Exploring the functionality of mesoporous silica nanoparticles as a prebiotic agent

Abstract

Mesoporous silica nanoparticles (MSNs), particularly SBA15 and SBA16, provide a versatile platform due to their ordered structures, high surface area, and biocompatibility. This study investigates their role as prebiotic agents by evaluating their effect on the growth of Bacillus coagulans, an industrially significant probiotic. SEM and TEM analyses revealed that SBA15 had mesh-like hexagonal structure, while SBA16 featured hexagonal pores with tubular channels, enhancing surface area and porosity for bacterial attachment and proliferation. BET analysis showed SBA15 had a surface area of 718 m²/g with 8.5 nm pores, whereas SBA16 exhibited 740 m²/g with 5.4 nm pores, influencing nutrient diffusion and bacterial interactions. UV–Vis spectroscopy confirmed structural stability with lambda maxima at 225 nm (SBA15) and 231 nm (SBA16). DLS analysis showed that SBA15 (267.7 nm) and SBA16 (367 nm) had high dispersibility in aqueous media, fostering a stable microenvironment. Optical density measurements and colony-forming unit assays demonstrated significant growth enhancement of Bacillus coagulans in the presence of MSNs, at lower concentrations (0.1–1 ppm). SBA15 promoted bacterial proliferation more effectively than SBA16, due to its larger pore size. The porosity facilitated bacterial adhesion and nutrient absorption, leading to enhanced metabolic activity. Enzyme assays confirmed a rise in ATP levels, suggesting increased energy metabolism, while a paradoxical increase in the Minimum Inhibitory Concentration (MIC) of Ampicillin was observed, attributed to nanoparticle-mediated antibiotic adsorption, reducing the bioavailability of the antibiotic and allowing bacterial survival. These findings highlight MSNs as growth modulators and antibiotic stress mitigators with applications in biotechnology and healthcare.

Graphical Abstract