Yeast β-Glucan Altered Intestinal Microbiome and Metabolome in Older Hens

Phenomenological and mechanistic insights into potential dietary nucleotide - probiotic synergies in layer chickens: A review

Despite their growing popularity as alternatives to antibiotic growth promoters (AGPs), the individual effects of nucleotides and probiotics on poultry gut functionality remain poorly understood. In addition, inconsistent outcomes are quite common in studies where these two additives have been used separately to modify gut function and related parameters in birds. These inconsistencies, which have limited the potential of probiotics and nucleotides as AGP replacements, stem from various factors and need to be addressed. Combining probiotics and nucleotides could potentially enhance their effectiveness and lead to more consistent outcomes in layer chickens. Since their mechanisms of action complement each other, some level of synergy is expected when used together. Both additives have been shown to support gut health, boost immune function, and improve performance in chickens when used individually. However, no studies have investigated the possible synergistic effects of nucleotides and probiotics in poultry. This review makes the case for combined use of probiotics and nucleotides in layer chickens by providing phenomenological and mechanistic insights into hypothetical synergistic effects. This paper highlights the need for AGP alternatives and reviews studies on the effects and mechanisms of probiotics and nucleotides in layer chickens when used individually. We then propose potential mechanisms for their synergistic effects on gut health, performance, and egg quality based on logical deductions from observed biological responses. These proposed mechanisms are hypothetical and require experimental validation. Finally, the review explores how this synergy could lead to more consistent outcomes and enhance the feasibility of AGP-free egg production.

Long-term soy dietary fiber diet modifies the intestinal internal environment: Focus on chronic ulcerative colitis

Okara is a major by-product of soybean processing, which not only has negative impacts on the environment but also leads to resource waste. Soybean residue is rich in insoluble dietary fiber, which is known to have a positive effect on ulcerative colitis. This study aimed to investigate whether long-term consumption of high-purity soy isolate dietary fiber (HPSIDF) promotes the proliferation of beneficial intestinal substances, thereby alleviating intestinal damage caused by chronic ulcerative colitis (CUC). This study induced CUC using 2 % dextran sulfate sodium (DSS) and conducted a three-phase (9-week) intervention experiment. The study showed that long-term consumption of HPSIDF can regulate the level of inflammatory factors in mice and relieve damage to intestinal tissue. In addition, long-term intake of HPSIDF inhibited the degradation of Lactobacillus intestinalis and promoted the proliferation of Oscillospira and the production of beneficial substances such as Agmatine and Betaine, which played an important role in the maintenance of intestinal bacterial flora and the improvement of the internal environment. This study clarified that long-term intake of HPSIDF not only changes the intestinal self-properties but also promotes the proliferation of beneficial flora and metabolites, providing a solution strategy for the high-value utilization of okara.

Serum Metabolomic Profiling in Healthy Dogs Supplemented with Increasing Levels of Purified Beta-1,3/1,6-Glucans

Metabolomics has proven to be an effective tool for elucidating mechanisms and assessing the effectiveness of dietary interventions in canine and feline nutrition. In this context, the present study aimed to perform a metabolomic analysis of the serum of dogs supplemented with increasing levels of beta-1,3/1,6-glucans to generate evidence and gain a deeper understanding of the metabolic responses associated with this supplementation. Eight dogs were evenly assigned to two balanced 4 × 4 Latin squares. Four diets were tested, differing only in beta-glucan content (0.0%, 0.07%, 0.14%, and 0.28%), and the dogs were fed according to their individual maintenance energy requirements. Each experimental period lasted 35 days. On day 35, 5 mL of blood was collected via jugular venipuncture to obtain serum for metabolomic analysis. Nuclear magnetic resonance analysis identified 12 key serum metabolites. Hierarchical heat map analysis revealed differences in metabolite intensity between treatments (p < 0.05). Additionally, the most relevant metabolic pathways were phenylalanine, tyrosine, and tryptophan metabolism; alanine, aspartate, and glutamate metabolism; and glyoxylate and dicarboxylate metabolism. This study demonstrated that increasing levels of purified beta-1,3/1,6-glucans from Saccharomyces cerevisiae modulated key metabolic pathways in dogs, particularly those related to amino acid, lipid and energy metabolisms, and gut microbiota. These findings provide insights into the mechanisms by which beta-glucans influence canine health.

Cooling redistributed endotoxin across different biofluids via modulating the ruminal microbiota and metabolome without altering quorum sensing signal levels in heat-stressed beef bulls

BACKGROUND

Cooling is one of the most common and economical methods to ameliorate heat stress (HS), and it has been discovered to alter the lipopolysaccharide (LPS) endotoxin level in ruminants. However, whether the endotoxin variation induced by cooling relates to the quorum sensing (QS) within the ruminal microflora remains unknown. The current study was consequently performed to examine whether cooling could influence the endotoxin distribution across different biofluids, ruminal microbiota, and ruminal metabolisms through affecting the QS of rumen microorganisms in beef cattle exposed to HS. Thirty-two Simmental bulls were used as experimental animals and randomly assigned to either the control (CON) group, or the mechanical ventilation and water spray (MVWS) treatment. The temperature-humidity index (THI) was recorded throughout this trial, and samples of the rumen liquid, blood, and urine were collected.

RESULTS

Cooling significantly lowered (P < 0.05) the temperature-humidity index (THI), ruminal endotoxin, and endotoxin concentration and excretion in urine, and significantly raised endotoxin level in blood (P < 0.05), but did not change the ruminal concentrations of QS signals including 3-OXO-C6-HSL and the AI-2 (P > 0.05). The linear discriminant analysis effect size (LEfSe) analysis revealed that Prevotellaceae, Rikenellaceae, Monoglobales and their affiliated members, as well as other bacterial taxa were significantly differently (P < 0.05) enriched between the two treatments. The Tax4Fun2 prediction suggested that QS function was upregulated in MVWS compared to CON. The metabolomic analysis indicated that cooling altered the ruminal metabolism profile and downregulated the pathways of lysine degradation, phenylalanine, tyrosine and tryptophan biosynthesis, and ubiquinone and other terpenoid-quinone biosynthesis. The significant (P < 0.05) correlations of the differential bacteria and metabolites with endotoxin and QS molecules were also demonstrated through Spearman analysis.

CONCLUSIONS

Based on the results of this trial, it could be speculated that the cooling reshaped the endotoxin distribution across different biofluids through manipulating ruminal microbiota and metabolome, which might involve the participation of QS. Further investigations are warranted to disclose and verify the mechanisms for those correlations found in this study.

Effects of luxS gene on biofilm formation and fermentation property in Lactobacillus plantarum R

The biofilm formation of Lactobacilli is regulated by the LuxS/AI-2 quorum sensing (QS) system, but the mechanism of QS regulating the formation of Lactobacilli biofilm is not clear. This study aimed to investigate the mechanism of producing biofilm in L. plantarum R and its effect on the quality of fermented pickles based on LuxS/AI-2 QS system. Compared with L. plantarum R, the AI-2 activity of L. plantarum RΔluxS was significantly reduced, but the biofilm, extracellular protein, and eDNA were significantly increased. Moreover, expression of oppA, livJ, livH and comD genes was up-regulated and luxS, peg.3090 and peg.3093 was down-regulated. Results showed that peg.3093 was most significantly down-regulated in L. plantarum RΔluxS, and extremely significant negatively correlated with biofilm. The biofilm, eDNA, and extracellular protein of L. plantarum RΔpeg.3093 was higher than those of L. plantarum R. Moreover, metabolomics showed that deletion of luxS gene could decrease AI-2 level, promote anthocyanin and flavonol biosynthesis, lead to improving the antioxidant properties and quality of pickles. Thus, luxS gene knockout may increase biofilm by down-regulating the expression of peg.3093 to increase extracellular protein and eDNA. This study provides a theoretical basis for the enhancement of Lactobacillus biofilm and its application.

Microbiome and metabolome reveal beneficial effects of baicalin on broiler growth performance and intestinal health

Normal function and health of the intestinal tract were necessary for the growth and development of broilers. Baicalin (BA) possessed a variety of biological activities. The objective of this study was to examine the impact of BA on the growth performance, intestinal barrier function, intestinal microbiota, and mucosal metabolism in broilers. A total of 720 21-day-old broilers were randomly allocated into 3 groups and fed with either basal diet (Con group) or basal diet supplemented with 6 or 12 mg/kg baicalin (BA6 and BA12 groups) for a continuous feeding period of 40 days. Results showed that BA had a trend towards improving (P = 0.086) the 60-day body weight of broilers, and the BA12 group exhibited significantly higher (P < 0.05) average daily gain from day 39 to 60 compared to the Con group. Additionally, in the BA12 group, the ratio of villus height to crypt depth and the expression levels of tight junction protein-related genes significantly increased (P < 0.05), while intestinal permeability significantly decreased (P < 0.05). Supplementation with 12 mg/kg BA significantly enhanced antioxidant capacity, promoted (P < 0.05) crypt proliferation, increased (P < 0.05) immunoglobulin levels, upregulated (P < 0.05) IL-2 and IL-8 mRNA levels, and downregulated (P < 0.05) IL-4 and TGF-β2 mRNA levels. Metabolomics analysis revealed that BA improved the metabolic characteristics of intestinal mucosa, significantly upregulating pathways associated with ascorbate and aldarate metabolism, glyoxylate and dicarboxylate metabolism, phosphatidylinositol signaling system, alpha-linolenic acid metabolism, and galactose metabolism. 16S rRNA sequencing results indicated that BA increased the richness of intestinal microbiota community and the relative abundance of Actinobacteria phylum, while reducing the relative abundance of contains mobile elements, potentially pathogenic, and facultatively anaerobic. Overall, 12 mg/kg BA improved intestinal health by modulating intestinal barrier function, antioxidant capacity, immunity, intestinal microbiota, and intestinal mucosal metabolism levels, ultimately enhancing broiler growth performance.

Exploring the therapeutic potential of yeast β-glucan: Prebiotic, anti-infective, and anticancer properties - A review

Yeast β-glucan (YBG), an indigestible polysaccharide from yeast cell walls, is multifunctional. It plays a pivotal role in regulating gut microbiota (GM) and boosting the immune system, which is central to research on inflammation, cancer, and metabolic diseases. By modulating the GM, YBG exhibits various prebiotic effects, including hypoglycemic, hypolipidemic, and immune-regulating properties. Additionally, acting as a bioreactor modulator, it activates immune responses, demonstrating potential in anti-infection and anticancer applications. This article synthesizes the latest data from in vitro, in vivo, and clinical studies. It comprehensively evaluates the therapeutic potential of YBG, starting from its structure-function relationship. It particularly focuses on the application prospects of yeast β-glucan in probiotic-like effects, anti-infectious properties, and anti-cancer activity, and explores the underlying mechanisms of these actions. The aim of this article is to elucidate the positive impact of YBG on health by modulating the gut microbiota and enhancing immune responses. Simultaneously, it identifies critical areas for future research to provide theoretical support for its development in biomedical applications.

Evaluation of the activity of antimicrobial peptides against bacterial vaginosis

New drugs for the treatment of bacterial vaginosis (BV) are yet to be developed due to concerns that they may contribute to the increase in antibiotic resistance in BV. Antimicrobial peptides (AMPs) are one of the most promising options for next-generation antibiotics. In this study, we investigated the bacteriostatic activity of the AMPs Pexiganan, plectasin, melittin, and cathelicidin-DM against Gram-negative and Gram-positive bacteria both in vitro and in a mouse model of BV infection. The results showed that Pexiganan, melittin, and cathelicidin-DM had significant antibacterial activity against both Gram-negative and Gram-positive bacteria. AMPs have great potential for clinical application in the treatment of vaginitis, and this study provides an experimental basis for their use in the active immunoprophylaxis of BV.

A comparative evaluation of the kefir yeast Kluyveromyces marxianus A4 and sulfasalazine in ulcerative colitis: anti-inflammatory impact and gut microbiota modulation

Although only Saccharomyces boulardii has been studied for ulcerative colitis (UC), probiotic yeasts have immense therapeutic potential. Herein, we evaluated the kefir yeast Kluyveromyces marxianus A4 (Km A4) and its anti-inflammatory effect with sulfasalazine in BALB/c mice with dextran sulfate sodium (DSS)-induced colitis. Oral administration continued for 7 days after the mice were randomly divided into seven groups: control (CON, normal mice administered with saline), DSS-induced colitis mice administered saline (DSS), and DSS-induced colitis mice administered sulfasalazine only (S), Km A4 only (A4), Km A4 plus sulfasalazine (A4 + S), S. boulardii ATCC MYA-796 (Sb MYA-796) only (Sb), and Sb MYA-796 plus sulfasalazine (Sb + S). The β-glucan content of Km A4 was significantly higher than that of Sb MYA-796 (P < 0.05). Body weight gain (BWG) significantly correlated with colon length, cyclooxygenase-2 (Cox-2) levels, and Bacteroides abundance (P < 0.05). In colitis-induced mice, the A4 + S group had the lowest histological score (6.00) compared to the DSS group (12.67), indicating the anti-inflammatory effects of this combination. The A4 + S group showed significantly downregulated expression of interleukin (Il)-6, tumor necrosis factor-α (Tnf-α), and Cox-2 and upregulated expression of Il-10 and occludin (Ocln) compared to the DSS group. Mice treated with A4 + S had enhanced Bacteroides abundance in their gut microbiota compared with the DSS group (P < 0.05). Bacteroides were significantly correlated with all colitis biomarkers (BWG, colon length, Il-6, Tnf-α, Il-10, Cox-2, and Ocln; P < 0.05). The anti-inflammatory effects of Km A4 could be attributed to high β-glucan content and gut microbiota modulation. Thus, treatment with Km A4 and sulfasalazine could alleviate UC.

The Effects of Lentinan on the Hematological and Immune Indices of Dairy Cows

In this study, we investigated the effects of lentinan (LNT) on hematological parameters, immune indices, and metabolite levels in dairy cows. We randomly assigned forty Holstein cows to four treatment groups. The treatments consisted of 0, 5, 10, and 15 g/d of LNT. Compared with the control group, the addition of 10 g/d of LNT decreased the content of ALT and IL-8 but simultaneously increased the content of IL-4 in the cows' serum. Supplementation with 10 g/d of LNT decreased the levels of lymphocyte, RDW, ALT, AST, TC, IL-2, and IL-8, but, concurrently, in-creased the levels of granulocytes and IL-4 in their serum. In addition, supplementation with 15 g/d of LNT decreased the levels of RDW, TC, IL-2, and IL-8, but, at the same time, increased the levels of IL-4 and IgM in their serum. For the metabolomic analysis, cows fed with 0 and 10 g/d of LNT were selected. The results showed that 10 metabolites, including reduced nicotinamide riboside and trehalose, were upregulated in the 10 g/d group. These differential metabolites were enriched in tyrosine metabolism and trehalose degradation and altered two metabolic pathways of ubiquinone and other terpene quinone biosynthesis, as well as starch and sucrose metabolism. These findings provide evidence that LNT could be used to reduce the risk of inflammation in dairy cows.

Effects of dietary chlorogenic acid on cecal microbiota and metabolites in broilers during lipopolysaccharide-induced immune stress

Aims

The aim of this study was to investigate the effects of chlorogenic acid (CGA) on the intestinal microorganisms and metabolites in broilers during lipopolysaccharide (LPS)-induced immune stress.

Methods

A total of 312 one-day-old Arbor Acres (AA) broilers were randomly allocated to four groups with six replicates per group and 13 broilers per replicate: (1) MS group (injected with saline and fed the basal diet); (2) ML group (injected with 0.5 mg LPS/kg and fed the basal diet); (3) MA group (injected with 0.5 mg LPS/kg and fed the basal diet supplemented with 1,000 mg/kg CGA); and (4) MB group (injected with saline and fed the basal diet supplemented with 1,000 mg/kg CGA).

Results

The results showed that the abundance of beneficial bacteria such as Bacteroidetes in the MB group was significantly higher than that in MS group, while the abundance of pathogenic bacteria such as Streptococcaceae was significantly decreased in the MB group. The addition of CGA significantly inhibited the increase of the abundance of harmful bacteria such as Streptococcaceae, Proteobacteria and Pseudomonas caused by LPS stress. The population of butyric acid-producing bacteria such as Lachnospiraceae and Coprococcus and beneficial bacteria such as Coriobacteriaceae in the MA group increased significantly. Non-targeted metabonomic analysis showed that LPS stress significantly upregulated the 12-keto-tetrahydroleukotriene B4, riboflavin and mannitol. Indole-3-acetate, xanthurenic acid, L-formylkynurenine, pyrrole-2-carboxylic acid and L-glutamic acid were significantly down-regulated, indicating that LPS activated inflammation and oxidation in broilers, resulting in intestinal barrier damage. The addition of CGA to the diet of LPS-stimulated broilers significantly decreased 12-keto-tetrahydro-leukotriene B4 and leukotriene F4 in arachidonic acid metabolism and riboflavin and mannitol in ABC transporters, and significantly increased N-acetyl-L-glutamate 5-semialdehyde in the biosynthesis of amino acids and arginine, The presence of pyrrole-2-carboxylic acid in D-amino acid metabolism and the cecal metabolites, indolelactic acid, xanthurenic acid and L-kynurenine, indicated that CGA could reduce the inflammatory response induced by immune stress, enhance intestinal barrier function, and boost antioxidant capacity.

Conclusion

We conclude that CGA can have a beneficial effect on broilers by positively altering the balance of intestinal microorganisms and their metabolites to inhibit intestinal inflammation and barrier damage caused by immune stress.

Emerging relevance of cell wall components from non-conventional yeasts as functional ingredients for the food and feed industry

Non-conventional yeast species, or non-Saccharomyces yeasts, are increasingly recognized for their involvement in fermented foods. Many of them exhibit probiotic characteristics that are mainly due to direct contacts with other cell types through various molecular components of their cell wall. The biochemical composition and/or the molecular structure of the cell wall components are currently considered the primary determinant of their probiotic properties. Here we first present the techniques that are used to extract and analyze the cell wall components of food industry-related non-Saccharomyces yeasts. We then review the current understanding of the cell wall composition and structure of each polysaccharide from these yeasts. Finally, the data exploring the potential beneficial role of their cell wall components, which could be a source of innovative functional ingredients, are discussed. Such research would allow the development of high value-added products and provide the food industry with novel inputs beyond the well-established S. cerevisiae.

Effects of microbial-derived biotics (meta/pharma/post-biotics) on the modulation of gut microbiome and metabolome; general aspects and emerging trends

Potential effects of metabiotics (probiotics effector molecules or signaling factors), pharmabiotics (pro-functional metabolites produced by gut microbiota (GMB)) and postbiotics (multifunctional metabolites and structural compounds of food-grade microorganisms) on GMB have been rarely reviewed. These multifunctional components have several promising capabilities for prevention, alleviation and treatment of some diseases or disorders. Correlations between these essential biotics and GMB are also very interesting and important in human health and nutrition. Furthermore, these natural bioactives are involved in modulation of the immune function, control of metabolic dysbiosis and regulation of the signaling pathways. This review discusses the potential of meta/pharma/post-biotics as new classes of pharmaceutical agents and their effective mechanisms associated with GMB-host cell to cell communications with therapeutic benefits which are important in balance and the integrity of the host microbiome. In addition, cutting-edge findings about bioinformatics /metabolomics analyses related to GMB and these essential biotics are reviewed.

Interaction of beta-glucans with gut microbiota: Dietary origins, structures, degradation, metabolism, and beneficial function

Beta-glucan (BG), a polysaccharide comprised of interfacing glucose monomers joined via beta-glycosidic linkages, can be defined as a type of dietary fiber with high specificity based on its interaction with the gut microbiota. It can induce similar interindividual microbiota responses, thereby having beneficial effects on the human body. In this paper, we review the four main sources of BG (cereals, fungi, algae, and bacteria) and their differences in structure and content. The interaction of BG with gut microbiota and the resulting health effects have been highlighted, including immune enhancement, regulation of serum cholesterol and insulin levels, alleviation of obesity and improvement of cognitive disorders. Finally, the application of BG in food products and its beneficial effects on the gut microbiota of consumers were discussed. Although some of the mechanisms of action remain unclear, revealing the beneficial functions of BG from the perspective of gut microbiota can help provide theoretical support for the development of diets that target the regulation of microbiota.

Yeast Cell Wall Compounds on The Formation of Fermentation Products and Fecal Microbiota in Cats: An In Vivo and In Vitro Approach

The effects of yeast cell wall compounds (YCWs) being added to cat food on hindgut fermentation metabolites and fecal microbiota were assessed in in vivo Experiment 1 (Exp. 1) and in vitro Experiments 2 and 3 (Exp. 2 and 3). In Exp. 1, the cats' diets were supplemented with two dietary concentrations (46.2 and 92.4 ppm) of YCWs (YCW-15 and YCW-30, respectively), and a negative control diet with no compound in three groups (six cats per group) was used to assess the fecal score, pH, digestibility, fermentation products, and microbiota. In Exp. 2, feces from the cats that were not supplemented with YCWs (control) were used as an inoculum. A blend of pectin, amino acids, and cellulose was used as a substrate, and the YCW compound was added at two levels (5 and 10 mg). In Exp. 3, feces from cats fed YCWs were used as an inoculum to test three different substrates (pectin, amino acids, and cellulose). In Exp. 2 and 3, the gas production, pH, and fermentation products (ammonia, SCFAs, and BCFAs) were assessed. YCW-30 resulted in a higher digestibility coefficient of the crude protein, organic matter (OM) (p < 0.05), and energy of the diet (p < 0.10). Regarding the fermentation products, YCW-15 showed a trend toward higher concentrations of propionate, acetate, lactate, ammonia, isobutyrate, and valerate, while YCW-30 showed a trend (p < 0.10) toward higher levels of butyrate and pH values. The bacteroidia class and the genus Prevotella were increased by using YCW-30 and the control. At the gender level, decreased (p < 0.01) Megasphaera was observed with YCW inclusion. The microbiota differed (p < 0.01) among the groups in their Shannon indexes. For beta diversity, YCW-30 showed higher indexes (p = 0.008) than the control. The microbiota metabolic profile differed in the pathway CENTFERM-PWY; it was more expressed in YCW-30 compared to the control. In Exp. 2, the YCWs showed a higher ratio (p = 0.006) of the fermentation products in the treatments with additives with a trend towards a high dose of the additive (10 mg). In Exp. 3, the effects of the substrates (p < 0.001), but not of the YCWs, on the fermentation products were observed, perhaps due to the low dietary concentrations we used. However, the marked responses of the fermentation products to the substrates validated the methodology. We could conclude that the YCWs, even at low dietary concentrations, affected fecal SCFA production, reduced the fecal pH, and modulated the fecal microbiota in the cats. These responses were more pronounced under in vitro conditions.

Dietary Supplementation with Chlorogenic Acid Enhances Antioxidant Capacity, Which Promotes Growth, Jejunum Barrier Function, and Cecum Microbiota in Broilers under High Stocking Density Stress

Chlorogenic acids (CGA) are widely used as feed additives for their ability to improve growth performance and intestinal health in poultry. However, whether dietary CGAs could reverse the impaired intestinal condition caused by high stocking density (HD) in broiler chickens is unknown. We determined the effect of dietary CGA on growth, serum antioxidant levels, jejunum barrier function, and the microbial community in the cecum of broilers raised under normal (ND) or HD conditions. HD stress significantly decreased growth and body weight, which was restored by CGA. The HD group showed increased serum malondialdehyde, an oxidative byproduct, and decreased SOD and GSH-Px activity. CGA reduced malondialdehyde and restored antioxidant enzyme activity. HD stress also significantly decreased jejunal villus length and increased crypt depth. Compared with ND, the expression of tight-junction genes was significantly decreased in the HD group, but this decrease was reversed by CGA. HD also significantly upregulated TNF-α. Compared with ND, the cecal microbiota in the HD group showed lower alpha diversity with increases in the harmful bacteria Turicibacter and Shigella. This change was altered in the HD + CGA group, with enrichment of Blautia, Akkermansia, and other beneficial bacteria. These results demonstrated that HD stress decreased serum antioxidant capacity, inhibited the development of jejunal villi, and downregulated expression of tight-junction genes, which increased intestinal permeability during the rapid growth period (21 to 35 days). Dietary CGA enhanced antioxidant capacity, improved intestinal integrity, and enhanced beneficial gut bacteria in chickens raised under HD conditions.

Microbiome-metabolome analysis reveals alterations in the composition and metabolism of caecal microbiota and metabolites with dietary Enteromorpha polysaccharide and Yeast glycoprotein in chickens

The intestinal microbiome is responsible for the fermentation of complex carbohydrates and orchestrates the immune system through gut microbiota-derived metabolites. In our previous study, we reported that supplementation of Enteromorpha polysaccharide (EP) and yeast glycoprotein (YG) in combination synergistically improved antioxidant activities, serum lipid profile, and fatty acid metabolism in chicken. However, the mechanism of action of these polysaccharides remains elusive. The present study used an integrated 16S-rRNA sequencing technology and untargeted metabolomics technique to reveal the mechanism of action of EP+YG supplementation in broiler chickens fed basal diet or diets supplemented with EP+YG (200mg/kg EP + 200mg/kg YG). The results showed that EP+YG supplementation altered the overall structure of caecal microbiota as evidenced by β diversities analysis. Besides, EP+YG supplementation changed the microbiota composition by altering the community profile at the phylum and genus levels. Furthermore, Spearman correlation analysis indicated a significant correlation between altered microbiota genera vs serum cytokine levels and microbiota genera vs volatile fatty acids production. Predicted functional analysis showed that EP+YG supplementation significantly enriched amino acid metabolism, nucleotide metabolism, glycan biosynthesis and metabolism, energy metabolism, and carbohydrate metabolism. Metabolomics analysis confirmed that EP+YG supplementation modulates a myriad of caecal metabolites by increasing some metabolites, including pyruvic acid, pyridoxine, spermidine, spermine, and dopamine, and decreasing metabolites related to lipid metabolisms such as malonic acid, oleic acid, and docosahexaenoic acid. The quantitative enrichment analysis results further showed that glycolysis/gluconeogenesis, citric acid cycle, tyrosine metabolism, glycine, serine, and threonine metabolism, and cysteine and methionine metabolism were the most important enriched pathways identified with enrichment ratio >11, whereas, fatty acid biosynthesis and biosynthesis of unsaturated fatty acids pathways were suppressed. Together, the 16S-rRNA and untargeted metabolomics results uncovered that EP+YG supplementation modulates intestinal microbiota and their metabolites, thereby influencing the important metabolism pathways, suggesting a potential feed additive.

Oral administration of Euglena gracilis paramylon ameliorates chemotherapy-induced leukocytopenia and gut dysbiosis in mice

Euglena gracilis (EUG) is a food supplement rich in beta-glucans, which are stored in the form of granules called paramylon. We determined whether EUG improved chemotherapy-induced leukocytopenia and dysbiosis. Mice were orally administered EUG prior to gemcitabine treatment. Analyses of the blood cell count, leukocyte population in the spleen, granulocyte/macrophage-colony-stimulating factor (GM-CSF) production by splenocytes, and fecal microbiome were conducted. The recovery of total leukocytes, neutrophils, and monocytes was accelerated after a single gemcitabine treatment. A more rapid lymphocyte recovery rate was observed after four gemcitabine treatments. No difference was observed in the percentage of T, B, or myeloid cells or in the expression of Dectin-1 in the spleens of the gemcitabine and EUG/gemcitabine groups. The EUG/gemcitabine group showed an enhanced GM-CSF production by lipopolysaccharides-stimulated splenocytes. Next-generation sequencing revealed that gemcitabine-induced dysbiosis was alleviated. This study demonstrated that EUG-derived beta-glucans could act as a biological response modifier as well as prebiotics for ameliorating chemotherapy-induced adverse effects.

Functionality of Yeast β-Glucan Recovered from Kluyveromyces marxianus by Alkaline and Enzymatic Processes

β-Glucan (BG), one of the most abundant polysaccharides containing glucose monomers linked by β-glycosidic linkages, is prevalent in yeast biomass that needs to be recovered to obtain this valuable polymer. This study aimed to apply alkaline and enzymatic processes for the recovery of BG from the yeast strain Kluyveromyces marxianus TISTR 5925. For this purpose, the yeast was cultivated to produce the maximum yield of raw material (yeast cells). The effective recovery of BG was then established using either an alkaline or an enzymatic process. BG recovery of 35.45% was obtained by using 1 M NaOH at 90 °C for 1 h, and of 81.15% from 1% (w/v) hydrolytic protease enzyme at 55 °C for 5 h. However, BG recovered by the alkaline process was purer than that obtained by the enzymatic process. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy confirmed the purity, the functional groups, and the linkages of BG obtained from different recovery systems and different raw materials. The results of this study suggest that an alkaline process could be an effective approach for the solubilization and recovery of considerable purity of BG from the yeast cells. In addition, the obtained BG had comparable functional properties with commercially available BG. This study reveals the effectiveness of both chemical and biological recovery of BG obtained from yeast as a potential polymeric material.