A prebiotic hydrogel based on gellan gum and arabinoxylan from flaxseed (Linum usitatissimum) for advanced probiotic delivery

Existing hydrogels for probiotic delivery require various encapsulation layers, multiple raw materials, crosslinkers, multi-step formulation process yet struggle with a combination of stability, solubility, and protective strength, limiting their use in probiotic delivery. This study investigated hydrogels formulated using gellan gum (GG) as a gelator and arabinoxylan (AX, extracted from flaxseeds) as a functional prebiotic for encapsulation of two standard probiotic strains, Lactobacillus casei subsp. casei NCIM 5752 and Lactiplantibacillus plantarum NCMR 2034. Hydrogels were prepared at various GG:AX ratios (1:4, 2:3, 3:2) and concentrations (1-5 % w/w). Among them, GX1A (0.2 % GG and 0.8 % AX) demonstrated overall optimal performance, with moderate swelling indices (16.88 ± 0.08 % for L. casei NCIM 5752 and 14.81 ± 1.28 % for L. plantarum NCMR 2034), low hardness (314.67 ± 1.53 g and 331.00 ± 1.00 g), and high encapsulation efficiencies (88.08 ± 0.91 % and 87.42 ± 0.76 %, respectively). Under simulated gastrointestinal conditions, GX1A released 74.92 ± 0.33 % (L. casei NCIM 5752) and 78.41 ± 0.51 % (L. plantarum NCMR 2034), supported by fluorescence microscopy. FTIR spectra confirmed physically formed hydrogels, while rheological analysis showed predominant elastic behavior (G’ > G″), indicating a stable gel network. These findings highlight the potential of GG-AX hydrogels as biocompatible, prebiotic-enhanced matrices for probiotic delivery. Future in vivo studies should explore gut colonization, host immune response, toxicity study and microbiota modulation to validate functional benefits and explore application in functional foods or therapeutics.