Wolffia globosa-Mankai Plant-Based Protein Contains Bioactive Vitamin B 12 and Is Well Absorbed in Humans.

Background: Rare plants that contain corrinoid compounds mostly comprise cobalamin analogues, which may compete with cobalamin (vitamin B ₁₂ (B ₁₂ )) metabolism. We examined the presence of B ₁₂ in a cultivated strain of an aquatic plant: Wolffia globosa (Mankai), and predicted functional pathways using gut-bioreactor, and the effects of long-term Mankai consumption as a partial meat substitute, on serum B ₁₂ concentrations.
Methods: We used microbiological assay, liquid-chromatography/electrospray-ionization-tandem-mass-spectrometry (LC-MS/MS), and anoxic bioreactors for the B ₁₂ experiments. We explored the effect of a green Mediterranean/low-meat diet, containing 100 g of frozen Mankai shake/day, on serum B ₁₂ levels during the 18-month DIRECT-PLUS (ID:NCT03020186) weight-loss trial, compared with control and Mediterranean diet groups.
Results: The B ₁₂ content of Mankai was consistent at different seasons ( p = 0.76). Several cobalamin congeners (Hydroxocobalamin(OH-B ₁₂ ); 5-deoxyadenosylcobalamin(Ado-B ₁₂ ); methylcobalamin(Me-B ₁₂ ); cyanocobalamin(CN-B ₁₂ )) were identified in Mankai extracts, whereas no pseudo B ₁₂ was detected. A higher abundance of 16S-rRNA gene amplicon sequences associated with a genome containing a KEGG ortholog involved in microbial B ₁₂ metabolism were observed, compared with control bioreactors that lacked Mankai. Following the DIRECT-PLUS intervention ( n = 294 participants; retention-rate = 89%; baseline B ₁₂ = 420.5 ± 187.8 pg/mL), serum B ₁₂ increased by 5.2% in control, 9.9% in Mediterranean, and 15.4% in Mankai-containing green Mediterranean/low-meat diets ( p = 0.025 between extreme groups).
Conclusions: Mankai plant contains bioactive B ₁₂ compounds and could serve as a B ₁₂ plant-based food source.