Insoluble/soluble fraction ratio determines effects of dietary fiber on gut microbiota and serum metabolites in healthy mice.

Both soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) play pivotal roles in maintaining gut microbiota homeostasis; whether the effects of the different ratios of IDF and SDF are consistent remains unclear. Consequently, we selected SDFs and IDFs from six representative foods (apple, celery, kale, black fungus, oats, and soybeans) and formulated nine dietary fiber recipes composed of IDF and SDF with a ratio from 1 : 9 to 9 : 1 (NDFR) to compare their impact on microbial effects with healthy mice. We discovered that NDFR treatment decreased the abundance of Proteobacteria and the ratio of Firmicutes/Bacteroidetes at the phylum level. The α diversity and relative richness of Parabacteroides and Prevotella at the genus level showed an upward trend along with the ratio of IDF increasing, while the relative abundance of Akkermansia at the genus level and the production of acetic acid and propionic acid exhibited an increased trend along with the ratio of SDF increasing. The relative abundance of Parabacteroides and Prevotella in the I9S1DF group (the ratio of IDF and SDF was 9 : 1) was 1.72 times and 5.92 times higher than that in the I1S9DF group (the ratio of IDF and SDF was 1 : 9), respectively. The relative abundance of Akkermansia in the I1S9DF group was 17.18 times higher than that in the I9S1DF group. Moreover, a high ratio of SDF (SDF reaches 60% or more) enriched the glycerophospholipid metabolism pathway; however, a high ratio of IDF (IDF reaches 80% or more) regulated the tricarboxylic acid cycle. These findings are helpful in the development of dietary fiber supplements based on gut microbiota and metabolites.

Tea polyphenol and epigallocatechin gallate ameliorate hyperlipidemia via regulating liver metabolism and remodeling gut microbiota.

Hyperlipidemia can directly cause metabolic diseases that seriously endanger disorder and metabolism and gut health. Tea polyphenol (TP) and epigallocatechin gallate (EGCG) was found to improve blood lipid levels and gut microbiota. This study aimed to investigate the effects of TP and EGCG on alleviating hyperlipidemia and liver fat accumulation with physiology, genomics, and metabolomics. Results showed that both TP and EGCG reduced body weight, and TP showed advantages in the decrease of serum cholesterol and triglycerides in hyperlipidemic rats induced by the high-fat diet. Moreover, EGCG may protect liver function via reducing the glycerophospholipids increased by high-fat diet intervention. TP remodeled the gut microbiota composition and enriched the abundance of beneficial bacteria (Bacteroides, Faecalibacterium, Parabacteroides, Akkermansia), and EGCG may improve gut health via promoting the acid-producing bacteria (such as Butyricimonas, Desulfovibrio). The above results provided new insights into the hypolipidemic mechanism of TP and EGCG.

Structural characteristic of pectin-glucuronoxylan complex from Dolichos lablab L. hull.

Polysaccharides are important constituents in Dolichos lablab hull. Herein, pectin-glucuronoxylan complex from D. lablab hull designated as DLHP-3 (D. lablab hull polysaccharide,) was prepared by ion exchange and gel permeation chromatography, and further characterized by acid degradation and enzymatic hydrolysis, methylation combined with GC-MS, NMR and MALDI-TOF-MS analysis. Both of pectin and glucuronoxylan regions were found in DLHP-3. The glucuronoxylan region consisted of a →4)-ß-Xylp-(1→ backbone with branches of α-GlcpA-(1→ substituted at O-2 site, and the ratio of xylose to glucuronic acid was about 5:1. Acetyl groups were mainly attached to O-3 site of →2,4)-ß-Xylp-(1→ residues. The main chain of pectin region could be represented by →4)-α-GalpA-(1→4)-α-GalpA-(1→ and →2)-α-Rhap-(1→4)-α-GalpA-(1→ with partial methyl-esterification. The side chains were deduced to embrace arabinan and arabinogalactan linked to rhamnogalacturonan-I region. Pectin was probably covalently bound to glucuronoxylan. Our findings uncovered the molecular structure of pectin-glucuronoxylan complex from D. lablab hull.

Review of structure and bioactivity of the Plantago (Plantaginaceae) polysaccharides.

Plantago (Plantaginaceae) is an herbal plant, which is used in folk medicine, functional food, and dietary supplement products. Recent pharmacological and phytochemical studies have shown that polysaccharides isolated from Plantago have multiple medicinal and nutritional benefits, including improve intestinal health, hypoglycemic effect, immunomodulatory effect, etc. These health and pharmacological benefits are of great interest to the public, academia, and biotechnology industries. This paper provides an overview of recent advances in the physicochemical, structural features, and biological effects of Plantago polysaccharides and highlights the similarities and differences of the polysaccharides from different species and in different parts, including leaves, seeds, and husks. The scientific support for its use as a prebiotic is also addressed. The purpose of this review is to provide background as well as useful and up-to-date information for future research and applications of these polysaccharides.

Polysaccharides from fermented Momordica charantia L. with Lactobacillus plantarum NCU116 ameliorate metabolic disorders and gut microbiota change in obese rats.

Obesity is a chronic disease characterized by overweight resulting from fat accumulation, along with disturbance of metabolism and gut microbiota. Fermentation, as a green processing method, is beneficial for improving the nutrition capacity of food components. Polysaccharides are considered as one of the important components in food and are also potential supplements for anti-obesity treatment. This study aimed to investigate the anti-obesity effects of polysaccharides from fermented and non-fermented Momordica charantia L. with Lactobacillus plantarum NCU116 (FP and NFP) on obese rats by serum metabolomics and gut microbiota analysis. Metabolomics results revealed that abnormal lipid metabolism was formed due to obesity. The supplement of FP and NFP improved the glycerophospholipids, glycosphingolipids, and amino acid metabolism of the obese rats, which alleviated the hypercholesterolemia and overweight in rats. Furthermore, the disorder of gut microbiota was ameliorated by FP and NFP. FP promoted the growth of beneficial bacteria, such as phylum Firmicutes, Actinobacteria, and genera Anaerostipes, Coprococcus, Lactobacillus, and Bifidobacterium. FP also reduced several harmful bacteria belonging to the phylum Proteobacteria and genera Helicobacter. The positive correlation of the weight loss and lowering of serum lipids with the increased beneficial bacteria further elucidated that the anti-obesity effect of FP in obese rats is associated with the regulation of gut microbiota and serum metabolites. The results of this study could provide information for developing probiotic products in the future that may have beneficial effects on the prevention or treatment of obesity.

Hypoglycemic mechanism of polysaccharide from Cyclocarya paliurus leaves in type 2 diabetic rats by gut microbiota and host metabolism alteration.

Diabetes mellitus is a serious threat to human health. Cyclocarya paliurus (Batal.) Iljinskaja (C.paliurus) is one of the traditional herbal medicine and food in China for treating type 2 diabetes, and the C. paliurus polysaccharides (CP) were found to be one of its major functional constituents. This research aimed at investigating the hypoglycemic mechanism for CP. It was found that CP markedly attenuated the symptoms of diabetes, and inhibited the protein expression of Bax, improved the expression of Bcl-2 in pancreas of diabetic rats, normalized hormones secretion and controlled the inflammation which contributed to the regeneration of pancreatic ß-cell and insulin resistance. CP treatment increased the beneficial bacteria genus Ruminococcaceae UCG-005 which was reported to be a key genus for protecting against diabetes, and the fecal short-chain fatty acids levels were elevated. Uric metabolites analysis showed that CP treatment helped to protect with the diabetes by seven significantly improved pathways closely with the nutrition metabolism (amino acids and purine) and energy metabolism (TCA cycle), which could help to build up the intestinal epithelial cell defense for the inflammation associated with the diabetes. Our study highlights the specific mechanism of prebiotics to attenuate diabetes through multi-path of gut microbiota and host metabolism.

Hypoglycemic and Hypolipidemic Mechanism of Tea Polysaccharides on Type 2 Diabetic Rats via Gut Microbiota and Metabolism Alteration.

Diabetes mellitus is a serious threat to human health. Tea is cultivated around the world, and its polysaccharide components are reported to be an effective approach for managing type 2 diabetes with fewer adverse effects than medication. To examine the therapeutic effect of tea polysaccharides on diabetes, a type 2 diabetic rat model was generated. We showed that tea polysaccharides remarkably decreased fasting blood glucose and the levels of total cholesterol, total triglyceride, low-density lipoprotein cholesterol, and free fatty acid of type 2 diabetic rats. 16S rRNA sequencing and metabolomics were used to investigate the variation of gut microbiota and the metabolites profiles of diabetic rats after intervention of tea polysaccharides. We found that tea polysaccharides maintained the diversity of gut microbiota and restored the relative abundance of some bacterial genera (Lachnospira, Victivallis, Roseburia, and Fluviicola) which was reduced by diabetes. According to metabolomics analysis, we found that amino acid and other related metabolites was influenced by tea polysaccharides intervention. Correlation analysis among metabolites, gut microbiota, and parameters of hypoglycemic indicated that tea polysaccharides had hypoglycemic and hypolipidemic effect on type 2 diabetes via the modulation of gut microbiota and the improvement of host metabolism.

Preventive effects of pectin with various degrees of esterification on ulcerative colitis in mice.

This work investigated the physiochemical characteristics and preventive effects of purified pectin (H121, L13 and L102) with different esterification degrees on dextran sulfate sodium (DSS)-induced colitis in mice. Three doses of each type of pectin were administered to C57BL/6J mice for 7 days before the DSS treatment, with dextran and mesalazine as positive controls. Results showed that pathological factors including the body weight, the disease activity index (DAI), the colonic weight/length ratio and the organ index of the spleen were improved with pre-intervention of a high dose of L13 or L102. Further studies showed that administration of a low dose of L13, low dose and medium dose of L102 or dextran improved intestinal permeability and tight junction function in colitis mice. Treatments of L13 of all doses and L102 of a high dose downregulated the oxidative stress-associated factors, while L102 of a low dose and H121 ameliorated the inflammatory cytokine production in serum and the colon. The above results suggested that pectin could attenuate DSS-induced intestinal epithelial injury, inflammation and oxidative stress. Specifically, compared to high esterified pectin, low esterified pectin displayed better protective effects in acute colitis mice.

Fermented Momordica charantia L. juice modulates hyperglycemia, lipid profile, and gut microbiota in type 2 diabetic rats.

The effect of Lactobacillus plantarum-fermentation on the anti-diabetic functionality of Momordica charantia was examined using a high-fat-diet and low-dose streptozocin-induced type 2 diabetic rat model. Fermented Momordica charantia juice (FMCJ) administration mitigated the hyperglycemia, hyperinsulinemia, hyperlipidemia, and oxidative stress in diabetic rats more favorably than the non-fermented counterpart. Treatments with FMCJ improved ergosterols and lysomonomethyl-phosphatidylethanolamines metabolisms more effectively. Supplement of FMCJ regulated the composition of the gut microbiota, such as increased the abundance of Bacteroides caecigallinarum, Oscillibacter ruminantium, Bacteroides thetaiotaomicron, Prevotella loescheii, Prevotella oralis, and Prevotella melaninogenica, in diabetic rats compared with untreated diabetic rats. Moreover, FMCJ-treated diabetic rats exhibited higher concentrations of acetic acid, propionic acid, butyric acid, total short-chain fatty acids and lower pH values in colonic contents than that in non-fermented juice-treated rats. These results demonstrated that Lactobacillus plantarum-fermentation enhanced the anti-diabetic property of MC juice by favoring the regulation of gut microbiota and the production of SCFAs.

Polysaccharides from fermented Momordica charantia ameliorate obesity in high-fat induced obese rats.

Momordica charantia (M. charantia) has been widely used to treat obesity due to its bioactive ingredients. This research aimed to investigate the anti-obesity effect of polysaccharides (FP) from fermented M. charantia with Lactobacillus plantarum NCU116 on high-fat induced obese rats. We found that FP could effectively lower the body weight gain, Lee's index, insulin resistance and cell sizes of epididymal adipose tissues in obese rats compared with polysaccharides from non-fermented M. charantia (NFP). FP treatments decreased the total cholesterol, triacylglycerols, and low-density lipoprotein cholesterol, leptin, whereas they elevated the high-density lipoprotein cholesterol, adiponectin, significantly in the serum of obese rats. Furthermore, administrations of FP notably improved oxidative balance in obese rats. Lipidomics results indicated that 24 potential biomarkers have been identified in serum. Additionally, 21 lipids were considerably altered by FP and NFP intakes, such as fatty acyls, glycerolipids, sphingolipids, sterol lipids and glycerophospholipids. The anti-obesity properties of FP were revealed via relieving insulin resistance and fat accumulation of obese rats, which was associated with the regulation of lipid metabolism. Overall, FP exerted more favourable impacts on the anti-obesity effect than NFP, which may be attributed to fermentation.

Dietary compounds and traditional Chinese medicine ameliorate type 2 diabetes by modulating gut microbiota.

Diabetes mellitus (DM) and its complications are major public health concerns which strongly influence the quality of humans' life. Modification of gut microbiota has been widely used for the management of diabetes. In this review, the relationship between diabetes and gut microbiota, as well as the effects of different dietary components and traditional Chinese medicine (TCM) on gut microflora are summarized. Dietary compounds and TCM possessing bioactive components (fiber and phytochemicals) first change the composition of gut microbiota (inhibiting pathogens and promoting the beneficial bacteria growth) and then influence the production of their metabolites, which would further modify the intestinal environment through inhibiting the production of detrimental compounds (such as lipopolysaccharide, hydrogen sulfide, indol, etc.). Importantly, metabolites (short chain fatty acids and other bioactive components) fermented/degraded by gut microbiota can target multiple pathways in intestine, liver, pancreas, etc., resulting in the improvement of gut health, glycemic control, lipids profile, insulin resistance and inflammation. Furthermore, understanding the interaction between different dietary components and gut microbiota, as well as underlying mechanisms would help design different diet formula for the management of diabetes. Further researches could focus on the combination of different dietary components for preventing and treating diabetes, based on the principle of "multiple components against multiple targets" from the perspective of gut microbiota.

Tea Polysaccharide Prevents Colitis-Associated Carcinogenesis in Mice by Inhibiting the Proliferation and Invasion of Tumor Cells.

The imbalance between cell proliferation and apoptosis can lead to tumor progression, causing oncogenic transformation, abnormal cell proliferation and cell apoptosis suppression. Tea polysaccharide (TPS) is the major bioactive component in green tea, it has showed antioxidant, antitumor and anti-inflammatory bioactivities. In this study, the chemoprophylaxis effects of TPS on colitis-associated colon carcinogenesis, especially the cell apoptosis activation and inhibition effects on cell proliferation and invasion were analyzed. The azoxymethane/dextran sulfate sodium (AOM/DSS) was used to induce the colorectal carcinogenesis in mice. Results showed that the tumor incidence was reduced in TPS-treated AOM/DSS mice compared to AOM/DSS mice. TUNEL staining and Ki-67 immunohistochemistry staining showed that the TPS treatment increased significantly the cell apoptosis and decreased cell proliferation among AOM/DSS mice. Furthermore, TPS reduced the expression levels of the cell cycle protein cyclin D1, matrix metalloproteinase (MMP)-2, and MMP-9. In addition, in vitro studies showed that TPS, suppressed the proliferation and invasion of the mouse colon cancer cells. Overall, our findings demonstrated that TPS could be a potential agent in the treatment and/or prevention of colon tumor, which promoted the apoptosis and suppressed the proliferation and invasion of the mouse colon cancer cells via arresting cell cycle progression.

Isolation, structure, and bioactivities of polysaccharides from Cyclocarya paliurus (Batal.) Iljinskaja.

Cyclocarya paliurus (Batal.) Iljinskaja, a well-known edible and medicinal plant, has been widely used in China as a traditional medicine for treating hypertension and diabetes. C. paliurus possesses various bioactivities, such as antihyperglycemic, antihyperlipidemic, antihypertensive, anticancer, antifatigue, antioxidation, antimicrobial, colon health-promoting, and immunological activities. Polysaccharides, as natural macromolecules with various biological activities, are considered to be the main effective components in C. paliurus. Here, we summarize studies of polysaccharides from C. paliurus over the past 20 years, including extraction and purification processes, structure, and bioactivities.

Metabolism and health effects of phyto-estrogens.

Phyto-estrogens are plant-derived compounds that can exert various estrogenic and anti-estrogenic effects, and are usually used as a natural alternative to estrogen replacement due to their health benefits, including a lowered risk of osteoporosis, heart disease, breast cancer, and menopausal symptoms. Phyto-estrogens are also considered as endocrine disruptors due to their structure similar to human female hormone 17-ß oestradiol. However, the issue of whether phyto-estrogens are beneficial or harmful to human health remains unknown, as this may depend on the dose, form, level and duration of administration of phyto-estrogens, and influence by genetics, metabolism, gut physiology, age, diet, and the health status of individuals. Clarification on this issue is necessary for the sake of their two-side effects on human health and rapidly increasing global consumption of phyto-estrogens. This review mainly includes the metabolism of phyto-estrogens and weighs the evidence for and against the purported health benefits and adverse effects of phyto-estrogens.

Bidirectional Estrogen-Like Effects of Genistein on Murine Experimental Autoimmune Ovarian Disease.

This study was to investigate the bidirectional estrogen-like effects of genistein on murine experimental autoimmune ovarian disease (AOD). Female BALB/c mice were induced by immunization with a peptide from murine zona pellucida. The changes of estrous cycle, ovarian histomorphology were measured, and the levels of serum sex hormone were analyzed using radioimmunoassay. Proliferative responses of the ovary were also determined by immunohistochemistry. Administration of 25 or 45 mg/kg body weight genistein enhanced ovary development with changes in serum sex hormone levels and proliferative responses. Meanwhile, the proportions of growing and mature follicles increased and the incidence of autoimmune oophoritis decreased, which exhibited normal ovarian morphology in administration of 25 or 45 mg/kg body weight genistein, while a lower dose (5 mg/kg body weight genistein) produced the opposite effect. These findings suggest that genistein exerts bidirectional estrogen-like effects on murine experimental AOD, while a high dose (45 mg/kg body weight) of genistein may suppress AOD.

Polysaccharide from seeds of Plantago asiatica L. affects lipid metabolism and colon microbiota of mouse.

Polysaccharide from the seeds of Plantago asiatica L. was given via oral administration to mice (0.4 g/kg body weight, 30 days) to observe its effects on mouse nutrient metabolism and colon microbiota. It was found the polysaccharide intake could lower the apparent absorption of lipid. Total triglyceride, cholesterol, and atherogenic index in blood serum with total lipid and cholesterol levels in liver of polysaccharide group mice were all significantly lower than those of the control group (p < 0.05). Furthermore, the effect of the polysaccharide intake on mouse colon bacterial communities was investigated. Mice from the polysaccharide group showed a higher colon bacterial diversity than the control group. Bacteroides sp., Eubacterium sp., butyrate-producing bacteria Butyrivibrio sp., and probiotics Bifidobacterium bifidum , Lactobacillus fermentum , and Lactobacillus reuteri in mouse colon were all increased after polysaccharide intake. These indicated that the intake of polysaccharide from P. asiatica L. could be beneficial for lipid metabolism and colon microbiota.

High pressure homogenization increases antioxidant capacity and short-chain fatty acid yield of polysaccharide from seeds of Plantago asiatica L.

Physiological properties of homogenized and non-homogenized polysaccharide from the seeds of Plantago asiatica L., including antioxidant capacity and short-chain fatty acid (SCFA) production, were compared in this study. High pressure homogenization decreased particle size of the polysaccharide, and changed the surface topography from large flake-like structure to smaller porous chips. FT-IR showed that high pressure homogenization did not alter the primary structure of the polysaccharide. However, high pressure homogenization increased antioxidant capacity of the polysaccharide, evaluated by 4 antioxidant capacity assays (hydroxyl radical-scavenging, superoxide radical-scavenging, 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH)-scavenging and lipid peroxidation inhibition). Additionally, the production of total SCFA, propionic acid and n-butyric acid in ceca and colons of mice significantly increased after dieting supplementation with homogenized polysaccharide. These results showed that high pressure homogenization treatment could be a promising approach for the production of value-added polysaccharides in the food industry.

Polysaccharide from seeds of Plantago asiatica L. increases short-chain fatty acid production and fecal moisture along with lowering pH in mouse colon.

Mice (20.0 ± 2.0 g, n = 48 per group) were given 30 days oral administration of polysaccharide from Plantago asiatica L. seeds at the dose of 0.4 g/kg body weight by gavage to investigate the effects of the polysaccharide on mouse colon. Results showed that the concentrations of total short-chain fatty acids (SCFA), acetic, propionic, and n-butyric acids in mouse colonic content of polysaccharide treated group were all significantly higher than that of control group (water) (p < 0.05). In addition, moisture of mouse colonic content of polysaccharide treated group was also notably higher than that of the control group (p < 0.05) indicating the intake of polysaccharide from P. asiatica L. resulted in a stronger water-holding capacity for colonic content throughout the experimental period. Furthermore, a decreased pH (from 7.5 ± 0.1 to 7.2 ± 0.1) was observed in mouse colon of the polysaccharide treated group compared with the control group (pH from 7.5 ± 0.1 to 7.5 ± 0.1). These results suggested that the intake of the polysaccharide from P. asiatica L. might be beneficial for the colon health.

Antimicrobial activity of saponin-rich fraction from Camellia oleifera cake and its effect on cell viability of mouse macrophage RAW 264.7.

BACKGROUND: As a by-product of oil production, several million tons of Camellia oleifera cake is discarded every year in China. The aim of this study was to evaluate the antimicrobial activity of a saponin-rich fraction isolated from C. oleifera cake and investigate its effect on the cell viability of RAW 264.7, a macrophage-like cell line present in almost all mouse tissues. RESULTS: The saponin-rich fraction was isolated from C. oleifera cake in several steps and had a saponin content of 95.42 ± 0.10% (w/w). It showed significant inhibitory activity against the bacteria Staphylococcus aureus, Escherichia coli and Bacillus subtilis and the fungi Mucor racemosus, Aspergillus oryzae, Rhizopus stolonifer, Saccharomyces cerevisiae and Penicillium glaucum, with minimum inhibitory concentrations of 31.3, 31.3, 62.5, 250, 250, 250, 31.3 and 125 µg ml(-1) respectively. In addition, mouse macrophage RAW 264.7 pretreated with the saponin-rich fraction (80-200 µg mL(-1) ) exhibited a significant loss of cell viability in a dose-dependent manner. CONCLUSION: These results may be useful for the future application of saponins from C. oleifera cake. However, the potential use of the saponin-rich fraction as an antimicrobial agent should be decided according to the target micro-organisms in order to avoid causing harm in humans.

[Determination of inorganic elements in oleum camelliae by ICP-AES].

In the present study, the contents of eighteen inorganic elements such as Ca, K, Mg, Cu, Cr, Zn and Sr in oleum camelliae during different stages of refining process were determined using ICP-AES technique. The recoveries obtained by the standard addition method ranged between 82.7% and 112.5%, and RSDs were lower than 6.66%. The detection limits of the method for the eighteen elements were in the range of 0.4-10 microg x L(-1). The experimental results proved that oleum camelliae is rich in inorganic elements. The results also showed that depending on the intensity of refining, the contents of elements will decrease accordingly. After the degumming process, the contents of elements P, Ca and Mg in oleum camelliae declined remarkably. Besides, the contents of some trace elements such as Fe, Cu, Mn and Ni that cause oxidation to occur decreased significantly after refining. In addition, Pb was not detected after the degumming and deacidification process while Co and Cd were not detected both in the crude oil and the refined oil. In conclusion, through refining many excessive metal elements in oleum camelliae were removed effectively and the levels of these elements were able to meet the national standards set by the government. Meanwhile, the experimental results indicated that the ICP-AES technique, which can be used to determine the inorganic elements in oleum camelliae, is easy to operate, rapid, accurate, and highly sensitive, and can also determine many elements simultaneously.