Plant-Based Protein Contains Bioactive Vitamin B and Is Well Absorbed in Humans.

BACKGROUND

Rare plants that contain corrinoid compounds mostly comprise cobalamin analogues, which may compete with cobalamin (vitamin B (B)) metabolism. We examined the presence of B in a cultivated strain of an aquatic plant: (Mankai), and predicted functional pathways using gut-bioreactor, and the effects of long-term Mankai consumption as a partial meat substitute, on serum B concentrations.

METHODS

We used microbiological assay, liquid-chromatography/electrospray-ionization-tandem-mass-spectrometry (LC-MS/MS), and anoxic bioreactors for the B experiments. We explored the effect of a green Mediterranean/low-meat diet, containing 100 g of frozen Mankai shake/day, on serum B levels during the 18-month DIRECT-PLUS (ID:NCT03020186) weight-loss trial, compared with control and Mediterranean diet groups.

RESULTS

The B content of Mankai was consistent at different seasons ( = 0.76). Several cobalamin congeners (Hydroxocobalamin(OH-B); 5-deoxyadenosylcobalamin(Ado-B); methylcobalamin(Me-B); cyanocobalamin(CN-B)) were identified in Mankai extracts, whereas no pseudo B was detected. A higher abundance of 16S-rRNA gene amplicon sequences associated with a genome containing a KEGG ortholog involved in microbial B metabolism were observed, compared with control bioreactors that lacked Mankai. Following the DIRECT-PLUS intervention ( = 294 participants; retention-rate = 89%; baseline B = 420.5 ± 187.8 pg/mL), serum B increased by 5.2% in control, 9.9% in Mediterranean, and 15.4% in Mankai-containing green Mediterranean/low-meat diets ( = 0.025 between extreme groups).

CONCLUSIONS

Mankai plant contains bioactive B compounds and could serve as a B plant-based food source.