A Review of Lignan Metabolism, Milk Enterolactone Concentration, and Antioxidant Status of Dairy Cows Fed Flaxseed

Abstract

Lignans are polyphenolic compounds with a wide spectrum of biological functions including antioxidant, anti-inflammatory, and anticarcinogenic activities, therefore, there is an increasing interest in promoting the inclusion of lignan-rich foods in humans’ diets. Flaxseed is the richest source of the lignan secoisolariciresinol diglucoside—a compound found in the outer fibrous-containing layers of flax. The rumen appears to be the major site for the conversion of secoisolariciresinol diglucoside to the enterolignans enterodiol and enterolactone, but only enterolactone has been detected in milk of dairy cows fed flaxseed products (whole seeds, hulls, meal). However, there is limited information regarding the ruminal microbiota species involved in the metabolism of secoisolariciresinol diglucoside. Likewise, little is known about how dietary manipulation such as varying the nonstructural carbohydrate profile of rations affects milk enterolactone in dairy cows. Our review covers the gastrointestinal tract metabolism of lignans in humans and animals and presents an in-depth assessment of research that have investigated the impacts of flaxseed products on milk enterolactone concentration and animal health. It also addresses the pharmacokinetics of enterolactone consumed through milk, which may have implications to ruminants and humans’ health.

Bioavailability and Bioefficacy of Hemp By-Products in Ruminant Meat Production and Preservation: A Review

“…Kuhnle et al ( 90 ) reported lignans in beef (6–16 μg/100 g wet weight) and lamb (4–17 μg/100 g wet weight). Ruminal biohydrogenation leads to the conversion of dietary lignans to enterolactones, which are absorbed from the gut and deposited in tissues including milk ( 91 ) and meat ( 90 ). Manipulation of dietary phenolic compounds has been confirmed to change their contents in meat ( 92 , 93 ).…”

Metabolomic and transcriptomic analyses reveal the regulation of pigmentation in the purple variety of Dendrobium officinale

“…One COMT gene ( caffeic acid 3-O-methyltransferase ) increased 3.80-fold in Pr compared to CK. Lignan is also an important active compound in Chinese herbs, which shares a common upstream pathway with lignins and branches after the synthesis of coniferyl alcohol 30 . These results suggest that the medicinal value of D. officinale requires further exploration.…”

Insight into Polyphenol and Gut Microbiota Crosstalk: Are Their Metabolites the Key to Understand Protective Effects against Metabolic Disorders?

“…The most frequent forms of dietary lignans are secoisolariciresinol, lariciresinol, pinoresinol, and matairesinol, which are metabolized by gut microflora enzymes into enterolignans such as enterodiol and enterolactone undergoing enterohepatic circulation [ 305 , 306 ]. At least, 28 bacterial species belonging to 12 different genera (e.g., Bacteroides , Clostridium , Bifidobacterium , and Ruminococcus ) have been identified to be involved in the transformation of lignans to enterolignans [ 307 ]. Several groups have quantified the concentrations of the enterolactone metabolite in blood and urine, and reported a protective association in view of the reduction (30–45%) of cardiovascular mortality [ 308 ].…”