Higher Bile Acid Binding Capacity Research Articles

Extraction and Characterization of β-Glucan from Kombucha Bacterial Cellulose and Concentrated Kombucha: Evaluating their Bile Acid Binding Capacity

β-glucan is a water-soluble polysaccharide present in natural products and has many health benefi ts such as its role as a dietary fi ber. This study aimed to extract and characterize β-glucan in kombucha bacterial cellulose (KBC) powder and concentrated kombucha. The extraction method used was ultrasound sonication combined with enzymatic treatment. The results showed that the content of β-glucan was 19.70% (w/w) in KBC extract and 8.34% (w/v) in concentrated kombucha extract, determined using β-glucan assay kit (Mixed linkage). Fourier-transform infrared (FTIR) spectroscopy analysis confi rmed the presence of β-glucan with β-(1→3) and β-(1→4) glucan linkages, as well as the presence of proteins, mannans, and other components in both KBC β-glucan and concentrated kombucha β-glucan extracts. Regarding bile acid binding potential, concentrated kombucha β-glucan exhibited a high bile acid binding capacity for up to 24 hours, while KBC β-glucan only retained this capacity for up to 4 hours. Altogether, these fi ndings highlight the presence and properties of β-glucan in kombucha, suggesting its potential as a functional ingredient with health benefi ts.

Colesevelam – a bile acid sequestrant for treating hypercholesterolemia and improving hyperglycemia

ABSTRACT Introduction Low density Lipoprotein cholesterol)LDL-C) levels show a clear relationship with cardiovascular disease (CVD). Statins are first line agents to reduce LDL-C and CVD risk. However, combination lipid-lowering therapy is often required to achieve large reductions in LDL-C. Area covered Colesevelam HCl is a bile acid sequestrant (BAS), which reduces LDL-C by 16–22% in monotherapy and adds a further 12–14% reduction in LDL-C when combined with other lipid-lowering drugs. Like statins, colesevelam reduces C-reactive protein levels by 16% in monotherapy and additional 6% when added to statins. Colesevelam also reduced HbA1c by 4 mmol/mol (0.5%) when used alone and added to other hypoglycemic drugs in studies of patients with diabetes . Expert Opinion Bile acid sequestrants reduce LDL-C and HbA1c and have some CVD outcome evidence. The uses of these agents are limited in patients with gastrointestinal disease or high triglycerides due to adverse effects on gut function and raising triglycerides and they interfere with the absorption of lipid-soluble drugs. Colesevelam has a higher bile acid binding capacity, and fewer adverse effects than other BAS. Colesevelam may be useful as a third line agent for treatment of hypercholesterolemia with some additional specific benefits on glycemic control.

Novel double cross-linked gels of soybean protein isolates and soluble dietary fiber from soybean coats with their functionalities

Traditional hydrocolloids made by materials of soybeans is mainly composed by soy protein isolated (SPI) with ions. Another main component of the resource of soybean coats, the soluble dietary fiber (SDF), was firstly added to SPI gels to form double cross-linked network by using calcium ions and transglutaminase (TGase), which was called as M-TG-Ca. Rheological, microstructure, mechanical, thermodynamic and hydration properties of composite gels were investigated. Rheological studies proved that the addition of SDF, Ca2+ and TGase could significantly improve the G′ value of SPI gel. M-TG-Ca had the highest hardness value and the densest network. The thermal analysis found that gels cross-linked by TGase showed different thermodynamic properties compared to those only added with Ca2+. In addition, M-TG-Ca exhibited the lowest pH sensitivity and the highest bile acid binding capacity, which was indicated that it had potential to prevent the chronic disease. The research on novel double cross-linked gels may provide an idea to the utilization of soybean resources. In addition, the composite gels of protein and soluble dietary fibers of soybeans can be developed as functional additives in food industry.

Amino Acid, Mineral, and Degree of Hydrolysis of Vinegar-Egg and Its Lipid Lowering and Antioxidant Effects in vitro and in vivo

Vinegar-egg, a product derived from vinegar and eggs, is a healthy beverage that has been popular in China for a long time. It contains abundant essential and hydrophobic amino acids, and minerals especially Ca and Mg via chemical analyses. The results showed changes of degree of hydrolysis (DH) by different soaking time. In vitro, vinegar-egg showed higher bile acid binding capacity and exhibited inhibition percentages of cholesterol micellar solubility. The DPPH radical-scavenging activity and lipid peroxidation inhibitory activity of vinegar-egg were evaluated, respectively. Additionally, after a 11-week experiment in vivo, high-fat diet (HFD) fed mice had higher weight gains, adipose tissue (EAT and SAT) and serum/liver lipids than the standard chow diet (SCD) fed ones, but vinegar-egg supplementation decreased (p < 0.05) them which may resulted in hyperlipidemia. Serum alanine aminotransferase (ALT) value and aspartate aminotransferase (AST) value in HFD-fed mice were reduced (p < 0.05) by supplementing vinegar-egg due to decreased (p < 0.05) malonaldehyde (MDA) levels, increased superoxide dismutase (SOD) and glutathione peroxidase (GPH-Px) activities. Compared with those fed the SCD, HFD induced extensive intrahepatic lipid droplets and hepatic necrosis. However, supplementing the HFD with vinegar-egg attenuated these anomalies in a dose-dependent manner. Taken together, the component profiles of vinegar-egg contributed the lipid lowering and antioxidant effects on HFD-fed mice. Hence, vinegar-egg is expected to be a useful ingredient in physiologically functional foods for the treatment of hyperlipidemia.

Resistant starch isolated from enzymatic, physical, and acid treated pea starch: Preparation, structural characteristics, and in vitro bile acid capacity

The multi-scale structural order and bile acid (BA) binding capacity of resistant starch (RS) isolated from native, different processed and recrystallized pea starch samples were studied. Different treatments applied include acid hydrolysis (AHPRS), pullulanase-debranching (PDPRS), autoclaving (ACPRS), ultrasound-autoclaving (UAPRS), and microwave cooking (MCPRS). Subsequently, the native, processed and recrystallized starch were subjected to in vitro digestion using thermostable α-amylase and amyloglucosidase to obtain the isolated RS. The Mw values of RS samples ranged from 2.448 × 104−9.750 × 106 g/mol, with the highest value noticed for ACPRS, and the lowest one for NPRS. The B-type and a small amount of V-type crystalline pattern was observed in all RS samples. Based on X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) measurement, the RS isolated from native pea starch, which is of type II resistant starch, exhibited the significantly lowest crystallinity and degree of order (DO), compared with RS3 samples prepared from processed and recrystallized starch. The relative crystallinities measured by 13CNMR (16.78–18.97%) were generally higher than the values of crystallinity obtained from XRD (3.36–12.23%). The strongest absorption that is related to O-H stretching between 3000 and 3600/cm on the FT-IR spectra, the highest DO value, and the highest BA binding capacity were observed for AHPRS.

Valorizing cabbage (Brassica oleracea L. var. capitata) and capsicum (Capsicum annuum L.) wastes: in vitro health-promoting activities.

The capsicum seed core and cabbage outer leaves are common wastes generated in the vegetable processing industry. We explored the in vitro health-promoting activity of these waste products for valorization. Freeze-dried and pulverized cabbage wastes had a high bile acid binding capacity and the capsicum wastes inhibited glucose dialysis more effectively. Methanolic extracts prepared with conventional solvent extraction and ultrasound-assisted extraction were analyzed to determine their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, in vitro α-amylase inhibitory, in vitro lipase inhibitory, and prebiotic activity. Crude extracts of cabbage and capsicum wastes were screened using GC-MS analysis. The cabbage waste extracts showed high antioxidant activities but did not inhibit α-amylase. The capsicum waste extracts inhibited both lipase and α-amylase activities and supported the growth of the probiotic bacterium, Lactobacilli brevis. Volatile compounds of the vegetables consisted mainly of phenols and fatty acid esters. In all assays except the α-amylase inhibition assay, the extracts prepared with ultrasound-assisted solvent extraction showed higher activity than those prepared using the conventional method. The capsicum seed core and cabbage outer leaves are potential sources of phytochemicals and antioxidant fibers. Capsicum waste extract supported probiotic bacterial growth without a lag phase. These waste products may be processed into high-value functional ingredients.

Potential of date seeds as a functional food components

The aim of this study was to determine proximate compositions, dietary fiber contents, technological properties and bile acid binding capacity of the date seeds of three cultivars (Safawi, Suhgai, and Mebruum) and to suggest their potential utilization as dietary fibre sources and bile acid binders. Total dietary fiber content of date seeds was in the range of 85.6–87.4% where the insoluble and soluble dietary fiber contents were in the range of 82.1–84.4% and 2.8–3.5%, respectively. Water-holding capacity ranged between 5.96 and 6.87 g/g DM for the all samples. Safawi seed contain the highest amount of total phenolic compounds (TPC) and the highest antioxidant activity. The bile acid bound by Safawi (94.11%) was significantly higher (p < 0.05) than the others. The higher bile acid binding capacity attributed to the hydrophobic interactions between dietary fiber fractions and bile acids. The results indicate that date seeds are more bound bile acids by providing more dietary fiber in the diet. The physicochemical and antioxidant properties of date seeds may also promote a valuable source to use as a novel food ingredient and supplemental product for health.

In Vitro Bile Acid Binding Capacities of Red Leaf Lettuce and Cruciferous Vegetables.

In the present study, we tested the bile acid binding capacity of red leaf lettuce, red cabbage, red kale, green kale, and Brussels sprouts through in vitro digestion process by simulating mouth, gastric, and intestinal digestion using six bile acids at physiological pH. Green and red kale exhibited significantly higher (86.5 ± 2.9 and 89.7 ± 0.9%, respectively) bile acid binding capacity compared to the other samples. Further, three different compositions of bile acids were tested to understand the effect on different health conditions. To predict the optimal dose for bile acid binding, we established a logistic relationship between kale dose and bile acid binding capacity. The results indicated that kale showed significantly higher bile acid binding capacity (82.5 ± 2.9% equivalent to 72.06 mg) at 1.5 g sample and remained constant up to 2.5 g. In addition, minimally processed (microwaved 3 min or steamed 8 min) green kale showed significantly enhanced bile acid binding capacity (91.1 ± 0.3 and 90.2 ± 0.7%, respectively) compared to lyophilized kale (85.5 ± 0.24%). Among the six bile acids tested, kale preferentially bound hydrophobic bile acids chenodeoxycholic acid and deoxycholic acid. Therefore, regular consumption of kale, especially minimally processed kale, can help excrete more bile acids and, thus, may lower the risk of hypercholesterolemia.

Purification and identification of hypocholesterolemic peptides from freshwater clam hydrolysate with in vitro gastrointestinal digestion

The muscles of freshwater clams were extracted separately using hot water. Subsequently, the edible muscle part was freeze-dried, hydrolyzed at 50°C using Protamex to obtain the freshwater clam hydrolysate (PX), and then digested with pepsin. The bile-acid-binding capacity and inhibition of cholesterol micelle formation were subsequently investigated using pepsin-digested PX (PXP) through ultrafiltration (UF) fractionation or size exclusion chromatography. After the UF treatment, soluble protein (171.0 mg/g) and peptide (109.4 mg/g) contents in fraction III were found to be higher than those of all other membrane fractions. Assuming that bile acid binds to PXP at 100%, the relative bile-acid-binding capacities of fractions I, II, and III were 161.2%, 64.3%, and 55.1%, respectively. Fraction f showed the highest inhibitory efficiency ratio (IER), and its inhibition-peptide content percentage was 831.5% mg/mL. The amino acid sequences of two hypocholesterolemic peptides were Val–Lys–Pro and Val–Lys–Lys, with IERs of 64.8% and 10.2% mg/mL, respectively. Practical applications The edible muscle part of freshwater clam after hot water extraction can be recovered as value-added by-product. After hydrolysis by commercial and digestive proteases, the edible muscle part of clams, including the viscera, showed higher bile acid binding capacity and exhibited in vitro inhibition percentages of cholesterol micellar solubility. Novel hypocholesterlemic peptides (Val-Lys-Pro and Val-Lys-Lys) were identified from the freshwater clam hydrolysate. Notably, this hydrolysate was confirmed to have hypocholesterolemic and hypolipidemic effects in vivo. Additionally, in vivo antihypertensive effects were confirmed in spontaneously hypertensive rats. This freshwater clam hydrolysate is expected to be a useful ingredient in physiologically functional foods for the prevention of hypertension and hypercholesterolemia.

Salmon Protamine Decreases Serum and Liver Lipid Contents by Inhibiting Lipid Absorption in an In Vitro Gastrointestinal Digestion Model and in Rats.

Protamine has been used as an antiheparin drug and a natural preservative in various food products. However, limited studies have evaluated the physicochemical and functional properties of protamine. Hence, we assessed the mechanisms underlying the inhibition of lipid absorption following salmon protamine intake in in vitro and in vivo studies. In initial experiments, a salmon protamine hydrolyzate (PH) was prepared using in vitro simulated gastrointestinal digestion suppressed pancreatic lipase activity and micellar cholesterol solubility. This PH had higher bile acid-binding capacity and emulsion breakdown activity than casein hydrolyzate and l-arginine. However, the hypolipidemic functions of protamine were dramatically reduced by pancreatin digestion. In further experiments, groups of male Wistar rats were fed an AIN-93G diet containing 5% (wt/wt) salmon protamine or a protamine amino acid mixture. After 4 wk of feeding with experimental diets, reductions in serum and liver triacylglycerol (TAG) and cholesterol contents were observed in the presence of protamine, reflecting inhibition of TAG, cholesterol, and bile acid absorption. These data suggest that the formation of insoluble PH-bile acid complexes is critical before the bile acid-binding capacity is reduced. Therefore, dietary salmon protamine may ameliorate lifestyle-related diseases such as hyperlipidemia and obesity.

Dietary ε-Polylysine Decreased Serum and Liver Lipid Contents by Enhancing Fecal Lipid Excretion Irrespective of Increased Hepatic Fatty Acid Biosynthesis-Related Enzymes Activities in Rats

ɛ-Polylysine (EPL) is used as a natural preservative in food. However, few studies have been conducted to assess the beneficial functions of dietary EPL. The purpose of this study was to elucidate the mechanism underlying the inhibition of neutral and acidic sterol absorption and hepatic enzyme activity-related fatty acid biosynthesis following EPL intake. EPL digest prepared using an in vitro digestion model had lower lipase activity and micellar lipid solubility and higher bile acid binding capacity than casein digest. Male Wistar rats were fed an AIN-93G diet containing 1% (wt/wt) EPL or l-lysine. After 4 weeks of feeding these diets, the marked decrease in serum and liver triacylglycerol contents by the EPL diet was partly attributed to increased fecal fatty acid excretion. The activities of hepatic acetyl-coenzyme A carboxylase and glucose-6-phosphate dehydrogenase, which are key enzymes of fatty acid biosynthesis, were enhanced in rats fed EPL diet. The increased fatty acid biosynthesis activity due to dietary EPL may be prevented by the enhancement of fecal fatty acid excretion. The hypocholesterolemic effect of EPL was mediated by increased fecal neutral and acidic sterol excretions due to the EPL digest suppressing micellar lipid solubility and high bile acid binding capacity. These results show that dietary EPL has beneficial effects that could help prevent lifestyle-related diseases such as hyperlipidemia and atherosclerosis.

Preparation, characterization, and biochemical activities of N-(2-Carboxyethyl)chitosan from squid pens.

Chitosan was prepared by alkaline N-deacetylation of β-chitin from squid pens, and N-carboxyethylated derivatives (N-CECS) with different degrees of substitution (DS) were synthesized. The carboxyethylation of the polysaccharide was identified by Fourier transform infrared, (1)H and (13)C nuclear magnetic resonance (NMR), and X-ray diffraction analyses. The DS of the derivatives was calculated by (1)H NMR and elemental analysis. All three N-CECS samples showed good water solubility at pH > 6.5. The antioxidant properties and bile acid binding capacity of the derivatives were studied in vitro. The highest bile acid binding capacity of all N-CECS reached 36.9 mg/g, which was 2.6-fold higher than that of chitosan. N-CECS showed a stronger scavenging effect on 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical ability, and EC50 values were below 2 mg/mL. The scavenging ability of N-CECS against superoxide radicals correlated well with the DS and concentration of N-CECS. These results indicated that N-carboxyethylation is a possible approach to prepare chitosan derivatives with desirable in vitro biochemical properties.

Relative Bile Acid Binding Potential of Extruded Lentil Snacks

Previously we have reported that extrusion significantly improved healthful potential of cereals. It was hypothesized that snacks produced by extrusion would be more healthful than their raw formulations. Bile acid binding has been reported to indicate cholesterol lowering and cancer risk reduction potential of food and fractions. Bile acid binding potential of five lentil snack raw formulations and their extruded snacks were evaluated. The raw formulations were 100% lentils (F01), 69% lentils (F02), 57% lentils + 12% supplement (F03), F03 with 125 μg/100g Chromium (F04), F03 with 536 μg/100g Chromium (F05), and their respective extruded (E) snacks E01, E02, E03, E04 and E05. The in vitro bile acid binding on an equal dry matter basis relative to cholestyramine, was F01 (0.5%), E01 (3.7%), F02 (0.6%), E02 (3.0%), F03 (1.6%), E03 (5.1%), F04 (2.0%), E04 (4.2%), F05 (0.8%) and E05 (3.6%). Replacing 12% lentils with high protein supplements (F02 vs. F03) resulted in significantly higher bile acid binding, suggesting that the supplement appears to have higher bile acid binding capacity than that of lentils. All the extruded lentil snacks had significantly higher bile acid binding compared with their raw formulations. Extruding with added chromium containing yeast resulted in significantly lower bile acid binding in a dose dependent manner. Most healthful lentil snacks were produced with the addition of high protein supplement without added chromium-containing yeast (E03). Data proved the hypothesis that lentil snacks produced by extrusion are significantly more healthful than their raw formulations.

In Vitro Binding Capacity of Bile Acids by Defatted Corn Protein Hydrolysate

Defatted corn protein was digested using five different proteases, Alcalase, Trypsin, Neutrase, Protamex and Flavourzyme, in order to produce bile acid binding peptides. Bile acid binding capacity was analyzed in vitro using peptides from different proteases of defatted corn hydrolysate. Some crystalline bile acids like sodium glycocholate, sodium cholate and sodium deoxycholate were individually tested using HPLC to see which enzymes can release more peptides with high bile acid binding capacity. Peptides from Flavourzyme defatted corn hydrolysate exhibited significantly (p < 0.05) stronger bile acid binding capacity than all others hydrolysates tested and all crystalline bile acids tested were highly bound by cholestyramine, a positive control well known as a cholesterol-reducing agent. The bile acid binding capacity of Flavourzyme hydrolysate was almost preserved after gastrointestinal proteases digestion. The molecular weight of Flavourzyme hydrolysate was determined and most of the peptides were found between 500-180 Da. The results showed that Flavourzyme hydrolysate may be used as a potential cholesterol-reducing agent.

Colesevelam: an improved bile acid sequestrant for treating hypercholesterolemia and improving diabetes

There is a well-established association between serum cholesterol and coronary heart disease. Statins are the first-line agents for the treatment of hypercholesterolemia, yet combination therapy is required to achieve the desired reduction in low-density lipoprotein cholesterol (LDL-C). Niacin and bile acid sequestrants were among the first lipid-lowering drugs developed to lower LDL-C and have been established to be effective both in monotherapy and in combination therapy. However, tolerability and compliance issues have limited their use. Colesevelam HCl is the newest bile acid sequestrant and reduces LDL-C by 16–22% in monotherapy and adds 12–14% in combination dual therapy with statins, fibrates and ezetimibe or in triple therapy with statin and ezetimibe. It reduces C-reactive protein levels by 16–19% in monotherapy or by 23% in combination with statins and other lipid-lowering therapies. In addition, it consistently reduces hemoglobin A1c by 0.5% in addition to other hypoglycemic drugs in studies of patients with diabetes. Compared with other bile acid sequestrants it has a higher bile acid-binding capacity, reduced adverse effects and, therefore, has better compliance. Colesevelam HCl is thus a useful addition to the lipid-lowering formulary as a second-line agent, particularly for patients with metabolic syndrome requiring extra reduction in LDL-C.

CARDIOVASCULAR EFFECTS OF WHEY FROM PROZYME 6-FACILITATED LACTIC ACID BACTERIA FERMENTATION OF MILK

Fresh low-fat milk was fermented for up to 30 h at 42C with five mixed lactic acid bacteria. A protease, Prozyme 6, was added 5 h after the beginning of bacterial fermentation. The whey was separated from the fermented milk and freeze-dried. As the fermentation time extended to 30 h, the inhibition of lipoxygenase increased as indicated by a decrease of IC50from 3.79 to 0.47 mg powder/mL. The relative percentage of binding bile acid by whey was 39.3% in comparison to cholestyramine. Inhibition of angiotensin I-converting enzyme increased as shown by a decrease of IC50 from 1.18 to 0.24 mg powder/mL. The systolic blood pressure and diastolic blood pressure were reduced 22.6 and 21.5 mmHg, respectively, in spontaneously hypertensive rat, after 8 weeks of oral administration of diluted whey (12.5 mg powder/mL). PRACTICAL APPLICATIONS A new technique was developed in this experiment using a combination of lactic acid bacteria fermentation and protease hydrolysis to accelerate the production of bioactive peptides from fresh low-fat milk. The fermented whey product exhibited in vitro inhibition on lipoxygenase (LOX) and angiotensin I-converting enzyme, and reduced the LOX-catalyzed low-density lipoprotein oxidation. The whey product also showed higher bile acid binding capacity; thus, it might possibly have the potential of reducing serum cholesterol in vivo. Also, in vivo antihypertensive effect was confirmed on spontaneouosly hypertensive rat by long- or short-term administration. This fermented milk whey was expected to be a useful ingredient in physiologically functional foods for reduction of cardiovascular disease risk.

Hypocholesterolemic Mechanism ofChlorella:Chlorellaand Its Indigestible Fraction Enhance Hepatic Cholesterol Catabolism through Up-Regulation of Cholesterol 7α-Hydroxylase in Rats

Chlorella powder (CP) has a hypocholesterolemic effect and high bile acid-binding capacity; however, its effects on hepatic cholesterol metabolism are still unclear. In the present study, male Wistar rats were divided into four groups and fed a high sucrose + 10% lard diet (H), an H + 10% CP diet (H+CP), an H + 0.5% cholesterol + 0.25% sodium cholate diet (C), or a C + 10% CP diet (C+CP) for 2 weeks. CP decreased serum and liver cholesterol levels significantly in rats fed C-based diets, but did not affect these parameters in rats fed H-based diets. CP increased the hepatic mRNA level and activity of cholesterol 7alpha-hydroxylase (CYP7A1). CP increased hepatic HMG-CoA reductase (HMGR) activity in the rats fed H-based diets, but not in rats fed C-based diets. CP did not affect hepatic mRNA levels of sterol 27-hydroxylase, HMGR, low-density lipoprotein (LDL) receptor, scavenger receptor class B1, ATP-binding cassette (ABC) A1, ABCG5, or ABCB11. Furthermore, the effect of a 3.08% Chlorella indigestible fraction (CIF, corresponding to 10% CP) on hepatic cholesterol metabolism was determined using the same animal models. CIF also decreased serum and liver cholesterol levels significantly in rats fed C-based diets. CIF increased hepatic CYP7A1 mRNA levels. These results suggest that the hypocholesterolemic effect of CP involves enhancement of cholesterol catabolism through up-regulation of hepatic CYP7A1 expression and that CIF contributes to the hypocholesterolemic effect.

Mechanisms of cholesterol-lowering effects of dietary insoluble fibres: relationships with intestinal and hepatic cholesterol parameters

Fibres with a range of abilities to perturb cholesterol homeostasis were used to investigate how the serum cholesterol-lowering effects of insoluble dietary fibres are related to parameters of intestinal cholesterol absorption and hepatic cholesterol homeostasis in mice. Cholestyramine, chitosan and cellulose were used as examples of fibres with high, intermediate and low bile acid-binding capacities, respectively. The serum cholesterol levels in a control group of mice fed a high fat/high cholesterol (HFHC) diet for 3 weeks increased about 2-fold to 4.3 mm and inclusion of any of these fibres at 7.5 % of the diet prevented this increase from occurring. In addition, the amount of cholesterol accumulated in hepatic stores due to the HFHC diet was reduced by treatment with these fibres. The three kinds of fibres showed similar hypocholesterolaemic activity; however, cholesterol depletion of liver tissue was greatest with cholestyramine. The mechanisms underlying the cholesterol-lowering effect of cholestyramine were (1) decreased cholesterol (food) intake, (2) decreased cholesterol absorption efficiency, and (3) increased faecal bile acid and cholesterol excretion. The latter effects can be attributed to the high bile acid-binding capacity of cholestyramine. In contrast, incorporation of chitosan or cellulose in the diet reduced cholesterol (food) intake, but did not affect either intestinal cholesterol absorption or faecal sterol output. The present study provides strong evidence that above all satiation and satiety effects underlie the cholesterol-lowering properties of insoluble dietary fibres with moderate or low bile acid-binding capabilities.

Hypocholesterolemic effect of indigestible fraction of Chlorella regularis in cholesterol-fed rats.

The effects of Chlorella regularis powder (CP) and Chlorella regularis indigestible fraction (CIF) on serum and liver lipid concentrations and on fecal steroid excretion were estimated in rats fed diets containing 5 g/kg cholesterol and 2.5 g/kg sodium cholate. The ingestion of 12.7% CP or 5.3% CIF did not influence food intake or growth. CP and CIF decreased the levels of serum cholesterol, but had no effect on the levels of serum triacylglycerol and phospholipid. Liver cholesterol contents were lower in the CP and CIF groups than in the control group, but CP and CIF did not affect liver triacylglycerol content. CP and CIF increased the total amount of fecal neutral steroids excreted, but did not modify the total bile acid excretion. However, the soluble bile acid concentrations of reconstituted fecal water in the rats fed CP and CIF diets were lower than the control value. Moreover, CP and CIF had a high bile acid binding capacity in vitro. These results indicated that CIF had a hypocholesterolemic effect and enhanced fecal neutral steroid excretion while decreasing the soluble fecal bile acid concentration.

Plasma cholesterol reduction by defatted soy ontjom (fermented with Neurospora intermedia) in rats fed a cholesterol-free diet.

To popularize defatted soy ontjom (DSB-ontjom, soy product fermented with Neurospora intermedia) as a new food, I examined the plasma cholesterol-reducing effects of DSB-ontjom and DSB in rats fed cholesterol-free diets and compared the efficiencies of these effects. DSB-ontjom greatly reduced the plasma cholesterol level and increased fecal steroid excretion as compared to DSB. DSB-ontjom was rich in pepsin-resistant protein having a high bile acid binding capacity and was abundant in isoflavone-aglycones, especially daizein. The dietary fiber (DF) of DSB-ontjom stimulated the production of short-chain fatty acids (SCFAs) by intestinal microflora. The effect of DSB-ontjom on plasma cholesterol reduction was attributed to the collaborative effects of pepsin-resistant-protein, isoflavone-aglycones and SCFA-producing DF in DSB-ontjom.