infections, lowering serum cholesterol levels and improving the host’s lactose tolerance levels[46, 47]
Silk fibroinResistant to gastric acid and bile acid; resistant to enzymatic action; improved adhesion to IECsCan be brittleLactobacillus plantarum, Enterococcus faecium KCTC 13115BP (EF-3), Streptococcus thermophilus KCTC 14471BP (ST-27), Bifidobacterium animalis subsp. lactis KCTC 13116BP (BL-5), Bifidobacterium bifidum KCTC 13114BP (BB-1), Lactobacillus acidophilus KCTC 13117BP (LA-7)Reducing diarrhea, inhibiting pathogenic bacteria, reducing blood cholesterol, and improving liver cirrhosis and obesity[48, 49]
Polysaccharides
AlginateHigh encapsulation efficiency; significant increase in the survival rate of probiotics; cost-effectiveReduced probiotic protection at low pHSaccharomyces cerevisiae strains, Saccharomyces boulardii, Enterococcus faecium, Bacillus licheniformis, fruit-derived lactic acid bacteria (LAB)Preventing and treating diarrheal diseases (acute infantile diarrhoea, antibiotic-associated diarrhoea, nosocomial infection); preventing systemic infection; managing IBD; immunomodulation; prevention and treatment of allergies; anticancer effects, treating high cholesterol, and relieving lactose intolerance[50]
ChitosanThe only commercially available water-soluble cationic polymer, quick biodegradationReported to have some antimicrobial and antifungal actions; therefore can be used as the shell but not the capsule during encapsulation strategiesLactobacillus and Bifidobacterium spp.Boosting host immunity; improving growth of targeted microorganisms; eliminating harmful bacteria[51]
PectinItself a prebiotic, meaning it can be fermented by beneficial bacteria in the gut, further supporting their growth and activity; resistant to enzymatic digestion in the stomach and small intestineMight modify probiotics’ metabolismLactobacillus plantarumProtection against intestinal epithelial barrier disruption[52, 53]
CarrageenanImproved probiotic survival in acidic conditionsNo significant resistance to bile saltsLactobacillus plantarumEnhancing gut health by securing a good number of probiotic bacteria in the GI tract in highly acidic conditions[54]
Gellan and/or xanthan gumExcellent gelling and malleability properties; biocompatible and biodegradable; heat and acid-stableMay be unstable in physiological conditionsLactobacillus paracasei 28.4Antifungal activity against Candida albicans in the oral cavity[55, 56]
CelluloseCheap; can be used to make pH-responsive capsules when complexed with other materialsIt can lead to structural defects when used in complexesLactobacillus spp., Bifidobacterium spp.Treatment of severe skin infections and chronic wounds[57]
Starch and/or dextranAcid-resistantCan be unstable under thermal stress; can form irregular aggregatesLactobacillus rhamnosusEnhancing probiotic stability and viability under simulated gastrointestinal conditions[58]
PullulanItself a potential prebiotic; increased probiotic viability after acid and bile exposureCan be expensiveLactobacillus acidophilus NRRL-B 4495Preventing and treating gastrointestinal infections and diarrhoea; stimulating immune responses that promote the effects of vaccination or even prevent certain allergic symptoms[59, 60]
Lipids
Plant oils (olive, sunflower, soybean, corn)Improved survival in gastric and pancreatic juicesMay interfere with probiotic survivabilityCandida adriatica, Candida diddensiae, Nakazawaea molendini-olei, Nakazawaea wickerhamii, Wickerhamomyces anomalus, Yamadazyma terventinaSynthesizing polyunsaturated fatty acids (PUFAs), which provide health benefits[61]
Dioleoylphosphatidic acid and cholesterolPreserves the native viability and biosafety of naked probioticsMight induce an inflammatory responseEscherichia coli Nissle 1917 (EcN)Preventing and treating Salmonella typhimurium (STm) and dextran sulfate sodium (DSS) induced colitis[62]

IBD: inflammatory bowel disease; IBS: irritable bowel syndrome; IECs: intestinal epithelial cells.