Production of enterodiol from defatted flaxseeds through biotransformation by human intestinal bacteria

Abstract

BackgroundThe effects of enterolignans, e.g., enterodiol (END) and particularly its oxidation product, enterolactone (ENL), on prevention of hormone-dependent diseases, such as osteoporosis, cardiovascular diseases, hyperlipemia, breast cancer, colon cancer, prostate cancer and menopausal syndrome, have attracted much attention. To date, the main way to obtain END and ENL is chemical synthesis, which is expensive and inevitably leads to environmental pollution. To explore a more economic and eco-friendly production method, we explored biotransformation of enterolignans from precursors contained in defatted flaxseeds by human intestinal bacteria.ResultsWe cultured fecal specimens from healthy young adults in media containing defatted flaxseeds and detected END from the culture supernatant. Following selection through successive subcultures of the fecal microbiota with defatted flaxseeds as the only carbon source, we obtained a bacterial consortium, designated as END-49, which contained the smallest number of bacterial types still capable of metabolizing defatted flaxseeds to produce END. Based on analysis with pulsed field gel electrophoresis, END-49 was found to consist of five genomically distinct bacterial lineages, designated Group I-V, with Group I strains dominating the culture. None of the individual Group I-V strains produced END, demonstrating that the biotransformation of substrates in defatted flaxseeds into END is a joint work by different members of the END-49 bacterial consortium. Interestingly, Group I strains produced secoisolariciresinol, an important intermediate of END production; 16S rRNA analysis of one Group I strain established its close relatedness with Klebsiella. Genomic analysis is under way to identify all members in END-49 involved in the biotransformation and the actual pathway leading to END-production.ConclusionBiotransformation is a very economic, efficient and environmentally friendly way of mass-producing enterodiol from defatted flaxseeds.

Plant and mammalian lignans: A review of source, intake, metabolism, intestinal bacteria and health

“…Although Wang et al (2010) obtained a group of mixed bacteria able to metabolise flaxseed to produce END with potential application for large-scale production of enterolignans, END and ENL have not been produced commercially as a supplement so far.…”

“…Accordingly, Wang et al (2010) obtained a bacterial consortium, designated as END-49, which transformed flaxseed to END. Based on analysis using pulsed field gel electrophoresis, END-49 was found to consist of five genomically distinct bacterial lineages.…”

“…Recently, Wang et al (2010) cultured faecal specimens from healthy young adults in media containing defatted flaxseeds and then went on to detect END from the culture supernatant. They demonstrated that the biotransformation of flaxseed to END using human intestinal microbiota is a very economic, efficient and environmentally friendly way of mass-producing END.…”

Oilseeds ameliorate metabolic parameters in male mice, while contained lignans inhibit 3T3-L1 adipocyte differentiation in vitro

“…Higher intakes (up to 13.5 mg/day) have been found in Germany [12]. Lignans are expected to have beneficial effects in humans after fermentative conversion in the colon to the mammalian lignans ENL and END [13,14]. Subpopulations with higher consumption of lignans display considerable lower disease frequency [7,[15][16][17][18][19][20][21][22].…”

The role of gut microbiota (commensal bacteria) and the mucosal barrier in the pathogenesis of inflammatory and autoimmune diseases and cancer: contribution of germ-free and gnotobiotic animal models of human diseases

“…Gut microbiota can metabolize certain plant-derived foods into biologically active compounds, e.g., enterolignans, that may play a role in carcinogenesis. 148 A recent meta-analysis indicated that these phytohormones may decrease the incidence of breast cancer. 149 The highest production of carcinogens was associated with gut anaerobic bacteria and was lowered by supplementation with live lactobacilli.…”