Probiotic fortification of plant-based foods has attracted significant interest due to its potential benefits for gut and metabolic health. However, maintaining adequate probiotic viability during processing and storage remains a key challenge, especially in non-dairy systems with low buffering capacity and limited nutrient composition. Walnut-based products represent a promising yet underexplored food matrix because they naturally provide unsaturated fatty acids, proteins, phenolic compounds, and bioactive peptides, which may support microbial survival and confer additional health benefits. Previous studies have indicated that under optimal fermentation conditions, several strains, including Lactiplantibacillus plantarum, Bifidobacterium breve, Lacticaseibacillus casei, Lacticaseibacillus rhamnosus, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. bulgaricus, can maintain viable cell counts above the functional threshold of 6 log CFU/ml in walnut-based matrices. This review synthesizes the current evidence on the use of walnut milk and walnut-based products as probiotic carriers and discusses how fermentation can be used to develop functional foods that consistently confer health benefits.
Al-Subaie et al. (Wed,) studied this question.