Wolffia globosa–Mankai Plant-Based Protein Contains Bioactive Vitamin B12 and Is Well Absorbed in Humans

Abstract

Background: Rare plants that contain corrinoid compounds mostly comprise cobalamin analogues, which may compete with cobalamin (vitamin B12 (B12)) metabolism. We examined the presence of B12 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 B12 concentrations. Methods: We used microbiological assay, liquid-chromatography/electrospray-ionization-tandem-mass-spectrometry (LC-MS/MS), and anoxic bioreactors for the B12 experiments. We explored the effect of a green Mediterranean/low-meat diet, containing 100 g of frozen Mankai shake/day, on serum B12 levels during the 18-month DIRECT-PLUS (ID:NCT03020186) weight-loss trial, compared with control and Mediterranean diet groups. Results: The B12 content of Mankai was consistent at different seasons (p = 0.76). Several cobalamin congeners (Hydroxocobalamin(OH-B12); 5-deoxyadenosylcobalamin(Ado-B12); methylcobalamin(Me-B12); cyanocobalamin(CN-B12)) were identified in Mankai extracts, whereas no pseudo B12 was detected. A higher abundance of 16S-rRNA gene amplicon sequences associated with a genome containing a KEGG ortholog involved in microbial B12 metabolism were observed, compared with control bioreactors that lacked Mankai. Following the DIRECT-PLUS intervention (n = 294 participants; retention-rate = 89%; baseline B12 = 420.5 ± 187.8 pg/mL), serum B12 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 B12 compounds and could serve as a B12 plant-based food source.

The World Smallest Plants (Wolffia Sp.) as Potential Species for Bioregenerative Life Support Systems in Space

“…Wolffia species grown under optimal conditions also resulted rich in phenolic substances [58], a class of bioactive compounds that plays a crucial role in the defence against biotic and abiotic stress in plants [ [59][60][61] is also well known to be essential for human wellbeing. W. globose plants were also reported to be rich in cobalamin (vitamin B12), in a form that is bioactive and well absorbed by the human body [62].…”

The Metabolomic-Gut-Clinical Axis of Mankai Plant-Derived Dietary Polyphenols

“…This study provides a complementary view of polyphenol-rich foods' metabolomegut-clinical axis, taking Mankai as a case study. Considering the latest evidence regarding the nutritional profile of the aquatic plant Mankai [20,22], the acceptance among our participants in the DIRECT PLUS trial, and current knowledge regarding its effects as part of green-MED diet on fatty liver, glycemic control, cardiometabolic risk and the gut microbiome [29,30,52,53], it can potentially offer a green, healthy meat substitute. However, further studies should be conducted to examine the direct effect of Mankai on health outcomes.…”

“…Inclusion criteria were age above 30 years with abdominal obesity or dyslipidemia. Exclusion criteria and ethical issues are described elsewhere [22,29,30].…”

“…Wolffia globosa 'Mankai' is an aquatic plant of the duckweed family recently identified for its nutritional value [16,17]. It is a source of omega-3 fatty acids [18], dietary fiber, polyphenols [19] and, as reported by us, a rich source of protein [20], iron [21], vitamin B12 [22] and folate. Consuming one cup of Mankai shake exclusively provided in the DIRECT PLUS trial, equivalent to~20 g of dry matter, provides the following proportions of recommended intakes: 18% whole bioavailable protein, 75% bioavailable iron, 60% folic acid and 21% vitamin B12.…”

“…Performed at Biodesign Swette Center for Environmental Biotechnology, Arizona State University, USA Microbiota Reactors (Human Fecal Mixture) & Media, Anoxic Bioreactor, MankaiLysate, and Sampling: The procedure of preparing the reactors (artificial gut) is detailed elsewhere, along with the chemical and molecular analyses[22].…”