Effects of a ferment soy product on the adipocyte area reduction and dyslipidemia control in hypercholesterolemic adult male rats

Impact of Gut Microbiota and Microbiota-Related Metabolites on Hyperlipidemia

Hyperlipidemia, defined as the presence of excess fat or lipids in the blood, has been considered as a high-risk factor and key indicator of many metabolic diseases. The gut microbiota has been reported playing a vital role in regulating host lipid metabolism. The pathogenic role of gut microbiota in the development of hyperlipidemia has been revealed through fecal microbiota transplantation experiment to germ-free mice. The effector mechanism of microbiota-related metabolites such as bile acids, lipopolysaccharide, and short-chain fatty acids in the regulation of hyperlipidemia has been partially unveiled. Moreover, studies on gut-microbiota-targeted hyperlipidemia interventions, including the use of prebiotics, probiotics, fecal microbiota transplantation, and natural herbal medicines, also have shown their efficacy in the treatment of hyperlipidemia. In this review, we summarize the relationship between gut microbiota and hyperlipidemia, the impact of gut microbiota and microbiota-related metabolites on the development and progression of hyperlipidemia, and the potential therapeutic management of hyperlipidemia targeted at gut microbiota.

Effect of Soybean and Soybean Koji on Obesity and Dyslipidemia in Rats Fed a High-Fat Diet: A Comparative Study

Soybean koji refers to steamed soybeans inoculated with microbial species. Soybean fermentation improves the health benefits of soybeans. Obesity is a serious health concern owing to its increasing incidence rate and high association with other metabolic diseases. Therefore, we investigated the effects of soybean and soybean koji on high-fat diet-induced obesity in rats. Five-week-old male Sprague-Dawley rats were randomly divided into four groups (n = 8/group) as follows: (1) regular diet (RD), (2) high-fat diet (HFD), (3) HFD + steamed soybean (HFD+SS), and (4) HFD + soybean koji (HFD+SK). SK contained more free amino acids and unsaturated fatty acids than SS. In a rat model of obesity, SK consumption significantly alleviated the increase in weight of white adipose tissue and mRNA expression of lipogenic genes, whereas SS consumption did not. Both SS and SK reduced serum triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels, and increased high-density lipoprotein cholesterol levels. SS and SK also inhibited lipid accumulation in the liver and white adipose tissue and reduced adipocyte size. Although both SS and SK could alleviate HFD-induced dyslipidemia, SK has better anti-obesity effects than SS by regulating lipogenesis. Overall, SK is an excellent functional food that may prevent obesity.

Cholesterol-lowering potentials of Lactobacillus strain overexpression of bile salt hydrolase on high cholesterol diet-induced hypercholesterolemic mice

Hypercholesterolemia is closely associated with cardiovascular disease. Supplementation with probiotics has been shown to contribute to improving lipid metabolism. The probiotic mechanisms of cholesterol reduction are complicated and remain unclear. One of the potential probiotic mechanisms for cholesterol reduction is the deconjugation of bile salts. We previously found a high bile salt hydrolase (BSH) activity of Lactobacillus casei pWQH01 (overexpression of bsh1) and Lactobacillus plantarum AR113, but found no BSH activity for Lactobacillus casei LC2W in vitro. Therefore, we decided to investigate whether the high BSH activity of L. plantarum AR113 and L. casei pWQH01 could exert a cholesterol-reducing effect in vivo. Compared to the high-cholesterol diet (HCD) group, AR113 and pWQH01 groups had a significantly lower body weight (BW), serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) levels and atherogenic index (AI), whereas the LC2W group had a poor capability to mitigate the blood lipid levels in the hypercholesterolemic mice. In addition, the AR113 and pWQH01 groups decreased the hepatic levels of TC and LDL-C and improved hepatic steatosis compared with the HCD group. To explore their cholesterol-lowering mechanisms of action, we determined the expression levels of these genes on the cholesterol metabolic pathways. AR113 and pWQH01 groups downregulated the expression of farnesoid X receptor (FXR) and small heterodimer partner (SHP) genes, but upregulated the expression of the cholesterol 7α-hydroxylase (CYP7A1) gene in the liver. Simultaneously, the expression of cholesterol liver X receptor (LXR) and low density lipoprotein receptor (LDLR) genes was upregulated in the liver. These results indicated that L. plantarum AR113 and L. casei pWQH01 could inhibit the cholesterol absorption and accelerate the cholesterol transportation. Taken together, these findings suggest that Lactobacillus strain overexpression of bile salt hydrolase has beneficial effects against hypercholesterolemia by reducing cholesterol absorption and increasing cholesterol catabolism.

Bioactivity of soy-based fermented foods: A review

For centuries, fermented soy foods have been dietary staples in Asia and, now, in response to consumer demand, they are available throughout the world. Fermentation bestows unique flavors, boosts nutritional values and increases or adds new functional properties. In this review, we describe the functional properties and underlying action mechanisms of soy-based fermented foods such as Natto, fermented soy milk, Tempeh and soy sauce. When possible, the contribution of specific bioactive components is highlighted. While numerous studies with in vitro and animal models have hinted at the functionality of fermented soy foods, ascribing health benefits requires well-designed, often complex human studies with analysis of diet, lifestyle, family and medical history combined with long-term follow-ups for each subject. In addition, the contribution of the microbiome to the bioactivities of fermented soy foods, possibly mediated through direct action or bioactive metabolites, needs to be studied. Potential synergy or other interactions among the microorganisms carrying out the fermentation and the host's microbial community may also contribute to food functionality, but the details still require elucidation. Finally, safety evaluation of fermented soy foods has been limited, but is essential in order to provide guidelines for consumption and confirm lack of toxicity.

Mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotics

CVD affect a large proportion of the world's population, with dyslipidaemia as the major risk factor. The regular consumption of both probiotic bacteria and yeast has been associated with improvement in the serum lipid profile. Thus, the present review aims to describe and discuss the potential mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotic bacteria and yeast. Regarding the hypocholesterolaemic effect of probiotic bacteria, the potential mechanisms responsible include: deconjugation of bile salts; modulation of lipid metabolism; and decreased absorption of intestinal cholesterol through co-precipitation of intestinal cholesterol with the deconjugated bile salts, incorporation and assimilation of cholesterol in the cell membrane of the probiotics, intestinal conversion of cholesterol in coprostanol, and inhibition of the expression of the intestinal cholesterol transporter Niemann-Pick C1 like 1 (NPC1L1) in the enterocytes. The potential mechanisms responsible for the hypocholesterolaemic effect of probiotic yeasts include: deconjugation of bile salts; co-precipitation of intestinal cholesterol with the deconjugated bile salts; incorporation and assimilation of cholesterol in the cell membrane; and inhibition of hepatic cholesterol synthesis. The regular consumption of probiotic bacteria and yeast, as a non-pharmaceutical approach to help manage cardiovascular risk, holds promise, according to the beneficial hypocholesterolaemic effects described herein. However, the hypocholesterolaemic effects vary according to the strains used, the physiological state of the host, and the type of diet to which the probiotics are added. Further studies are necessary to fill the gaps with regard to the knowledge related to this topic.

Effects of Soy Flour Fortified Bread Consumption on Cardiovascular Risk Factors According to APOE Genotypes in Overweight and Obese Adult Women: A Cross-over Randomized Controlled Clinical Trial

Recent studies suggest that inclusion of soy product in the diet may have favorable effects on relief of cardiovascular diseases (CVDs) and risk factors. These effects might be associated with the presence of specific polymorphism in gene. The aim of this study was to examine the effects of consumption of soy flour fortified bread on cardiovascular risk factors in overweight and obese women according to APOE genotype. In a randomized cross-over clinical trial 30 overweight and obese women received a mild weight loss diet and assigned to a regular diet and a soy bread diet, each for 6 weeks and a washout period for 20 days. Subjects in the soy bread diet were asked to replace 120 grams of their daily usual bread intake with equal amount of soy bread. No significant effects of soy bread on serum lipid, systolic blood pressure and anthropometric indices were observed compared to the regular diet (p > 0.05). For diastolic blood pressure (DBP), comparison of mean differences between two groups showed a marginally significant effect of soy bread (p = 0.06). Compared to regular diet, soy bread had a significant effect on DBP in E2 genotype group (ε2/ε2) (p = 0.03). Having ε2 allele may influences responses of CVD risk factor to soy bread consumption. However more nutrigenetic studies are required.

Modulatory effects of dietary inclusion of garlic (Allium sativum) on gentamycin-induced hepatotoxicity and oxidative stress in rats

OBJECTIVE

To investigate the ameliorative effect of dietary inclusion of garlic (Allium sativum) on gentamycin-induced hepatotoxicity in rats.

METHODS

Adult male rats were randomly divided into four groups with six animals in each group. Groups 1 and 2 were fed basal diet while Groups 3 and 4 were fed diets containing 2% and 4% garlic respectively for 27 d prior to gentamycin administration. Hepatotoxicity was induced by the intraperitoneal administration of gentamycin (100 mg/kg body weight) for 3 d. The liver and plasma were studied for hepatotoxicity and antioxidant indices.

RESULTS

Gentamycin induces hepatic damage as revealed by significant (P<0.05) elevation of liver damage marker enzymes (aspartate transaminase and alanine aminotransferase) and reduction in plasma albumin level. Gentamycin also caused a significant (P<0.05) alteration in plasma and liver enzymatic (catalase, glutathione and super oxygen dehydrogenises) and non-enzymatic (glutathione and vitamin C) antioxidant indices with concomitant increase in the malondialdehyde content; however, there was a significant (P<0.05) restoration of the antioxidant status coupled with significant (P<0.05) decrease in the tissues' malondialdehyde content, following consumption of diets containing garlic.

CONCLUSIONS

These results suggest that dietary inclusion of garlic powder could protect against gentamycin-induced hepatotoxicity, improve antioxidant status and modulate oxidative stress; a function attributed to their phenolic constituents.

Functional foods-based diet as a novel dietary approach for management of type 2 diabetes and its complications: A review

Type 2 diabetes is a complicated metabolic disorder with both short- and long-term undesirable complications. In recent years, there has been growing evidence that functional foods and their bioactive compounds, due to their biological properties, may be used as complementary treatment for type 2 diabetes mellitus. In this review, we have highlighted various functional foods as missing part of medical nutrition therapy in diabetic patients. Several in vitro, animal models and some human studies, have demonstrated that functional foods and nutraceuticals may improve postprandial hyperglycemia and adipose tissue metabolism modulate carbohydrate and lipid metabolism. Functional foods may also improve dyslipidemia and insulin resistance, and attenuate oxidative stress and inflammatory processes and subsequently could prevent the development of long-term diabetes complications including cardiovascular disease, neuropathy, nephropathy and retinopathy. In conclusion available data indicate that a functional foods-based diet may be a novel and comprehensive dietary approach for management of type 2 diabetes.

Hypolipidemic effects of lactic acid bacteria fermented cereal in rats

BACKGROUND

The objectives of the present study were to investigate the efficacy of the mixed culture of Lactobacillus acidophilus (DSM 20242), Bifidobacterium bifidum (DSM 20082) and Lactobacillus helveticus (CK60) in the fermentation of maize and the evaluation of the effect of the fermented meal on the lipid profile of rats.

METHODS

Rats were randomly assigned to 3 groups and each group placed on a Diet A (high fat diet into which a maize meal fermented with a mixed culture of Lb acidophilus (DSM 20242), B bifidum (DSM 20082) and Lb helveticus (CK 60) was incorporated), B (unfermented high fat diet) or C (commercial rat chow) respectively after the first group of 7 rats randomly selected were sacrificed to obtain the baseline data. Thereafter 7 rats each from the experimental and control groups were sacrificed weekly for 4 weeks and the plasma, erythrocytes, lipoproteins and organs of the rats were assessed for cholesterol, triglyceride and phospholipids.

RESULTS

Our results revealed that the mixed culture of Lb acidophilus (DSM 20242), B bifidum (DSM 20082) and Lb helveticus (CK 60) were able to grow and ferment maize meal into 'ogi' of acceptable flavour. In addition to plasma and hepatic hypercholesterolemia and hypertriglyceridemia, phospholipidosis in plasma, as well as cholesterogenesis, triglyceride constipation and phospholipidosis in extra-hepatic tissues characterized the consumption of unfermented hyperlipidemic diets. However, feeding the animals with the fermented maize diet reversed the dyslipidemia.

CONCLUSION

The findings of this study indicate that consumption of mixed culture lactic acid bacteria (Lb acidophilus (DSM 20242), Bifidobacterium bifidum (DSM 20082) and Lb helveticus (CK 60) fermented food results in the inhibition of fat absorption. It also inhibits the activity of HMG CoA reductase. This inhibition may be by feedback inhibition or repression of the transcription of the gene encoding the enzyme via activation of the sterol regulatory element binding protein (SREBP) transcription factor. It is also possible that consumption of fermented food enhances conversion of cholesterol to bile acids by activating cholesterol-7α-hydroxylase.

Effect of Soymilk Consumption on Waist Circumference and Cardiovascular Risks among Overweight and Obese Female Adults

BACKGROUND

Soy milk replacement in the diet might have beneficial effects on waist circumference and cardiovascular risk factors for overweight and obese subjects. Therefore, we are going to determine the effects of soy milk replacements on the waist circumference and cardiovascular risk factors among overweight and obese female adults.

METHODS

In this crossover randomized clinical trail, 24 over weight and obese female adults were on a diet with soy milk or the diet with cow's milk for four weeks. In the diet with soy milk only one glass of soy milk (240 cc) was replaced instead of one glass of cow's milk (240 cc). Measurements were done according to the standard protocol.

RESULTS

WAIST CIRCUMFERENCE REDUCED SIGNIFICANTLY FOLLOWING SOY MILK PERIOD (MEAN PERCENT CHANGE IN SOY MILK PERIOD FOR WAIST CIRCUMFERENCE: -3.79 ± 0.51 vs. -1.78 ± 0.55 %; P = 0.02 in the cow's milk period). Blood pressure, weight, liver enzymes and glycemic control indices did not changed significantly after soy milk period compared to the cow's milk period.

CONCLUSION

Among over weight and obese patients, soy milk can play an important role in reducing waist circumference. However, soy milk replacement had no significant effects on weight, glycemic control indices, liver enzymes, fibrinogen and blood pressure in a short term trial.

Anti-hyperlipidemic effect of soybean extract fermented by Bacillus subtilis MORI in db/db mice

The purpose of this study was to investigate the anti-hyperlipidemic effect of soy bean extract solution fermented by Bacillus subtilis MORI (BTD-1E) in obese db/db mice. Eight-week-old male db/db mice were administered 33.3 mg/kg BTD-1E solution orally once a day for four weeks. The BTD-1E group showed significantly lower body weight compared with the db control group (P<0.05). The BTD-1E group showed significantly lower serum total cholesterol and LDL cholesterol levels compared with the db control group, respectively (P<0.05, P<0.01). The BTD-1E group showed significantly decreased liver weight relative to final body weight compared with the db control group (P<0.01). After four weeks of BTD-1E administration, lipid droplets in the liver were apparently decreased in the BTD-1E group compared to the db control group. In summary, our results suggest that BTD-1E has an anti-hyperlipidemic effect in the obese mouse model.

Doenjang, a fermented soybean paste, decreased visceral fat accumulation and adipocyte size in rats fed with high fat diet more effectively than nonfermented soybeans

Soybean is known to have an anti-obesity effect. We compared the anti-obesity effect of doenjang, a fermented soybean paste, with that of nonfermented soybeans in rats. Steamed soybeans and doenjang (steamed soybeans fermented and aged for 10 months) were sampled and freeze-dried. Male Sprague-Dawley rats were fed basal (BA) (5% fat), high fat (HF) (30% fat), HF+steamed soybeans (SOY), or HF+doenjang (DJ) diet ad libitum for 8 weeks. HF significantly increased body weight gain, liver weight, hepatic triglyceride (TG) and cholesterol levels, and epididymal fat pad weight compared with BA. Compared with HF, body weight gain and hepatic TG and cholesterol levels were significantly lower in SOY and DJ groups, but they were not significantly different from each other. DJ significantly reduced visceral fat weight and epididymal adipocyte size compared with HF, whereas SOY resulted in a mild reduction without significance. This was possibly because DJ showed lowered fatty acid synthase (FAS) activity and elevated carnitine palmitoyltransferase (CPT)-1 activity in liver tissue more than SOY. SOY and DJ did not affect serum total and high-density lipoprotein-cholesterol levels compared with HF; however, DJ significantly lowered the atherogenic index and serum leptin level. In conclusion, doenjang, a fermented soybean product, was more effective than soybeans for preventing diet-induced visceral fat accumulation, possibly because of its greater effects on CPT-1 activity stimulation and FAS activity suppression. These effects may be due in part to the higher content of aglycone isoflavones in doenjang.

Grape juice concentrate prevents oxidative DNA damage in peripheral blood cells of rats subjected to a high-cholesterol diet

The goal of the present study was to investigate whether subchronic treatment with grape juice concentrate is able to protect liver and peripheral blood cells against cholesterol-induced injury in rats. The effects of the grape juice concentrate treatment on histopathological changes, immunohistochemistry for cyclo-oxygenase-2 (COX-2), and basal and oxidative DNA damage induced by H2O2 using a single-cell gel (comet) assay were evaluated. Male Wistar rats (n 18) were divided into three groups: group 1 – negative control; group 2 – cholesterol at 1 % (w/w) in their diet, treated for 5 weeks; group 3 – cholesterol at 1 % in their chow, treated for 5 weeks, and grape juice concentrate at 222 mg/d in their drinking-water in the final week only. The results indicated that the treatment with grape juice concentrate did not show remarkable differences regarding liver tissue in group 3 compared with group 2. However, grape juice concentrate was able to decrease oxidative DNA damage induced by H2O2 in peripheral blood cells, as depicted by the tail moment results. COX-2 expression in the liver did not show statistically significant differences (P>0·05) between groups. Taken together, the present results suggest that the administration of subchronic grape juice concentrate prevents oxidative DNA damage in peripheral blood cells.