Discriminatory and cooperative effects within the mouse gut microbiota in response to flaxseed and its oil and lignan components

Flaxseed Lignan Alleviates the Paracetamol-Induced Hepatotoxicity Associated with Regulation of Gut Microbiota and Serum Metabolome

This study examined the protective effect of flaxseed lignans on liver damage caused by an overdose of paracetamol (PAM). The findings demonstrated that administering 800 mg/kg/d flaxseed lignan prior to PAM significantly decreased the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TBi) levels, while it increased liver superoxide dismutase (SOD) and glutathione (GSH) levels in mice. Flaxseed lignan renovated the gut microbiota dysbiosis induced by PAM by promoting the proliferation of sulfonolipid (SL) producing bacteria such as Alistipes and lignan-deglycosolating bacteria such as Ruminococcus while inhibiting the growth of opportunistic pathogen bacteria such as Acinetobacter and Clostridium. Furthermore, flaxseed lignan modulated the serum metabolomic profile after PAM administration, specifically in the taurine and hypotaurine metabolism, phenylalanine metabolism, and pyrimidine metabolism. The study identified eight potential biomarkers, including enterolactone, cervonyl carnitine, acutilobin, and PC (20:3(5Z, 8Z, 11Z)/20:0). Overall, the results suggest that flaxseed lignan can alleviate PAM-induced hepatotoxicity and may be beneficial in preventing drug-induced microbiome and metabolomic disorders.

Cecal microbiota and mammary gland microRNA signatures are related and modifiable by dietary flaxseed with implications for breast cancer risk

IMPORTANCE

Breast cancer is a leading cause of cancer mortality worldwide. There is a growing interest in using dietary approaches, including flaxseed (FS) and its oil and lignan components, to mitigate breast cancer risk. Importantly, there is recognition that pubertal processes and lifestyle, including diet, are important for breast health throughout life. Mechanisms remain incompletely understood. Our research uncovers a link between mammary gland miRNA expression and the gut microbiota in young female mice. We found that this relationship is modifiable via a dietary intervention. Using data from The Cancer Genome Atlas, we also show that the expression of miRNAs involved in these relationships is altered in breast cancer in humans. These findings highlight a role for the gut microbiome as a modulator, and thus a target, of interventions aiming at reducing breast cancer risk. They also provide foundational knowledge to explore the effects of early life interventions and mechanisms programming breast health.

The What and Who of Dietary Lignans in Human Health: Special Attention to Estrogen Effects and Safety Evaluation

Lignans are a group of phenolic compounds found in plant-based diets. The human body can obtain lignans through diet, which are then metabolized into enterolignans. The enterolignans have been linked to several health benefits, including anticancer, anti-inflammatory, antioxidant effects, and estrogen effects. This review explores the relationship between the estrogenic effects of lignans and health. This review not only considers the estrogen-like activity of lignans but also discusses the safe dosage of lignans at different life stages. In addition, this review also identified other types of bioactive compounds that can act synergistically with lignans to promote health. Studies have shown that lignan administration during pregnancy and lactation reduces the risk of breast cancer in offspring. Further studies are needed to investigate the estrogenic safety effects of lignan on pregnant women and children. Whether lignans combine with other nutrients in complex food substrates to produce synergistic effects remains to be investigated. This review provides a basis for future studies on the safe dose of lignan and recommended dietary intake of lignan. We believe that the acquired as discussed here has implications for developing dietary therapies that can promote host nutrition and modulate estrogenic diseases.

Pharmacological, nutraceutical, and nutritional properties of flaxseed (Linum usitatissimum): An insight into its functionality and disease mitigation

Flaxseed (Linum usitatissimum L.) is derived from the flax plant, an annual herb. The primary relevance of flaxseed is in the human nutrition sector, where it is emerging as a significant functional food component due to its high level of active chemicals, which have been linked to health benefits. Flaxseed may be consumed in numerous forms, including milled, oil, and bakery items. The phytochemicals that are present in flaxseed have greatly drawn interest as bioactive molecules beneficial for health. It is naturally enriched with alpha-linolenic acid, omega-3 fatty acid, lignin, secoisolariciresinol diglucoside, and fiber which are physiologically active in the protection of some chronic illnesses such as cancer, diabetes, cardiovascular disease, and cerebrovascular stroke. Furthermore, the benefits of flaxseed eating have been demonstrated in the animal nutrition industry, resulting in healthier food from animal origin. In reality, the fatty acid profile of meat and fat in swine and poultry is directly impacted by the source of fat in the diet. Feeding omega-3-enriched diets with flaxseed will improve the omega-3 content in eggs and meat, enriching the products. The current study focuses on the latest evidence on the chemical makeup of flaxseed and its positive benefits.

Dietary Flaxseed and Flaxseed Oil Differentially Modulate Aspects of the Microbiota Gut-Brain Axis Following an Acute Lipopolysaccharide Challenge in Male C57Bl/6 Mice

The microbiota gut-brain axis (mGBA) is an important contributor to mental health and neurological and mood disorders. Lipopolysaccharides (LPS) are endotoxins that are components of Gram-negative bacteria cell walls and have been widely shown to induce both systemic and neuro-inflammation. Flaxseed (Linum usitatissimum) is an oilseed rich in fibre, n3-poly-unsaturated fatty acid (alpha-linolenic acid (ALA)), and lignan, secoisolariciresinol diglucoside, which all can induce beneficial effects across varying aspects of the mGBA. The objective of this study was to determine the potential for dietary supplementation with flaxseed or flaxseed oil to attenuate LPS-induced inflammation through modulation of the mGBA. In this study, 72 5-week-old male C57Bl/6 mice were fed one of three isocaloric diets for 3 weeks: (1) AIN-93G basal diet (BD), (2) BD + 10% flaxseed (FS), or (3) BD + 4% FS oil (FO). Mice were then injected with LPS (1 mg/kg i.p) or saline (n = 12/group) and samples were collected 24 h post-injection. Dietary supplementation with FS, but not FO, partially attenuated LPS-induced systemic (serum TNF-α and IL-10) and neuro-inflammation (hippocampal and/or medial prefrontal cortex IL-10, TNF-α, IL-1β mRNA expression), but had no effect on sickness and nest-building behaviours. FS-fed mice had enhanced fecal microbial diversity with increased relative abundance of beneficial microbial groups (i.e., Lachnospiraceae, Bifidobacterium, Coriobacteriaceae), reduced Akkermansia muciniphila, and increased production of short-chain fatty acids (SCFAs), which may play a role in its anti-inflammatory response. Overall, this study highlights the potential for flaxseed to attenuate LPS-induced inflammation, in part through modulation of the intestinal microbiota, an effect which may not be solely driven by its ALA-rich oil component.

Dietary Modulation of the Human Gut Microbiota and Metabolome with Flaxseed Preparations

Flaxseeds are typically consumed either as whole flaxseed, ground flaxseed, flaxseed oil, partially defatted flaxseed meal, or as a milk alternative. They are considered a rich source of vitamins, minerals, proteins and peptides, lipids, carbohydrates, lignans, and dietary fiber, which have shown hypolipidemic, antiatherogenic, anticholesterolemic, and anti-inflammatory property activity. Here, an in vitro batch culture model was used to investigate the influence of whole milled flaxseed and partially defatted milled flaxseed press cake on the gut microbiota and the liberation of flaxseed bioactives. Microbial communities were profiled using 16S rRNA gene-based high-throughput sequencing with targeted mass spectrometry measuring lignan, cyclolinopeptide, and bile acid content and HPLC for short-chain fatty acid profiles. Flaxseed supplementation decreased gut microbiota richness with Firmicutes, Proteobacteria, and Bacteroidetes becoming the predominant phyla. Secoisolariciresinol, enterodiol, and enterolactone were rapidly produced with acetic acid, butyric acid, and propionic acid being the predominant acids after 24 h of fermentation. The flaxseed press cake and whole flaxseed were equivalent in microbiota changes and functionality. However, press cake may be superior as a functional additive in a variety of foods in terms of consumer acceptance as it would be more resistant to oxidative changes.

Beneficial Effects of Linseed Supplementation on Gut Mucosa-Associated Microbiota in a Physically Active Mouse Model of Crohn's Disease

The Western diet, rich in lipids and in n-6 polyunsaturated fatty acids (PUFAs), favors gut dysbiosis observed in Crohn's disease (CD). The aim of this study was to assess the effects of rebalancing the n-6/n-3 PUFA ratio in CEABAC10 transgenic mice that mimic CD. Mice in individual cages with running wheels were randomized in three diet groups for 12 weeks: high-fat diet (HFD), HFD + linseed oil (HFD-LS-O) and HFD + extruded linseed (HFD-LS-E). Then, they were orally challenged once with the Adherent-Invasive Escherichia coli (AIEC) LF82 pathobiont. After 12 weeks of diet, total energy intake, body composition, and intestinal permeability were not different between groups. After the AIEC-induced intestinal inflammation, fecal lipocalin-2 concentration was lower at day 6 in n-3 PUFAs supplementation groups (HFD-LS-O and HFD-LS-E) compared to HFD. Analysis of the mucosa-associated microbiota showed that the abundance of Prevotella, Paraprevotella, Ruminococcus, and Clostridiales was higher in the HFD-LS-E group. Butyrate levels were higher in the HFD-LS-E group and correlated with the Firmicutes/Proteobacteria ratio. This study demonstrates that extruded linseed supplementation had a beneficial health effect in a physically active mouse model of CD susceptibility. Additional studies are required to better decipher the matrix influence in the linseed supplementation effect.

Could Dietary Supplementation with Different Sources of N-3 Polyunsaturated Fatty Acids Modify the Rabbit Gut Microbiota?

The present study evaluated the effects of feed supplemented with two dietary sources of n-3 polyunsaturated fatty acids (PUFAs; fish oil and extruded flaxseed) on the gut microbiota, caecal fermentations, gastrointestinal histology, and histochemistry in rabbits. Fifteen male New Zealand White rabbits were divided into three groups (n = 5/group) and fed with different diets from weaning (35 days of age) until slaughtering (90 days of age): C group, fed with a commercial diet; F group, supplemented with 10% of extruded flaxseed; and O group, supplemented with 3.5% of fish oil. At slaughter, the content of the stomach, duodenum, jejunum, ileum, caecum, and colon was collected and analyzed by Next Generation 16S rRNA gene sequencing. Tissue samples of the same tracts were evaluated with histological and histochemical analysis. Ammonia and lactic acid in the caecum were also quantified. Twenty-nine operational taxonomic units (OTUs) were significantly different between groups. Groups receiving n-3 PUFAs supplementation showed an increase in Bacteroidetes and Lachnospiraceae in several gastrointestinal tracts, while Bacilli abundance, as well as Firmicutes/Bacteroidetes ratio, were reduced compared to the control group (for all p < 0.05). Caecal ammonia was lower in the F than C group (p < 0.032), whereas no difference was found for lactic acid. Finally, histological evaluations revealed a mild hemorrhagic infiltration and vessels ectasia in the stomach mucosa of both F and O groups, but no effect of nutritional treatment was evidenced by the histochemical analyses. In conclusion, n-3 PUFAs supplementation could modify the rabbit gut microbiota and fermentation. The increase in beneficial bacterial populations may, at least partially, explain the positive effects of n-3 PUFAs diet supplementation on human and animals’ health, although the appropriate dosage should be established.

Data on cecal and fecal microbiota and predicted metagenomes profiles of female mice receiving whole flaxseed or its oil and secoisolariciresinol diglucoside components

Dietary flaxseed (FS) and its components including FS oil (FSO), secoisolariciresinol diglucoside (SDG) and fiber, are processed by the gut microbiota. These data are in support of the article entitled “Discriminatory and cooperative effects within the mouse gut microbiota in response to flaxseed and its oil and lignan components”, Journal of Nutritional Biochemistry [1]. Here we describe data generated by 16S rRNA sequencing of DNA obtained from cecum contents and feces of C57BL/6 female mice fed either a basal diet (BD, AIN93G), or isocaloric diets containing 10% FS, or 10% FS-equivalent amounts of FSO or SDG for 21 days. These include bacterial community composition and inferred KEGG pathways; the raw data are publicly available at the NCBI SRA database (BioProject ID PRJNA683934). Furthermore, this work includes detailed experimentation procedures, total bacterial counts (qPCR) in the cecum content and feces, and correlation analysis between a selected bacterial genus, Bacteroides and a predicted metabolic pathway. FS is utilized worldwide, especially for the prevention and/or treatment of diseases including cardiovascular diseases, diabetes and cancer. These data will be valuable as a reference to study different FS cultivars and SDG- or FSO- enriched products on the gut microbiota, to study gut microbial responses to FS and its components in different mouse strains and mammalian hosts to elucidate individualized effects, and to understand the importance of the gut microbiota for FS benefits.