Non-isoflavone phytochemicals in soy and their health effects

Opportunities and Challenges of Soy Proteins with Different Processing Applications

Soybean meal (SBM) is a prevailing plant protein supplement in animal diets because of its nutritional value and availability. This review paper explores the significance of SBM and processed soy products, emphasizing their nutritional and bioactive components, such as isoflavones and soyasaponins. These compounds are known for their antioxidant and anti-inflammatory properties and are associated with a reduced prevalence of chronic diseases. However, the presence of antinutritional compounds in SBM presents a significant challenge. The paper evaluates various processing methods, including ethanol/acid wash, enzyme treatment, and fermentation, which are aimed at enhancing the nutritional value of soy products. It highlights the significance to maintain a balance between nutritional enhancement and the preservation of beneficial bioactive compounds, emphasizing the importance of different processing techniques to fully exploit the health benefits of soy-based products. Therefore, this review illuminates the complex balance between nutritional improvement, bioactive compound preservation, and the overall health implications of soy products.

Gut Microbiota Plays Essential Roles in Soyasaponin's Preventive Bioactivities against Steatohepatitis in the Methionine and Choline Deficient (MCD) Diet-Induced Non-Alcoholic Steatohepatitis (NASH) Mice

SCOPE

Gut microbiota (GM) is involved in nonalcoholic steatohepatitis (NASH) development. Phytochemicals soyasaponins can prevent NASH possibly by modulating GM. This study aims to investigate the preventive bioactivities of soyasaponin monomers (SS-A1 and SS-Bb) against NASH and explores the mechanisms by targeting GM.

METHODS AND RESULTS

Male C57BL/6 mice are fed with methionine and choline deficient (MCD) diet containing SS-A1 , SS-Bb, or not for 16 weeks. Antibiotics-treated pseudo germ-free (PGF) mice are fed with MCD diet containing SS-A1 , SS-Bb, or not for 8 weeks. GM is determined by 16S rRNA amplicon sequencing. Bile acids (BAs) are measured by UPLC-MS/MS. In NASH mice, SS-A1 and SS-Bb alleviate steatohepatitis and fibrosis, reduce ALT, AST, and LPS in serum, decrease TNF-α, IL-6, α-SMA, triglycerides, and cholesterol in liver. SS-A1 and SS-Bb decrease Firmicutes, Erysipelotrichaceae, unidentified-Clostridiales, Eggerthellaceae, Atopobiaceae, Aerococcus, Jeotgalicoccus, Gemella, Rikenella, increase Proteobacteria, Verrucomicrobia, Akkermansiaceae, Romboutsia, and Roseburia. SS-A1 and SS-Bb alter BAs composition in liver, serum, and feces, activate farnesoid X receptor (FXR) in liver and ileum, increase occludin and ZO-1 in intestine. However, GM clearance abrogates the preventive bioactivities of SS-A1 and SS-Bb against NASH.

CONCLUSION

GM plays essential roles in soyasaponin's preventive bioactivities against steatohepatitis in MCD diet-induced NASH mice.

How Food Choices Impact on Male Fertility

PURPOSE OF REVIEW

Increasing evidence on the significance of nutrition in reproduction is emerging from both animal and human studies, suggesting an association between nutrition and male fertility. Here, we have highlighted the impact of the various food groups on reproductive hormones and on spermatogenesis, and the effects of classical and latest dietary patterns such as Mediterranean diet, Western diet, intermittent fasting, ketogenic diet, and vegan/vegetarian diet on male fertility.

RECENT FINDINGS

Nutrients are the precursors of molecules involved in various body's reactions; therefore, their balance is essential to ensure the correct regulation of different systems including the endocrine system. Hormones are strongly influenced by the nutritional status of the individual, and their alteration can lead to dysfunctions or diseases like infertility. In addition, nutrients affect sperm production and spermatogenesis, controlling sexual development, and maintaining secondary sexual characteristics and behaviors. The consumption of fruit, vegetables, fish, processed meats, dairy products, sugars, alcohol, and caffeine importantly impact on male fertility. Among dietary patterns, the Mediterranean diet and the Western diet are most strongly associated with the quality of semen. Nutrients, dietary patterns, and hormonal levels have an impact on male infertility. Therefore, understanding how these factors interact with each other is important for strategies to improve male fertility.

Different types of milk consumption and the risk of dementia: Analysis from a large-scale cohort study

BACKGROUND & AIMS

Previous studies have investigated whether milk consumption has a role in preventing the development of cognitive impairment, but the results were inconsistent. Importantly, most of them have disregarded the role of different types of milk. This study aimed to examine the associations between different types of milk consumption and the risk of dementia.

METHODS

In this large-scale cohort study, participants without cognitive impairment at baseline were included from the UK Biobank. The type of milk mainly used was self-reported at baseline, including full-cream milk, skimmed-milk, soy milk, other milk, and no milk. The primary outcome was all-cause dementia. Secondary outcomes included Alzheimer's disease and vascular dementia.

RESULTS

Of the 307,271 participants included in the study (mean age 56.3 [SD 8.1] years), 3789 (1.2%) incident all-cause dementia cases were observed over a median follow-up of 12.3 years. After adjustment for potential confounders, only soy milk consumers had a statistically significantly lower risk of all-cause dementia compared with no milk consumers (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.54 to 0.90). When compared with soy milk non-consumers consisting of full-cream milk, skimmed-milk, and other milk consumers, soy milk consumers still showed a lower risk of all-cause dementia (HR, 0.76; 95% CI, 0.63 to 0.92), and there was no significant interaction with genetic risk for dementia (P for interaction = 0.15). Soy milk consumers showed a lower risk of Alzheimer's disease (HR, 0.70; 95% CI, 0.51 to 0.94; P = 0.02), while the association was not significant for vascular dementia (HR, 0.72; 95% CI, 0.47 to 1.12; P = 0.14).

CONCLUSIONS

The main consumption of soy milk was associated with a lower risk of dementia, particularly non-vascular dementia. Additional studies are needed to investigate how this association varies with the dose or frequency of the consumption of soy milk and to examine the generalizability of these findings in different populations.

The Role of Hemp (Cannabis sativa L.) as a Functional Food in Vegetarian Nutrition

Recently, there has been a renewed interest in Cannabis sativa and its uses. The recreational use of inflorescences as a source of THC has led to the legal restriction of C. sativa cultivation to limit the detrimental effects of psychotropic substance abuse on health. However, this has also limited the cultivation of textile/industrial varieties with a low content of THC used for textile and nutritional purposes. While previously the bans had significantly penalized the cultivation of C. sativa, today many countries discriminate between recreational use (marijuana) and industrial and food use (hemp). The stalks of industrial hemp (low in psychotropic substances) have been used extensively for textile purposes while the seeds are nutritionally versatile. From hemp seeds, it is possible to obtain flours applicable in the bakery sector, oils rich in essential fatty acids, proteins with a high biological value and derivatives for fortification, supplementation and nutraceutical purposes. Hemp seed properties seem relevant for vegetarian diets, due to their high nutritional value and underestimated employment in the food sector. Hemp seed and their derivatives are a valuable source of protein, essential fatty acids and minerals that could provide additional benefit to vegetarian nutrition. This document aims to explore the information available in the literature about hemp seeds from a nutritional point of view, highlighting possible beneficial effects for humans with particular attention to vegetarian nutrition as a supplemental option for a well-planned diet.

Associations between food groups and liver cancer: a systematic review and meta-analysis of observational studies

CONTEXT

Diet is emerging as a modifiable component of lifestyle for influencing the incidence of liver cancer.

OBJECTIVE

To investigate and quantify the potential relationship between food groups and liver cancer.

DATA SOURCES

PubMed and Web of Science were searched for eligible observational studies until 31st March, 2023.

DATA EXTRACTION

The meta-analysis was conducted by pooling relative risk (RR), odds ratio (OR) or hazards ratio (HR) with 95% confidence intervals (CIs). Potential sources of heterogeneity were detected by subgroup analysis. Sensitivity analysis and publication bias test were also carried out.

DATA ANALYSIS

Through stepwise screening, a total of 27 studies were included. The pooled estimates of liver cancer for whole grains and legumes intake were 0.66 (95% CI: 0.54-0.82; I² = 25.3%) and 0.86 (95% CI: 0.75-0.99; I² = 14.3%), respectively. However, there were null associations of nuts, poultry, egg and sweetened beverages consumption with liver cancer and the association between refined grains and liver cancer was inconclusive. In dose-response meta-analysis, the pooled estimates of liver cancer were 0.77 (95% CI: 0.65-0.91) for every 50 g/day increment in whole grains intake. Non-linear dose-response relationship (P = 0.031) was observed in the association between the intake of legumes and liver cancer, and the protective effect occurred with the dose ranging from 8 g/day to 40 g/day.

CONCLUSIONS

This meta-analysis shows that whole grains and legumes were inversely associated with liver cancer, whereas intake of nuts, poultry, egg and sweetened beverages may not be associated with liver cancer. Further quantitative research needs to be undertaken within a range of populations to investigate the relationship between food groups and liver cancer.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021246142.

Anti-inflammatory Oleanane-Type Triterpenoids Produced by Nonomuraea sp. MYH522 through Microbial Transformation

Eleven oleanane-type triterpenoids named soyasapogenols B1-B11 have been obtained unexpectedly from a marine actinomycete Nonomuraea sp. MYH522. Their structures have been determined by extensive analysis of spectroscopic experiments and X-ray crystallographic data. Soyasapogenols B1-B11 exhibit subtle differences in the positions and degrees of oxidation on an oleanane skeleton. The feeding experiment suggested that soyasapogenols might be derived from soyasaponin Bb through microbial-mediated conversion. The biotransformation pathways from soyasaponin Bb to five oleanane-type triterpenoids and six A-ring cleaved analogues were proposed. The assumed biotransformation involves an array of reactions including regio- and stereo-selective oxidation. These compounds alleviated the 5,6-dimethylxanthenone-4-acetic acid-induced inflammation in Raw264.7 cells via the stimulator of interferon genes/TBK1/NF-κB signaling pathway. The present work provided an efficient approach for rapid diversification of soyasaponins and for developing food supplements with potent anti-inflammatory effects.

Modulation of allergic contact dermatitis via gut microbiota modified by diet, vitamins, probiotics, prebiotics, and antibiotics

Allergic contact dermatitis is one of the most common recorded occupational diseases. There are many different substances that the skin comes into contact with on a daily basis and that can cause ACD, e.g., preservatives, surfactants, and antimicrobial agents. The development of a mouse model of ACD has provided insight into the immune mechanisms involved. Drugs used in the treatment of skin diseases have many side effects. Therefore, alternative methods of suppressing the immune response to reduce the symptoms of skin diseases are being sought. In recent years, high hopes have been placed on dietary modulation and supplementation to affect the intestinal microbial composition and promote anti-inflammatory responses. In addition, other studies have shown the crucial role of intestinal microbiota in many immune-mediated diseases. Recognition and characterization of pro- and anti-inflammatory nutrients and supplements may be crucial to support the treatment of diseases such as atopic dermatitis, acne vulgaris, psoriasis, and allergic contact dermatitis.

The Fate and Intermediary Metabolism of Soyasapogenol in the Rat

Research suggests that soyasaponins are poorly absorbed in the GI tract and that soyasaponin aglycones or soyasapogenols are absorbed faster and in greater amounts than the corresponding soyasaponins. Therefore, it is important to understand the bioavailability of these compounds for the potential development of functional foods containing their components. In this paper, to investigate the metabolic characteristics of soyasapogenols A and B, the pharmacokinetic parameters in rats were determined via oral and intravenous administration. The liver metabolites of soyasapogenols were identified using UPLC-/Q-TOF-MS/MS, and their metabolic pathways were also speculated. The results show that, after oral administration, there was a bimodal phenomenon in the absorption process. T_max was about 2 h, and soyasapogenol was completely metabolized 24 h later. The bioavailability of soyasapogenol was superior, reaching more than 60%. There were sixteen metabolites of soyasapogenol A and fifteen metabolites of soyasapogenol B detected in rat bile. Both phase I and II metabolic transformation types of soyasapogenols, including oxidation, dehydrogenation, hydrolysis, dehydration, deoxidization, phosphorylation, sulfation, glucoaldehyde acidification, and conjugation with cysteine, were identified. In addition, soyasapogenol A could be converted into soyasapogenols B and E in the metabolic process. These results suggest that it is feasible to use soyasapogenols as functional ingredients in nutraceuticals or food formulations.

Characterisation of a High Fibre Flour Prepared from Soy Milk By-Product and Its Potential Use in White Wheat Bread

The commercial production of soy milk renders a large quantity of wet soybean by-product (SMB), which is typically dumped, incinerated, or partially used as animal fodder. This wet SMB has a high moisture content that is rich in nutritional and biologically active compounds. This study aimed to characterise the composition and properties of a flour milled from SMB dried at 100 °C (SMB100) and assess its possible application as a fibre substitute in white bread. The results showed that SMB100 has high levels of dietary fibre (40.6%) and protein (26.5%). It also contains high levels of saponins (31.4 mg/g) and isoflavones (698.0 µg/g). SMB100 has a light-yellow colour with low moisture content and water activity (8.2% and 0.55, respectively). The results also indicated that replacement of wheat flour with SMB100 at 10 or 12.5% by flour weight negatively impacted the raising volume, density, and texture of white bread. Alternatively, substituting wheat flour with 5% of SMB100, did not significantly impact the physical properties of white bread, while significantly improving its dietary fibre content in comparison with the control, revealing that SMB100 is a potential substitute of wheat flour for improvement of dietary fibre in bread. Future studies are needed to optimise bread formulation and improve the processing condition which produces quality white bread with high dietary fibre using SMB100.

Advances in the Bioactivities of Phytochemical Saponins in the Prevention and Treatment of Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease characterized by hardening and narrowing of arteries. AS leads to a number of arteriosclerotic vascular diseases including cardiovascular diseases, cerebrovascular disease and peripheral artery disease, which pose a big threat to human health. Phytochemicals are a variety of intermediate or terminal low molecular weight secondary metabolites produced during plant energy metabolism. Phytochemicals from plant foods (vegetables, fruits, whole grains) and traditional herb plants have been shown to exhibit multiple bioactivities which are beneficial for prevention and treatment against AS. Many types of phytochemicals including polyphenols, saponins, carotenoids, terpenoids, organic sulfur compounds, phytoestrogens, phytic acids and plant sterols have already been identified, among which saponins are a family of glycosidic compounds consisting of a hydrophobic aglycone (sapogenin) linked to hydrophilic sugar moieties. In recent years, studies have shown that saponins exhibit a number of biological activities such as anti-inflammation, anti-oxidation, cholesterol-lowering, immunomodulation, anti-platelet aggregation, etc., which are helpful in the prevention and treatment of AS. This review aims to summarize the recent advances in the anti-atherosclerotic bioactivities of saponins such as ginsenoside, soyasaponin, astra-galoside, glycyrrhizin, gypenoside, dioscin, saikosaponin, etc.

Dietary Affects On Chronic Venous Disease

BACKGROUND

Diet is fundamental to maintaining and improving human health. There is ample evidence identifying the beneficial and/or harmful effects of diet on noncommunicable diseases such as obesity, diabetes mellitus and cardiovascular disease. However, the associations of the diet to chronic venous disease has not been fully described.

METHODS

Data were collected through a cross-sectional survey conducted on 1,571 community-dwelling adults in 2018. Diet intake frequency was assessed using valid food group consumption frequency questionnaires. Multivariable logistic regression models were used to evaluate the association of diet with chronic venous disease.

RESULTS

857 participants were diagnosed with chronic venous disease. Those who ate soybean products daily and 4-6 days per week had a 51% - 31% lower risk of chronic venous disease compared with those who only occasionally consumed soybean food, respectively. Participants who consumed eggs and egg products 1 to 3 days per week versus those who only occasionally ate eggs showed a lower risk of chronic venous disease (OR = 0.542, 95%CI: 0.375 - 0.782). Eating fried food 4 to 6 days each week was associated with an increased risk of chronic venous disease (OR = 3.872, 95%CI: 1.263 - 11.599) compared with those who only occasionally ate fried foods. There is a decreasing tendency of the adjusted OR for eating soybean products daily with the severity of disease (CVD (C0-C2),OR = 0.575, 95%CI: 0.408-0.812; CVI (C3-C6), OR = 0.222, 95%CI: 0.114-0.435).

CONCLUSIONS

A higher frequency in the consumption of soybean products and eggs were associated with a lower risk of chronic venous disease. High level of fried food consumption was positively associated with risk of chronic venous disease. There are a certain of specific trends in the relation of dietary consumption and the severity of disease, although the trends were less strong. These associations are largely independent of other dietary and non-dietary factors.

Soyasapogenol C from Fermented Soybean (Glycine Max) Acting as a Novel AMPK/PPARα Dual Activator Ameliorates Hepatic Steatosis: A Novel SANDA Methodology

(1) Background: Soyasapogenol C (SSC), a derivative of soyasapogenol B (SSB), is specifically found high in many fermented soybean (Glycine max) products, including Cheonggukjang (in Korean). However, the biological activities for preventing and treating hepatic steatosis, and the precise underlying mechanisms of SSC, remain to be explored. (2) Methods: A novel SANDA (structural screening, ADMET prediction, network pharmacology, docking validation, and activity evaluation) methodology was used to examine whether SSC exerts hepatoprotective effects in silico and in vitro. (3) Results: SSC had better ADMET characteristics and a higher binding affinity with predicted targets chosen from network pathway analysis than SSB. SSC induced the phosphorylation of AMP-activated protein kinase (AMPK) and stimulated the nuclear translocation of peroxisome proliferator-activated receptor alpha (PPARα), further enhancing PPAR response element (PPRE) binding activity in HepG2 cells. Concurrently, SSC significantly inhibited triglyceride accumulation, which was associated with the suppression of lipogenesis genes and the enhancement of fatty acid oxidation gene expression in HepG2 cells. (4) Conclusions: Soyasapogenol C, discovered using a novel SANDA methodology from fermented soybean, is a novel AMPK/PPARα dual activator that is effective against hepatic steatosis. Dietary supplementation with soyasapogenol C may prevent the development of hepatic steatosis and other diseases associated with fat accumulation in the liver.

Flavor challenges in extruded plant-based meat alternatives: A review

Demand for plant-based meat alternatives has increased in recent years due to concerns about health, ethics, the environment, and animal welfare. Nevertheless, the market share of plant-based meat alternatives must increase significantly if they are to support sustainable food production and consumption. Flavor is an important limiting factor of the acceptability and marketability of plant-based meat alternatives. Undesirable chemosensory perceptions, such as a beany flavor, bitter taste, and astringency, are often associated with plant proteins and products that use them. This study reviewed 276 articles to answer the following five research questions: (1) What are the volatile and nonvolatile compounds responsible for off-flavors? (2) What are the mechanisms by which these flavor compounds are generated? (3) What is the influence of thermal extrusion cooking (the primary structuring technique to transform plant proteins into fibrous products that resemble meat in texture) on the flavor characteristics of plant proteins? (4) What techniques are used in measuring the flavor properties of plant-based proteins and products? (5) What strategies can be used to reduce off-flavors and improve the sensory appeal of plant-based meat alternatives? This article comprehensively discusses, for the first time, the flavor issues of plant-based meat alternatives and the technologies available to improve flavor and, ultimately, acceptability.

Bio-Refinery of Oilseeds: Oil Extraction, Secondary Metabolites Separation towards Protein Meal Valorisation—A Review

Edible oil extraction is a large and well-developed sector based on solvent assisted extraction using volatile organic compounds such as hexane. The extraction of oil from oilseeds generates large volumes of oilseed by-products rich in proteins, fibres, minerals and secondary metabolites that can be valued. This work reviews the current status and the bio-macro-composition of oilseeds, namely soybean, rapeseed, sunflower and flaxseed, and the refining process, comprising the extraction of oil, the valorisation and separation of valuable secondary metabolites such as phenolic compounds, and the removal of anti-nutritional factors such as glucosinolates, while retaining the protein in the oilseed meal. It also provides an overview of alternative solvents and some of the unconventional processes used as a replacement to the conventional extraction of edible oil, as well as the solvents used for the extraction of secondary metabolites and anti-nutritional factors. These biologically active compounds, including oils, are primordial raw materials for several industries such as food, pharmaceutical or cosmetics.

Current perspectives on the beneficial effects of soybean isoflavones and their metabolites on plants

Soybeans have traditionally been a staple part of the human diet being highly rich in protein and lipid content. In an addition to the high nutritional components, soybeans have several functional components, like isoflavones, saponins, lecithin, and oligosaccharides. Soybeans emerge as a healthy functional food option. Isoflavones are most notable functional component of soybeans, exhibiting antioxidant activity while preventing plant-related diseases (e.g., antimicrobial and antiherbivore activities) and having positive effects on the life quality of plants. Isoflavones are thus sometimes referred to as phytochemicals. The latest research trends evince substantial interest in the biological efficacy of isoflavones in the human body as well as in plants and their related mechanisms. However, there is little information on the relationship between isoflavones and plants than beneficial human effects. This review discusses what is known about the physiological communication (transport and secretion) between isoflavones and plants, especially in soybeans.

Ayurvedic lipid based rasayans - A perspective on the preparation and pharmacological significance of lipids on the bioavailability of phytoconstituents

For thousands of years, lipid based Ayurvedic formulations have been made in India, and the craft has survived down the millennia up to the present time. Some of these deliciously potent phytonutrient preparations are very popular and have sustained the test of time pertaining to their efficacy. Recent researches on the role of phytonutrients in promoting cardio-pulmonary, brain and immune health substantially buttress the philosophy underlying the use of lipids in preparing these emulsions, since a large number of these bioactives are lipophilic. Being lipoidic, they are absorbed through the lacteals in the small intestine, and are then transported through the thoracic duct directly to the heart, bypassing the liver. The formulations utilizing ghee (clarified butter) or sesame oil as the carrier lipid, either while frying the myrobalams or as Anupana (adjuvant), have special significance in modulating bodily immunity, since the immune system is housed in lymphatics which are lipid rich. Amla and lipid based Ayurvedic rasayans (rejuvenating formulations) are a popular and highly palatable group of phytonutraceutical preparations. This group of polyherbal adaptogenic formulations is classified separately from other formulations in Ayurvedic therapeutics. Several of these health-promoting rasayans are suitable to be consumed by all age-groups in the recommended season and dose. Current research on endothelial and immune cell receptor mediated uptake of lipoidic molecules, together with the knowledge of lipid absorption pathways, lends credence to the usefulness of rasayans in targeting the cardio-pulmonary and immune systems. An attempt has been made in this paper to elucidate the mechanisms underpinning the complex interplay between lipid delivered hydrophobic phyto-molecules, systemic lymphatics and the Immune system.

The role of soy and soy isoflavones on women's fertility and related outcomes: an update

Soy is a key food in human nutrition. It is widely used in eastern traditional cuisine and it has recently diffused among self-conscious and vegetarian diets. The success of soy mainly depends on versatility and supposed healthy properties of soy foods and soy components. Meanwhile, the possible influence on endocrine system, in particular by isoflavones, raised concerns among some researchers. The present paper aims to conduct a review of available data on the effect of soy, soy foods and soy components on women's fertility and related outcomes. Eleven interventional studies, eleven observational studies and one meta-analysis have been selected from the results of queries. A weak, not clinically relevant effect has been highlighted on cycle length and hormonal status. However, a suggestive positive influence has been shown among women with fertility issues and during assisted reproductive technologies. Overall, soy and soy components consumption do not seem to perturb healthy women's fertility and can have a favourable effect among subjects seeking pregnancy. However, because of the paucity of studies exploring the impact of soy intake on women's fertility, as well as the limited population sample size, the frequently incomplete specimens’ collection to investigate all cycle phases and the insufficient characterisation of participants, the evidence is suggestive and it needs further in-depth research taking into account all these aspects.

Soy consumption, cognitive function, and dementia

PURPOSE OF REVIEW

With the rising number of people living with dementia, the interest in modifiable risk factors including dietary intake for dementia is increasing. Although there is a growing body of evidence investigating soy's health effects, the direction and strength of the association between soy consumption and risk of dementia and cognitive decline are still uncertain. Thus, we aimed to review the evidence linking soy consumption to dementia and cognitive function.

RECENT FINDINGS

Some studies showed that higher intake of total soy products was associated with a lower risk or prevalence of cognitive impairment. Some studies pointed to an inverse association between higher tofu consumption and cognitive function, whereas a higher intake of soybean was associated with better cognitive function.

SUMMARY

Previous studies are scarce and have provided contradictory results. Soy is a high-protein alternative to red meat and processed meat. Further studies are needed to clarify the safety and potential preventive effects particularly in healthy populations before clinical disease manifestation and irreversible injury have occurred.

Derivatization of Soyasapogenol A through Microbial Transformation for Potential Anti-inflammatory Food Supplements

For the optimum use of soyasaponins isolated from soybean cake and to explore the potential anti-inflammatory agents from pentacyclic triterpenes as natural food supplements, microbial transformation of soyasapogenol A was carried out. Four strains of microbes, including Bacillus megaterium CGMCC 1.1741, Penicillium griseofulvum CICC 40293, Bacillus subtilis ATCC 6633, and Streptomyces griseus ATCC 13273, showed robust catalytic capacity to the substrate. Preparative biotransformation and column chromatographic purification led to the isolation of 10 novel and 1 reported metabolites. The structure elucidation was performed using 1D/2D NMR and HR-ESI-MS analytical method. Several novel tailoring reactions, such as allyl oxidation, C-C double bond rearrangement, hydroxylation, dehydrogenation, and glycosylation, were observed in the biotransformation. In the follow-up bioassay, most of the metabolites exhibited low cytotoxicity and potent inhibitory activity against the production of nitric oxide (NO) in RAW 264.7 cells stimulated by lipopolysaccharide. Especially compound 6 (3-oxo-11α,21β,22β,24-tetrahydroxy-olean-12-ene) showed comparable activity to the positive control of quercetin with an IC₅₀ value of 16.70 μM. These findings provided an experimental approach to achieve the derivatization of natural aglycons in soybeans through microbial transformation for developing potent anti-inflammatory food supplements.

Soyasaponin A2 Alleviates Steatohepatitis Possibly through Regulating Bile Acids and Gut Microbiota in the Methionine and Choline-Deficient (MCD) Diet-induced Nonalcoholic Steatohepatitis (NASH) Mice

SCOPE

Nonalcoholic steatohepatitis (NASH) is a chronic progressive disease with complex pathogenesis of which the bile acids (BAs) and gut microbiota are involved. Soyasaponins (SS) exhibits many health-promoting effects including hepatoprotection, but its prevention against NASH is unclear. This study aims to investigate the preventive bioactivities of SS monomer (SS-A₂ ) against NASH and further clarify its mechanism by targeting the BAs and gut microbiota.

METHODS AND RESULTS

The methionine and choline deficient (MCD) diet-fed male C57BL/6 mice were intervened with obeticholic acid or SS-A₂ for 16 weeks. Hepatic pathology is assessed by hematoxylin-eosin and Masson's trichrome staining. BAs in serum, liver, and colon are measured by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-TQMS). Gut microbiota in caecum are determined by 16S rDNA amplicon sequencing. In the MCD diet-induced NASH mice, SS-A₂ significantly reduces hepatic steatosis, lobular inflammation, ballooning, nonalcoholic fatty liver disease activity score (NAS) scores, and fibrosis, decreases Erysipelotrichaceae (Faecalibaculum) and Lactobacillaceae (Lactobacillus) and increases Desulfovibrionaceae (Desulfovibrio). Moreover, SS-A₂ reduces serum BAs accumulation and promotes fecal BAs excretion. SS-A₂ changes the BAs profiles in both liver and serum and specifically increases the taurohyodeoxycholic acid (THDCA) level. Faecalibaculum is negatively correlated with serum THDCA.

CONCLUSION

SS-A₂ alleviates steatohepatitis possibly through regulating BAs and gut microbiota in the MCD diet-induced NASH mice.

Soyasaponin ameliorates obesity and reduces hepatic triacylglycerol accumulation by suppressing lipogenesis in high-fat diet-fed mice

Soyasaponins are triterpenoid glycosides found in soybean. We investigated whether soyasaponin ameliorates lipid metabolism and its possible mechanisms. In C57BL/6J mice fed a high-fat diet (HFD), soyasaponin (SAP) was orally administered for 9 weeks. Additionally, we evaluated the effect of soyasapogenols on 3T3-L1 adipocytes. In HFD-fed mice, the SAP significantly reduced body weight by 7% and relative adipose tissue weight by 35%. X-ray computed tomography demonstrated that the SAP reduced visceral and subcutaneous adipose tissue weights during week 3 of feeding. The SAP reduced sterol regulatory element-binding protein-1c (SREBP-1c) mRNA levels by 32% in the epididymal adipose tissue, significantly decreasing the triacylglycerol (TAG) content by 37% and SREBP-1c and fatty acid synthase mRNA levels by 52% and 61%, respectively, in the liver. In 3T3-L1 adipocytes, soyasapogenol B significantly decreased lipid droplets. The SAP containing soyasaponin A and B as conjugates demonstrate anti-obesity effects by suppressing adipocyte differentiation and lipogenesis, with a preventive effect on hepatic TAG accumulation by suppressing lipogenesis. PRACTICAL APPLICATION: Soyasaponin is one of the oleanane triterpenoids in soybeans. We have demonstrated that soyasaponin potently reduces body weight and white adipose tissue weight, and hepatic triacylglycerol accumulation in high-fat diet-fed mice. Thus, soyasaponin is a beneficial compound to prevent obesity and fatty liver.

Regulation of Intestinal Inflammation by Soybean and Soy-Derived Compounds

Environmental factors, particularly diet, are considered central to the pathogenesis of the inflammatory bowel diseases (IBD), Crohn’s disease and ulcerative colitis. In particular, the Westernization of diet, characterized by high intake of animal protein, saturated fat, and refined carbohydrates, has been shown to contribute to the development and progression of IBD. During the last decade, soybean, as well as soy-derived bioactive compounds (e.g., isoflavones, phytosterols, Bowman-Birk inhibitors) have been increasingly investigated because of their anti-inflammatory properties in animal models of IBD. Herein we provide a scoping review of the most studied disease mechanisms associated with disease induction and progression in IBD rodent models after feeding of either the whole food or a bioactive present in soybean.

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

Fermented Soy Products: Beneficial Potential in Neurodegenerative Diseases

Fermented soybean products, such as cheonggukjang (Japanese natto), doenjang (soy paste), ganjang (soy sauce), and douchi, are widely consumed in East Asian countries and are major sources of bioactive compounds. The fermentation of cooked soybean with bacteria (Bacillus spp.) and fungi (Aspergillus spp. and Rhizopus spp.) produces a variety of novel compounds, most of which possess health benefits. This review is focused on the preventive and ameliorative potential of fermented soy foods and their components to manage neurodegenerative diseases, including Alzheimer's and Parkinson's diseases.

Phytochemicals in Legumes: A Qualitative Reviewed Analysis

Legumes are an excellent source of nutrients and phytochemicals. They have been recognized for their contributions to health, sustainability, and the economy. Although legumes comprise several species and varieties, little is known about the differences in their phytochemical composition and the magnitude of these. Therefore, the aim of this review is to describe and compare the qualitative profile of phytochemicals contained in legumes and identified through LC-MS and GC-MS methods. Among the 478 phytochemicals reported in 52 varieties of legumes, phenolic compounds were by far the most frequently described (n = 405, 85%). Metabolomics data analysis tools were used to visualize the qualitative differences, showing beans to be the most widely analyzed legumes and those with the highest number of discriminant phytochemicals (n = 180, 38%). A Venn diagram showed that lentils, beans, soybeans, and chickpeas shared only 7% of their compounds. This work highlighted the huge chemical diversity among legumes and identified the need for further research in this field and the use of metabolomics as a promising tool to achieve it.

Comparison between the impact of fermented and unfermented soy intake on the risk of liver cancer: the JPHC Study

PURPOSE

The aim of this study was to compare the impact of fermented and unfermented soy intake, based on the following soy-derived products: tofu, soymilk, natto, and miso, on the risk of liver cancer among Japanese adults.

METHODS

75,089 Participants of the Japan Public Health Center-based Prospective Study (JPHC Study) were followed from the time of the 5-year follow-up questionnaire until the end of 2012-2013. Subjects with available data on hepatitis B virus (HBV) and hepatitis C virus (HCV) infection status from blood samples (n = 14,016) and those who were anti-HCV antibody (anti-HCV) or hepatitis B virus antigen (HBsAg) positive (n = 1033) were also analyzed separately. Cox proportional hazard models were employed to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs).

RESULTS

During 1,145,453 person-years, 534 newly diagnosed cases of liver cancer were identified in the JPHC Study. For miso intake among men, the multivariate-adjusted highest versus lowest quartile HR was 0.65 (95% CI, 0.48-0.89); p for trend = 0.006. Results were similar in those who were anti-HCV or HBsAg positive, 0.24 (0.08-0.70); p for trend = 0.004 highest versus lowest tertile. For the sub-analysis among only participants with known hepatitis infection status and HCV and HBsAg adjustment, a similar association was observed. In the multivariate complete cohort analysis, among women, the highest intake of fried tofu was inversely associated with the risk of liver cancer, HR = 0.45 (0.26-0.80); p for trend = 0.014.

CONCLUSIONS

We observed no association between total soy intake, fermented and unfermented, and risk of liver cancer, and only an inverse association between miso intake and liver cancer among men.

The Antioxidant Role of Soy and Soy Foods in Human Health

Oxidative stress seems to play a role in many chronic diseases, such as cardiovascular diseases, diabetes, and some cancers. Research is always looking for effective approaches in the prevention and treatment of these pathologies with safe strategies. Given the central role of nutrition, the identification of beneficial healthy foods can be the best key to having a safe and at the same time effective approach. Soy has always aroused great scientific interest but often this attention is galvanized by the interaction with estrogen receptors and related consequences on health. However, soy, soy foods, and soy bioactive substances seem to have antioxidant properties, suggesting their role in quenching reactive oxygen species, although it was frequently mentioned but not studied in depth. The purpose of this review is to summarize the scientific evidence of the antioxidant properties of soy by identifying the human clinical trials available in the literature. A total of 58 manuscripts were individuated through the literature search for the final synthesis. Soy bioactive substances involved in redox processes appear to be multiple and their use seems promising. Other larger clinical trials with adequate standardization and adequate choice of biomarkers will fill the gap currently existing on the suggestive role of soy in antioxidant mechanisms.

Metabolism of Soy Isoflavones by Intestinal Bacteria: Genome Analysis of an Adlercreutzia Equolifaciens Strain That Does Not Produce Equol

Isoflavones are transformed in the gut into more estrogen-like compounds or into inactive molecules. However, neither the intestinal microbes nor the pathways leading to the synthesis of isoflavone-derived metabolites are fully known. In the present work, 73 fecal isolates from three women with an equol-producing phenotype were considered to harbor equol-related genes by qPCR. After typing, 57 different strains of different taxa were tested for their ability to act on the isoflavones daidzein and genistein. Strains producing small to moderate amounts of dihydrodaidzein and/or O-desmethylangolensin (O-DMA) from daidzein and dihydrogenistein from genistein were recorded. However, either alone or in several strain combinations, equol producers were not found, even though one of the strains, W18.34a (also known as IPLA37004), was identified as Adlercreutzia equolifaciens, a well-described equol-producing species. Analysis and comparison of A. equolifaciens W18.34a and A. equolifaciens DSM19450^T (an equol producer bacterium) genome sequences suggested a deletion in the former involving a large part of the equol operon. Furthermore, genome comparison of A. equolifaciens and Asaccharobacter celatus (other equol-producing species) strains from databases indicated many of these also showed deletions within the equol operon. The present results contribute to our knowledge to the activity of gut bacteria on soy isoflavones.

Biotransformation of Erythrodiol for New Food Supplements with Anti-Inflammatory Properties

Erythrodiol, a typical pentacyclic triterpenic diol in olive oil and its byproduct, olive pomace, frequently appears in food additives for the prevention of cardiovascular diseases because of its antioxidation, anti-inflammatory, and antitumor activities. To develop new derivatives of erythrodiol (1), preparative biotransformations were investigated through Streptomyces griseus ATCC 13273, Penicilium griseofulvum CICC 40293, and Bacillus subtilis ATCC 6633, and ten new (1a-1j) and one known metabolites were isolated. Their structures were elucidated by high resolution electrospray ionization mass spectrometry (HR-ESI-MS) and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy. Furthermore, relative to 1, most metabolites exhibited lower toxicity and more potent inhibitory activities against nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. In particular, the glycosylated metabolite 1k showed a dramatically increased inhibitory effect with an IC₅₀ value of 2.40 μM, which is even lower than that of quercetin. Thus, biotransformation of erythrodiol is a viable strategy for discovering new triterpenes as food supplements with anti-inflammatory properties.

Exploitation of Lactic Acid Bacteria and Baker's Yeast as Single or Multiple Starter Cultures of Wheat Flour Dough Enriched with Soy Flour

Sourdough fermentation presents several advantageous effects in bread making, like improved nutritional quality and increased shelf life. Three types of experiments aimed to evaluate comparatively the efficiency of two Lactobacillus (Lb.) strains, Lb. plantarum ATCC 8014 and Lb. casei ATCC 393, to metabolize different white wheat flour and soybeans flour combinations to compare their efficiency, together with/without Saccharomyces cerevisiae on sourdough fermentation. For this purpose, the viability, pH, organic acids, and secondary metabolites production were investigated, together with the dynamic rheological properties of the sourdough. During sourdough fermentation, LAB presented higher growth, and the pH decreased significantly from above pH 6 at 0 h to values under 4 at 24 h for each experiment. Co-cultures of LAB and yeast produced a higher quantity of lactic acid than single cultures, especially in sourdough enriched with soy-flour. In general, sourdoughs displayed a stable, elastic-like behavior, and the incorporation of soy-flour conferred higher elasticity in comparison with sourdoughs without soy-flour. The higher elasticity of sourdoughs enriched with soy-flour can be attributed to the fact that through frozen storage, soy proteins have better water holding capacity. In conclusion, sourdough supplemented with 10% soy-flour had better rheological properties, increased lactic, acetic, and citric acid production.

Sapogenol is a Major Microbial Metabolite in Human Plasma Associated with High Protein Soy-Based Diets: The Relevance for Functional Food Formulations

Legumes are a source of health-promoting macro- and micronutrients, but also contain numerous phytochemicals with useful biological activities, an example of which are saponins. Epidemiological studies suggest that saponins may play a role in protection from cancer and benefit human health by lowering cholesterol. Therefore, they could represent good candidates for specialised functional foods. Following the consumption of a soya-rich high-protein weight-loss diet (SOYA HP WL), the concentrations of Soyasaponin I (SSI) and soyasapogenol B (SSB) were determined in faecal samples from human volunteers (n = 10) and found to be between 1.4 and 17.5 mg per 100 g fresh faecal sample. SSB was the major metabolite identified in volunteers' plasma (n = 10) after consumption of the soya test meal (SOYA MEAL); the postprandial (3 h after meal) plasma concentration for SSB varied between 48.5 ng/mL to 103.2 ng/mL. The metabolism of SSI by the gut microbiota (in vitro) was also confirmed. This study shows that the main systemic metabolites of soyasaponin are absorbed from the gut and that they are bioavailable in plasma predominantly as conjugates of sapogenol. The metabolism and bioavailability of biologically active molecules represent key information necessary for the efficient development of functional foods.

Soyasaponin II protects against acute liver failure through diminishing YB-1 phosphorylation and Nlrp3-inflammasome priming in mice

Acute liver failure is characterized by the rapid development of liver dysfunction and remarkably high mortality. Accumulating evidence suggests that soyasaponin possesses potential anti-inflammatory activities. Here, we aimed to investigate the potential role of soyasaponin II in acute liver failure and establish the underlying mechanism.

Methods: Lipopolysaccharide/D-galactosamine (LPS/GalN) was employed to induce acute liver failure. We applied liquid chromatography and mass spectrometry (LC/MS) to characterize the changes of soyasaponin II levels in the cecal content and liver. Transcriptomics and proteomics analysis were used to evaluate the functional molecule mediated by soyasaponin II in macrophages.

Results: LPS/GalN administration markedly decreased fecal and hepatic soyasaponin II levels. Soyasaponin II treatment protected mice against LPS/GalN induced acute liver injury. Additionally, soyasaponin II markedly diminished Y-Box Binding Protein 1 (YB-1) phosphorylation and nuclear translocation, Nlrp3 inflammasome priming, and interleukin 1β (Il-1β) production in macrophages. Phosphorylated YB-1 could activate Nlrp3 mRNA transcription by binding the promoter region. Finally, immunofluorescence analysis showed elevated p-YB-1 nuclear translocation in macrophages of acute liver failure patients compared to controls.

Conclusion: Our data shows that soyasaponin II which serves as a novel inhibitor for YB-1 phosphorylation and Nlrp3 inflammasome priming could protect mice against LPS/GalN induced acute liver failure.

Soyasaponins A1 and A2 exert anti-atherosclerotic functionalities by decreasing hypercholesterolemia and inflammation in high fat diet (HFD)-fed ApoE-/- mice

Atherosclerosis is a chronic inflammatory disease causing coronary heart attacks and strokes. Soyasaponins (SS), the phytochemicals naturally existing in soybeans and their products, have been shown to reduce hypercholesterolemia and inflammation, which are intimately related to the genesis and development of atherosclerosis. However, the anti-atherosclerotic functionality of soyasaponins remains unknown. The aim of this study was to investigate the effects of the supplementation of two types of soyasaponin monomers (A1 and A2) on atherosclerotic plaque formation, serum lipid profiles, and inflammation in ApoE gene knockout (ApoE-/-) mice. Sixty 5-week-old ApoE-/- male mice were fed with a high-fat diet (HFD) and intervened by SSA1 and SSA2 (10 and 20 μmol per kg BW, respectively) or simvastatin (10 μmol per kg BW) for 24 weeks. The atherosclerotic lesions in the aorta, aortic root, and innominate artery, lipid profile and inflammatory markers in serum, and TLR4/MyD88/NF-κB signaling in arterial tissues were determined. SSA1 and SSA2 decreased the plaque ratio in the aortic root and innominate artery but not in the entire aorta. In serum, SSA1 reduced TG, TC, and LDL-C but increased HDL-C; SSA2 decreased TC, TG, and LDL-C but did not affect HDL-C. Meanwhile, SSA1 increased TG, SSA2 increased TC, and both of them increased bile acids in the feces. SSA1 and SSA2 lowered TNF-α, MCP-1, and hs-crp in serum. Furthermore, SSA1 and SSA2 reduced the TLR4 and MyD88 expressions in the aorta and innominate artery and inhibited NF-κB p65 and IκBα phosphorylation in the aorta. These results suggest that SSA1 and SSA2 exert anti-atherosclerotic functionalities by decreasing hypercholesterolemia and inflammation in HFD-fed ApoE-/- mice.

Phytoestrogens inhibit key-enzymes linked to obesity, type 2 diabetes and liver-kidney toxicity in high fructose-fat diet in mice

Objective: To evaluate the effect of the administration of phytoestrogens on obesity, type 2 diabetes, and liver-kidney toxicity. Methods: Phytoestrogens (phyto(E2)) were administrated to high fructose-fat diet (HFFD). Results: This study showed that administration of phyto(E2) to HFFD-mice inhibited lipase activity by 34%, decreased body weight by 20% and modulated lipid profile, showed a decrease in total-cholesterol (TC) and LDL-cholesterol (LDL-C) rates in the plasma by 59% and 42%, respectively, and increased the HDL-cholesterol (HDL-C) level by 31%. In addition, the administration of phytoestrogens to HFFD-mice exerts an inhibitory effect on α-amylase activity and decreased glucose level by 28% and increase in liver glycogen level by 33%; and ameliorate oral glucose tolerance test. Conclusions: This study demonstrate that phyto(E2) has both a promising potential with regards to the inhibition of intestinal lipase and α-amylase activities, and a valuable hypoglycemic and hypolipidemic function.

The effects of soy on scopolamine-induced spatial learning and memory impairments are comparable to the effects of estradiol

Background Modulatory effects of soy extract and estradiol on the central nervous system (CNS) have been reported. The effect of soy on scopolamine-induced spatial learning and memory in comparison to the effect of estradiol was investigated. Materials and methods Ovariectomized rats were divided into the following groups: (1) control, (2) scopolamine (Sco), (3) scopolamine-soy 20 (Sco-S 20), (4) scopolamine-soy 60 (Sco-S 60), (5) scopolamine-estradiol 20 (Sco-E 20) and (6) scopolamine-estradiol 60 (Sco-E 60). Soy extract, estradiol and vehicle were administered daily for 6 weeks before training in the Morris water maze (MWM) test. Scopolamine (2 mg/kg) was injected 30 min before training in the MWM test. Results In the MWM, the escape latency and traveled path to find the platform in the Sco group was prolonged compared to the control group (p < 0.001). Treatment by higher doses of soy improved performances of the rats in the MWM (p < 0.05 - p < 0.001). However, treatment with both doses of estradiol (20 and 60 μg/kg) resulted in a statistically significant improvement in the MWM (p < 0.01 - p < 0.001). Cortical, hippocampal and serum levels of malondialdehyde (MDA), as an index of lipid peroxidation, were increased which was prevented by soy extract and estradiol (p < 0.001). Cortical, hippocampal as well as serum levels of the total thiol, superoxide dismutase (SOD) and catalase (CAT) in Sco group were lower than the control group (p < 0.001) while they were enhanced when the animals were treated by soy extract and estradiol (p < 0.01 - p < 0.001). Conclusions It was observed that both soy extract and estradiol prevented learning and memory impairments induced by scopolamine in ovariectomized rats. These effects can be attributed to their protective effects on oxidative damage of the brain tissue.

Soy, Soy Isoflavones, and Protein Intake in Relation to Mortality from All Causes, Cancers, and Cardiovascular Diseases: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

OBJECTIVE

We conducted a systematic review and dose-response meta-analysis of prospective studies to summarize findings on the associations between intakes of soy, soy isoflavones, and soy protein and risk of mortality from all causes, cancers, and cardiovascular diseases.

METHODS

Online databases were systematically searched to identify relevant articles published earlier than May 2018. We applied restricted cubic splines using random-effects analysis to assess dose-response associations. Between-study heterogeneity was assessed by I2 value and Cochrane Q test. Potential publication bias was assessed by visual inspection of funnel plots and Begg regression test.

RESULTS

In total, 23 prospective studies with an overall sample size of 330,826 participants were included in the current systematic review and the meta-analysis. Soy/soy products consumption was inversely associated with deaths from cancers (pooled relative risk 0.88, 95% CI 0.79 to 0.99; P=0.03; I2=47.1%, 95% CI 0.0% to 75.4%) and cardiovascular diseases (pooled effect size: 0.85, 95% CI 0.72 to 0.99; P=0.04; I2=50.0%, 95% CI 0.0% to 77.6%). Such significant associations were also observed for all-cause mortality in some subgroups of the included studies, particularly those with higher quality. In addition, higher intake of soy was associated with decreased risk of mortality from gastric, colorectal, and lung cancers as well as ischemic cardiovascular diseases. Participants in the highest category of dietary soy isoflavones intake had a 10% lower risk of all-cause mortality compared with those in the lowest category. We also found that a 10-mg/day increase in intake of soy isoflavones was associated with 7% and 9% decreased risk of mortality from all cancers and also breast cancer respectively. Furthermore, a 12% reduction in breast cancer death was indicated for each 5-g/day increase in consumption of soy protein. However, intake of soy protein was not significantly associated with all-cause and cardiovascular diseases mortality.

CONCLUSIONS

Soy and its isoflavones may favorably influence risk of mortality. In addition, soy protein intake was associated with a decreased risk in the mortality of breast cancer. Our findings may support the current recommendations to increase intake of soy for greater longevity.

Dietary soyasaponin attenuates 2,4-dinitrofluorobenzene-induced contact hypersensitivity via gut microbiota in mice

Soyasaponins (SSs) are abundant in soybeans and display inhibitory activity against contact hypersensitivity (CHS), which is often used as a mouse model for allergic contact dermatitis (ACD); however, their therapeutic mechanisms remain unknown. Here, we attempted to clarify the role of gut microbiota in the inhibition of CHS by dietary soyasaponins. For antibiotic treatment, mice were administered a mixture of ciprofloxacin and metronidazole or vancomycin. These antibiotics and SSs were given to mice via drinking water 3-weeks prior to CHS induction with 2,4-dinitrofluorobenzene, and the mice were analysed for ear swelling, tissue oedema, infiltration of Gr-1-positive immune cells, the composition of faecal microbiota and regulatory T (Treg ) cells. The soyasaponin diets attenuated ear swelling and tissue oedema, and reduced the number of Gr-1-positive cells infiltrating ear tissues. CHS caused changes in the structure of the gut microbiota, but dietary SSs blocked the changes in the microbiota composition. Ciprofloxacin and metronidazole treatments significantly enhanced the severity of CHS symptoms, whereas vancomycin treatment blocked the suppressive effect of dietary SSs on CHS. These antibiotic treatments differed in their effects on the gut microbiota composition. Treg cells in auricular lymph node and spleen increased under SS-enriched diets, but this increase was blocked by vancomycin treatment. These results suggest that dietary SSs exert their inhibitory activity on CHS via the gut microbiota in mice, suggesting that dietary supplementation with SSs may have beneficial effects on ACD patients, but that the gut microbiota is a critical determinant of the therapeutic value of dietary SSs.

Impact of soymilk consumption on 2,4-dinitrofluorobenzene-induced contact hypersensitivity and gut microbiota in mice

Soymilk is rich in phytochemicals such as soy isoflavones (SIs) and soyasaponins (SSs). Dietary SIs and SSs display inhibitory effects on contact hypersensitivity (CHS), which was reported in a mouse model for allergic contact dermatitis (ACD); however, the beneficial effects of soymilk consumption on CHS remain unknown. Here, we studied the effects of drinking soymilk on CHS and gut microbiota. Soymilk consumption attenuated ear oedema and swelling, decreased the infiltration of Gr-1-positive cells into ear tissues, and reduced the production of chemokine (C-X-C motif) ligand 2 and triggering receptor expressed on myeloid cells-1 in ear tissues. The analysis of bacterial 16S ribosomal RNA gene sequences indicated that CHS caused changes in the gut microbiota structure and that consuming soymilk reduced these changes. These results suggest that soymilk consumption may be of therapeutic value for patients with ACD and may help control the balance of intestinal microbiota.