Globulins are the main proteins in oat and they have a similar structure to soy 11S protein, also aggregating under 100 \({}^{\circ}\)C [37] and allowing gelation. The major component of oat groats carbohydrates is starch (40-60%) [38] and its functionality has a positive effect on the rheological properties of fermented products, contributing to gelatinization. Oat lipids range from 2 to 13% and their oxidation is responsible for the off-flavor of oat-based products [39]. Volatile compounds generated through lipid oxidation, such as hexanal, pentanal, and certain carbonyl compounds [40; 41], give oat drink an unpleasant aftertaste related to rancidity. Additionally, the presence of long-chain hydroxy fatty acids causes bitter off-notes in oat flavor [42]. These negative attributes should be masked to achieve consumer acceptance of an oat-based dairy alternative. Coconut is another popular raw material for the development of plant-based products; especially its oil is used in cheese alternatives. It has the highest amount of fat and the lowest amount of protein [1]. Commercial coconut milk has ca. 1 g of protein or less and 4-6 g of fat per 100 g of product [13; 43]. 87% of the fat is saturated [1] and it is mostly constituted by myristic acid, lauric acid, palmitic acid, and capric acid [14]. The high saturated fatty acids content in coconut oil enables the formation of a solid structure at ambient temperature with a small melting temperature range (18.3-26.4 \({}^{\circ}\)C [44]) influenced by short chain lauric acid [45]. Its ability to provide solid textures makes it a good candidate to obtain firmer products, such as non-dairy yogurt or non-dairy cheese, but, because of its lack of protein and high saturated fat content, it is not the most optimal replacement for dairy alternatives [13]. coconut milk contains a low carbohydrate content (5.5 g/100 g of product) that can be reduced to 1.32 g/100 g of product after fermentation [46]. Previous studies reported coconut milk as a favorable medium for probiotic bacterial growth [12] and for the preservation of cell viability after fermentation [9]. Fermentation is an essential process to transform plant-based raw material into non-dairy alternatives. Lactic acid bacteria (LAB) have been used since ancient times to ferment cereals, fruits, vegetables, meat, and milk, among others, with the preservation and organoleptic improvement purposes [6; 47]. LAB are a group of gram-positive, non-spore-forming, facultative anaerobic bacteria whose main carbohydrate fermentation product is, lactic acid [48]. LAB can generate an extended portfolio of aromatic compounds, endowing fermented products with characteristic flavors and aromas originated with the breakdown of the predominant macronutrients in the food matrix [49]. A wide range of alcohols, aldehydes, and acids are obtained from pyruvate precursors and amino acids metabolism. Certain LAB can produce exopolysaccharides (EPS), compounds that are known to improve texture in fermented products, increasing viscosity and improving stability [34]. This feature can enable the replacement of thickening agents. LAB that have already been used in the development of fermented plant-based dairy alternatives are L. _debrueckii_[50], _S. thermophilus_, and _L. delbrueckii_ subsp. _bulgaricus_[10], _B. longum_ or L. _mamosus_[51]. In order to observe synergistic effects similar to those in dairy fermentation, plant-based fermentation with pure and mixed cultures has been evaluated [52]. It was found that both pure and mixed cultures are suitable for oat fermentation, but pure cultures showed better flavor profiles. In the current study, different cultures were combined with _Lactobacillus rhamnus_, LGG\({}^{\circledR}\), a registered trademark of Chr. Hansen A/S identifying the _L. rhamnus_ strain and related products. LGG\({}^{\circledR}\) is one of the world's most documented probiotic strains. It originates from human intestinal microbiota and has been used worldwide since 1990. Previous studies showed that _L.