Extraction, characterization of aloe polysaccharides and the in-depth analysis of its prebiotic effects on mice gut microbiota

Modulation of gut microbiota and metabolites by Flammulina velutipes polysaccharides during in vitro human fecal fermentation: Unveiling Bacteroides as a potential primary degrader

Flammulina velutipes, a widely cultivated species of edible fungus, exhibits diverse functional activities attributed to its polysaccharides. In this study, we employed an in vitro model to investigate the impact of F. velutipes polysaccharides (FVP) fermentation on gut microbiota, with a particular focus on Bacteroides. FVP fermentation resulted in the proliferation of microbiota associated with short-chain fatty acid (SCFA) metabolism and suppression of Escherichia-Shigella. Bacteroides emerged as potential primary degraders of FVP, with species-level analysis identifying the preference of B. thetaiotaomicron and B. intestinalis in FVP degradation. Metabolomics analysis revealed significant increases in hypoxanthine and 7-methyladenine contents, with histidine metabolism emerging as the most enriched pathway. B. nordii and B. xylanisolvens exhibited the most influence on amino acid and SCFA metabolism. Understanding the mechanisms by which gut microbiota metabolize FVP can provide valuable insights into the potential of FVP to promote intestinal health and disease prevention.

The regulatory effect of polysaccharides on the gut microbiota and their effect on human health: A review

Polysaccharides with low toxicity and high biological activities are a kind of biological macromolecule. Recently, growing studies have confirmed that polysaccharides could improve obesity, diabetes, tumors, inflammatory bowel disease, hyperlipidemia, diarrhea, and liver-related diseases by changing the intestinal micro-environment. Moreover, polysaccharides could promote human health by regulating gut microbiota, enhancing production of short-chain fatty acids (SCFAs), improving intestinal mucosal barrier, regulating lipid metabolism, and activating specific signaling pathways. Notably, the biological activities of polysaccharides are closely related to their molecular weight, monosaccharide composition, glycosidic bond types, and regulation of gut microbiota. The intestinal microbiota can secrete glycoside hydrolases, lyases, and esterases to break down polysaccharides chains and generate monosaccharides, thereby promoting their absorption and utilization. The degradation of polysaccharides can produce SCFAs, further regulating the proportion of gut microbiota and achieving the effect of preventing and treating various diseases. This review aims to summarize the latest studies: 1) effect of polysaccharides structures on intestinal flora; 2) regulatory effect of polysaccharides on gut microbiota; 3) effects of polysaccharides on gut microbe-mediated diseases; 4) regulation of gut microbiota on polysaccharides metabolism. The findings are expected to provide important information for the development of polysaccharides and the treatment of diseases.

The inhibitory effects of endophytic metabolites on glycated proteins under non-communicable disease conditions: A review

Protein glycation in human body is closely linked to the onset/progression of diabetes associated complications. These glycated proteins are commonly known as advanced glycation end products (AGEs). Recent literature has also highlighted the involvement of AGEs in other non-communicable diseases (NCDs) such as cardiovascular, cancer, and Alzheimer's diseases and explored the impact of plant metabolites on AGEs formation. However, the significance of endophytic metabolites against AGEs has recently garnered attention but has not been thoroughly summarized thus far. Therefore, the objective of this review is to provide a comprehensive overview of the importance of endophytic metabolites in combating AGEs under NCDs conditions. Additionally, this review aims to elucidate the processes of AGEs formation, absorption, metabolism, and their harmful effects. Collectively, endophytic metabolites play a crucial role in modulating signaling pathways and enhancing the digestibility properties of gut microbiota (GM) by targeting on AGEs/RAGE (receptor for AGEs) axis. Furthermore, these metabolites exhibit anti-AGEs activities similar to those derived from host plants, but at a lower cost and higher production rate. The use of endophytes as a source of such metabolites offers a risk-free and sustainable approach that holds substantial potential for the treatment and management of NCDs.

Evaluation of Physicochemical Properties and Prebiotics Function of a Bioactive Pleurotus eryngii Aqueous Extract Powder Obtained by Spray Drying

A bioactive Pleurotus eryngii aqueous extract powder (SPAE) was obtained by spray drying and its performance in terms of physicochemical properties, in vitro digestion, inflammatory factors, and modulation of the intestinal microbiota was explored. The results indicated that the SPAE exhibited a more uniform particle size distribution than P. eryngii polysaccharide (PEP). Meanwhile, a typical absorption peak observed at 843 cm-1 in the SPAE FTIR spectra indicated the existence of α-glycosidic bonds. SPAE exhibited higher antioxidant abilities and superior resistance to digestion in vitro. In addition, SPAE supplementation to mice significantly reduced the release of factors that promote inflammation, enhanced the secretion of anti-inflammatory factors, and sustained maximum production of short-chain fatty acids (SCFAs). Additionally, it significantly enhanced the relative abundance of SCFAs-producing Akkermansia and reduced the abundance of Ruminococcus and Clostridiides in intestines of mice. These results show the potential of SPAE as a novel material with prebiotic effects for the food and pharmaceutical industries.

Preparation, antibacterial activity, and structure-activity relationship of low molecular weight κ-carrageenan

κ-Carrageenan (KC) is a polysaccharide widely used in food industry. It has been widely studied for its excellent physicochemical and beneficial properties. However, the high molecular weight and high viscosity of KC make it difficult to be absorbed and to exert its' biological activities, thus limit its extensive industrial application. In order to solve this problem, five low molecular weight κ-carrageenans (DCPs) were prepared by the degradation of KC using hydrogen peroxide (H2O2) and ascorbic acid (AH2). The chemical compositions and structure characteristics of the DCPs were then determined. The results showed that H2O2 and AH2 could effectively degrade KC to DCPs, and DCPs remained the basic skeletal structure of KC. DCPs showed good antibacterial activities against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis. The Minimum Inhibitory Concentration (MIC) of DCPs with the highest antibacterial effects were 5.25, 4.5, 5.25, and 4.5 mg/mL, respectively. This is due to the underlying mechanism of DCPs that bind to the bacterial membrane proteins and change the membrane permeability, thus exerting antibacterial activity. In addition, Spearman's rank correlation and Ridge regression analysis revealed that the molecular weight and the contents of 3,6-anhydro-D-galactose, aldehyde group, carboxyl, and sulfate were the main structural characteristics affecting the antibacterial activity. Our findings reveal that the H2O2-AH2 degradation treatment could significantly improve the antibacterial activity of KC and provide insights into the quantitative structure-activity relationships of the antibacterial activity of DCPs.

Nano polysaccharides derived from aloe vera and guar gum as a potential fat replacer for a promising approach to healthier cake production

In recent years, there increment demand for healthier food options that can replace high-fat ingredients in bakery products without compromising their taste and texture. This research was focused on a formulation study of the blend of nano polysaccharides derived from aloe vera and guar gum at various concentrations. This study selected the blend concentration of 1 % aloe vera mucilage (AM) and 1 % guar gum (GG) due to its optimal gelling properties. Different magnetic stirring time durations were employed to formulate AGB (aloe vera guar gum blend). The particle size of AGB revealed the lowest nanoparticle size (761.03 ± 62 nm) with a stirring time of 4 h. The FTIR analysis found the presence of monomer sugars in AGB nano polysaccharide powder such as mannose, arabinose, and glucose. The thermogram results displayed an endothermic peak for all samples with a glass transition temperature (Tg) between 16 and 50 °C. The SEM image of the AGB indicated uniform spherical particles. The AGB powder exhibited good functional properties. The antimicrobial activity of AGB powder against Staphylococcus aureus, Escherichia coli, and Candida albicans was 22.32 ± 0.02, 21.56 ± 0.02, and 19.33 ± 0.33 mm, respectively. Furthermore, the effects of different levels of vegetable fat replacement with AGB powder on cake sensory properties, thermal stability, and texture characteristics were also examined. Notably, the cake containing a 50 % substitution of vegetable fat with AGB (C50) supplied desirable physicochemical, textural, and sensory properties. These results can provide advantages for the development of fat replacers in bakery products.

Yucca schidigera purpurea-sourced arabinogalactan polysaccharides augments antioxidant capacity facilitating intestinal antioxidant functions

This study isolated and purified a novel homogeneous arabinogalactan polysaccharide from Yucca schidigera extract (YSE), unveiled its unique structure and explored its antioxidant function. Firstly, the antioxidant potential of YSE was demonstrated in piglet trials. A homogeneous polysaccharide with a molecular weight of 24.2 kDa, designated as Yucca schidigera polysaccharide B (YPB), was isolated and purified from YSE. The monosaccharide composition of YPB was Rha, Araf, Galp, and Glcp, whose molar percentages were 2.8 %, 11.6 %, 45.5 %, and 40.0 %, respectively. Methylation analysis combined with 1D and 2D nuclear magnetic resonance showed that YPB was a complex polysaccharide with a main glycosidic linkage pattern of →2)-α-ʟ-Rha-(1 → 3)-β-ᴅ-Galp-(1→3)-β-ᴅ-Galp-(1 → 3)-β-ᴅ-Galp-(1 → 3)-β-ᴅ-Glcp-(1→, and branched Araf and Galp fragments were connected with the main chain through →3,6)-β-ᴅ-Galp-(1→, →3,4)-β-ᴅ-Glcp-(1→, and →2,4)-α-ʟ-Rha-(1→ linkages. Following the in vitro biochemical assays of bioactive components, YPB should be the contributor to the antioxidant activity in YSE. Based on the establishment of oxidative stress model, YPB exhibited strong antioxidant capacity and activated NRF2 pathway, and then provided protection against the damage induced oxidative stress in IPEC-J2 cells and rats. Further analysis with inhibitors found that this antioxidant effect was attributed to its interaction with epidermal growth factor receptor and mannose receptor, and stimulating PI3K/AKT pathway.

Purslane (Portulacae oleracea L.) polysaccharide relieves cadmium-induced colonic impairments by restricting Cd accumulation and inhibiting inflammatory responses

This study aimed to assess the protective effects of purslane polysaccharide (PP) on colonic impairments in mice exposed to cadmium (Cd). C57BL/6 mice were administered with PP (200-800 mg/kg/day) by gavage for 4 weeks after treatment with 100 mg·L-1 CdCl2. PP significantly reduced Cd accumulation in the colon tissue and promoted the excretion of Cd in the feces. PP could reduce the expression levels of inflammatory factors (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6) and inhibit the activation of the TLR4/MyD88/NF-κB signaling pathway. In addition, the results of 16S rRNA analysis revealed that PP significantly increased the abundance of probiotics (Lactobacillus), while decreased the abundance of pathogenic bacteria (Lachnospiraceae_NK4A136_group). Following the augmentation of beneficial intestinal bacteria, the treatment with PP led to an increase in the levels of intestinal microbial metabolites, specifically short-chain fatty acids (SCFAs). The SCFAs are known for their anti-inflammatory properties, immune-regulatory effects, and promotion of intestinal barrier function. Additionally, the results suggested that PP effectively impeded the enterohepatic circulation by inhibiting the FXR-FGF15 axis in the intestines of Cd-exposed mice. In summary, PP mitigated the toxic effects of Cd by limiting its accumulation and suppressing inflammatory responses in colon.

Zanthoxylum bungeanum amides ameliorates nonalcoholic fatty liver via regulating gut microbiota and activating AMPK/Nrf2 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum bungeanum Maxim. (Rutaceae) is a known herbal medicine with various bioactivities, including anti-obesity, lipid-lowering, learning & memory improving and anti-diabetes, and amides in Z. bungeanum (AZB) are considered as the major active agents for its bioactivities.

AIM OF THE STUDY

This research was carried out to uncover the anti-NAFL effect of AZB and its corresponding molecular mechanisms.

METHODS

The central composite design-response surface methodology (CCD-RSM) was utilized to optimize the AZB extraction process, and the anti-NAFL effect of AZB was investigated on high fat diet (HFD) fed mice (HFD mice). The levels of ROS in liver tissues were determined using laser confocal microscopy with DCFH-DA probe staining, and anti-enzymes (such as HO-1, SOD, CAT & GSH-PX) and MDA in liver tissues were measured using commercial detecting kits. GC-MS was used to determine the short-chain fatty acids (SCFAs) contents in feces and blood of mice. 16S high-throughput sequencing, western blotting (WB) assay and immunofluorescence (IF) were used to explore the intestinal flora changes in mice and the potential mechanisms of AZB for treatment of NAFL.

RESULTS

Our results showed AZB reduced body weight, alleviated liver pathological changes, reduced fat accumulation, and improved oxidative stress in HFD mice. In addition, we also found AZB improved OGTT and ITT, reduced TG, TC, LDL-C, whereas increased HDL-C in HFD mice. AZB increased total number of the species and interspecies kinship of gut microbiota and reduced the richness and diversity of gut microbiota in HFD mice. Moreover, AZB decreased the ratio of Firmicutes/Bacteroidota, whereas increased the abundance of Allobaculum, Bacteroides and Dubosiella in feces of HFD-fed mice. Furthermore, AZB increased the production of SCFAs, and up-regulated the phosphorylation of AMPK and increased the nuclear transcription of Nrf2 in liver of HFD mice.

CONCLUSION

Collectively, our results suggested AZB can improve NAFL, which could reduce body weight, reverse liver lesions and fat accumulation, improve oxidative stress in liver tissues of HFD mice. Furthermore, the mechanisms are related to increase of the abundance of high-producing bacteria for SCFAs (e.g. Allobaculum, Bacteroides and Dubosiella) to activate AMPK/Nrf2 signaling.

Platinum nanoflowers stabilized with aloe polysaccharides for detection of organophosphorus pesticides in food

Organophosphorus pesticides can inhibit the activity of acetylcholinesterase and cause neurological diseases. Therefore, it is crucial to establish an efficient and sensitive platform for organophosphorus pesticide detection. In this work, we extracted aloe polysaccharide (AP) from aloe vera with the number average molecular weight of 27760 Da and investigated its reducing property. We prepared aloe polysaccharide stabilized platinum nanoflowers (AP-Ptn NFs), their particle size ranges were 29.4-67.3 nm. Furthermore, AP-Ptn NFs exhibited excellent oxidase-like activity and the catalytic kinetics followed the typical Michaelis-Menten equation. They showed strong affinity for 3,3',5,5'-tetramethylbenzidine substrates. More importantly, we developed a simple and effective strategy for the sensitive colorimetric detection of organophosphorus pesticides in food using biocompatible AP-Ptn NFs. The detection range was 0.5 μg/L - 140 mg/L, which was wider than many previously reported nanozyme detection systems. This colorimetric biosensor had good selectivity and good promise for bioassay analysis.

Xylooligosaccharides from corn cobs alleviate loperamide-induced constipation in mice via modulation of gut microbiota and SCFA metabolism

This study aimed to optimize the structure and efficacy of xylooligosaccharides (XOSs) from corn cobs in constipated mice. Structural analysis revealed that XOSs from corn cobs were composed of β-Xyl-(1 →4)-[β-Xyl-(1→4)]n-α/β-Xyl (n = 0-5) without any other substituents. XOS administration significantly reduced the defecation time, increased the gastrointestinal transit rate, restored the gastrointestinal neurotransmitter imbalance, protected against oxidative stress, and reversed constipation-induced colonic inflammation. Fecal metabolite and microbiota analysis showed that XOS supplementation significantly increased short chain fatty acid (SCFA) levels and improved the gut microbial environment. These findings highlighted the potential of XOSs from corn cobs as an active ingredient for functional foods or as a therapeutic agent in constipation therapy.

Recent progress in plant-derived polysaccharides with prebiotic potential for intestinal health by targeting gut microbiota: a review

Natural products of plant origin are of high interest and widely used, especially in the food industry, due to their low toxicity and wide range of bioactive properties. Compared to other plant components, the safety of polysaccharides has been generally recognized. As dietary fibers, plant-derived polysaccharides are mostly degraded in the intestine by polysaccharide-degrading enzymes secreted by gut microbiota, and have potential prebiotic activity in both non-disease and disease states, which should not be overlooked, especially in terms of their involvement in the treatment of intestinal diseases and the promotion of intestinal health. This review elucidates the regulatory effects of plant-derived polysaccharides on gut microbiota and summarizes the mechanisms involved in targeting gut microbiota for the treatment of intestinal diseases. Further, the structure-activity relationships between different structural types of plant-derived polysaccharides and the occurrence of their prebiotic activity are further explored. Finally, the practical applications of plant-derived polysaccharides in food production and food packaging are summarized and discussed, providing important references for expanding the application of plant-derived polysaccharides in the food industry or developing functional dietary supplements.

Water-Insoluble Polysaccharide Extracted from Poria cocos Alleviates Antibiotic-Associated Diarrhea Based on Regulating the Gut Microbiota in Mice

Antibiotics are very effective in treating a variety of bacterial infections, while clinical overuse of antibiotics can lead to diseases such as antibiotic-associated diarrhea. Numerous studies have shown that natural polysaccharides can be used as prebiotics to alleviate antibiotic-associated diarrhea (AAD). Poria cocos is a medicinal and edible mushroom widely used for thousands of years in China, and our former study demonstrated that water-insoluble polysaccharide (PCY) has the potential prebiotic function. Therefore, we simulated the digestion and fermentation of PCY using feces from volunteers, and then administered it to C57BL/6 mice with AAD to study its effects on the gut microbiota and metabolites. The results indicated that PCY effectively alleviated the symptoms of AAD in mice, restored the intestinal barrier function, improved the content of short-chain fatty acids (SCFAs), decreased the level of inflammatory cytokines, and changed the structure of gut microbiota by increasing the relative abundance of norank_f__Muribaculaceae and unclassified_f__Lachnospiraceae, and decreasing that of Escherichia-Shigella, Staphylococcus and Acinetobacter. This study further demonstrated that PCY is an effective functional prebiotic for improving AAD disease, and provided a new avenue and insight for developing PCY as a functional food or prebiotic for alleviating gastrointestinal diseases.

A New Biomaterial Derived from Aloe vera-Acemannan from Basic Studies to Clinical Application

Aloe vera is a kind of herb rich in polysaccharides. Acemannan (AC) is considered to be a natural polysaccharide with good biodegradability and biocompatibility extracted from Aloe vera and has a wide range of applications in the biomedical field due to excellent immunomodulatory, antiviral, antitumor, and tissue regeneration effects. In recent years, clinical case reports on the application of AC as a novel biomedical material in tissue regenerative medicine have emerged; it is mainly used in bone tissue engineering, pulp-dentin complex regeneration engineering, and soft tissue repair, among other operations. In addition, multiple studies have proved that the new composite products formed by the combination of AC and other compounds have excellent biological and physical properties and have broader research prospects. This paper introduces the preparation process, surface structure, and application forms of AC; summarizes the influence of acetyl functional group content in AC on its functions; and provides a detailed review of the functional properties, laboratory studies, clinical cutting-edge applications, and combined applications of AC. Finally, the current application status of AC from basic research to clinical treatment is analyzed and its prospects are discussed.

Metabolism of resistant starch RS3 administered in combination with Lactiplantibacillus plantarum strain 84-3 by human gut microbiota in simulated fermentation experiments in vitro and in a rat model

This study aimed to investigate the metabolic and population responses of gut microbiota to resistant starch (RS3) in the presence of exogenous Lactiplantibacillus plantarum strain 84-3 (Lp84-3) in vitro and in vivo. Lp84-3 promoted acetate, propionate, and butyrate production from RS3 by gut microbiota and increased Lactobacillus and Blautia contents in vitro. Furthermore, in the presence of Lp84-3, starch granules presented a "dot-by-hole" fermentation pattern. Administration of Lp84-3 with RS3 increased the level of SCFA-producing Faecalibaculum, Parabacteroides, Alistipes, and Anaeroplasma in the faeces of rates, with Lactobacillus and Akkermansia representing the key genera that significantly promoted SCFAs, especially propionate and butyrate. Lp84-3 with RS3 promoted genes related to tryptophan synthase (EC 4.2.1.20) and beta-glucosidase (EC 3.2.1.21) in faecal bacteria. Our findings highlight the ability of Lp84-3 to enhance RS3 degradation, possibly by promoting SCFA-producing bacteria, and indicate that Lp84-3 could be a potential probiotic with a beneficial effect on gut microbiota.

Ultrasonic assisted extraction, characterization and gut microbiota-dependent anti-obesity effect of polysaccharide from Pericarpium Citri Reticulatae 'Chachiensis'

Pericarpium Citri Reticulatae 'Chachiensis' (PCRC), the premium aged pericarps of Pericarpium Citri Reticulatae, is widely used in traditional Chinese medicines with a diversity of promising bioactivity. Herein we report the extraction, characterization and underlying mechanism of anti-metabolic syndrome of an arabinan-rich polysaccharide from PCRC (PCRCP). This polysaccharide was obtained in a 7.0% yield by using ultrasound-assisted extraction under the optimized conditions of 30 mL/g liquid-to-solid ratio, 250 W ultrasound power for 20 min at 90 °C with pH 4.5. The PCRCP with an average molecular weight of 122.0 kDa, is mainly composed of D-galacturonic acid, arabinose and galactose, which may link via 1,4-linked Gal(p)-UA, 1,4-linked Ara(f) and 1,4-linked Gal(p). Supplementation with PCRCP not only effectively alleviated the weight gain, adiposity and hyperglycemia, but also regulated the key metabolic pathways involved in the de novo synthesis and β-oxidation of fatty acid in high-fat diet (HFD)-fed mice. Furthermore, PCRCP treatment caused a significant normalization in the intestinal barrier and composition of gut microbiota in mice fed by HFD. Notably, PCRCP selectively enriched Lactobacillus johnsonii at the family-genus-species levels, a known commensal bacterium, the level of which was decreased in mice fed by HFD. The depletion of microbiome induced by antibiotics, significantly compromised the effects of anti-metabolic syndrome of PCRCP in mice fed by HFD, demonstrating that the protective phenotype of PCRCP against anti-obesity is dependent on gut microbiota. PCRCP is exploitable as a potential prebiotic for the intervention of obesity and its complications.

Structure, anti-fatigue activity and regulation on gut microflora in vivo of ethanol-fractional polysaccharides from Dendrobium officinale

This study was to investigate the antifatigue, prebiotic effects and their relationships to the structure properties of three ethanol precipitated polysaccharides from Dendrobium officinale (EPDO), as EPDO-40, EPDO-60 and EPDO-80. EPDOs with anti-fatigue activity were screened out by forced swimming test, and blood lactic acid (BLA), blood urea nitrogen (BUN), superoxide dismutase (SOD), liver glycogen, muscle glycogen, and intestinal microflora were investigated. Results showed that purified EPDO-60, 277.3 kDa, with a backbone consisted of 4-Manp and 4-Glcp. EPDO-60 had the best anti-fatigue activity, because it could significantly prolong the forced swimming time, as well as down-regulating the levels of BLA and BUN, increasing SOD. Proportions of Bacteroidetes and Firmicutes and abundance of Lactobacillus and Bifidobacterium in gut microflora increased after treated with EPDO-60. Accordingly, EPDO-60 could affect the community structure of gut microflora, leading to promote the balance of oxidation and antioxidation, and accelerated the fatigue metabolism in vivo.

Effect of Short-Chain Fatty Acids and Polyunsaturated Fatty Acids on Metabolites in H460 Lung Cancer Cells

Lung cancer is the most common primary malignant lung tumor. However, the etiology of lung cancer is still unclear. Fatty acids include short-chain fatty acids (SCFAs) and polyunsaturated fatty acids (PUFAs) as essential components of lipids. SCFAs can enter the nucleus of cancer cells, inhibit histone deacetylase activity, and upregulate histone acetylation and crotonylation. Meanwhile, PUFAs can inhibit lung cancer cells. Moreover, they also play an essential role in inhibiting migration and invasion. However, the mechanisms and different effects of SCFAs and PUFAs on lung cancer remain unclear. Sodium acetate, butyrate, linoleic acid, and linolenic acid were selected to treat H460 lung cancer cells. Through untargeted metabonomics, it was observed that the differential metabolites were concentrated in energy metabolites, phospholipids, and bile acids. Then, targeted metabonomics was conducted for these three target types. Three LC-MS/MS methods were established for 71 compounds, including energy metabolites, phospholipids, and bile acids. The subsequent methodology validation results were used to verify the validity of the method. The targeted metabonomics results show that, in H460 lung cancer cells incubated with linolenic acid and linoleic acid, while the content of PCs increased significantly, the content of Lyso PCs decreased significantly. This demonstrates that there are significant changes in LCAT content before and after administration. Through subsequent WB and RT-PCR experiments, the result was verified. We demonstrated a substantial metabolic disparity between the dosing and control groups, further verifying the reliability of the method.

Preventive and therapeutic effects of an exopolysaccharide produced by Lacticaseibacillus rhamnosus on alcoholic gastric ulcers

Crude exopolysaccharides produced by Lacticaseibacillus rhamnosus SHA113 were previously found to exhibit anti-alcoholic gastric ulcer activity in mice, but their major active fraction, structural characteristics, and underlying mechanisms remain unknown. Here, LRSE1 was identified as the active exopolysaccharide fraction produced by L. rhamnosus SHA113 responsible for the above effects. Purified LRSE1 had a molecular weight of 4.9 × 10⁴ Da and was comprised of L-fucose, D-mannose, D-glucuronic acid, d-glucose, D-galactose, and L-arabinose in the molar ratio of 2.4:6.5:1.2:1.00:0.3:0.6, respectively. The oral administration of LRSE1 resulted in a significant protective and therapeutic effect on alcoholic gastric ulcers in mice. These effects were identified to involve a reduction in reactive oxygen species, apoptosis, and the inflammatory response, increases in antioxidant enzyme activities, and increases in the phylum Firmicutes and decreases in the genera Enterococcus, Enterobacter, and Bacteroides in the gastric mucosa of mice. In vitro experiments showed that the administration of LRSE1 both inhibited apoptosis in GEC-1 cells via the TRPV1-P65-Bcl-2 pathway and inhibited the inflammatory response in RAW264.7 cells via the TRPV1-PI3K pathway. For the first time, we have identified the active exopolysaccharide fraction produced by Lacticaseibacillus that protects against alcoholic gastric ulcers and determined that its effect involves TRPV1-mediated pathways.

Ginseng polysaccharides: Potential antitumor agents

As a famous herbal medicine in China and Asia, ginseng (Panax ginseng C. A. Meyer) is also known as the "King of All Herbs" and has long been used in medicine and healthcare. In addition to the obvious biological activities of ginsenosides, ginseng polysaccharides (GPs) exhibit excellent antitumor, antioxidant stress, and immunomodulatory effects. In particular, GPs can exert an antitumor effect and is a potential immunomodulator. However, due to the complexity and diversity in the structures and components of GPs, their specific physicochemical properties, and underlying mechanisms remain unclear. In this article, we have summarized the factors influencing the antitumor activity of GPs and their mechanism of action, including the stimulation of the immune system, regulation of the gut microbiota, and direct action on tumor cells.

The water extract of Aloe vera prevents fluoxetine-induced multiple-drug resistance of E. coli by inhibiting reactive oxygen species formation and membrane permeability

BACKGROUND

The medication of synthetic chemical is one of the main treatments for depressive disorders. Different lines of evidence reveal that a long-term exposure to anti-depressants, e.g., fluoxetine, is causing multiple-drug resistance (MDR) of gut microbiomes. The MDR bacterial strains in gut pose a threat to intestinal balance and treatment of future microbial infection. Effective strategies are thus in urgent need to prevent the anti-depressant-mediated MDR of gut microbes.

PURPOSE

We aimed to investigate the potential role of Aloe vera (L.) Burm. f. (aloe; Liliaceae family) to prevent MDR of E. coli being co-cultured with fluoxetine.

METHODS

The extract of A. vera was co-cultured with E. coli and fluoxetine to analyze the preventive effect of MDR. To figure out the mechanistic action, the formation of reactive oxygen species (ROS) and the expression of key biomarkers, including outer membrane proteins (OmpF and OmpC), superoxidative stress activator (SoxS) and efflux pumps (AcrA/B-TolC), were determined in E. coli being treated with fluoxetine and aloe extract. In addition, the genetic mutation of transcriptional factors of these biomarkers was determined in the fluoxetine-treated E. coli.

RESULTS

The water extract of A. vera showed considerable potential to reduce the number of fluoxetine-mediated MDR colonies. The extract robustly suppressed the formation of ROS in E. coli. However, thiourea and N-acetylcysteine, two well-known antioxidants, showed no activity in preventing the formation of bacterial MDR. Additionally, A. vera extract directly affected the fluoxetine-triggered early stress response of E. coli and the expression of downstream genes. Meanwhile, A. vera extract was able to inhibit the genetic mutation of SoxR gene in E. coli, as induced by co-cultured with fluoxetine. By fractionation of the aloe extract, the ethanol precipitate, composing mainly polysaccharides, showed robust activity in preventing the fluoxetine-mediated MDR.

CONCLUSION

This study therefore suggested that the extract of A. vera could be an adjuvant agent to combat bacterial MDR during anti-depressant treatment.

MetaLP: An integrative linear programming method for protein inference in metaproteomics

Metaproteomics based on high-throughput tandem mass spectrometry (MS/MS) plays a crucial role in characterizing microbiome functions. The acquired MS/MS data is searched against a protein sequence database to identify peptides, which are then used to infer a list of proteins present in a metaproteome sample. While the problem of protein inference has been well-studied for proteomics of single organisms, it remains a major challenge for metaproteomics of complex microbial communities because of the large number of degenerate peptides shared among homologous proteins in different organisms. This challenge calls for improved discrimination of true protein identifications from false protein identifications given a set of unique and degenerate peptides identified in metaproteomics. MetaLP was developed here for protein inference in metaproteomics using an integrative linear programming method. Taxonomic abundance information extracted from metagenomics shotgun sequencing or 16s rRNA gene amplicon sequencing, was incorporated as prior information in MetaLP. Benchmarking with mock, human gut, soil, and marine microbial communities demonstrated significantly higher numbers of protein identifications by MetaLP than ProteinLP, PeptideProphet, DeepPep, PIPQ, and Sipros Ensemble. In conclusion, MetaLP could substantially improve protein inference for complex metaproteomes by incorporating taxonomic abundance information in a linear programming model.

Three main metabolites from Wolfiporia cocos (F. A. Wolf) Ryvarden & Gilb regulate the gut microbiota in mice: A comparative study using microbiome-metabolomics

Wolfiporia cocos (F. A. Wolf) Ryvarden & Gilb, also known as Poria cocos is an ancient edible and medicinal mushroom that has been valued for thousands of years for its tranquilizing, diuretic, and spleen-enhancing properties. Because of the mushroom’s complex composition, its pharmacological effects have not been fully clarified. Therefore, to expand our knowledge of these effects from a pharmacological perspective and exploit potential medicinal value of fungal mushroom, we extracted three main metabolites from P. cocos, including water-soluble polysaccharides (PCX), water-insoluble polysaccharides (PCY), and triterpenoid saponins (PCZ) for intragastric injection into mice. These injections were made to explore the component’s effects on the mice’s gut microbiota and their metabolomics. The microbiota analysis showed that PCY had the strongest effect on regulating gut microbiota through altering its composition and increasing the number of Lactobacillus (p < 0.01). A total of 1,828 metabolites were detected using metabolomics methods, and the results showed that the three main active metabolites of P. cocos significantly changed the content of short-chain peptides in intestinal metabolites. In conclusion, our study further investigated the pharmacological functions of P. cocos, and revealed the differing effects of its three main metabolites on gut microbiota. The results suggested that PCY is a prominent prebiotic, and provided us with new insights into the potential development of fungal polysaccharides in Chinese traditional medicine.

Extraction, purification, structural characterization, and gut microbiota relationship of polysaccharides: A review

Intestinal dysbiosis is one of the major causes of the occurrence of metabolic syndromes, such as obesity, diabetes, nonalcoholic fatty liver disease, and cardiovascular diseases. Polysaccharide-based microbial therapeutic strategies have excellent potential in the treatment of metabolic syndromes, but the underlying regulatory mechanisms remain elusive. Identification of the internal regulatory mechanism of the gut microbiome and the interaction mechanisms involving bacteria and the host are essential to achieve precise control of the gut microbiome and obtain valuable clinical data. Polysaccharides cannot be directly digested; the behavior in the intestinal tract is considered a "bridge" between microbiota and host communication. To provide a relatively comprehensive reference for researchers in the field, we will discuss the polysaccharide extraction and purification processes and chemical and structural characteristics, focusing on the polysaccharides in gut microbiota through the immune system, gut-liver axis, gut-brain axis, energy axis interactions, and potential applications.

Purple red rice anthocyanins alleviate intestinal damage in cyclophosphamide-induced mice associated with modulation of intestinal barrier function and gut microbiota

The regulatory effects of purple red rice bran anthocyanins (PRBA) on intestinal barrier function and gut microbiota in mice were investigated. Results showed that PRBA had an ameliorative effect on intestinal barrier damage, including restoration of villus length, improvement in the number of cupped cells and promotion of sIgA secretion. PRBA stimulated the production of cytokines, reduced the levels of endotoxin (ET) and lipopolysaccharide binding protein (LBP) in serum, as well as upregulated the expression of tight junction proteins (TJs) and NF-κB pathway proteins. Furthermore, PRBA not only promoted the production of short-chain fatty acids (SCFAs), but also regulated the intestinal microbiota by increasing beneficial bacteria (Lachnospiraceae, Bacteroidaceae, Ruminococcaceae) and reducing pathogenic bacteria (Shigella) to maintained intestinal homeostasis. Above results indicated that PRBA could ameliorate cyclophosphamide-induced impairment of intestinal barrier function and dysregulation of the gut microbiota, which provides a new idea for broadening the exploitation of PRBA.

Comfrey polysaccharides modulate the gut microbiota and its metabolites SCFAs and affect the production performance of laying hens

Effects of dietary supplementation of comfrey polysaccharides (CPs) on production performance, egg quality, and microbial composition of cecum in laying hens were evaluated. A total of 240 laying hens were allocated into 4 groups with 6 replicates per group. The laying hens were fed diets containing CPs at levels of 0, 0.5, 1.0, and 1.5 %, respectively. The results showed that the egg production rate increased by 5.97 %, the egg mass improved by 6.71 %, and the feed conversion rate reduced by 5.43 % in the 1.0 % supplementation group of CPs compared with those in the control group. The digestibility of ash, crude fat, and phosphorus was notably improved by the addition of CPs at 1.0 % (P < 0.05). The relative abundances of Bacteroidetes at the phylum level, Bacteroidaceae, Rikenellaceae, and Prevotellaceae at the family level were increased by CPs (P < 0.05). The relative abundances of Bacteroides, Megamonas, Rikenellaceae_RC9_gut_group, [Ruminococcus]_torques_group, Methanobrevibacter, Desulfovibrio, Romboutsia, Alistipes, and Intestinimonas at the genus level were increased by CPs (P < 0.05). Dietary supplementation of CPs could enhance the production performance of laying hens, which might be related to the improvement of nutrient digestibility and microbial community modulations in the cecum. Therefore, CPs have potential application value as prebiotics in laying hens.

Characterization and prebiotic properties of pectin polysaccharide from Clausena lansium (Lour.) Skeels fruit

Pectins have proven to be advantageous for human health as they regulate beneficial microbial communities and enhance immunity. The fruit of Clausena lansium (Lour.) Skeels (Wampee), also referred to as "treasure in fruit", is rich in pectin polysaccharides. In this study, a homogalacturonan-type pectin (CCP2) with a molecular weight of 8.9 × 10⁴ Da and degree of esterification of 42.86% was isolated from Wampee fruit. The gut microbiota regulation and phagocytosis-enhancing properties of CCP2 were examined in vivo and in vitro, respectively. Oral administration of CCP2 dramatically decreased the abundance of Bacteroidetes and increased the abundance of Firmicutes in intestinal bacteria in mice. The content of short-chain fatty acids in the feces also significantly improved. Moreover, CCP2 exhibited excellent phagocytosis-enhancing activities on RAW 264.7 macrophages. These results suggested that CCP2 could be a potential gut microbiota regulator and phagocytosis-enhancer, which could be used in food products to promote health through beneficial manipulation of gut microbiota.

Aloe polysaccharide promotes osteogenesis potential of adipose-derived stromal cells via BMP-2/Smads and prevents ovariectomized-induced osteoporosis

BACKGROUND

Aloe polysaccharide (AP) is a type of an active macromolecule of Aloe vera, which contributes to its function. However, whether AP possesses anti-osteoporosis properties is unknown.

METHODS

Adipose-derived stromal cells were treated with different concentrations of AP. Early and late osteogenesis were, respectively, evaluated by ALP and Alizarin Red S staining. The effect of AP on the processes of adipogenesis inhibition in ADSCs was analyzed by oil red O staining. Western blot was used to assess the expression of osteogenic and adipogenic related factors. Then, Noggin was administered to further confirm the mechanism by which AP promotes the osteogenesis of ADSCs. Finally, 40 female SD rats were classified into a bilateral laparotomy group (Sham group) and three bilateral ovariectomy groups: OVX group, OVX + AP group, and OVX + AP + Noggin group. The bilateral rat femurs were collected to perform micro-CT scanning, HE, Masson trichrome, and Oil red O staining.

RESULTS

The results indicated that AP could increase ALP expression and calcium deposition. Through molecular mechanisms, AP promotes the protein expression of COL1A1, OPN, and ALP in ADSCs, but downregulates the expression of PPARγ. Also, AP directs ADSCs' fate by stimulating the BMP2/Smads signaling pathway. In vivo, the rat AP-treated had more trabecular bone than the OVX rat, indicating partial protection from cancellous bone loss after treatment with AP.

CONCLUSION

Our results show that AP may promote osteogenesis of ADSCs through BMP-2/Smads signaling pathway and inhibits lipogenic differentiation. Thus, AP might be a promising alternative medicine to treat postmenopausal osteoporosis.

Structure Characterization of Polysaccharide from Chinese Yam (Dioscorea opposite Thunb.) and Its Growth-Promoting Effects on Streptococcus thermophilus

To clarify the mechanisms underlying the growth-promoting effects of yam polysaccharide on Streptococcus thermophilus (S. thermophilus), the yam polysaccharide was extracted using a deep eutectic solvents (DESs) method and separated into four fractions by DEAE-cellulose 52. These fractions were used as the alternative carbon source to substitute lactose to compare their growth-promoting effects on S. thermophilus. Furthermore, their molecular weight, monosaccharide and functional groups' composition, microscopic forms and other basic structure characterizations were analyzed. The results showed that all the fractions could significantly promote S. thermophilus growth, and fractions exhibited significantly different growth-promoting effects, whose viable count increased by 6.14, 6.03, 11.48 and 11.29%, respectively, relative to those in the M17 broth medium. Structure-activity relationship analysis revealed that the high growth-promoting activity of yam polysaccharide might be more dependent on the higher molecular weight, the higher galacturonic acid content and its complex spatial configuration, and the existence of β-glycosides would make the yam polysaccharide have a better growth-promoting effect on S. thermophilus.

Polysaccharides confer benefits in immune regulation and multiple sclerosis by interacting with gut microbiota

Pharmacological and clinical studies have consistently demonstrated that polysaccharides exhibit great potential on immune regulation. Polysaccharides can interact directly or indirectly with the immune system, triggering cell-cell communication and molecular recognition, leading to immunostimulatory responses. Gut microbiota is adept at foraging polysaccharides as energy sources and confers benefits in the context of immunity and chronic autoimmune disease, such as multiple sclerosis. A compelling set of interconnectedness between the gut microbiota, natural polysaccharides, and immune regulation has emerged. In this review, we highlighted the available avenues supporting the existence of these interactions, with a focus on cytokines-mediated and SCFAs-mediated pathways. Additionally, the neuroimmune mechanisms for gut microbiota communication with the brain in multiple sclerosis are also discussed, which will lay the ground for ameliorate multiple sclerosis via polysaccharide intervention.

The Renaissance of Plant Mucilage in Health Promotion and Industrial Applications: A Review

Plant mucilage is a renewable and cost-effective source of plant-based compounds that are biologically active, biodegradable, biocompatible, nontoxic, and environmentally friendly. Until recently, plant mucilage has been of interest mostly for technological purposes. This review examined both its traditional uses and potential modern applications in a new generation of health-promoting foods, as well as in cosmetics and biomaterials. We explored the nutritional, phytochemical, and pharmacological richness of plant mucilage, with a particular focus on its biological activity. We also highlighted areas where more research is needed in order to understand the full commercial potential of plant mucilage.

Oat β-glucan alleviates DSS-induced colitis via regulating gut microbiota metabolism in mice

Ulcerative colitis (UC) is one of the most prevalent inflammatory bowel diseases (IBD) worldwide, while oat β-glucan has been shown to suppress the progress of colitis in UC mice. However, the underlying mechanism of oat β-glucan in ameliorating colitis is unclear and the role of gut microbiota in the protective effect of oat β-glucan against colitis remains unknown. In the present study, we aim to investigate the effect of oat β-glucan on gut microbiota in colitis mice and explore the health effect related mechanism. Dextran sulfate sodium (DSS) was used to induce the colitis model in mice. The results showed that β-glucan treatment attenuated hematochezia, splenomegaly and colon shortening in colitis mice. Histological evaluation of H&E and TUNEL staining showed that β-glucan treatment suppressed DSS-induced colonic inflammatory infiltration and reduced cell apoptosis levels of colon tissues. mRNA expression levels of the pro-inflammatory factors were also significantly reduced in the β-glucan group. Moreover, β-glucan treatment increased the protein and mRNA expression levels of tight junction proteins. Analysis of gut microbiota community showed that β-glucan treatment modulated gut microbial composition and structure at the OTU level in colitis mice. Further analysis of gut microbial metabolism revealed that β-glucan treatment significantly increased acetate, propionate and butyrate concentrations, and affected microbial metabolome in colitis mice. Notably, the increased acetate and propionate concentrations could directly affect pro-inflammatory factor expression levels and tight junction protein levels. In contrast, the changes in metabolic profiles affected pro-inflammatory factor levels and thus affected tight junction protein levels. Overall, our study revealed that oat β-glucan ameliorated DSS-induced colitis in mice simultaneously through regulating gut-derived short-chain fatty acids (SCFAs) and microbial metabolic biomarkers. Our study demonstrated that oat β-glucan could be an effective nutritional intervention strategy towards targeting gut microbiota metabolism for ameliorating colitis.

In-depth analysis of the mechanisms of aloe polysaccharides on mitigating subacute colitis in mice via microbiota informatics

Aloe polysaccharides (APs) are indigestible bioactive polysaccharides, while can be fermented by colonic microbiota. Although plant polysaccharides can alleviate subacute ulcerative colitis (SUC), the mechanisms APs regulated SUC via colonic microbiota have not been fully explored. Hence, to elucidate the complex interactions between the novel APs, colonic microbiota, SCFAs, and inflammation, the SUC mouse model and in-depth analysis were performed, including multiple bioinformatics analysis and structural equation modeling (SEM). After APs intervention, SCFAs and SCFAs-producing genus, including Akkermansia and Blautia, were increased in colon, and the colonic inflammation and barrier dysfunction were alleviated significantly in SUC mice. Spearman analysis found positive correlations between microbiota and SCFAs. PICRUSt2 and KEGG analysis revealed 6-pyruvoyltetra hydropterin synthase in folate biosynthesis metabolism pathway was activated, while phosphotransferase system was inhibited. SEM results further proved APs was beneficial to gut micro-ecological balance in mice via SCFAs metabolism and anti-inflammatory functions. Together, APs could be exploited to alleviate SUC as dietary therapeutics.