Oral bioavailability enhancement of MK-7 from natto extract via HyperCelle nanoencapsulation in a clinical study

Abstract In this study, we investigated the bioavailability of MK-7 from Bacillus subtilis natto extract Vitamin K2 using the HyperCelle method in a randomized, double-blind, controlled, parallel-group clinical trial. HyperCelle Vitamin K2 showed an average diameter of 321.4 nm with a polydispersity index (PI) of 0.210 and exhibited a population of spherical nanoparticles with a well-defined core-shell structure using dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. Its water solubility was higher than that of the powdered form of Bacillus subtilis natto extract Vitamin K2 (negative control). The plasma concentration of Menaquinone-7 (MK-7) from HyperCelle Vitamin K2 was significantly higher than that of the negative control group at 6-, 10-, 24-, and 72-hours post-ingestion ( p < 0.05). Both AUC (106.407 ± 73.794 µg·h/mL) and Cmax (3.038 ± 2.184 µg/mL) of MK-7 from HyperCelle Vitamin K2 were significantly greater compared to the negative control (AUC: 36.216 ± 18.985 µg·h/mL, Cmax: 1.474 ± 0.696 µg/mL) ( p < 0.05). These results indicate that HyperCelle Vitamin K2, which was well encapsulated with a smaller particle size, enhanced water solubility and consequently improved the bioavailability of MK-7. Given the well-recognized role of MK-7 in supporting bone health, the improved absorption observed in this study suggests potential benefits for biological activity, although further validation is needed before confirming its efficacy in functional food applications.