Indeed, plant-based products are raising interest as innovative potential carriers ensuring probiotics for vegan consumers. Moreover, due to the increase in vegan, vegetarian and allergic consumers, food and pharmaceutical industries are currently searching for alternatives in plant-based carriers. Reconstitution (as a result of rehydration by adding water) has been known for decades in the case of spray-dried animal (bovine, camel) milks. An innovative idea is to obtain reconstituted plant water extracts (also known as plant milks) and was already reported in for spray-dried reconstituted soymilk and almond-based milk. However, there are very limited information about maintaining probiotic properties of LAB after spray drying. Various carriers such as skim milk and calcium-fortified skim milk, whey proteins, maltodextrin, native rice starch and inulin, fructooligosaccharides, agava fructans and buttermilk proteins, trehalose, polysaccharides (alginate, carrageenan, pectin, xantan, gellan), vegetable juices as well as almond milk can be considered a promising strategy to improve stability and viability of probiotics. Many natural-based wall/carrier materials have been proposed for improving LAB (including probiotic strains) survivability during spray drying and passage through the GIT. Polysaccharides and proteins are widely used to prepare carriers/delivery systems, playing a pivotal role in their structure and stability. Moreover, spray drying is one of the encapsulation methods, which refers to a process where the active ingredients or cells are surrounded (encapsulated) by a protective continuous film of polymeric materials. Spray drying is a fast and cost-effective technique to produce powders (solid microparticles) from starting liquid raw materials, being one of the promising processes to produce dry, probiotic formulations, as well as a strategy to protect and improve their viability within the GIT. The technological issues related to the development of products containing beneficial microflora at recommended levels, maintaining their viability during shelf life and stabilization throughout the GIT are a challenge. Probiotic microorganisms should be present in the product at minimum numbers of 10 6–10 7 CFU (Colony Forming Units) per mL or g of product. One of the LGG characteristics responsible for its health-benefit properties is resisting low pH levels, the ability to adhere mucus and epithelial cells as well as prolonged residence in GIT. The competition with pathogens for binding sites and production of antimicrobial compounds are the main mechanisms suggested to contribute to the probiotic action of LGG in the gastrointestinal tract (GIT). It has been previously reported that LGG exerts beneficial effects in treating and/or preventing several disorders, including ulcerative colitis, diarrhea, atopic dermatitis, rotavirus infections, sepsis and meningitis. This strain exhibits most of the features required for probiotics, and has been shown to be safe and non-pathogenic. Lacticaseibacillus rhamnosus GG (LGG) is a Gram-positive Lactic Acid Bacterium (LAB), and one of the best-studied probiotics in clinical trials. Probiotic bacteria (defined as: “living microorganisms which exert beneficial effect on the host health when consumed in adequate amounts”) are intensively studied worldwide. This study demonstrated that FOCE is an appropriate matrix for spray drying (due to flaxseed proteins and polysaccharides) providing high survivability of bacteria (89.41–96.32%), that passed meaningfully through the simulated gastrointestinal tract (4.39–5.97 log reduction), largely maintaining their probiotic properties, being a promising environmentally-friendly carrier for probiotic LGG. Results revealed that all physicochemical and functional characteristics of the powders were affected by the inlet temperature. The preservation of LGG probiotic features such as cholesterol reduction, hydrophobicity and adhesion to mucin were examined. For all variants, the survival of bacteria during spray drying, and simulated passage through the gastrointestinal tract was evaluated. The influence of temperature on water activity, morphology, chemical composition, flowability and cohesiveness of the powders was estimated. The powders were obtained using three spray drying inlet temperatures (110 ☌, 140 ☌, 170 ☌), and reconstituted. This study was designed to evaluate the flaxseed oil cake extract (FOCE) as natural encapsulating material and carrier for probiotic Lacticaseibacillus rhamnous GG (LGG). Agro-industrial by-products are promising source of biopolymers, including proteins and polysaccharides.