Regulation effects of indigestible dietary polysaccharides on intestinal microflora: An overview

Effects of molecular weight on simulated digestion and fecal fermentation of polysaccharides from longan pulp in vitro

The gastrointestinal digestion and fermentation in vitro of longan polysaccharide (LP) and its degraded products (DLP-1, DLP-4, and DLP-8) with different molecular weights (Mw) were investigated. Results indicated that four polysaccharides were only slightly degraded in the gastrointestinal digestion and mainly utilized by gut microbiota in the colon. Among them, DLP-8 with the lowest Mw was easily utilized by intestinal bacteria accompanied by the highest production of acetic and butyric acids. The DLP-8 group exhibited the best growth of beneficial bacteria including Dialister, Bifidobacterium, and Bacteroides. Correlation analysis further verified that the modulatory effect of longan polysaccharide on gut microbiota was structure-dependent, and Mw performed a key role in selectively regulating gut microbial composition. These results showed the smaller Mw longan polysaccharides were more readily fermented leading to modulation of gut microbiota in vitro.

Dietary supplementation of Lycium barbarum polysaccharides alleviates soybean meal-induced enteritis in spotted sea bass Lateolabrax maculatus

The aim of this experiment was to investigate the effect of Lycium barbarum polysaccharides (LBP) on alleviating soybean meal-induced enteritis (SBMIE) in spotted sea bass Lateolabrax maculatus. The diet with 44% fishmeal (FM) content was used as a blank control, and soybean meal (SM) was used to replace 50% FM as an experimental control to induce enteritis. Then, on the basis of experimental control, 0.10%, 0.15%, and 0.20% LBP were added as experimental diets. A total of 225 spotted sea bass (44.52 ± 0.24 g) were randomly divided into 5 groups and fed the corresponding diets for 52 d. The results showed that 0.15% LBP decreased serum D-lactic acid (D-LA) content and diamine oxidase (DAO) activity (P < 0.05). In addition, in all LBP supplementation groups, the intestinal tissue morphology was significantly improved (P < 0.05); the intestinal microbial structure gradually recovered to a level close to that without adding SM; and the microbial species richness and diversity were significantly increased (P < 0.05). Through transcriptomic and metabolomic analysis, it was found that the expression of proinflammatory factors such as interleukin-1β (IL-1β), interleukin-12 (IL-12), nuclear factor kappa B subunit 2 (NF-κB2), and Toll-like receptor 2 (TLR2) were significantly down-regulated in the mitogen-activated protein kinase (MAPK) and Toll-like receptor signaling pathways (P < 0.05), and the important tight junction protein gene Occludin was up-regulated (P < 0.05). In addition, LBP down-regulated saponin metabolites and up-regulated amino acid metabolites (P < 0.05). In conclusion, LBP demonstrated a significant alleviating effect on SBMIE of spotted sea bass L. maculatus.

The relationship between acrylamide and neurodegenerative diseases: gut microbiota as a new intermediate cue

Acrylamide (AA), a compound formed during the thermal processing of high-carbohydrate foods, has been implicated in the onset and progression of neurodegenerative diseases. An increasing number of reports support that gut microbiota plays a significant role in brain function and diseases, suggesting it may act as a mediator between AA exposure and the development of neurodegenerative diseases. Available studies have shown that AA intake affects the composition of the gut microbiota and the integrity of the intestinal barrier, both of which are often thought to be associated with the pathogenesis of neurodegenerative diseases, given the numerous evidences linking gut microbiota with the brain. Based on the current understanding, this paper discusses that AA induces the onset and progression of neurodegenerative diseases by disrupting the composition of the gut microbiota and the structure of the intestinal barrier. Furthermore, it explores the interaction between probiotics and AA exposure, as well as the potential for polysaccharides and polyphenols to improve the gut microenvironment, which provides novel perspectives on modulating the neurodegenerative diseases caused by AA exposure through diet.

Identification, heterologous expression, and characterisation of β-1,3-xylanase BcXyn26B from human gut bacterium Bacteroides cellulosilyticus WH2

The cell walls of red and green algae contain β-1,3-xylan, which is hydrolysed by the endo-type enzyme β-1,3-xylanase. Notably, only marine-bacteria-derived β-1,3-xylanases have been functionally characterised to date. In this study, we characterised the enzymatic properties of a potential β-1,3-xylanase (BcXyn26B) derived from the human gut bacterium, Bacteroides cellulosilyticus WH2. The codon optimized BcXyn26B gene was synthesised and expressed in Escherichia coli BL21(DE3). The recombinant protein was purified by a two-step purification process using Ni-affinity chromatography followed by anion exchange chromatography, and its enzymatic properties were characterised. The recombinant BcXyn26B exhibited specific hydrolytic activity against β-1,3-xylan and released various β-1,3-xylooligosaccharides, with β-1,3-xylobiose as the primary product. The optimum reaction temperature was 50 °C, higher than that for other enzymes derived from marine bacteria. This study represents the first report on the identification, heterologous expression, and characterisation of β-1,3-xylanase from human gut microbes. Notably, the substrate specificity of BcXyn26B indicates that human gut Bacteroides species possess an unknown β-1,3-xylan utilisation system.

Edible fungi polysaccharides modulate gut microbiota and lipid metabolism: A review

Edible fungi polysaccharides (EFPs) and gut microbiota (GM) play an important role in lipid metabolism. The structure of GM is complex and can be dynamically affected by the diet. EFPs can be used as dietary intervention to improve lipid metabolism directly, or by regulate the GM to participate in the host lipid metabolism by a complex mechanism. In this paper, we reviewed that EFPs regulate the balance of GM by increasing the number of beneficial bacteria and decreasing the number of harmful bacteria in the intestinal tract. The metabolites of GM are mainly bile acids (BAs), short-chain fatty acids (SCFAs), and lipopolysaccharides (LPS). EFPs can promote the synthesis of BAs and increase the content of SCFAs that produced by GM fermented EFPs, but reduce the content of LPS to regulate lipid metabolism. This review provides a valuable reference for further elucidation of the relationship between EFPs-GM-lipid metabolism and EFPs targeted regulation of GM to improve public health.

Polysaccharides from fermented garlic attenuate high-fat diet-induced obesity in mice through gut microbes

The weight loss and lipid-lowering effects of fermented garlic polysaccharides (BGP) in obese mice were analyzed by detecting the intestinal flora and short-chain fatty acids. An obesity model was established by feeding mice a high-fat diet (HFD) for 8 weeks. After euthanasia, biochemical index testing and hematoxylin and eosin staining were performed. Spearman analysis was used to assess the relationship between the 16S rRNA sequencing results and the fatty acid content in mouse feces. Compared with the obese model mice, the BGP group had significantly reduced body weight and serum triglycerides, total cholesterol, low-density lipoprotein cholesterol, malondialdehyde, and free fatty acids in the serum. Moreover, BGP reversed HFD-induced gut microbiota dysbiosis, as indicated by the elevated populations of Paraclostridium, Lachnospiraceae_UCG_006, Enterorhabdus, and Lachnospiraceae-NK4A136. BGP also significantly increased the contents of acetic, propionic, butyric, and valeric acids. These results indicate that BGP may serve as a potential prebiotic agent that modulates particular bacteria in the gut and their byproducts that play a crucial role in preventing diseases associated with obesity.

Study on the physicochemical properties and gut microbiota regulation of Poria cocos pachyman treated by ball milling

The effect of ball milling on the physicochemical properties and gut microbiota regulation of Poria cocos pachyman (PAC) was investigated. Ball milling reduced the particle size of PAC from 102 μm to 25.19 μm after 12 h, resulting in increasing particle uniformity. Scanning electron microscopy (SEM) revealed surface roughening and fragmentation of PAC after ball milling. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) indicated reduced crystallinity and increased hydroxyl group exposure in ball-milled PAC (BMP). Thermogravimetric analysis (TGA) showed decreased thermal stability in BMP. The optimal ball milled time was 7 h. Moisture contents in PAC and BMP-7 h were 10.30 ± 0.47 % and 10.72 ± 0.12 %, and carbohydrate contents were 81.02 ± 2.27 % and 74.54 ± 1.46 %. In vivo studies on mice demonstrated that both PAC and BMP-7 h increased diversity and reshaped the composition of gut microbiota, with BMP-7 h showing a more pronounced effect. BMP-7 h reduced the Firmicutes/Bacteroidetes ratio, and raised the abundance of Bacteroides, suggesting enhanced prebiotic potential. These findings highlight the role of ball milling in improving the physicochemical properties and prebiotic potential of water-insoluble polysaccharides and provide a theoretical basis for its broader application in the food and biopharmaceutical industries.

Construction of resveratrol and quercetin nanoparticles based on folic acid targeted Maillard products between Jiuzao glutelin isolate and carboxymethyl chitosan: Improved stability and function

Advanced targeted nanoparticles (NPs) were designed to enhance the targeted delivery of resveratrol (RES) and quercetin (QUE) by utilizing carboxymethyl chitosan (CTS) and Jiuzao glutelin isolate (JGI) conjugates. Briefly, RES and QUE were encapsuled within CTS-JGI-2 (CTS/JGI, m/m, 2:1). The carrier's targeting properties were further improved through the incorporation of folic acid (FA) and polyethylenimine (PEI). Moreover, the stability against digestion was enhanced by incorporating baker yeast cell walls (BYCWs) to construct RES-QUE/FA-PEI/CTS-JGI-2/MAT/BYCW NPs. The results demonstrated that FA-PEI/CTS-JGI-2/MAT/BYCW NPs could improve cellular uptake and targeting property of RES and QUE through endocytosis of folic acid receptors (FOLRs). Additionally, RES-QUE successfully alleviated LPS- and DSS-induced inflammation by regulating NF-κB/IkBa/AP-1 and AMPK/SIRT1signaling pathways and reducing the secretion of inflammatory mediators and factors. These findings indicate FA-PEI/CTS-JGI-2/MAT/BYCW NPs hold promise as an oral drug delivery system with targeted delivery capacities for functional substances prone to instability in dietary supplements.

Updated Progress on Polysaccharides with Anti-Diabetic Effects through the Regulation of Gut Microbiota: Sources, Mechanisms, and Structure-Activity Relationships

Diabetes mellitus (DM) is a common chronic metabolic disease worldwide. The disturbance of the gut microbiota has a complex influence on the development of DM. Polysaccharides are one type of the most important natural components with anti-diabetic effects. Gut microbiota can participate in the fermentation of polysaccharides, and through this, polysaccharides regulate the gut microbiota and improve DM. This review begins by a summary of the sources, anti-diabetic effects and the gut microbiota regulation functions of natural polysaccharides. Then, the mechanisms of polysaccharides in regulating the gut microbiota to exert anti-diabetic effects and the structure-activity relationship are summarized. It is found that polysaccharides from plants, fungi, and marine organisms show great hypoglycemic activities and the gut microbiota regulation functions. The mechanisms mainly include repairing the gut burrier, reshaping gut microbiota composition, changing the metabolites, regulating anti-inflammatory activity and immune function, and regulating the signal pathways. Structural characteristics of polysaccharides, such as monosaccharide composition, molecular weight, and type of glycosidic linkage, show great influence on the anti-diabetic activity of polysaccharides. This review provides a reference for the exploration and development of the anti-diabetic effects of polysaccharides.

Butyrate and Propionate are Negatively Correlated with Obesity and Glucose Levels in Patients with Type 2 Diabetes and Obesity

Background

Growing evidence has demonstrated the important roles of gut microbiota and short chain fatty acids, especially acetate, propionate and butyrate, in the development of obesity and metabolic diseases. To date, the effects of acetate, propionate and butyrate on human adiposity and glucose metabolism remain controversial. This study aimed to explore the associations of systemically acetate, propionate and butyrate with obesity and glucose homeostasis in patients with type 2 diabetes (T2D) and obesity.

Methods

A total of 12 patients with T2D and obesity and 8 age- and sex-matched healthy individuals with BMI <24 kg/m2 were enrolled in this study. Height, weight, body composition, blood pressure, biochemical indices, a 75-g oral glucose tolerance test, and plasma acetate, propionate and butyrate were measured at baseline. Then, participants in T2D group were given a weight control therapy, in addition to conventional medication, and all the measurements were repeated 12 months from baseline. The direct segmental multi-frequency bioelectrical impedance analysis was used to assess body composition. Acetate, propionate and butyrate levels were determined by liquid chromatography coupled to tandem mass spectrometry.

Results

Butyrate concentration significantly increased from baseline after obvious weight loss (P<0.05). Correlation analysis showed that propionate was negatively correlated with percent of body fat (PBF) and 2-h plasma glucose (2-h PG) (P<0.05), and butyrate was negatively associated with body mass index, visceral fat area, PBF and 2-h PG (P<0.05). No association was found between acetate and obesity.

Conclusion

Butyrate and propionate are negatively correlated with obesity and glucose levels in patients with T2D and obesity.

Along the microbiota-gut-brain axis: Use of plant polysaccharides to improve mental disorders

With the development of gut microbiota-specific interventions for mental disorders, the interactions between plant polysaccharides and microbiota in the intestinal and their consequent effects are becoming increasingly important. In this review, we discussed the role of plant polysaccharides in improving various mental disorders via the microbiota-gut-brain axis. The chemical and structural characteristics and metabolites of these plant polysaccharides were summarised. Plant polysaccharides and their metabolites have great potential for reshaping gut microbiota profiles through gut microbiota-dependent fermentation. Along the microbiota-gut-brain axis, the consequent pharmacological processes that lead to the elimination of the symptoms of mental disorders include 1) regulation of the central monoamine neurotransmitters, amino acid transmitters and cholinergic signalling system; 2) alleviation of central and peripheral inflammation mainly through the NLRP3/NF-κB-related signalling pathway; 3) inhibition of neuronal apoptosis; and 4) enhancement of antioxidant activities. According to this review, monosaccharide glucose and structure -4-α-Glcp-(1→ are the most potent compositions of the most reported plant polysaccharides. However, the causal structure-activity relationship remains to be extensively explored. Moreover, mechanistic elucidation, safety verification, and additional rigorous human studies are expected to advance plant polysaccharide-based product development targeting the microbiota-gut-brain axis for people with mental disorders.

Lactobacillus induced by irbesartan on spontaneously hypertensive rat contribute to its antihypertensive effect

OBJECTIVE

Hypertension is linked to gut dysbiosis. Here, the impact of the angiotensin receptor antagonist irbesartan on the gut microbiota of spontaneously hypertensive rats (SHR) were investigated. In addition, we assessed their contribution to its antihypertensive effect.

METHODS

Eight-week-old Wistar-Kyoto (WKY) rats and SHR were administered irbesartan for 8 weeks. Fecal microbiota transplantation (FMT) was performed from SHR treated with irbesartan or untreated SHR to recipient untreated SHR. The preventive effect of Lactobacillus on hypertension in SHR was evaluated. Blood pressure (BP) was calculated using a tail-sleeve sphygmomanometer. To better assess the composition of the gut microbiota, the V3-V4 region of the 16S rRNA gene was amplified while short-chain fatty acids (SCFAs) in feces were tested by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS).

RESULTS

Irbesartan restored gut dysbiosis, increased the abundance of Lactobacillus , and improved anti-inflammatory ability, antioxidative ability, intestinal integrity, and intestinal inflammation in SHR. The microbiota in SHR-treated irbesartan could reduce BP and improve antioxidative ability and gut integrity in SHR. Lactobacillus johnsonii ( L. johnsonii ) and Lactobacillus reuteri ( L. reuteri ) reduced BP, restored gut dysbiosis and improved anti-inflammatory ability, antioxidative ability, intestinal integrity in SHR. Most notably, irbesartan, L. johnsonii , and L. reuteri can significantly increase SCFA content in SHR feces.

CONCLUSION

The current study demonstrated that irbesartan treatment ameliorated gut dysbiosis in SHR. Irbesartan induced alterations in gut microbiota, with increased prevalence of Lactobacillus .

Fingerprinting and characterization of the polysaccharides from Polygonatum odoratum and the in vitro fermented effects on Lactobacillus johnsonii

Polygonatum odoratum (Yu-Zhu) can be utilized to treat the digestive and respiratory illness. Previous studies have revealed that the underlying therapeutic mechanism of P. odoratum polysaccharides (POPs) is associated with remodeling the gut microbiota. However, POPs in terms of the chemical composition and fermentation activities have been understudied. Here we developed the three-level fingerprinting approaches to characterize the structures of POPs and probed into the beneficial effects on promoting the growth and fermentation of Lactobacillus johnsonii. POPs were prepared by water decoction followed by alcohol sedimentation, while trifluoroacetic acid under different conditions to prepare the hydrolyzed oligosaccharides and monosaccharides. POPs exhibited three main molecular distribution of 601-620 kDa, 4.12-6.09 kDa, and 3.57-6.02 kDa. Hydrolyzed oligosaccharides with degree of polymerization (DP) 2-13 got primarily characterized by analyzing the rich fragmentation information obtained by hydrophilic interaction chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (HILIC/IM-QTOF-MS). Amongst them, the DP5 oligosaccharide was characterized as 1,6,6-kestopentaose. The molecular ratio of Fru: Ara: Glc: Gal: Xyl was 87.72: 0.30: 11.56: 0.19: 0.23. In vitro fermentation demonstrated that 4.5 mg/mL of POPs could significantly promote the growth of L. johnsonii. Co-cultivated with 4.5 mg/mL of POPs, L. johnsonii exhibited stronger antimicrobial activity against Klebsiella pneumoniae. The concentrations of short-chain fatty acids in the POPs-lactobacilli fermented products, including acetic acid, isobutyric acid, and isovaleric acid, were increased. Conclusively, POPs represent the promising prebiotic candidate to facilitate lactobacilli, which is associated with exerting the health benefits.

Elephantopus scaber L. Polysaccharides Alleviate Heat Stress-Induced Systemic Inflammation in Mice via Modulation of Characteristic Gut Microbiota and Metabolites

Elephantopus scaber L. (ESL) is a Chinese herb that is used both as a food and medicine, often being added to soups in summer in south China to relieve heat stress (HS), but its exact mechanism of action is unknown. In this study, heat-stressed mice were gavaged with ESL polysaccharides (ESLP) at 0, 150, 300, and 450 mg/kg/d-1 (n = 5) for seven days. The gut microbiota composition, short-chain fatty acids (SCFAs), seven neurotransmitters in faeces, expression of intestinal epithelial tight junction (TJ) proteins (Claudin-1, Occludin), and serum inflammatory cytokines were measured. The low dose of ESLP (ESLL) improved the adverse physiological conditions; significantly reduced the cytokines (TNF-α, IL-1β, IL-6) and lipopolysaccharide (LPS) levels (p < 0.05); upregulated the expression of Claudin-1; restored the gut microbiota composition including Achromobacter and Oscillospira, which were at similar levels to those in the normal control group; significantly increased beneficial SCFAs like butyric acid and 5-HT levels in the faeces of heat-stressed mice; and significantly decreased the valeric acid and glutamic acid level. The level of inflammatory markers significantly correlated with the above-mentioned indicators (p < 0.05). Thus, ESLL reduced the HS-induced systemic inflammation by optimizing gut microbiota (Achromobacter, Oscillospira) abundance, increasing gut beneficial SCFAs like butyric acid and 5-HT levels, and reducing gut valeric and glutamic acid levels.

Non-starch polysaccharides from kidney beans: comprehensive insight into their extraction, structure and physicochemical and nutritional properties

Kidney beans (Phaseolus vulgaris L.) are an important legume source of carbohydrates, proteins, and bioactive molecules and thus have attracted increasing attention for their high nutritional value and sustainability. Non-starch polysaccharides (NSPs) in kidney beans account for a high proportion and have a significant impact on their biological functions. Herein, we critically update the information on kidney bean varieties and factors that influence the physicochemical properties of carbohydrates, proteins, and phenolic compounds. Furthermore, their extraction methods, structural characteristics, and health regulatory effects, such as the regulation of intestinal health and anti-obesity and anti-diabetic effects, are also summarized. This review will provide suggestions for further investigation of the structure of kidney bean NSPs, their relationships with biological functions, and the development of NSPs as novel plant carbohydrate resources.

Polysaccharide from Sparassis latifolia alleviates intestinal barrier dysfunction in mice exposed to lead

Exposure to lead can have harmful effects on the intestines and gut microbiota, leading to toxicity. This study aimed to explore the protective role of Sparassis latifolia polysaccharide (SLP) in safeguarding the intestinal barrier of Kunming mice exposed to lead. The findings indicated that SLP effectively alleviates intestinal lesions, increases the density of cupped cells in the intestine, and reduces inflammation in both serum and the small intestine. Furthermore, SLP maintains the expression of key genes such as ZO-1, Occludin, Claudin-1, Lyz, Ang4, and ZO-2, as well as proteins like claudin-1 and Occludin-1. Furthermore, SLP positively impacts the diversity and richness of microorganisms in the mouse gut microbiota at both the genus and gate levels. It also increases the levels of short-chain fatty acids (SCFAs), including acetic acid, butyric acid, and propionic acid, to varying degrees. In summary, SLP plays a role in alleviating the impaired small intestinal barrier in lead-exposed mice by modulating the intestinal flora, which is consistent with reduced lead absorption. This modulation enhances the integrity of the intestinal barrier, suppresses inflammation, and facilitates the excretion of lead.

Polysaccharide from Ziyang Selenium-Enriched Green Tea Prevents Obesity and Promotes Adipose Thermogenesis via Modulating the Gut Microbiota

The objective of the current study was to explore the potential mechanism of Ziyang selenium-enriched green tea polysaccharide (Se-GTP) against obesity. The results showed that Se-GTP significantly alleviated obesity and related metabolic disorders caused by high-fat diet (HFD) in mice. 16S rRNA gene sequencing results revealed that Se-GTP improved gut microbiota disturbance of obese mice and facilitated proliferation of probiotics such as Bacteroides, Bifidobacterium, Lactobacillus, and Akkermansia. In addition, the colonic content of succinate, a product of microbial metabolite in connection with adipocyte thermogenesis, was significantly enhanced by Se-GTP treatment. Therefore, Se-GTP facilitated brown adipose tissue (BAT) thermogenesis and inguinal white adipose tissue (iWAT) browning in obese mice, which could be revealed by increased expressions of thermogenic marker proteins UCP1, PGC-1α, and CIDEA in BAT and iWAT. Interestingly, Se-GTP intervention also observably increased the content of M2-like macrophages in iWAT of obese mice. To summarize, the results of this study are the first to show that Se-GTP can stimulate the browning of iWAT and BAT thermogenesis to counteract obesity, which may be pertinent with the alteration of gut microbiota in obese mice.

Are gut dysbiosis, barrier disruption, and endotoxemia related to adipose tissue dysfunction in metabolic disorders? Overview of the mechanisms involved

Recently, compelling evidence points to dysbiosis and disruption of the epithelial intestinal barrier as major players in the pathophysiology of metabolic disorders, such as obesity. Upon the intestinal barrier disruption, components from bacterial metabolism and bacteria itself can reach peripheral tissues through circulation. This has been associated with the low-grade inflammation that characterizes obesity and other metabolic diseases. While circulating bacterial DNA has been postulated as a common feature of obesity and even type 2 diabetes, almost no focus has been given to the existence and effects of bacteria in peripheral tissues, namely the adipose tissue. As a symbiont population, it is expected that gut microbiota modulate the immunometabolism of the host, thus influencing energy balance mechanisms and inflammation. Gut inflammatory signals cause direct deleterious inflammatory responses in adipose tissue and may also affect key gut neuroendocrine mechanisms governing nutrient sensing and energy balance, like incretins and ghrelin, which play a role in the gut-brain-adipose tissue axis. Thus, it is of major importance to disclose how gut microbiota and derived signals modulate neuroendocrine and inflammatory pathways, which contribute to the dysfunction of adipose tissue and to the metabolic sequelae of obesity and related disorders. This review summarizes the current knowledge regarding these topics and identifies new perspectives in this field of research, highlighting new pathways toward the reduction of the inflammatory burden of metabolic diseases.

Enhanced In Vitro Anti-Photoaging Effect of Degraded Seaweed Polysaccharides by UV/H2O2 Treatment

The high molecular weight and poor solubility of seaweed polysaccharides have limited their function and application. In this study, ultraviolet/hydrogen peroxide (UV/H2O2) treatment was used to prepare low-molecular-weight seaweed polysaccharides from Sargassum fusiforme. The effects of UV/H2O2 treatment on the physicochemical properties and anti-photoaging activity of S. fusiforme polysaccharides were studied. UV/H2O2 treatment effectively degraded polysaccharides from S. fusiforme (DSFPs), reducing their molecular weight from 271 kDa to 26 kDa after 2 h treatment. The treatment did not affect the functional groups in DSFPs but changed their molar percentage of monosaccharide composition and morphology. The effects of the treatment on the anti-photoaging function of S. fusiforme polysaccharides were investigated using human epidermal HaCaT cells in vitro. DFSPs significantly improved the cell viability and hydroxyproline secretion of UVB-irradiated HaCaT cells. In particular, DSFP-45 obtained from UV/H2O2 treatment for 45 min showed the best anti-photoaging effect. Moreover, DSFP-45 significantly increased the content and expression of collagen I and decreased those of pro-inflammatory cytokines, including interleukin-1β, interleukin-6, and tumor necrosis factor-α. Thus, UV/H2O2 treatment could effectively improve the anti-photoaging activity of S. fusiforme polysaccharides. These results provide some insights for developing novel and efficient anti-photoaging drugs or functional foods from seaweed polysaccharides.

Houttuynia cordata Polysaccharide Ameliorates Chronic Inflammation-Induced Intestinal Impairment by Zonula Occludens-1 in Rats

This study aimed to investigate the protective effects of Houttuynia cordata polysaccharide (HCP) against chronic intestinal inflammation in rats that were subjected to low-dose lipopolysaccharide once weekly for 6 weeks. Here, administration of HCP significantly restored morphological changes in the intestine along with enhancement of antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase activities, and reduction of malondialdehyde contents. HCP treatment was also found to attenuate the inflammatory mediators nitric oxide, inducible nitric oxide synthase, total nitric oxide synthase, and interleukin-1beta (IL-lβ) and enhanced the production of short-chain fatty acids. Correspondingly, a significant elevation of zonula occludens-1 (ZO-1) was displayed in the intestine of HCP-treated rats, indicating that the intestinal mechanical barrier could be repaired by HCP treatment. Therefore, these findings suggested that HCP performed protective effects against chronic inflammation-induced intestinal impairment through alleviating inflammation, modifying the redox system, and recovering the intestinal mechanical barrier, mediated by the control of ZO-1 in rats.

Effects of kiwi fruit (Actinidia chinensis) polysaccharides on metabolites and gut microbiota of acrylamide-induced mice

Introduction

Kiwifruit (Actinidia chinensis) has rich nutritious and medicinal properties. It is widely consumed worldwide for the intervention of metabolism disorders, however, the underlying mechanism remains unclear. Acrylamide, a well-known toxic ingredient, mainly forms in high-temperature processed carbohydrate-rich food and causes disorders of gut microbiota and systemic metabolism.

Methods

This study explored the protective effects and underlying mechanisms of kiwifruit polysaccharides against acrylamide-induced disorders of gut microbiota and systemic metabolism by measuring the changes of gut microbiota and serum metabolites in mice.

Results

The results showed that kiwifruit polysaccharides remarkably alleviated acrylamide-induced toxicity in mice by improving their body features, histopathologic morphology of the liver, and decreased activities of liver function enzymes. Furthermore, the treatment restored the healthy gut microbiota of mice by improving the microbial diversity and abundance of beneficial bacteria such as Lactobacillus. Metabolomics analysis revealed the positive effects of kiwifruit polysaccharides mainly occurred through amino and bile acid-related metabolism pathways including nicotinate and nicotinamide metabolism, primary bile acid biosynthesis, and alanine, aspartate and glutamate metabolism. Additionally, correlation analysis indicated that Lactobacillus exhibited a highly significant correlation with critical metabolites of bile acid metabolism.

Discussion

Concisely, kiwifruit polysaccharides may protect against acrylamide-induced toxicity by regulating gut microbiota and metabolism.

Alleviation of DSS-induced colitis in mice by a new-isolated Lactobacillus acidophilus C4

Introduction

Probiotic is adjuvant therapy for traditional drug treatment of ulcerative colitis (UC). In the present study, Lactobacillus acidophilus C4 with high acid and bile salt resistance has been isolated and screened, and the beneficial effect of L. acidophilus C4 on Dextran Sulfate Sodium (DSS)-induced colitis in mice has been evaluated. Our data showed that oral administration of L. acidophilus C4 remarkably alleviated colitis symptoms in mice and minimized colon tissue damage.

Methods

To elucidate the underlying mechanism, we have investigated the levels of inflammatory cytokines and intestinal tight junction (TJ) related proteins (occludin and ZO-1) in colon tissue, as well as the intestinal microbiota and short-chain fatty acids (SCFAs) in feces.

Results

Compared to the DSS group, the inflammatory cytokines IL-1β, IL-6, and TNF-α in L. acidophilus C4 group were reduced, while the antioxidant enzymes superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT) were found to be elevated. In addition, proteins linked to TJ were elevated after L. acidophilus C4 intervention. Further study revealed that L. acidophilus C4 reversed the decrease in intestinal microbiota diversity caused by colitis and promoted the levels of SCFAs.

Discussion

This study demonstrate that L. acidophilus C4 effectively alleviated DSS-induced colitis in mice by repairing the mucosal barrier and maintaining the intestinal microecological balance. L. acidophilus C4 could be of great potential for colitis therapy.

Extraction, purification, structural features and biological activities of longan fruit pulp (Longyan) polysaccharides: A review

Dimocarpus longan Lour. (also called as longan) is a subtropical and tropical evergreen tree belonging to the Sapindaceae family and is widely distributed in China, Southeast Asia and South Asia. The pulp of longan fruit is a time-honored traditional medicinal and edible raw material in China and some Asian countries. With the advancement of food therapy in modern medicine, longan fruit pulp as an edible medicinal material is expected to usher in its rapid development as a functional nutrient. As one of the main constituents of longan fruit pulp, longan fruit pulp polysaccharides (LPs) play an indispensable role in longan fruit pulp-based functional utilization. This review aims to outline the extraction and purification methods, structural characteristics and biological activities (such as immunoregulatory, anti-tumor, prebiotic, anti-oxidant, anti-inflammatory and inhibition of AChE activity) of LPs. Besides, the structure-activity relationship, application prospect and patent application of LPs were analyzed and summarized. Through the systematic summary, this review attempts to provide a theoretical basis for further research of LPs, and promote the industrial development of this class of polysaccharides.

Polysaccharides from Callerya speciosa alleviate metabolic disorders and gut microbiota dysbiosis in diet-induced obese C57BL/6 mice

Callerya speciosa ("Niu Dali" in Chinese) is a well-known edible plant in Southeast China. C. speciosa roots contain a high level of polysaccharides, which have been reported to show multiple health-promoting effects. In the current study, the anti-obesity effects of a crude extract of C. speciosa polysaccharides (NP) and its underlying mechanisms of action are investigated. C57BL/6 mice were divided into three groups and fed either a standard diet or a high-fat diet (HFD). The HFD + NP group mice received oral administration of NP (100 mg per kg per day) every other day for 10 weeks. NP supplementation alleviated HFD-induced diabetic biomarkers including body weight gain, hyperlipidemia, liver steatosis, and adipocyte hypertrophy. Western blot and RT-PCR analyses revealed that NP inhibited hepatic de novo lipogenesis and adipogenesis (i.e. decreased expression of Srebp1c, Fas, Cebpα, and Pparγ), stimulated adipocyte lipolysis (enhanced mRNA expression of Hsl and Mgl), and attenuated HFD-induced hepatic inflammation (decreased expression of TNF-α and NF-κB p65). Furthermore, 16S rDNA and GC-MS analyses showed that NP supplementation restored the Firmicutes/Bacteroidetes proportion, elevated colon-derived SCFAs, especially acetic acid content, and increased the relative abundance of genera associated with SCFA production in HFD-fed mice. Findings from this study suggest that NP alleviated HFD-induced obesity in a mouse model, which was possibly due to its ameliorative effects on diet-induced gut dysbiosis. Polysaccharides from C. speciosa are promising prebiotics and they may be further developed as functional foods for the management of obesity.

Effects of fucoidans and alginates from Sargassum graminifolium on allergic symptoms and intestinal microbiota in mice with OVA-induced food allergy

Food allergy has been one of the main problems threatening people's health in recent years. However, there is still no way to completely cure it at present. Therefore, the development of food allergy related drugs is still necessary. Sargassum graminifolium (SG) is a kind of polysaccharide rich marine brown alga used in food and medicine. Sargassum graminifolium polysaccharides (SGP) is mainly composed of fucoidans and alginic acid. In our study, we compared the activity of fucoidans and alginates from SG against OVA-induced food allergy in a mouse model, observed the regulatory effects of fucoidans and alginates from SG on the intestinal microbiota and summarized the possible role of the intestinal microbiota in the anti-food allergy process because polysaccharides can further act on the body through the intestinal microbiota. The results showed that fucoidans and alginates from SG could relieve the symptoms of allergy, diarrhea and jejunum injury significantly in mice with food allergy (p < 0.05). Furthermore, fucoidans at 500 mg kg-1 could reduce OVA-specific IgE and TNF-α levels significantly in the serum of food allergic mice (p < 0.05), while alginates could only significantly down-regulate serum OVA-specific IgE (p < 0.05). The results also showed that fucoidans had a stronger regulatory effect on the richness and diversity of the intestinal microbiota in food allergic mice compared to alginates at the same dose. In addition, fucoidans at 500 mg kg-1 had the most significant regulatory effect on Firmicutes, Lactobacillus and Alistipes in food allergic mice. These results suggested that fucoidans and alginates might regulate food allergy in mice through different pathways. Together, this study enriched the research on the action of alga-derived polysaccharides against food allergy.

Functional Fermented Probiotics, Prebiotics, and Synbiotics from Non-Dairy Products: A Perspective from Nutraceutical

The current trend of health-conscious consumers and healthy food habits prompts researchers to explore developing food products with synbiotic benefits. Synbiotic foods have gained popularity in recent years due to their functional, nutritional, physiological, and therapeutic characteristics. Lactose intolerance, dyslipidemia, and allergic milk proteins become the barriers in the development of dairy probiotics. The present scenario of an increase in the demand for vegetarian products leads to a rise in the consumption of non-dairy probiotics. Prebiotics like, resistant starch, inulin, and polyphenols are selectively used by gut microbiota to enhance the selection and colonization of probiotics bacteria. Probiotic's action mechanisms include the production of bacteriocins, peptides, short-chain fatty acids, amino acids, vitamins, and other metabolites. Therefore, this review article explores the alternative sources of probiotics so it will help to an understanding of non-dairy based functional fermented foods for both pro and prebiotics. Dietary fibers in vegetables, fruits, and cereals are one of prospective prebiotics and highlighted the various methods for making non-dairy synbiotics based on dietary fibers, such as microencapsulation, freeze-drying, and spray drying is also addressed.

Influence of the ecological environment on the structural characteristics and bioactivities of polysaccharides from alfalfa (Medicago sativa L.)

Polysaccharides from alfalfa (Medicago sativa L.) (APS) exhibit a variety of bioactivities; however, little information is available on the effects of the ecological environment on the structural characteristics and bioactivities of APS.

The Role of Short-Chain Fatty Acids of Gut Microbiota Origin in Hypertension

Hypertension is a significant risk factor for cardiovascular and cerebrovascular diseases, and its development involves multiple mechanisms. Gut microbiota has been reported to be closely linked to hypertension. Short-chain fatty acids (SCFAs)-the metabolites of gut microbiota-participate in hypertension development through various pathways, including specific receptors, immune system, autonomic nervous system, metabolic regulation and gene transcription. This article reviews the possible mechanisms of SCFAs in regulating blood pressure and the prospects of SCFAs as a target to prevent and treat hypertension.

Immunosuppressive activity is attenuated by Astragalus polysaccharides through remodeling the gut microenvironment in melanoma mice

Astragalus polysaccharides (APS), the main effective component of Astragalus membranaceus, can inhibit tumor growth, but the underlying mechanisms remain unclear. Previous studies have suggested that APS can regulate the gut microenvironment, including the gut microbiota and fecal metabolites. In this work, our results showed that APS could control tumor growth in melanoma-bearing mice. It could reduce the number of myeloid-derived suppressor cells (MDSC), as well as the expression of MDSC-related molecule Arg-1 and cytokines IL-10 and TGF-β, so that CD8⁺ T cells could kill tumor cells more effectively. However, while APS were administered with an antibiotic cocktail (ABX), MDSC could not be reduced, and the growth rate of tumors was accelerated. Consistent with the changes in MDSC, the serum levels of IL-6 and IL-1β were lowest in the APS group. Meanwhile, we found that fecal suspension from mice in the APS group could also reduce the number of MDSC in tumor tissues. These results revealed that APS regulated the immune function in tumor-bearing mice through remodeling the gut microbiota. Next, we focused on the results of 16S rRNA, which showed that APS significantly regulated most microorganisms, such as Bifidobacterium pseudolongum, Lactobacillus johnsonii and Lactobacillus. According to the Spearman analysis, the changes in abundance of these microorganisms were related to the increase of metabolites like glutamate and creatine, which could control tumor growth. The present study demonstrates that APS attenuate the immunosuppressive activity of MDSC in melanoma-bearing mice by remodeling the gut microbiota and fecal metabolites. Our findings reveal the therapeutic potential of APS to control tumor growth.

Aqueous extracts of Aconite promote thermogenesis in rats with hypothermia via regulating gut microbiota and bile acid metabolism

Background

Intermittent or prolonged exposure to severe cold stress disturbs energy homeostasis and can lead to hypothermia, heart failure, Alzheimer’s disease, and so on. As the typical “hot” traditional Chinese medicine, Aconite has been widely used to treat cold-associated diseases for thousands of years, but its critical mechanisms for the promotion of thermogenesis are not fully resolved. Gut microbiota and its metabolites play a crucial role in maintaining energy homeostasis. Here, we investigated whether the aqueous extracts of Aconite (AA) can enhance thermogenesis through modulation of the composition and metabolism of gut microbiota in hypothermic rats.

Methods

The therapeutic effects of AA on body temperature, energy intake, and the histopathology of white adipose tissue and brown adipose tissue of hypothermic rats were assessed. Microbiota analysis based on 16 S rRNA and targeted metabolomics for bile acids (BAs) were used to evaluate the composition of gut microbiota and BAs pool. The antibiotic cocktail treatment was adopted to further confirm the relationship between the gut microbiota and the thermogenesis-promoting effects of AA.

Results

Our results showed a sharp drop in rectal temperature and body surface temperature in hypothermic rats. Administration of AA can significantly increase core body temperature, surface body temperature, energy intake, browning of white adipose tissue, and thermogenesis of brown adipose tissue. Importantly, these ameliorative effects of AA were accompanied by the shift of the disturbed composition of gut microbiota toward a healthier profile and the increased levels of BAs. In addition, the depletion of gut microbiota and the reduction of BAs caused by antibiotic cocktails reduced the thermogenesis-promoting effect of AA.

Conclusions

Our results demonstrated that AA promoted thermogenesis in rats with hypothermia via regulating gut microbiota and BAs metabolism. Our findings can also provide a novel solution for the treatment of thermogenesis-associated diseases such as rheumatoid arthritis, obesity, and type 2 diabetes.