Polysaccharide Degradation by the Intestinal Microbiota and Its Influence on Human Health and Disease

De-starched Panax ginseng polysaccharide: Preparation, in vitro digestion, fermentation properties and the activating effect of the resultant products on RAW264.7 cells

Panax ginseng C. A. Meyer (ginseng) neutral polysaccharides have been proven to be an immune enhancer, but their digestion and fermentation characteristics are unclear. This study aimed to prepare a de-starched polysaccharide (DGPN) from ginseng and investigate its degradation rules and the changes in immune activity by using an in vitro digestion and fermentation model. Results showed that in digestion process, the molecular weight of DGPN decreased from 4.72 × 104 to 4.04 × 104 Da, reducing sugar (CR) content increased from 0.0539 ± 0.0037 to 0.0919 ± 0.0015 mg/mL. During the fecal fermentation process, a significant decrease in total carbohydrate content and molecular weight, a significant increase in CR and change in the proportion of monosaccharide composition can be observed, indicating that DGPN was mainly degraded during fermentation process. DGPN modulated the microbial composition via increasing the relative abundance of beneficial bacteria including Bacteroides, [Eubacterium]_nodatum_group, Ligilactobacillus, Enterococcus and reducing harmful bacteria such as Escherichia_Shigela. DGPN also promoted the production of short chain fatty acids. Cell experiments results showed that fermentation product DGPN-F48 activated RAW264.7 cells via TLR4/Myd88/NF-κB signaling pathway and the activity was significantly enhanced after fermentation process. This study confirmed DGPN is beneficial for enhancing gut health and has prebiotic potential.

Differences in utilization and metabolism of Ulva lactuca polysaccharide by human gut Bacteroides species in the in vitro fermentation

Ulva lactuca polysaccharide (ULP), a sulfated polysaccharide, has been widely used in Asia. However, its digestion process and utilization by gut microbiota remain poorly understood. In this study, the in vitro simulated digestion and fermentation were used to analyze the digestibility of ULP. The results showed that ULP was not degraded during simulated digestion, but was utilized by human fecal microbiota. 16S rRNA sequencing revealed that ULP significantly increased the abundance of Bacteroides. Further evaluation of seven Bacteroides species showed that only B. thetaiotaomicron and B. vulgatus could utilize ULP. Interestingly, these two species exhibited different utilization patterns. B. vulgatus preferentially utilized rhamnose of ULP over glucuronic acid to promote growth. Metabolite profiles of B. thetaiotaomicron and B. vulgatus during in vitro fermentation with ULP as the sole carbon source were different. Although both B. thetaiotaomicron and B. vulgatus utilized ULP to produce various metabolites such as acetic acid, propionic acid, cysteic acid and riboflavin, B. thetaiotaomicron accumulated metabolites, such as linoleic acid, that were not accumulated by B. vulgatus. The effects of ULP on the metabolic pathways of B. thetaiotaomicron and B. vulgatus differed. These findings provide a new perspective on the utilization of ULP by human gut microbiota.

Polysaccharides from Yupingfeng granules ameliorated cyclophosphamide-induced immune injury by protecting intestinal barrier

Immune injury is the main side effect caused by cyclophosphamide and the disruption of the intestinal barrier may be an important cause. Yupingfeng granules have been reported to have immunomodulatory effects and polysaccharides are important components of them. This study aimed to investigate the ameliorative effect of polysaccharides from Yupingfeng granules (YPFP) on cyclophosphamide induced immune injury and reveal their potential mechanisms based on its protective effect on the intestine. YPFP were isolated and preliminarily characterized. Pharmacodynamic evaluation revealed that YPFP treatment could effectively mitigate lesions of immune organs, ameliorate white blood cells and downregulate IL-10 level. Further, the protective effect of intestinal barrier on the basis of intestinal tight junctions, MUC-2, microflora, endogenous metabolites, pathways and immune cells was discussed to outline mechanisms. The results showed that YPFP repaired the integrity of intestinal epithelium, enhanced the abundance of Muribaculaceae_unclassified, Bacteroide and Muribaculum, downgraded the abundance of Lachnospiraceae_NK4A136_group, improved the excretion of lipids and bile acids especially 3-oxo-LCA, increased the content of SCFAs in feces and inhibited the expression of key proteins of PI3K-AKT and MAPK-JUN pathways. More importantly, Th17 and Treg balance was remodeled after YPFP administration, which might be related to certain differential metabolites and pathways enriched by metabolomics. This study provides a rich understanding of YPFP and lays a foundation for further development of Yupingfeng granules. It was shown for the first time that the immunomodulatory effect of YPFP might be involved in multiple mechanisms of intestinal homeostasis. YPFP could be regarded as an immunomodulator to alleviate immune damage caused by cyclophosphamide.

Polysaccharide lyase PL3.3 possibly potentiating Clostridioides difficile clinical symptoms based on complete genome analysis of RT046/ST35 and RT012/ST54

Clostridioides difficile has rapidly become a major cause of nosocomial infectious diarrhea worldwide due to the misuse of antibiotics. Our previous study confirmed that RT046/ST35 strain is associated with more severe clinical symptoms compared to RT012/ST54 strain. We conducted genome comparison of the RT046/ST35 and RT012/ST54 strains using whole-genome sequencing technology. The RT046/ST35 strain had a genome length of 7,869,254 bp with a GC content of 29.49%. The original length of the RT012/ST54 strain was 7,499,568 bp with a GC content of 29.64%. Additionally, we detected plasmid1 in the RT046/ST54 strain. We found that the RT046/ST35 strain had more genomic islands compared to the RT012/ST54 strain, and we identified polysaccharide lyase (PL) in the region around 2.2 M. Furthermore, we discovered that the increased severity of clinical symptoms in the RT046/ST35 strain compared to the RT012/ST54 strain was unrelated to virulence factors and emphasized the potential crucial role of PL in RT046/ST35. There were almost no differences in eggNOG annotation and KEGG annotation between RT046/ST35 and RT012/ST54. RT046/ST35 had more mRNA processes in GO annotation. In conclusion, our study suggests that the core factor contributing to the more serious clinical symptoms of the RT046/ST35 strain compared to the RT012/ST54 strain is possibly PL.

Interactions of non-starch polysaccharides with the gut microbiota and the effect of non-starch polysaccharides with different structures on the metabolism of the gut microbiota: A review

Humans consume large amounts of non-starch polysaccharides(NPs) daily. Some NPs, not absorbed by the body, proceed to the intestines. An increasing number of studies reveal a close relationship between NPs and gut microbiota(GM) that impact the human body. This review not only describes in detail the structures of several common NPs and their effects on GM, but also elucidates the degradation mechanisms of NPs in the intestine. The purpose of this review is to elucidate how NPs interact with GM in the intestine, which can provide valuable information for further studies of NPs.

Targeting gut microbiota by starch molecular size and chain-length distribution to produce various short-chain fatty acids

The detailed relationships among starch fine molecular structures, gut microbiota, and short-chain fatty acids (SCFAs) are not fully understood. We hypothesized that specific starch molecular size and chain-length distribution are favored by gut bacteria for the secretion of SCFAs. To investigate this, different types of starches with diverse molecular size and chain-length distributions (e.g., amylose content ranging from about 1 % to 38 %) were subjected to in vitro fermentation with human fecal inocula. Tapioca and waxy maize starches were notably more effective at producing acetate and propionate compared to lentil, wheat, and pea starches (p < 0.05). Correlation analysis revealed, for the first time, that the number of amylose chains with a degree of polymerization between 500 and 5000 was positively correlated with the abundance of Bacteroides_coprocola_DSM_17136 and Bacteroides_plebeius, possibly relating to the higher production of acetate and propionate. These results indicate that starches with certain fine molecular structures could be used to target gut bacteria to produce various types of SCFAs, thereby amplifying beneficial effects on human health.

Protective effect of ginseng extract and total ginsenosides on hematopoietic stem cell damage by inhibiting cell apoptosis and regulating the intestinal microflora

Ginseng may improve the myelosuppression and intestinal microbiota disorder induced by cyclophosphamide (CY); however, the effect of ginseng components on hematopoietic stem cell (HSC) damage remains largely unexplored. The present study aimed to assess the protective effect of ginseng extract (GE), total ginsenosides (TG) and total polysaccharides (TP) from ginseng on the intestinal microflora and HSCs of model mice. In the present study, a mouse model of HSC damage induced by CY was constructed, intestinal microflora of fecal samples were sequenced using the 16S ribosomal RNA (rRNA) sequencing techniques, the differentially expressed genes (DEGs) of HSCs were analyzed using high‑throughput RNA‑sequencing, cell apoptosis and erythroid differentiation were detected using flow cytometry and the blood cell parameters were analyzed using a hematology analyzer. Analysis of the 16S rRNA in fecal samples showed that GE, TG and TP improved an imbalanced intestinal microflora, where the relative abundance of Lactobacillus intestinalis had a positive correlation with ginsenosides content. Specifically, TP significantly increased the expression of low‑abundance microflora. Transcriptomic analysis results revealed 2,250, 3,432 and 261 DEGs in the GE, TG and TP groups compared with those in the Model group, respectively. In the expression analysis of DEGs, both TG and GE were found to markedly increase the expression levels of Klf4, Hhex, Pbx1, Kmt2a, Mecom, Zc3h12a, Zbtb16, Lilr4b, Flt3 and Klf13. Furthermore, TG inhibited the apoptosis of HSCs by increasing the expression levels of Bcl2 and Mcl1, whilst decreasing the expression of Bax. By contrast, GE inhibited the apoptosis of HSCs by reducing the expression of Bax and Bad. Regarding erythroid differentiation and blood cell parameters, GE was found to significantly increase the expression of TER‑119. In addition, GE and TG improved all blood cell parameters, including the count of white blood cells, neutrophils (NEUT), lymphocytes (LYMPH), red blood cells (RBC), hemoglobin (HGB) and reticulocyte and platelets (PLT), whereas TP could only improve the counts of LYMPH, RBC, HGB and PLT. The improvement effect of GE and TG on WBC, NEUT and Ret was superior to TP. In conclusion, TG may protect the hematopoiesis function of HSCs in a CY‑induced mouse model of HSC damage, followed by GE. However, TP did not appear to improve HSC damage. Ginsenosides may therefore be considered essential ingredients in GE when protecting HSCs against damage. GE and TG exerted their protective effects on HSCs by inhibiting the apoptosis of HSCs whilst improving the imbalance of intestinal microflora.

The structure-function relationships and interaction between polysaccharides and intestinal microbiota: A review

The gut microbiota, as a complex ecosystem, can affect many physiological aspects of the host's diet, disease development, drug metabolism, and immune system regulation. Polysaccharides have various biological activities including antioxidant, anti-tumor, and regulating gut microbiota, etc. Polysaccharides cannot be degraded by human digestive enzymes. However, the interaction between gut microbiota and polysaccharides can lead to the degradation and utilization of polysaccharides. Disordered intestinal flora leads to diseases such as diabetes, hyperlipidemia, tumors, and diarrhea. Notably, polysaccharides can regulate the gut microbiota, promote the proliferation of probiotics and the SCFAs production, and thus improve the related-diseases and maintain body health. The relationship between polysaccharides and gut microbiota is gradually becoming clear. Nevertheless, the structure-function relationships between polysaccharides and gut microbiota still need further exploration. Hence, this paper systematically reviews the structure-function relationships between polysaccharides and gut microbiota from four aspects including molecular weight, glycosidic bonds, monosaccharide composition, and advanced structure. Moreover, this review outlines the effect of polysaccharides on gut microbiota metabolism and improves diseases by regulating gut microbiota. Furthermore, this article introduces the impact of gut microbiota on polysaccharide metabolism. The findings can provide the scientific basis for in-depth research on body health and reasonable diet.

Dissecting the anti-obesity components of ginseng: How ginseng polysaccharides and ginsenosides target gut microbiota to suppress high-fat diet-induced obesity

INTRODUCTION

Ginseng demonstrates therapeutic potential in treating obesity, with both experimental and clinical studies suggesting its anti-obesity effects are mediated by gut microbiota. Nonetheless, the specific chemical components responsible for this effect remain largely unidentified.

OBJECTIVES

This study aims to investigate the anti-obesity effects and mechanisms of ginseng polysaccharides (GP) and ginsenosides (GS), the primary chemical components of ginseng, with a focus on their impact on gut microbiota.

METHODS

The impact of GP and GS on high-fat diet (HFD)-induced obesity was assessed using a mouse model. Molecular mechanisms were explored through a combination of chemical analysis, metagenomics, RT-qPCR, ELISA, and biochemical assays.

RESULTS

GP or GS administration effectively prevented adiposity in HFD-fed mice, and both effects were mediated by gut microbiota. Chemical analysis revealed diverse glycosyl groups in GP and GS. Metagenomics data suggested that GP-enriched species, e.g., Bacteroides stercorirosoris and Clostridiales bacterium encoded carbohydrate-active enzymes GH35, GH43 and PL9_1, while GS-enriched Sulfurospirillum halorespirans encoded GH16_5. These enzymes facilitated the utilization of glycosyl groups in GP and GS, selectively stimulating bacterial growth and reshaping the gut microbiota. Furthermore, bacterial species enriched by GP or GS encoded specific functional genes involved in short-chain fatty acid (SCFA) synthesis (K00625 and K00925 for GP; K18118, K00100, and K18122 for GS) and intestinal gluconeogenesis (IGN) (K01678, K00024, and K01596 for GP; K18118 and K00278 for GS). Consequently, the SCFA-GLP-1/PYY signaling and IGN were activated by both GP and GS to ameliorate obesity phenotypes.

CONCLUSION

GP and GS, containing diverse glycosyl groups, selectively stimulate specific gut bacteria, triggering mechanisms involved in SCFA-GLP-1/PYY signaling and IGN activation to reduce adiposity in HFD-fed mice. The study enhances understanding of the chemical components crucial for the gut microbiota-mediated anti-obesity effect of ginseng. The mechanistic understanding provides valuable insights for developing ginseng-based drugs or health products to combat obesity.

Protective effects of insoluble dietary fiber from cereal bran against DSS-induced chronic colitis in mice: From inflammatory responses, oxidative stress, intestinal barrier, and gut microbiota

Insoluble dietary fiber (IDF) is a crucial component of cereals, and IDF from cereal bran (IDF-CB) has been reported to have multiple biological activities. However, the effect of IDF-CB on chronic colitis remains underexplored. The study aimed to investigate the impact of IDFs from wheat bran (WBIDF), rice bran (RBIDF), millet bran (MBIDF) and oat bran (OBIDF) on chronic colitis induced by dextran sulfate sodium (DSS). Our findings demonstrated that IDFs-CB supplementation mitigated DSS-induced weight loss and reduced lesions in the colon and spleen. Levels of proinflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) and oxidative stress markers (MPO, iNOS and MDA)were decreased, and anti-inflammatory cytokine (IL-10) and T-SOD activity were increased after IDF-CB inclusion. Furthermore, IDFs-CB restored intestinal barrier function by regulating gene expression (up-regulated Muc-2, ZO-1 and Occludin, and down-regulated Claudin-1 and Claudin-4). Additionally, we analyzed the gut microbiota and SCFAs composition. WBIDF, MBIDF and OBIDF inhibited the growth of Muribaculaceae_unclassified, Bacteroides and Parasutterella. Conversely, IDFs-CB promoted the growth of Candidatus_Saccharimonas and norank_f__norank_o__Clostridia_UCG-014. Notably, WBIDF enhanced the abundance of Allobaculum, while MBIDF and OBIDF increased the abundance of Lachnospiraceae_NK4A136. Moreover, supplementation with IDFs-CB significantly elevated certain SCFA concentrations-particularly acetic acid and isohexanoic acid. Our results suggested that IDF-CB effectively alleviated DSS-induced chronic colitis; among them，WBIDF exhibited superior efficacy followed by OBIDF，MBIDF，and RBIDF. This study provides a theoretical foundation for dietary recommendations for patients suffering from inflammatory bowel disease.

Enzyme applications in baking: From dough development to shelf-life extension

Enzymes play a vital role in baking, providing significant benefits from dough development to extending shelf life, which enhances product quality and consistency. Acting as biological catalysts, enzymes such as proteases and amylases break down proteins and starches, modifying dough rheology and improving fermentation. Lipases and oxidases further refine dough texture through emulsification and oxidation, while lipases also produce fatty acid derivatives during fermentation, contributing to the flavor and aroma of baked goods. Xylanases and cellulases optimize dough handling by altering fiber structure, and amylases help maintain moisture and texture, extending the shelf life of baked products. Ensuring regulatory compliance is essential when incorporating enzymes into baking processes, as bakers must address enzyme stability and determine appropriate dosages for reliable outcomes. Ongoing research is exploring innovative enzyme applications, including customized enzyme blends that target specific product qualities, offering new possibilities for product differentiation and innovation. In summary, enzyme-driven advancements present bakers with opportunities to improve product quality, shelf life, and consistency, while meeting industry regulations. This review emphasizes the critical impact enzymes have on dough properties and finished product characteristics, highlighting their role in driving future innovations within the baking industry.

Physicochemical, structural, and in-vitro release properties of carboxymethyl cellulose-based cryogel beads incorporating resveratrol-loaded microparticles for colon-targeted delivery system

The objective of this study was to investigate the physicochemical, structural, and in vitro release properties of carboxymethyl cellulose (CMC)-based cryogel beads incorporating resveratrol-loaded microparticles (MP) for colon-targeted delivery system. CMC-based cryogel beads were produced by ionic cross-linking with different concentrations (2%, 3%, and 4%) of AlCl3. Based on FE-SEM images, CMC-based cryogel beads showed a smoother surface and more compact internal structure with increasing AlCl3 concentrations, which was proven to be due to the new cross-linking between the -COO- group of CMC and Al3+ by FT-IR analysis. The encapsulation efficiency of the cryogel beads was significantly increased from 79.48% to 85.74% by elevating the concentrations of AlCl3 from 2% to 4%, respectively. In vitro release study showed that all CMC-based cryogel beads had higher stability for resveratrol than MP in simulated gastric conditions and can efficiently deliver resveratrol to colon without the premature release.

Fecal fermentation behaviors of Konjac glucomannan and its impacts on human gut microbiota

Dietary fiber targets the regulation of the intestinal flora and thus affects host health, however, the complex relationship between these factors lacks direct evidence. In this study, the regulatory effects of Konjac glucomannan (KGM) on key metabolites of host intestinal flora were examined by using in vitro fermentation. The results showed that KGM could be utilized by the intestinal flora, which inhibited the relative abundance of Paeniclostridium, Lachnoclostridium, Phascolarctobacterium, and Bacteroides and enriched the relative abundance of Desulfovibrio, Sutterella, etc. Fermentation is accompanied by the production of short-chain acids, including acetic and propionic acids. Metabolomics revealed that KGM significantly promoted amino acid metabolism, lipid metabolism, and the biosynthesis of other secondary metabolites. Correlation analysis results showed that the increase of panose and N-(1-carboxy-3-carboxanilidopropyl) alanylproline content was positively correlated with the relative abundance of Megamonas. These results provide evidence that KGM affects host health by regulating gut microbiota and its metabolites.

Structural characterization and immunomodulatory activity of polysaccharides from the lateral roots of Aconitum carmichaelii

Two polysaccharides, named FPS1-1 and FPS1-2, were separated from the neutral polysaccharides of the lateral roots of Aconitum carmichaelii, a widely used traditional Chinese medicine (Fuzi in Chinese). The monosaccharide composition analysis indicated that both FPS1-1 and FPS1-2 were glucans. However, further physicochemical analysis of FPS1-1 and FPS1-2 revealed distinct properties between the two glucans. FPS1-1 had a molecular weight (Mw) of 106.23 kDa with a spherical conformation, while FPS1-2 had a lower Mw of 19.23 kDa with a random coil conformation. The structure of FPS1-2 was further determined as a glucan whose backbone structure was composed of →4)-α-D-Glcp-(1→. The immunological activities of two polysaccharides were evaluated by a cyclophosphamide (CTX)-induced immunodeficiency model in mice. The result showed that FPS1-2 could restore CTX-induced immunosuppression by modulating CD4+ T cells differentiation and promoting cytokine secretion. Notably, FPS1-2 could modulate the colonic short-chain fatty acid (SCFA) levels and reverse the gut microbial dysbiosis induced by CTX. These findings reveal the potential benefits of Fuzi polysaccharides and provide evidences for developing immunologically functional products from Fuzi polysaccharides.

Danshen polysaccharides alleviate AFB1 induced Jejunal injury

AFB1 is a common foodborne toxin known for its potent carcinogenicity. Danshen polysaccharide (DSP) is an active ingredient of Danshen, which has been demonstrated to possess support intestinal homeostasis and anti-inflammatory activities. We utilized New Zealand White rabbits as an animal model to examine the impact of co-exposure to DSP and AFB1 on the intestines, as well as their underlying mechanisms. The results indicate that DSP elevated the abundance of Oscillospira, Coprococcus, Alistipes, Akkermansia, Bacteroides, Odoribacter, Blautia and Parabacteroides, while decreased the abundance of Sutterella, and Desulfovibrio, correcting AFB1-induced intestinal microbiota dysbiosis and enhancing microbial diversity within the gut. Moreover, DSP reduced the levels of diamine oxidase (DAO), D-Lactate, and malondialdehyde (MDA), while upregulating the expression of total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), zonula occludens-1 (ZO-1), occludin, claudin-4, mucin-2 (MUC2), and secretory immunoglobulin A (sIgA), thereby alleviating the oxidative stress and intestinal barrier dysfunction induced by AFB1. DSP downregulated jejunal lipopolysaccharide (LPS) levels and the mRNA expression and proteins abundance of toll-like receptor 4 (TLR4), myeloiddifferentiationfactor 88 (MyD88), and nuclear factor kappa-B (NF-κB), thereby inhibiting the jejunal inflammation induced by AFB1. In summary, DSP alleviates AFB1-induced jejunal injury by remodeling the gut microbiota, bolstering antioxidant capabilities within the jejunum, fortifying the intestinal barrier, and suppressing the TLR4-mediated release of pro-inflammatory cytokines.

Didymin Ameliorates Dextran Sulfate Sodium (DSS)-Induced Ulcerative Colitis by Regulating Gut Microbiota and Amino Acid Metabolism in Mice

Background: Didymin is a dietary flavonoid derived from citrus fruits and has been shown to have extensive biological functions, especially anti-inflammatory effects, but its mechanism is unclear. The purpose of this study was to investigate the potential mechanism of didymin that alleviates ulcerative colitis. Methods and Results: Our results indicated that didymin could alleviate the symptoms of ulcerative colitis, as it inhibited the expressions of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Didymin also promoted the expressions of claudin-1 and zona occludens-1(ZO-1), which are closely related with restoring colon barrier function. Didymin also increased the abundance of Firmicutes and Verrucomicobiota, while decreasing the abundance of Bacteroidota and Proteobacteria. Meanwhile, didymin significantly altered the levels of metabolites related to arginine synthesis and metabolism, and lysine degradation in the colitis mice. Utilizing network pharmacology and molecular docking, our results showed that the metabolites L-ornithine and saccharin could interact with signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa-B (NF-κB). In this in vitro study, L-ornithine could reduce the expressions of transcription factors STAT3 and NF-κB, and it also inhibited the expressions of IL-6 and IL-1β in the lipopolysaccharides (LPS) induced in RAW264.7 cells, while saccharin had the opposite effect. Conclusions: Taken together, didymin can regulate gut microbiota and alter metabolite products, which can modulate STAT3 and NF-κB pathways and inhibit the expressions of inflammatory factors and inflammatory response in the DSS-induced colitis mice.

Extraction, Characterization, and Antioxidant Activity of Eucommia ulmoides Polysaccharides

Herein, the ultrasound-assisted extraction conditions affecting the yield of EUPS (Eucommia ulmoides polysaccharide) were analyzed using a Box-Behnken response surface design. The alleviation effect of EUPS on diquat-induced oxidative stress in mice was also studied. A maximum EUPS yield of 2.60% was obtained under the following optimized conditions: an extraction temperature of 63 °C, extraction time of 1 h, and ratio of liquid to raw materials of 22:1. EUPS exhibited strong 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging ability (87.05%), 2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical-scavenging ability (101.17%), and hydroxyl radical-scavenging ability (62.92%). The administration of EUPS increased the activities of superoxide dismutase, catalase, and glutathione peroxidase and decreased malondialdehyde levels in the livers of mice exposed to diquat. EUPS may inhibit the downregulation of NAD(P)H:quinoneoxidoreductase 1 and heme oxygenase 1 mRNA expression in the livers of diquat-administered mice through the Nrf2-Keap1 signaling pathway. Moreover, the abundance of Firmicutes and Ligilactobacillus was enhanced, whereas that of Helicobacter decreased in the gut of the remaining groups of mice compared with that of the diquat-treated mice. Therefore, EUPS exhibited an antioxidant effect and improved oxidative stress and intestinal flora abundance in mice.

Genome Analysis and Safety Assessment of Achromobacter marplatensis Strain YKS2 Strain Isolated from the Rumen of Yaks in China

Achromobacter marplatensis strain YKS2 isolated from the yak rumen has the feature of producing cellulose. This study aims to analyze the genome and safety of strain YKS2 in vivo, considering its future research and application prospects. The genome of strain YKS2 was sequenced and used for genomic in silico studies. The administration of strain YKS2 in three doses was carried out on mice for 3 days of oral and 7 days of clinical observation tests. The BW, FI, organ indices, gut microbiota, and histological appearances of organs and intestines, along with hematological parameters and serum biochemistry, were measured in mice. The chromosome size of strain YKS2 was 6,588,568 bp, with a GC content of 65.27%. The 6058 coding sequences of strain YKS2 without plasmid were predicted and annotated and have multiple functions. The mice in all groups were alive, with good mental states and functional activities. Compared with the control group, there was no significant difference in the three dose groups on BW, FI, hematological parameters (WBC, LYM, etc.), and serum biochemistry (ALB, ALT, etc.). No abnormalities were observed in the main visceral organs, intestinal tissue, and V/C value in groups. However, the IEL number of duodenum and gut microbiota diversity (Shannon's index) in the high-dose group was significantly higher than in the control group (p < 0.05). Besides, the low dose of strain YKS2 also significantly affected the bacterial abundance of Firmicutes, Actinobacteria, and desulphurizing Bacteroidetes at the phylum level. There was no significant effect at genus levels in groups. In conclusion, the study revealed the genome and potential functional genes of strain YKS2, which is beneficial to understanding the features of the A. marplatensis strain and proved strain YKS2 to be without acute toxicity to mice. However, a long-term feeding toxicity experiment in vivo should be performed to further ensure its potential application value strain in the animal industry.

The pectin metabolizing capacity of the human gut microbiota

The human gastrointestinal microbiota, densely populated with a diverse array of microorganisms primarily from the bacterial phyla Bacteroidota, Bacillota, and Actinomycetota, is crucial for maintaining health and physiological functions. Dietary fibers, particularly pectin, significantly influence the composition and metabolic activity of the gut microbiome. Pectin is fermented by gut bacteria using carbohydrate-active enzymes (CAZymes), resulting in the production of short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate, which provide various health benefits. The gastrointestinal microbiota has evolved to produce CAZymes that target different pectin components, facilitating cross-feeding within the microbial community. This review explores the fermentation of pectin by various gut bacteria, focusing on the involved transport systems, CAZyme families, SCFA synthesis capacity, and effects on microbial ecology in the gut. It addresses the complexities of the gut microbiome's response to pectin and highlights the importance of microbial cross-feeding in maintaining a balanced and diverse gut ecosystem. Through a systematic analysis of pectinolytic CAZyme production, this review provides insights into the enzymatic mechanisms underlying pectin degradation and their broader implications for human health, paving the way for more targeted and personalized dietary strategies.

Decoding coffee cardiometabolic potential: Chemical composition, nutritional, and health relationships

Coffee is one of the most consumed beverages worldwide, recognized for its unique taste and aroma and for its social and health impacts. Coffee contains a plethora of nutritional and bioactive components, whose content can vary depending on their origin, processing, and extraction methods. Gathered evidence in literature shows that the regular coffee consumption containing functional compounds (e.g., polysaccharides, phenolic compounds, and melanoidins) can have potential beneficial effects on cardiometabolic risk factors such as abdominal adiposity, hyperglycemia, and lipogenesis. On the other hand, coffee compounds, such as caffeine, diterpenes, and advanced glycation end products, may be considered a risk for cardiometabolic health. The present comprehensive review provides up-to-date knowledge on the structure-function relationships between different chemical compounds present in coffee, one of the most prevalent beverages present in human diet, and cardiometabolic health.

The impact of high polymerization inulin on body weight reduction in high-fat diet-induced obese mice: correlation with cecal Akkermansia

Obesity presents a significant public health challenge, demanding effective dietary interventions. This study employed a high-fat diet-induced obesity mouse model to explore the impacts of inulin with different polymerization degrees on obesity management. Our analysis reveals that high-degree polymerization inulin (HDI) exhibited a significantly higher oil binding capacity and smaller particle size compared to low-degree polymerization inulin (LDI) (p < 0.05). HDI was more effective than LDI in mitigating body weight gain in high-diet induced obese mice, although neither LDI nor HDI affected blood sugar levels when compared to the high-fat diet control group (p < 0.05). Both HDI and LDI administrations reduced liver weight and enhanced brown adipose tissue thermogenesis compared to the high-fat diet induced control group (p < 0.05). Additionally, HDI suppressed hepatic lipogenesis, resulting in a further reduction in liver triglycerides compared to the high-fat diet-induced obese mice (p < 0.05). Notably, HDI improved gut health by enhancing intestinal morphology and modulating gut microbiota structure. HDI administration notably increased the relative abundance of cecal Akkermansia, a gut microbe associated with improved metabolic health, while LDI showed limited efficacy (p < 0.05 and p > 0.05, respectively). These findings underscore the importance of the structural properties of inulin in its potential to combat obesity and highlight the strategic use of inulin with varying polymerization degrees as a promising dietary approach for obesity management, particularly in its influence on gut microbiota composition and hepatic lipid metabolism regulation.

Metatranscriptomic analysis indicates prebiotic effect of isomalto/malto-polysaccharides on human colonic microbiota in-vitro

Isomalto/malto-polysaccharides (IMMPs) are a novel type of soluble dietary fibres with a prebiotic potential promoting growth of beneficial microbes in the gut. However, the mode of action of IMMPs remains unknown. Previous studies on IMMPs showed an increase in total bacteria, especially lactobacilli, and higher production of short chain fatty acids (SCFA) when IMMPs were fed to rats or used during in vitro fermentation. Here we used metatranscriptomics to investigate how IMMPs with different amounts of α - (1 → 6) glycosidic linkages affected microbial function during incubation with human fecal inoculum. We showed that active microbial community dynamics during fermentation varied depending on the type of IMMP used and that the observed changes were reflected in the community gene expression profiles. Based on metatranscriptome analysis, members of Bacteroides, Lactobacillus and Bifidobacterium were the predominant degraders of IMMPs, and the increased gene expression in these bacteria correlated with high amounts of α - (1 → 6) glycosidic linkages. We also noted an increase in relative abundance of these bacteria and an activation of pathways involved in SCFA synthesis. Our findings could provide a baseline for more targeted approaches in designing prebiotics for specific bacteria and to achieve more controlled modulation of microbial activity towards desired health outcomes.

Astragalus polysaccharides-induced gut microbiota play a predominant role in enhancing of intestinal barrier function of broiler chickens

BACKGROUND

The intestinal barrier is the first line of defense against intestinal invasion by pathogens and foreign antigens and is closely associated with the gut microbiota. Astragalus polysaccharides (APS) have a long history of use in traditional Chinese medicine owing to its protective properties against intestinal barrier function. The mechanism of APS-induced gut microbiota enhancing intestinal barrier function is urgently needed.

RESULTS

Dietary polysaccharide deprivation induced intestinal barrier dysfunction, decreased growth performance, altered microbial composition (Faecalibacterium, Dorea, and Coprobacillus), and reduced isobutyrate concentration. The results showed that APS facilitates intestinal barrier function in broiler chickens, including a thicker mucus layer, reduced crypt depth, and the growth of tight junction proteins. We studied the landscape of APS-induced gut microbiota and found that APS selectively promoted the growth of Parabacteroides, a commensal bacterium that plays a predominant role in enhancing intestinal barrier function. An in vitro growth assay further verified that APS selectively increased the abundance of Parabacteroides distasonis and Bacteroides uniformis. Dietary APS supplementation increased the concentrations of isobutyrate and bile acid (mainly chenodeoxycholic acid and deoxycholate acid) and activated signaling pathways related to intestinal barrier function (such as protein processing in the endoplasmic reticulum, tight junctions, and adherens junction signaling pathways).

CONCLUSIONS

APS intervention restored the dietary polysaccharide-induced dysfunction of the intestinal barrier by selectively promoting the abundance of Parabacteroides distasonis, and increasing the concentrations of isobutyrate and bile acids (mainly CDCA and DCA). These findings suggest that APS-induced gut microbiota and metabolic niches are promising strategies for enhancing intestinal barrier function.

The mechanisms in the gut microbiota regulation and type 2 diabetes therapeutic activity of resistant starches

Resistant starch (RS) can potentially prevent type 2 diabetes through the modulation of intestinal microbiota and microbial metabolites. Currently, it has been wildly noted that altering the intestinal microbial composition and short-chain fatty acids levels can achieve therapeutic effects, although the specific mechanisms were rarely elucidated. This review systematically explores the structural characteristics of different RS, analyzes the cross-feeding mechanism utilized by intestinal microbiota, and outlines the pathways and targets of butyrate, a primary microbial metabolite, for treating diabetes. Different RS types may have a unique impact on microbiota composition and their cross-feeding, thus exploring regulatory mechanisms of RS on diabetes through intestinal flora interaction and their metabolites could pave the way for more effective treatment outcomes for host health. Furthermore, by understanding the mechanisms of strain-level cross-feeding and metabolites of RS, precise dietary supplementation methods targeted at intestinal composition and metabolites can be achieved to improve T2DM.

A review of the fungal polysaccharides as natural biopolymers: Current applications and future perspective

As a unique natural resource, fungi are a sustainable source of lipids, polysaccharides, vitamins, proteins, and other nutrients. As a result, they have beneficial medicinal and nutritional properties. Polysaccharides are among the most significant bioactive components found in fungi. Increasing research has revealed that fungal polysaccharides (FPS) contain a variety of bioactivities, including antitumor, antioxidant, immunomodulatory, anti-inflammatory, hepatoprotective, cardioprotective, and anti-aging properties. However, the exact knowledge about FPS and their applications related to their future possibilities must be thoroughly examined to enhance a better understanding of this sustainable biopolymer source. Therefore, FPS' biological applications and their role in the food and feed industry, agriculture, and cosmetics applications were all discussed in this work. In addition, this review highlighted the mode of action of FPS on human diseases by regulating gut microbiota and discussed the mechanism of FPS as antioxidants in the living cell. The structure-activity connections of FPS were also highlighted and explored. Moreover, future perspectives were listed to pave the way for future studies of FPS applications. Hence, this study can be a scientific foundation for future FPS research and industrial applications.

Probiotics in Action: Enhancing Immunity and Combatting Diseases for Optimal Health

This review offers an in-depth examination of the mechanisms underlying the microbiome's defense against viral infections, with a specific focus on probiotic interventions. Mycotoxins, secondary compounds produced by microfungi, pose significant health risks. Yet, certain strains of Lactic Acid Bacteria (LAB) have exhibited remarkable efficacy in eliminating aflatoxin B1 (AFB1), the most toxic member of the aflatoxin family. Experimental setups demonstrated AFB1 binding to specific LAB strains, persisting even after gastric digestion. Laboratory studies revealed a potential protective mechanism wherein pre-incubation of probiotics with mycotoxins reduced their adhesion to mucus. Animal trials further underscored the benefits of oral probiotic administration, showcasing increased fecal excretion of mycotoxins and mitigation of associated health risks. Cyanobacteria-generated microcystins in drinking water pose a significant threat to human health. Probiotic bacteria, particularly strains like Bifidobacterium longum and Lactobacillus rhamnosus, have demonstrated exceptional efficacy in removing the cyanobacterial peptide toxin microcystin-LR. Optimized conditions resulted in rapid toxin elimination, highlighting the potential of probiotics in water purification. Engineered probiotics represent a cutting-edge approach to tailor microorganisms for specific therapeutic applications, exhibiting promise in treating metabolic disorders, Alzheimer's disease, and type 1 diabetes. Additionally, they serve as innovative diagnostic tools, capable of detecting pathogens and inflammation markers within the body. In the realm of antimicrobial peptide production, probiotics offer a promising platform, with genetically modified strains engineered to produce human β-defensin 2 (HBD2) for treating Crohn's disease, showcasing their potential in targeted theurapetic delivery. Biocontainment strategies have been implemented to prevent unintended environmental impacts.

Cross-feeding of bifidobacteria promotes intestinal homeostasis: a lifelong perspective on the host health

Throughout the life span of a host, bifidobacteria have shown superior colonization and glycan abilities. Complex glycans, such as human milk oligosaccharides and plant glycans, that reach the colon are directly internalized by the transport system of bifidobacteria, cleaved into simple structures by extracellular glycosyl hydrolase, and transported to cells for fermentation. The glycan utilization of bifidobacteria introduces cross-feeding activities between bifidobacterial strains and other microbiota, which are influenced by host nutrition and regulate gut homeostasis. This review discusses bifidobacterial glycan utilization strategies, focusing on the cross-feeding involved in bifidobacteria and its potential health benefits. Furthermore, the impact of cross-feeding on the gut trophic niche of bifidobacteria and host health is also highlighted. This review provides novel insights into the interactions between microbe-microbe and host-microbe.

Health-Related Composition and Bioactivity of an Agave Sap/Prickly Pear Juice Beverage

In this study, a beverage made from a combination of Agave sap (AS) and prickly pear juice (PPJ) was analyzed for its nutrients and bioactive and potentially health-promoting compounds. The beverage was evaluated for its ability to act as an antioxidant, regulate glycemic properties, and undergo gut bacterial fermentation in vitro. The major mono- and oligosaccharides present in the beverage were galacturonic acid (217.74 ± 13.46 mg/100 mL), rhamnose (227.00 ± 1.58 mg/100 mL), and fructose (158.16 ± 8.86 mg/mL). The main phenolic compounds identified were protocatechuic acid (440.31 ± 3.06 mg/100 mL) and catechin (359.72 ± 7.56 mg/100 mL). It was observed that the beverage had a low glycemic index (<40) and could inhibit digestive carbohydrases. The combination of ingredients also helped to reduce gas production during AS fermentation from 56.77 cm3 to 15.67 cm3. The major SCFAs produced during fermentation were butyrate, acetate, and propionate, with valerate being produced only during the late fermentation of the AS. This beverage is rich in bioactive compounds, such as polyphenols and dietary fiber, which will bring health benefits when consumed.

Human fecal alpha-glucosidase activity and its relationship with gut microbiota profiles and early stages of intestinal mucosa damage

OBJECTIVES

We investigated potential relationships among initial lesions of the intestinal mucosa, fecal enzymatic activities and microbiota profiles.

METHODS

Fecal samples from 54 volunteers were collected after recruitment among individuals participating in a colorectal cancer (CRC) screening program in our region (Northern Spain) or attending for consultation due to clinical symptoms; intestinal mucosa samples were resected during colonoscopy. Enzymatic activities were determined in fecal supernatants by a semi-quantitative method. The fecal microbiota composition was determined by 16S rRNA gene-based sequencing. The results were compared between samples from clinical diagnosis groups (controls and polyps), according with the type of polyp (hyperplastic polyps or conventional adenomas) and considering the grade of dysplasia for conventional adenomas (low and high grade dysplasia).

RESULTS

High levels of α-glucosidase activity were more frequent among samples from individuals diagnosed with intestinal polyps, reaching statistical significance for conventional adenomas and for low grade dysplasia adenomas when compared to controls. Regarding the microbiota profiles, higher abundance of Christensenellaceae_R-7 group and Oscillospiraceae_UCG-002 were found in fecal samples displaying low α-glucosidase activity as compared with those with higher activity as well as in controls with respect to conventional adenomas. A relationship was evidenced among intestinal mucosal lesions, gut glucosidase activities and intestinal microbiota profiles.

CONCLUSIONS

Our findings suggest a relationship among altered fecal α-glucosidase levels, the presence of intestinal mucosal lesions, which can be precursors of CRC, and shifts in defined microbial groups of the fecal microbiota.

Fecal microbiota transplantation and next-generation therapies: A review on targeting dysbiosis in metabolic disorders and beyond

The human microbiome, particularly the gut microbiome, has emerged as a central determinant of health and disease. Dysbiosis, an imbalance in the microbial composition of the gut, is associated with a variety of metabolic and other diseases, highlighting the potential for microbiota-targeted treatments. Fecal microbiota transplantation has received considerable attention as a promising therapy to modulate the gut microbiome and restore microbial homeostasis. However, challenges remain, including standardization, safety, and long-term efficacy. This review summarizes current knowledge on fecal microbiota transplantation and describes the next generation therapies targeting microbiome. This review looked at the mechanistic understanding of fecal microbiota transplantation and alternative strategies, elucidating their potential role in improving dysbiosis-associated metabolic disorders, such as obesity, and type 2 diabetes and others. Additionally, this review discussed the growing application of therapies targeting the gut microbiome. Insights from clinical trials, preclinical studies, and emerging technologies provide a comprehensive overview of the evolving landscape of microbiome-based interventions. Through a critical assessment of current advances and prospects, this review aims to highlight the therapeutic potential of targeting gut microbiome and pave the way for innovative approaches in precision medicine and personalized treatments.

A comprehensive review and advanced biomolecule-based therapies for osteoporosis

BACKGROUND

The prevalence of osteoporosis (OP) on a global scale is significantly elevated that causes life threatening issues. The potential of groundbreaking biomolecular therapeutics in the field of OP is highly encouraging. The administration of biomolecular agents has the potential to mitigate the process of bone demineralization while concurrently augmenting the regenerative capacity of bone tissue, thereby facilitating a personalized therapeutic approach. Biomolecules-based therapies showed promising results in term of bone mass protection and restoration in OP.

AIM OF REVIEW

We summarized the recent biomolecular therapies with notable progress in clinical, demonstrating the potential to transform illness management. These treatments frequently utilize different biomolecule based strategies. Biomolecular therapeutics has a targeted character, which results in heightened specificity and less off-target effects, ultimately leading to increased patient outcomes. These aspects have the capacity to greatly enhance the management of OP, thus resulting in a major enhancement in the quality of life encountered by individuals affected by this condition.

Banxia Xiexin decoction modulates gut microbiota and gut microbiota metabolism to alleviate DSS-induced ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Banxia Xiexin decoction (BXD) is a classic traditional Chinese medicine prescription for treating ulcerative colitis (UC). However, its potential mechanism of action is still unclear.

AIM OF THE STUDY

Reveal the correlation between the beneficial impacts of BXD on UC and the composition of the gut microbiota.

MATERIALS AND METHODS

The major constituents of BXD were identified using the HPLC-DAD technique. An experimental model of UC was induced in male C57BL/6 mice by administering dextran sodium sulfate (DSS). A total of 48 mice were divided into different groups, including control, model, high-dose BXD treatment, medium-dose BXD treatment, low-dose BXD treatment, and a group treated with 5-amino acid salicylic acid (5-ASA). Body weight changes and disease activity index (DAI) scores were documented; colon length, colon index, spleen index, and thymus index scores were determined; myeloperoxidase (MPO) and tumor necrosis factor-α (TNF-α) activities were assessed; and histological staining with hematoxylin-eosin and alcian blue/phosphate Schiff was performed. The immunofluorescence technique was employed to examine the presence of ZO-1 and occludin in the colon tissue. 16S rRNA sequencing was employed to assess the gut microbiota's diversity and metabolomics was utilized to examine alterations in metabolites within the gut microbiota. The impact of BXD on the gut microbiota was confirmed through fecal microbiota transplantation (FMT).

RESULTS

BXD exhibited a positive impact on UC mice, particularly in the high-dose BXD treatment group. The BXD group experienced weight recovery, decreased DAI scores, improved colon length, and restored of spleen and thymus index scores compared to the DSS group. Additionally, BXD alleviated colon damage and the inflammatory response while restoring intestinal barrier function. FMT in BXD-treated mice also showed therapeutic effects in UC mice. At the phylum level, the relative abundance of Desulfobacterota, Deferribacterota and Actinobacteriota increased; at the genus level, g__norank__f__Muribaculaceae, Dubosiella, Akkermansia, and Lactobacillus increased, whereas Faecalibaculum, Alloprevotella, Turicibacter, and g_Paraprevotella decreased. g__norank_f__Muribaculaceae was positively correlated with body weight and colon length and negatively with colon index scores, splenic index scores, and MPO levels; Alloprevotella was positively correlated with splenic index scores, histological scores, and TNF-α levels and negatively with thymus index scores and thymus index scores. Faecalibaculum was positively correlated with colon index scores and MPO levels. Metabolic investigations revealed 58 potential indicators, primarily associated with the metabolism of amino acids, purines, and lipids. Alloprevotella, g_Paraprevotella, and Bifidobacterium were strongly associated with metabolic pathways.

CONCLUSION

BXD showed beneficial therapeutic effects in UC mice. The mechanism may be by promoting the balance and variety of gut microbiota, as well as regulating the metabolism of amino acids, purines, and lipids.

Therapeutic Potential of Fucoidan in Alleviating Histamine-Induced Liver Injury: Insights from Mice Studies

Histamine, a bioactive component in certain foods such as Huangjiu has been associated with liver injury and disrupted intestinal balance. This study explored the potential therapeutic effects of fucoidan (FCD) in mitigating histamine-induced imbalances in mice. We found that FCD mitigated liver injury, reducing transaminases, oxidative stress, and inflammation. Histological improvements included decreased cell infiltration and necrosis. FCD restored tight junction proteins and suppressed inflammation-related genes. Western blot analysis revealed FCD's impact on TGF-β1, p-AKT, AKT, CYP2E1, Grp78, NLRP3, Cas-1, and GSDMD. Gut LPS levels decreased with FCD. Gut microbiota analysis showed FCD's modulation effect, reducing Firmicutes and increasing Bacteroides. FCD demonstrates potential in alleviating histamine-induced liver injury, regulating inflammation, and influencing gut microbiota. Further research exploring higher dosages and additional parameters is warranted.

Effects of Alhagi camelorum Fisch polysaccharide from different regions on growth performance and gastrointestinal microbiota of sheep lambs

Polysaccharides derived from Alhagi camelorum Fisch possess diverse activities, making them a potential prebiotic candidates for enhancing lamb health. This study investigated the immunomodulatory effects of Alhagi camelorum Fisch polysaccharides from Aksu (AK) and Shanshan (SS) regions on sheep lambs. The results showed that sheep lambs in the SS group exhibited significantly increased (p < 0.05) average daily gain, levels of growth hormone (GH), insulin (INS), IgA and IgM, and cytokines IL-4, IL-10, IL-17, TNF-α and IFN-γ compared to those in the control check (CK) group. Moreover, the SS treatment significantly increased the diversity and abundance of beneficial bacteria, while concurrently diminishing the prevalence of harmful bacteria. Additionally, it modulated various metabolic pathways, promoted lamb growth, improved immunity, reduced the risk of gastrointestinal disease and improved the composition of gastrointestinal microbiota. In summary, our findings highlight the potential of SS treatment in enhancing gastrointestinal health of sheep lambs by improving intestinal function, immunity, and gut microbiome. Consequently, these results suggest that Alhagi camelorum Fisch polysaccharides derived from Shanshan regions holds promising potential as a valuable intervention for optimizing growth performance in sheep lambs.

In-depth characterization of a selection of gut commensal bacteria reveals their functional capacities to metabolize dietary carbohydrates with prebiotic potential

The microbial utilization of dietary carbohydrates is closely linked to the pivotal role of the gut microbiome in human health. Inherent to the modulation of complex microbial communities, a prebiotic implies the selective utilization of a specific substrate, relying on the metabolic capacities of targeted microbes. In this study, we investigated the metabolic capacities of 17 commensal bacteria of the human gut microbiome toward dietary carbohydrates with prebiotic potential. First, in vitro experiments allowed the classification of bacterial growth and fermentation profiles in response to various carbon sources, including agave inulin, corn fiber, polydextrose, and citrus pectin. The influence of phylogenetic affiliation appeared to statistically outweigh carbon sources in determining the degree of carbohydrate utilization. Second, we narrowed our focus on six commensal bacteria representative of the Bacteroidetes and Firmicutes phyla to perform an untargeted high-resolution liquid chromatography-mass spectrometry metabolomic analysis: Bacteroides xylanisolvens, Bacteroides thetaiotaomicron, Bacteroides intestinalis, Subdoligranulum variabile, Roseburia intestinalis, and Eubacterium rectale exhibited distinct metabolomic profiles in response to different carbon sources. The relative abundance of bacterial metabolites was significantly influenced by dietary carbohydrates, with these effects being strain-specific and/or carbohydrate-specific. Particularly, the findings indicated an elevation in short-chain fatty acids and other metabolites, including succinate, gamma-aminobutyric acid, and nicotinic acid. These metabolites were associated with putative health benefits. Finally, an RNA-Seq transcriptomic approach provided deeper insights into the underlying mechanisms of carbohydrate metabolization. Restricting our focus on four commensal bacteria, including B. xylanisolvens, B. thetaiotaomicron, S. variabile, and R. intestinalis, carbon sources did significantly modulate the level of bacterial genes related to the enzymatic machinery involved in the metabolization of dietary carbohydrates. This study provides a holistic view of the molecular strategies induced during the dynamic interplay between dietary carbohydrates with prebiotic potential and gut commensal bacteria.

IMPORTANCE

This study explores at a molecular level the interactions between commensal health-relevant bacteria and dietary carbohydrates holding prebiotic potential. We showed that prebiotic breakdown involves the specific activation of gene expression related to carbohydrate metabolism. We also identified metabolites produced by each bacteria that are potentially related to our digestive health. The characterization of the functional activities of health-relevant bacteria toward prebiotic substances can yield a better application of prebiotics in clinical interventions and personalized nutrition. Overall, this study highlights the importance of identifying the impact of prebiotics at a low resolution of the gut microbiota to characterize the activities of targeted bacteria that can play a crucial role in our health.

Effects of acetyl groups on the prebiotic properties of glucomannan extracted from Artemisia sphaerocephala Krasch seeds

This study explores the structural modification of glucomannan extracted from Artemisia sphaerocephala Krasch seeds (60S) to assess the impact of acetyl groups on its prebiotic characteristics. The structural changes were examined, with a focus on the degree of acetyl group substitution (DS). Both deacetylation and acetylation had limited influence on the molecular properties of 60S. Despite these modifications, the apparent viscosity of all samples remained consistently low. In vitro fermentation experiments revealed that Escherichia-Shigella decreased as DS increased, while Bacteroides ovatus was enriched. Acetylation had no significant impact on the utilization rate of 60S but led to a reduction in the production of propionic acid. Furthermore, untargeted metabolomics analysis confirmed the changes in propionic acid levels. Notably, metabolites such as N-acetyl-L-tyrosine, γ-muricholic acid, and taurocholate were upregulated by acetylated derivatives. Overall, acetyl groups are speculated to play a pivotal role in the prebiotic properties of 60S.

Deciphering the nutritional strategies for polysaccharides effects on intestinal barrier in broilers: Selectively promote microbial ecosystems

The gut microbiota, a complex and dynamic microbial ecosystem, plays a crucial role in regulating the intestinal barrier. Polysaccharide foraging is specifically dedicated to establishing and maintaining microbial communities, contributing to the shaping of the intestinal ecosystem and ultimately enhancing the integrity of the intestinal barrier. The utilization and regulation of individual polysaccharides often rely on distinct gut-colonizing bacteria. The products of their metabolism not only benefit the formation of the ecosystem but also facilitate cross-feeding partnerships. In this review, we elucidate the mechanisms by which specific bacteria degrade polysaccharides, and how polysaccharide metabolism shapes the microbial ecosystem through cross-feeding. Furthermore, we explore how selectively promoting microbial ecosystems and their metabolites contributes to improvements in the integrity of the intestinal barrier.

Ant may well destroy a whole dam: glycans of colonic mucus barrier disintegrated by gut bacteria

The colonic mucus layer plays a critical role in maintaining the integrity of the colonic mucosal barrier, serving as the primary defense against colonic microorganisms. Predominantly composed of mucin 2 (MUC2), a glycosylation-rich protein, the mucus layer forms a gel-like coating that covers the colonic epithelium surface. This layer provides a habitat for intestinal microorganisms, which can utilize mucin glycans present in the mucus layer as a sustainable source of nutrients. Additionally, metabolites produced by the microbiota during the metabolism of mucus glycans have a profound impact on host health. Under normal conditions, the production and consumption of mucus maintain a dynamic balance. However, several studies have demonstrated that certain factors, such as dietary fiber deficiency, can enhance the metabolism of mucus glycans by gut bacteria, thereby disturbing this balance and weakening the mucus barrier function of the mucus layer. To better understand the occurrence and development of colon-related diseases, it is crucial to investigate the complex metabolic patterns of mucus glycosylation by intestinal microorganisms. Our objective was to comprehensively review these patterns in order to clarify the effects of mucus layer glycan metabolism by intestinal microorganisms on the host.

In vitro digestion and fecal fermentation of basidiospore-derived exopolysaccharides from Naematelia aurantialba

Mushroom polysaccharides exhibit numerous health-enhancing attributes that are intricately linked to the breakdown, assimilation, and exploitation of polysaccharides within the organism. Naematelia aurantialba polysaccharides (NAPS-A), highly prized polysaccharides derived from mushrooms, remain shrouded in uncertainty regarding their characteristics pertaining to gastrointestinal digestion and gut microbial fermentation. The study aimed to understand the digestion and fecal fermentation patterns of NAPS-A. After simulated digestion, NAPS-A's physicochemical properties remained unchanged. However, during in vitro fecal fermentation, indigestible NAPS-A underwent significant changes in various properties, such as reducing sugar, chemical composition, constituent monosaccharides, Molecular weight, apparent viscosity, FT-IR spectra, and microscopic morphology. Notably, NAPS-A was effectively utilized by the gut microbiota, with unchanged properties after digestion but altered after fermentation. It influenced gut microbe composition by increasing beneficial bacteria (Lactobacillus, Faecalibacterium, and Roseburia), lowering pH, and producing short-chain fatty acids. NAPS-A fermentation enriches carbohydrate, fatty acid, and amino acid metabolic pathways through PICRUSt prediction analysis. Overall, these findings emphasize NAPS-A's role in regulating gut bacteria and their metabolic functions, despite its challenging digestibility.

From Nature-Sourced Polysaccharide Particles to Advanced Functional Materials

Polysaccharides constitute over 90% of the carbohydrate mass in nature, which makes them a promising feedstock for manufacturing sustainable materials. Polysaccharide particles (PSPs) are used as effective scavengers, carriers of chemical and biological cargos, and building blocks for the fabrication of macroscopic materials. The biocompatibility and degradability of PSPs are advantageous for their uses as biomaterials with more environmental friendliness. This review highlights the progresses in PSP applications as advanced functional materials, by describing PSP extraction, preparation, and surface functionalization with a variety of functional groups, polymers, nanoparticles, and biologically active species. This review also outlines the fabrication of PSP-derived macroscopic materials, as well as their applications in soft robotics, sensing, scavenging, water harvesting, drug delivery, and bioengineering. The paper is concluded with an outlook providing perspectives in the development and applications of PSP-derived materials.

Novel Signal Peptides and Episomal Plasmid System for Enhanced Protein Secretion in Engineered Bacteroides Species

The genus Bacteroides, a predominant group in the human gut microbiome, presents significant potential for microbiome engineering and the development of live biotherapeutics aimed at treating gut diseases. Despite its promising capabilities, tools for effectively engineering Bacteroides species have been limited. In our study, we have made a breakthrough by identifying novel signal peptides in Bacteroides thetaiotaomicron and Akkermansia muciniphila. These peptides facilitate efficient protein transport across cellular membranes in Bacteroides, a critical step for therapeutic applications. Additionally, we have developed an advanced episomal plasmid system. This system demonstrates superior protein secretion capabilities compared to traditional chromosomal integration plasmids, making it a vital tool for enhancing the delivery of therapeutic proteins in Bacteroides species. Initially, the stability of this episomal plasmid posed a challenge; however, we have overcome this by incorporating an essential gene-based selection system. This novel strategy not only ensures plasmid stability but also aligns with the growing need for antibiotic-free selection methods in clinical settings. Our work, therefore, not only provides a more robust secretion system for Bacteroides but also sets a new standard for the development of live biotherapeutics.

Ecological dependencies and the illusion of cooperation in microbial communities

Ecological dependencies - where organisms rely on other organisms for survival - are a ubiquitous feature of life on earth. Multicellular hosts rely on symbionts to provide essential vitamins and amino acids. Legume plants similarly rely on nitrogen-fixing rhizobia to convert atmospheric nitrogen to ammonia. In some cases, dependencies can arise via loss-of-function mutations that allow one partner to benefit from the actions of another. It is common in microbiology to label ecological dependencies between species as cooperation - making it necessary to invoke cooperation-specific frameworks to explain the phenomenon. However, in many cases, such traits are not (at least initially) cooperative, because they are not selected for because of the benefits they confer on a partner species. In contrast, dependencies in microbial communities may originate from fitness benefits gained from genomic-streamlining (i.e. Black Queen Dynamics). Here, we outline how the Black Queen Hypothesis predicts the formation of metabolic dependencies via loss-of-function mutations in microbial communities, without needing to invoke any cooperation-specific explanations. Furthermore we outline how the Black Queen Hypothesis can act as a blueprint for true cooperation as well as discuss key outstanding questions in the field. The nature of interactions in microbial communities can predict the ability of natural communities to withstand and recover from disturbances. Hence, it is vital to gain a deeper understanding of the factors driving these dynamic interactions over evolutionary time.

Clostridium butyricum Prazmowski can degrade and utilize resistant starch via a set of synergistically acting enzymes

Resistant starch is a prebiotic fiber that is best known for its ability to increase butyrate production by the gut microbiota. This butyrate then plays an important role in modulating the immune system and inflammation. However, the ability to use this resistant starch appears to be a rare trait within the gut microbiota, with only a few species such as Ruminococcus bromii and Bifidobacterium adolescentis having been demonstrated to possess this ability. Furthermore, these bacteria do not directly produce butyrate themselves, rather they rely on cross-feeding interactions with other gut bacteria for its production. Here, we demonstrate that the often-used probiotic organism Clostridium butyricum also possesses the ability to utilize resistant starch from a number of sources, with direct production of butyrate. We further explore the enzymes responsible for this trait, demonstrating that they exhibit significant synergy, though with different enzymes exhibiting more or less importance depending on the source of the resistant starch. Thus, the co-administration of Clostridium butyricum may have the ability to improve the beneficial effects of resistant starch.IMPORTANCEClostridium butyricum is seeing increased use as a probiotic, due to potential health benefits tied to its ability to produce butyrate. Here, we demonstrate that this organism can use a variety of resistant starch sources and characterize the enzymes it uses to accomplish this. Given the relative rarity of resistant starch utilizing ability within the gut and the health benefits tied to resistant starch, the combined use of this organism with resistant starch in synbiotic formulations may prove beneficial.

Microbial Extracellular Vesicles in Host-Microbiota Interactions

Extracellular vesicles have emerged as key players in cellular communication, influencing various physiological processes and pathophysiological progression, including digestion, immune response, and tissue repairs. Recently, a class of EVs derived from microbial communities has gained significant attention due to their pivotal role in intercellular communication and their potential as biomarkers and biotherapeutic agents. Microbial EVs are membrane-bound molecules encapsulating bioactive metabolites that modulate host physiological and pathological processes. This chapter discusses the evolving history of microbiota-produced EVs, including their discovery, characterization, current research status, and their diverse mechanisms of interaction with other microbes and hosts. This review also highlights the importance of EVs in health and disease and discusses recent research that shows promising results for the therapeutic potential of EVs.

Functional Roles of N-Terminal Domains in Pullulanase from Human Gut Lactobacillus acidophilus

Pullulanases are multidomain α-glucan debranching enzymes with one or more N-terminal domains (NTDs) including carbohydrate-binding modules (CBMs) and domains of unknown function (DUFs). To elucidate the roles of NTDs in Lactobacillus acidophilus NCFM pullulanase (LaPul), two truncated variants, Δ41-LaPul (lacking CBM41) and Δ(41+DUFs)-LaPul (lacking CBM41 and two DUFs), were produced recombinantly. LaPul recognized 1.3- and 2.2-fold more enzyme attack-sites on starch granules compared to Δ41-LaPul and Δ(41+DUFs)-LaPul, respectively, as measured by interfacial kinetics. Δ41-LaPul displayed markedly lower affinity for starch granules and β-cyclodextrin (10- and >21-fold, respectively) in comparison to LaPul, showing substrate binding mainly stems from CBM41. Δ(41+DUFs)-LaPul exhibited a 12 °C lower melting temperature than LaPul and Δ41-LaPul, indicating that the DUFs are critical for LaPul stability. Notably, Δ41-LaPul exhibited a 14-fold higher turnover number (kcat) and 9-fold higher Michaelis constant (KM) compared to LaPul, while Δ(41+DUFs)-LaPul's values were close to those of LaPul, possibly due to the exposure of aromatic by truncation.

A multi-study analysis of gut microbiome data from the blue mussel (Mytilus edulis) emphasises the impact of depuration on biological interpretation

The blue mussel (Mytilus edulis) is a suspension feeder which has been used in gut-microbiome surveys. Although raw 16S sequence data are often publicly available, unifying secondary analyses are lacking. The present work analysed raw data from seven projects conducted by one group over 7 years. Although each project had different motivations, experimental designs and conclusions, all selected samples were from the guts of M. edulis collected from a single location in Long Island Sound. The goal of this analysis was to determine which independent factors (e.g., collection date, depuration status) were responsible for governing composition and diversity in the gut microbiomes. Results indicated that whether mussels had undergone depuration, defined here as voidance of faeces in a controlled, no-food period, was the primary factor that governed gut microbiome composition. Gut microbiomes from non-depurated mussels were mixtures of resident and transient communities and were influenced by temporal factors. Resident communities from depurated mussels were influenced by the final food source and length of time host mussels were held under laboratory conditions. These findings reinforce the paradigm that gut microbiota are divided into resident and transient components and suggest that depuration status should be taken into consideration when designing and interpreting future experiments.

Aerogels as Carriers for Oral Administration of Drugs: An Approach towards Colonic Delivery

Polysaccharide aerogels have emerged as a highly promising technology in the field of oral drug delivery. These nanoporous, ultralight materials, derived from natural polysaccharides such as cellulose, starch, or chitin, have significant potential in colonic drug delivery due to their unique properties. The particular degradability of polysaccharide-based materials by the colonic microbiota makes them attractive to produce systems to load, protect, and release drugs in a controlled manner, with the capability to precisely target the colon. This would allow the local treatment of gastrointestinal pathologies such as colon cancer or inflammatory bowel diseases. Despite their great potential, these applications of polysaccharide aerogels have not been widely explored. This review aims to consolidate the available knowledge on the use of polysaccharides for oral drug delivery and their performance, the production methods for polysaccharide-based aerogels, the drug loading possibilities, and the capacity of these nanostructured systems to target colonic regions.

Gut firmicutes: Relationship with dietary fiber and role in host homeostasis

Firmicutes and Bacteroidetes are the predominant bacterial phyla colonizing the healthy human gut. Accumulating evidence suggests that dietary fiber plays a crucial role in host health, yet most studies have focused on how the dietary fiber affects health through gut Bacteroides. More recently, gut Firmicutes have been found to possess many genes responsible for fermenting dietary fiber, and could also interact with the intestinal mucosa and thereby contribute to homeostasis. Consequently, the relationship between dietary fiber and Firmicutes is of interest, as well as the role of Firmicutes in host health. In this review, we summarize the current knowledge regarding the molecular mechanism of dietary fiber degradation by gut Firmicutes and explain the communication pathway of the dietary fiber-Firmicutes-host axis, and the beneficial effects of dietary fiber-induced Firmicutes and their metabolites on health. A better understanding of the dialogue sustained by the dietary fiber-Firmicutes axis and the host could provide new insights into probiotic therapy and novel dietary interventions aimed at increasing the abundance of Firmicutes (such as Faecalibacterium, Lactobacillus, and Roseburia) to promote health.

Structural changes of polysaccharides from Astragulus after honey processing and their bioactivities on human gut microbiota

BACKGROUND

Astragali Radix (also known as Astragulus) is a traditional medicinal and edible homologous plant for tonifying Qi. Honey-processed Astragalus is a dosage form of Astragali Radix processed with honey, which exhibited better efficacy of tonifying Qi than the raw product. Polysaccharides are their main active components.

RESULTS

APS2a and HAPS2a were initially isolated from Astragulus and honey-processed Astragulus. Both of them are highly branched acidic heteropolysaccharides containing ɑ-configuration and β-configuration glycosidic bonds. The molecular weight and the molecular dimension of HAPS2a decreased and the GalA contained in APS2a was converted to Gal in HAPS2a. The α-configuration galactose residue 1,3,4-α-Galp in the backbone of APS2a was converted to the corresponding β-configuration galactose residue 1,3,4-β-Galp in the backbone of HAPS2a and the uronic acid residue T-α-GalpA in the sidechain of APS2a was converted to the corresponding neutral residue T-α-Galp in the side chain of HAPS2a. Bioactivity results showed that HAPS2a had better probiotic effects on Bacteroides ovatus, Bacteroides thetaiotaomicron, Bifidobacterium longum and Lactobacillus rhamnosus strains than APS2a. After degradation, the molecular weights of HAPS2a and APS2a decreased with the changes in their monosaccharide composition. The contents of total short-chain fatty acids (SCFAs) and other organic acids in HAPS2a group were higher than APS2a group.

CONCLUSIONS

Two novel high-molecular-weight polysaccharides named APS2a and HAPS2a had different probiotic activities in vitro, which might be due to their structural differences before and after honey processing. Both of them might be possibly used as an immunopotentiator in healthy foods or dietary supplement. © 2023 Society of Chemical Industry.