The lack of the two broad peaks characteristic of the cell membrane lipid particles (P1, P2) signals a loss of its original structure and suggests lipid transfer. This is accompanied by the formation of two distinct H₂ structures with ~75 Å lattice size characterized by Bragg peaks with q-spacing ratio (√1:√3:√4) (Table ). Together, these observations are attributed to the transfer of bacterial phospholipids into the cubosome matrix and subsequent transformation to hexagonal structure, as previously reported. However, the lattice parameter of the H₂ phase resulting from lipid transfer is significantly larger (~75 Å) than the ones measured for the H₂ phase formed by the action of live S. aureus (~51 Å) and in the case of sterile monoolein hexosomes (~55 Å). This swelling may be due to the accumulation of other phospholipids, namely cardiolipin (CL), which cause dramatic increases in lattice parameter by ~50-100 Å when present in bulk MO V₂ mesophases at <1 % by mass. Given that the lattice parameters of all dispersed lipid nanoparticles were not significantly affected by exposure to any live microbiome strains, this suggests that lipid transfer from live bacteria to lipid mesophases did not occur to a significant extent for gram-positive and -negative strains. This might be due to the structure of the bacterial cell envelopes which encapsulate and protect cellular membranes, and low levels of lipid release from these live cells.