In vitro assessment of agave fructans (Agave salmiana) as prebiotics and immune system activators

The prebiotic effect of agave fructans (Agave salmiana) was evaluated through the growth of two lactic acid bacterial (LAB) strains (Lactobacillus casei and Bifidobacterium lactis). The immune system was activated through the stimulation of peripheral blood mononuclear cells (PBMC) of healthy subjects testing fructans, LAB or a mixture of these compounds at different concentrations. Immune responses, such as early cell activation (CD69), cell cycle progression, nitric oxide (NO) production and the expression of transcription factors for lymphocyte differentiation, were analyzed. Compared with other fructans, the extracted agave fructans showed the highest prebiotic activity and increased levels of CD69 expression, proliferative activity and NO production when administered with the probiotic L. casei. The Th1 lymphocyte differentiation produced through LAB stimulation was greatly diminished after the incorporation of agave fructans. In conclusion, these types of fructans (A. salmiana) are involved in the activation and selective differentiation of cells of the immune system through interactions with probiotics. Thus, agave fructans represent a novel immunomodulator that might benefit the functional food industry. (C) 2013 Elsevier B.V. All rights reserved.