Dietary Polysaccharides Research Articles

Bile-induced biofilm formation in Bacteroides thetaiotaomicron requires magnesium efflux by an RND pump.

Bacteroides thetaiotaomicron is a prominent member of the human gut microbiota contributing to nutrient exchange, gut function, and maturation of the host's immune system. This obligate anaerobe symbiont can adopt a biofilm lifestyle, and it was recently shown that B. thetaiotaomicron biofilm formation is promoted by the presence of bile. This process also requires a B. thetaiotaomicron extracellular DNase, which is not, however, regulated by bile. Here, we showed that bile induces the expression of several Resistance-Nodulation-Division (RND) efflux pumps and that inhibiting their activity with a global competitive efflux inhibitor impaired bile-dependent biofilm formation. We then showed that, among the bile-induced RND-efflux pumps, only the tripartite BT3337-BT3338-BT3339 pump, re-named BipABC [for Bile Induced Pump A (BT3337), B (BT3338), and C (BT3339)], is required for biofilm formation. We demonstrated that BipABC is involved in the efflux of magnesium to the biofilm extracellular matrix, which leads to a decrease of extracellular DNA concentration. The release of magnesium in the biofilm matrix also impacts biofilm structure, potentially by modifying the electrostatic repulsion forces within the matrix, reducing interbacterial distance and allowing bacteria to interact more closely and form denser biofilms. Our study therefore, identified a new molecular determinant of B. thetaiotaomicron biofilm formation in response to bile salts and provides a better understanding on how an intestinal chemical cue regulates biofilm formation in a major gut symbiont.IMPORTANCEBacteroides thetaiotaomicron is a prominent member of the human gut microbiota able to degrade dietary and host polysaccharides, altogether contributing to nutrient exchange, gut function, and maturation of the host's immune system. This obligate anaerobe symbiont can adopt a biofilm community lifestyle, providing protection against environmental factors that might, in turn, protect the host from dysbiosis and dysbiosis-related diseases. It was recently shown that B. thetaiotaomicron exposure to intestinal bile promotes biofilm formation. Here, we reveal that a specific B. thetaiotaomicron membrane efflux pump is induced in response to bile, leading to the release of magnesium ions, potentially reducing electrostatic repulsion forces between components of the biofilm matrix. This leads to a reduction of interbacterial distance and strengthens the biofilm structure. Our study, therefore, provides a better understanding of how bile promotes biofilm formation in a major gut symbiont, potentially promoting microbiota resilience to stress and dysbiosis events.

Structure dependent fermentation kinetics of dietary carrot rhamnogalacturonan-I in an in vitro gut model

Plant derived dietary polysaccharides are important for gut health and have the potential to modulate the gut microbial community. Dietary rhamnogalacturonan-I obtained by enzymatic treatment of carrot pomace has shown prebiotic properties. In the present study, fermentability of carrot rhamnogalacturonan-I (cRG-I) by faecal microbiota of four donors was studied in an adapted M-SHIME® intestinal model. Despite its complex structure, cRG-I was degraded rapidly in the proximal colon compartment and fermentation became quicker and more complete during three weeks of repeated supplementation. Tracking the change in the molecular weight distribution pattern of cRG-I during the supplementation showed two main donor-dependent gut microbial fermentation strategies designated as either the general or preferential pathway. In the general fermentation pathway, different cRG-I structures were hydrolysed concomitantly, while in the preferential pathway discrete structures were sequentially fermented in a selective manner. Especially arabinan sidechains were utilized before the RG-I backbone, which correlated with an increase in Bifidobacterium longum absolute abundance over the three weeks period. MALDI-TOF MS confirmed that arabinan-, galactan- and arabinogalactan-sidechains were first to be released and degraded. Donor specific production of all SCFA increased over time with a general trend of higher levels of acetate and propionate than butyrate. Strikingly, although the host's baseline gut microbiota composition led to distinct cRG-I hydrolysis routes, the final RG-I consumption was almost complete for both routes, leading to similar metabolic profiles at the end of the three weeks treatment period.

New Perspectives on the Risks of Hydroxylated Polychlorinated Biphenyl (OH-PCB) Exposure: Intestinal Flora α-Glucosidase Inhibition.

Polychlorinated biphenyls (PCBs) are a group of colorless and odorless environmental pollutants with a wide range of toxic effects. Some PCBs, especially less chlorinated ones, will rapidly undergo phase I metabolism after entering the body, and hydroxylated polychlorinated biphenyls (OH-PCBs) are the main metabolites of PCBs. Intestinal flora α-glucosidase is a common carbohydrate-active enzyme which is ubiquitous in human intestinal flora. It can convert complex dietary polysaccharides into monosaccharides, assisting the body in degrading complex carbohydrates and providing energy for the survival and growth of bacterial flora. The present study aims to investigate the inhibition of the activity of intestinal flora α-glucosidase by OH-PCBs. 4-Nitrophenyl-α-D-glucopyranoside (PNPG) was used as a probe substrate for α-glucosidase, and in vitro incubation experiments were conducted to study the inhibition of 26 representative OH-PCBs on α-glucosidase. Preliminary screening of in vitro incubation was performed with 100 μM of OH-PCBs. The results showed that 26 OH-PCBs generally exhibited strong inhibition of α-glucosidase. The concentration-dependent inhibition and half inhibition concentrations (IC50s) of OH-PCBs on α-glucosidase were determined. 4'-OH-PCB 86 and 4'-OH-PCB 106 were chosen as representative OH-PCBs, and the inhibition kinetic parameters (Kis) of inhibitors for α-glucosidase were determined. The inhibition kinetic parameters (Kis) of 4'-OH-PCB 86 and 4'-OH-PCB 106 for α-glucosidase are 1.007 μM and 0.538 μM, respectively. The silico docking method was used to further analyze the interaction mechanism between OH-PCBs and α-glucosidase. All these results will help us to understand the risks of OH-PCB exposure from a new perspective.

Effect of Saccharina japonica Intake on Blood Pressure and Gut Microbiota Composition in Spontaneously Hypertensive Rats.

It was reported that the consumption of Saccharina japonica (SJ) lowers blood pressure (BP) in hypertensive rats. Hypertension is related to gut microbiota, and hypertensive patients develop dysbiosis. It was reported that the intake of dietary fiber and polysaccharides contained in SJ changes gut microbiota and increases short-chain fatty acids (SCFAs). The present study examined the effect of BP lowering by SJ in spontaneously hypertensive rats (SHRs) and observed changes in gut microbiota composition and SCFAs concentration. Male SHRs and Wistar Kyoto rats (WKYs) were fed a diet containing 5% SJ or a control diet for six weeks. We measured systolic BP (SBP) weekly, as well as mean arterial BP (MAP), the 16S rRNA gene, and SCFAs in the cecal contents at the end of the period. As a result, the intake of SJ significantly decreased SBP and MAP in SHRs. As well, it significantly changed the microbial diversity by altering the gut microbiota composition. Particularly, it increased the abundance of Bacteroides acidifaciens, which may be associated with the antihypertensive effect of SJ. Thus, SJ intake suppressed the increase in BP and altered the gut microbiota composition, although it did not significantly change the SCFAs concentration in the cecal contents.

Temporal dynamics of gut microbiomes in non-industrialized urban Amazonia.

Increasing levels of industrialization have been associated with changes in gut microbiome structure and loss of features thought to be crucial for maintaining gut ecological balance. The stability of gut microbial communities over time within individuals seems to be largely affected by these changes but has been overlooked among transitioning populations from low- to middle-income countries. Here, we used metagenomic sequencing to characterize the temporal dynamics in gut microbiomes of 24 individuals living an urban non-industrialized lifestyle in the Brazilian Amazon. We further contextualized our data with 165 matching longitudinal samples from an urban industrialized and a rural non-industrialized population. We show that gut microbiome composition and diversity have greater variability over time among non-industrialized individuals when compared to industrialized counterparts and that taxa may present diverse temporal dynamics across human populations. Enterotype classifications show that community types are generally stable over time despite shifts in microbiome structure. Furthermore, by tracking genomes over time, we show that levels of bacterial population replacements are more frequent among Amazonian individuals and that non-synonymous variants accumulate in genes associated with degradation of host dietary polysaccharides. Taken together, our results suggest that the stability of gut microbiomes is influenced by levels of industrialization and that tracking microbial population dynamics is important to understand how the microbiome will adapt to these transitions.IMPORTANCEThe transition from a rural or non-industrialized lifestyle to urbanization and industrialization has been linked to changes in the structure and function of the human gut microbiome. Understanding how the gut microbiomes changes over time is crucial to define healthy states and to grasp how the gut microbiome interacts with the host environment. Here, we investigate the temporal dynamics of gut microbiomes from an urban and non-industrialized population in the Amazon, as well as metagenomic data sets from urban United States and rural Tanzania. We showed that healthy non-industrialized microbiomes experience greater compositional shifts over time compared to industrialized individuals. Furthermore, bacterial strain populations are more frequently replaced in non-industrialized microbiomes, and most non-synonymous mutations accumulate in genes associated with the degradation of host dietary components. This indicates that microbiome stability is affected by transitions to industrialization, and that strain tracking can elucidate the ecological dynamics behind such transitions.

Study on the Digestive Behavior of Chlorogenic Acid in Biomimetic Dietary Fiber and the Antioxidative Synergistic Effect of Polysaccharides and Chlorogenic Acid.

Chlorogenic acid (CA) is often combined with dietary fiber polysaccharides in plant foods, which may affect its digestive behavior and antioxidant activity. This study constructed a biomimetic dietary fiber (BDF) model by combining bacterial cellulose (BC) and pectin with CA and investigated the digestive behavior of CA in BDF. Additionally, the study examined the interaction and synergistic effects of polysaccharides and CA against oxidation. Results showed that BDF and natural dietary fiber had similar microstructures, group properties, and crystallization properties, and polysaccharides in BDF were bound to CA. After simulated gastrointestinal digestion, 41.03% of the CA existed in a conjugated form, and it was possibly influenced by the interaction between polysaccharides and CA. And the release of CA during simulated digestion potentially involved four mechanisms, including the disintegration of polysaccharide-CA complex, the dissolution of pectin, escape from BC-pectin (BCP) network structure, and diffusion release. And polysaccharides and CA may be combined through noncovalent interactions such as hydrogen bonding, van der Waals force, or electrostatic interaction force. Meanwhile, polysaccharides-CA combination had a synergistic antioxidant effect by the results of free-radical scavenging experiments, it was probably related to the interaction between polysaccharides and CA. The completion of this work has a positive significance for the development of dietary intervention strategies for oxidative damage.

Holo-analysis of the effects of xylo-oligosaccharides on broiler chicken performance

ABSTRACT 1. Xylo-oligosaccharides (XOS) stimulate proliferation of beneficial bacteria in the gastrointestinal tract of broiler chickens. This results in enhanced utilisation of dietary non-starch polysaccharides and increased production of valuable short-chain fatty acids. However, these positive effects do not always translate into improved bird productive performance, with inconsistent performance responses observed between bird trials. 2. A holo-analysis was conducted to determine the effects of supplementing XOS into broiler diets on bird feed intake, body weight gain, feed conversion and mortality. This was done by comparing the XOS supplemented treatment to the control treatment. A total of 53 studies which met the criteria for inclusion were used in the analysis. 3. The results showed that XOS had a notable positive impact on bird mortality; XOS reduced mortality by 0.69% for every 1% increment in the control group. XOS supplementation induced a positive effect on the feed conversion ratio (FCR). However, the efficacy of XOS at improving FCR was dependent on the efficiency of the control group (performance of the flock), and the concentration of total arabinoxylan, protein and phytase in the diet. There were insufficient data points to predict the effect of XOS on body weight and feed intake. 4. In conclusion, the holo-analysis revealed that supplementing XOS to broiler chicken diets reduces bird mortality. XOS can also improve FCR, but the scale of response is dependent on the diet composition and control flock performance. Additional studies are required to confirm the effects of XOS on body weight and feed intake.

A critical review on intestinal mucosal barrier protection effects of dietary polysaccharides.

Studies have shown that dietary polysaccharides, which are widely present in natural foods, have an important impact on the intestinal mucosal barrier. Dietary polysaccharides can maintain the intestinal barrier function through multiple mechanisms. The intestinal barrier is composed of mechanical, chemical, immune, and biological barriers, and dietary polysaccharides, as a bioactive component, can promote and regulate these four barriers. Dietary polysaccharides can enhance the expression of tight junction proteins and mucins such as occludin-1 and zonula occludens-1 (ZO-1) between intestinal epithelial cells, inhibit inflammatory response and oxidative stress, increase the growth of beneficial bacteria, produce beneficial metabolites such as short chain fatty acids (SCFAs), and promote the proliferation and metabolism of immune cells. Given the critical role of the intestinal mucosal system in health and disease, the protective effects of dietary polysaccharides may be potentially valuable for the prevention and treatment of gut-related diseases. Therefore, it is of great significance to further study the mechanism and application prospects of the intestinal mucosal barrier derived from plant, animal, fungal and bacterial sources.

The regulation of glucose and lipid metabolism through the interaction of dietary polyphenols and polysaccharides via the gut microbiota pathway.

The interaction of polyphenols-polysaccharides-gut microbiota to promote health benefits has become a hotspot and direction for precise dietary intervention strategies and foundational research in biomedicine. Both dietary polyphenols and polysaccharides possess biological activities that regulate body health. Single components, due to their inherent structure and physicochemical properties, have a low bioavailability, thus are unable to exert their optimal effects. The compound structure formed by the interaction of polyphenols and polysaccharides can enhance their functional properties, thereby more effectively promoting health benefits and preventing diseases. This review primarily focuses on the roles played by polyphenols and polysaccharides in regulating glucose and lipid metabolism, the improvement of glucose and lipid metabolism through the gut microbial pathway by polyphenols and polysaccharides, and the mechanisms by which polyphenols and polysaccharides interact to regulate glucose and lipid metabolism. A considerable amount of preliminary research has confirmed the regulatory effects of plant polyphenols and polysaccharides on glucose and lipid metabolism. However, studies on the combined effects and mechanisms of these two components are still very limited. This review aims to provide a reference for subsequent research on their interactions and changes in functional properties.

Regulatory effects of tea polysaccharides on hepatic inflammation, gut microbiota dysbiosis, and serum metabolomic signatures in beef cattle under heat stress.

Long-term heat stress (HS) severely restricts the growth performance of beef cattle and causes various health problems. The gut microbiota plays a crucial role in HS-associated inflammation and immune stress involving lymphocyte function. This study investigated the effects of dietary tea polysaccharide (TPS), a natural acidic glycoprotein, on HS-induced anorexia, inflammation, and gut microbiota dysbiosis in Simmental beef cattle. The cattle were divided into two groups, receiving either normal chow or normal chow plus TPS (8g/kg, 0.8%). Transcriptome sequencing analysis was used to analysis the differential signaling pathway of liver tissue. 16S rDNA sequencing was performed to analysis gut microbiota of beef cattle. Serum metabolite components were detected by untargeted metabolomics analysis. Hepatic transcriptomics analysis revealed that differentially expressed genes in TPS-fed cattle were primarily enriched in immune processes and lymphocyte activation. TPS administration significantly reduced the expression of the TLR4/NF-κB inflammatory signaling pathway, alleviating HS-induced hepatic inflammation. Gut microbiota analysis revealed that TPS improved intestinal homeostasis in HS-affected cattle by increasing bacterial diversity and increasing the relative abundances of Akkermansia and Alistipes while decreasing the Firmicutes-to-Bacteroidetes ratio and the abundance of Agathobacter. Liquid chromatography-tandem mass spectrometry (LC‒MS/MS) analysis indicated that TPS significantly increased the levels of long-chain fatty acids, including stearic acid, linolenic acid, arachidonic acid, and adrenic acid, in the serum of cattle. These findings suggest that long-term consumption of tea polysaccharides can ameliorate heat stress-induced hepatic inflammation and gut microbiota dysbiosis in beef cattle, suggesting a possible liver-gut axis mechanism to mitigate heat stress.

Microbial metabolites as modulators of host physiology.

The gut microbiota is increasingly recognised as a key player in influencing human health and changes in the gut microbiota have been strongly linked with many non-communicable conditions in humans such as type 2 diabetes, obesity and cardiovascular disease. However, characterising the molecular mechanisms that underpin these associations remains an important challenge for researchers. The gut microbiota is a complex microbial community that acts as a metabolic interface to transform ingested food (and other xenobiotics) into metabolites that are detected in the host faeces, urine and blood. Many of these metabolites are only produced by microbes and there is accumulating evidence to suggest that these microbe-specific metabolites do act as effectors to influence human physiology. For example, the gut microbiota can digest dietary complex polysaccharides (such as fibre) into short-chain fatty acids (SCFA) such as acetate, propionate and butyrate that have a pervasive role in host physiology from nutrition to immune function. In this review we will outline our current understanding of the role of some key microbial metabolites, such as SCFA, indole and bile acids, in human health. Whilst many studies linking microbial metabolites with human health are correlative we will try to highlight examples where genetic evidence is available to support a specific role for a microbial metabolite in host health and well-being.

Beyond Nutrients: Exploring the Potential of Phytochemicals for Human Health

Phytochemicals are a broad class of bioactive substances that are produced by plants and can be found in a variety of foods, including fruits, vegetables, nuts, and herbs. These phytochemicals, which include dietary fibers, polysaccharides, phytosterols, isoprenoids, carotenoids, and saponins, provide a variety of health advantages, including antiviral, antibacterial, and anti-inflammatory effects. They also have strong antioxidant qualities. This thorough analysis focuses on the several phytochemicals, their origins, and the health benefits that go along with them. Recognizing the variety and advantages of phytochemicals highlights how they might improve human nutrition and health. This article's summary material comes from reliable academic sources such as Pubmed, Google Scholar, and ScienceDirect. This page gives a brief introduction to the many and significant categories of plant-derived bioactive compounds by summarizing the major phytochemical classes, their origins, and their health advantages. Using the advantages of these substances to improve health outcomes points to a viable direction for further study and implementation in the promotion of overall wellness and health. Keywords: Phytochemicals, Carotenoids, Polyphenols, Bioactive compounds, Phytosterols, Saponins

Влияние растворимых пищевых волокон из larix dahurica на качество молочного биопродукта

Wood extracts of Daurian larch (Larix gmelinii) serve as raw material for the prebiotic food additive called Lavitol Arabinogalactan. Larch arabinogalactan is a soluble dietary polysaccharide fiber with a wide range of preventive effects. Fermented dairy products fortified with larch arabinogalactan become functional products with valuable therapeutic activities. This research featured the effect of various doses of larch arabinogalactan on fermentation of normalized milk mixes and the quality profile of the finished dairy bioproduct. The authors determined the optimal dose of dietary fiber, established its prebiotic properties, and determined the physicochemical profile of the final functional product. The experiments involved lyophilized starter on pure cultures of Str. thermophilus, Lac. delbrueckii subsp. Bulgaricus, and B. bifidum. The optimal cultivation temperature was (38 ± 2) °C. Larch arabinogalactan was added to normalized milk mixes in an amount of 0.5–2.5 %. The authors determined the active acidity during fermentation and established a direct relationship between the increase in acidity and the increase in the mass fraction of larch arabinogalactan. The study also involved the lactic acid microbial count and the bifidobacterial count in the fermented mixes. The viable microbial count in the fortified samples demonstrated lactic acid microorganisms (107–109 CFU/cm3) and bifidobacteria (106–108 CFU/cm3). The optimal dose of larch arabinogalactan proved to be 1.5 %. In this research, 0.5 L of the new functional dairy bioproduct was able to cover 36.8 % of human physiological daily need for dietary fibers.

Effect of dietary Glycyrrhiza polysaccharides on growth performance, hepatic antioxidant capacity and anti-inflammatory capacity of broiler chickens

The primary aim of this study was to investigate the impact of varying levels of dietary Glycyrrhiza polysaccharides (GPS) on the health status of broiler chickens. A total of 288 1-day-old Arbor Acres broilers were randomly assigned to four groups with six replicates, consisting of 12 chickens in each replicate. The control group (CON) was provided with the basal diet, while the experimental groups were administered 300, 600, and 900 mg/kg of GPS in the basal diet for 42 days. The results demonstrated a significant enhancement in average daily gain (ADG) as a result of GPS supplementation (P < 0.05). The dietary GPS significantly elevated total antioxidation capability (T-AOC) and the activity of antioxidant enzymes (P < 0.05), while effectively reducing the levels of malondialdehyde (MDA) in the serum and liver (P < 0.05). Administration of GPS notably inhibited the toll-like receptor 4 (TLR4) signaling pathway (P < 0.05), decreased interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) levels (P < 0.05), and increased IL-4 and IL-10 levels (P < 0.05). Additionally, the expression of crucial regulators involved in liver lipid metabolism, including sterol regulatory element binding protein 1 (SREBP-1), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC) were significantly reduced (P < 0.05). In contrast, the expression of peroxisome proliferator-activated receptor alpha (PPAR-α) was significantly enhanced in the GPS-supplemented groups (P < 0.05). In conclusion, the supplementation of GPS positively influenced the growth performance, the anti-inflammatory and antioxidant capacity of the liver, as well as liver lipid metabolism in broilers.

Microbiota-accessible fiber activates short-chain fatty acid and bile acid metabolism to improve intestinal mucus barrier in broiler chickens.

The intestinal mucus barrier, located at the interface of the intestinal epithelium and the microbiota, is the first line of defense against pathogenic microorganisms and environmental antigens. Dietary polysaccharides, which act as microbiota-accessible fiber, play a key role in the regulation of intestinal microbial communities. However, the mechanism via which dietary fiber affects the intestinal mucus barrier through targeted regulation of the gut microbiota is not clear. This study provides fundamental evidence for the benefits of dietary fiber supplementation in broiler chickens through improvement in the intestinal mucus barrier by targeted regulation of the gut ecosystem. Our findings suggest that the microbiota-accessible fiber-gut microbiota-short-chain fatty acid/bile acid axis plays a key role in regulating intestinal function.

Metabolic diversity in commensal protists regulates intestinal immunity and trans-kingdom competition

The microbiota influences intestinal health and physiology, yet the contributions of commensal protists to the gut environment have been largely overlooked. Here, we discover human- and rodent-associated parabasalid protists, revealing substantial diversity and prevalence in nonindustrialized human populations. Genomic and metabolomic analyses of murine parabasalids from the genus Tritrichomonas revealed species-level differences in excretion of the metabolite succinate, which results in distinct small intestinal immune responses. Metabolic differences between Tritrichomonas species also determine their ecological niche within the microbiota. By manipulating dietary fibers and developing invitro protist culture, we show that different Tritrichomonas species prefer dietary polysaccharides or mucus glycans. These polysaccharide preferences drive trans-kingdom competition with specific commensal bacteria, which affects intestinal immunity in a diet-dependent manner. Our findings reveal unappreciated diversity in commensal parabasalids, elucidate differences in commensal protist metabolism, and suggest how dietary interventions could regulate their impact on gut health.

Impact of structurally diverse polysaccharides on colonic mucin O-glycosylation and gut microbiota

Understanding how dietary polysaccharides affect mucin O-glycosylation and gut microbiota could provide various nutrition-based treatments. Here, the O-glycan profile of the colonic mucosa and gut microbiome were investigated in C57BL/6J mice fed six structurally diverse dietary polysaccharides and a mixture of six fibers. Dietary polysaccharides increased total O-glycans, mainly by stimulating neutral glycans. Highly branched arabinogalactan promoted terminally fucosylated core 1 O-glycans; whereas linear polysaccharides, including pectin, konjac glucomannan, inulin, and the fiber mixture, favored terminally di-fucosylated O-glycans. The last three polysaccharides also lowered the level of sulfated O-glycans and sialylated mono-fucosylated O-glycans. Varied monosaccharide composition in mixed polysaccharides had a synergistic beneficial effect, boosting fucosylated neutral glycans, decreasing acidic glycans, and stimulating microbial richness and diversity. Dietary polysaccharides containing arabinose and sulfate groups enhanced the relative abundances of Akkermansia and Muribaculaceae, respectively. The present comparison reveals the relationship between dietary polysaccharide structure, mucin O-glycan composition, and intestinal microorganisms.

Multi‐omics analyses reveal the interaction between colonic microbiota and host in Min and Yorkshire pigs

AbstractAdoption of microbial preparations is becoming more and more prevalent in the pig breeding industry. Digestive tract microbes are recognized as crucial elements affecting physical characteristics of pigs. Until now, it is still challenging to establish connections between colonic microbiome and the host. In this study, weight gain models were created for Min and Yorkshire pigs. The colonic contents and colonic tissues were collected from two pig purebred strains (n = 8/group) with similar weights for multi‐omics analysis. By difference analysis of colonic microbiota, Min pigs observed a significantly higher relative abundance of Bacteroides, Phocaeicola, Roseburia, and Parabacteroides, and Yorkshire pigs had a strongly higher relative abundance of Streptococcus, Vescimonas, Ligilactobacillus, and Lactococcus. Functional annotation showed that the colonic microbiota of Min pigs had extensive dietary polysaccharide and immunomodulatory capacity. Through the correlation analysis of colonic microbiota with metabolomics of colonic content or transcriptomics of colonic tissues, we provided direct and indirect relationships of microorganisms and hosts. By verification, the contents of Occludin, ZO‐1, and pIgR in colonic tissue and sIgA, sIgG, and sIgM in colonic contents of Min pigs were significantly higher than that in Yorkshire pigs. This study revealed characteristics and functions of the colonic microbiota in Min and Yorkshire pigs and analyzed their interactions with the host. Also, we identified immune‐related microorganisms. These results provided a theoretical basis for understanding the influence of colonic microbiota on phenotype shaping in pigs.

Macro insights into the shared and distinct regulations of dietary polysaccharides on gut microbiota and their roles in obesity

AbstractObesity has emerged as a global health epidemic, demanding a comprehensive understanding of its etiology and potential interventions. Recent studies have highlighted the crucial role of gut microbiota in maintaining host health. Additionally, dietary polysaccharides (DP), such as pectic polysaccharides, sulfated polysaccharides, glucan‐like polysaccharides, and fructan‐like polysaccharides, have been identified as crucial regulators that influence gut microbial composition, function, and metabolite production, thereby improving obesity and mitigating its complications. This review comprehensively summarizes the latest findings regarding the sources and structural characteristics of different DP, their shared and distinct effects on gut microbiota and associated metabolites, and the consequent influence on obesity and its complications. By unraveling the complex interplay among DP, gut microbiota, and obesity‐related outcomes, we strive to offer valuable insights that can inform the development of precise dietary interventions and therapeutic strategies aimed at tackling obesity and enhancing public health.

Protective effects of dietary Astragalus polysaccharides on large yellow croaker (Larimichthys crocea) against Vibrio alginolyticus infection

As one of the effective immunopotentiators, Astragalus polysaccharides (APS) are being used widely in prevention and control of fish bacteriosis. However, the understanding of the related immune protection mechanisms is still limited. In this study, the protective effects of dietary APS on large yellow croaker (Larimichthys crocea) following Vibrio alginolyticus infection were investigated. After continuous feeding for 42 d, fish in APS group exhibited higher survival rates against V. alginolyticus infection compared to the control group, and 500 mg/kg APS produced the highest relative percent survival (RPS) of 53.33%, therefore, 500 mg/kg (0.05%) supplementation was recommended in large yellow croaker farming from a standpoint of antibacterial infection. APS could enhance antioxidant level of fish by increasing serum T-AOC capacity and SOD activity and reducing MDA content, and improve innate immune response by increasing serum AKP and ACP activities. Head kidney differential transcriptome analysis between control group and 500 mg/kg APS group before and after V. alginolyticus infection corroborated the effects of APS on activation of antioxidant capacity and innate immunity by up-regulating the antioxidant-related genes and activating CTLR pathway, respectively. Additionally, APS could also activate fish adaptive immunity by reversing V. alginolyticus-induced inhibition on T and B cell receptor signaling pathways. All these findings suggested that APS may exert the protective effects against V. alginolyticus infection by improving antioxidant ability, innate and adaptive immune responses of large yellow croaker, thus providing insights into the protection mechanisms of APS in fish and highlighting their potential application in fish aquaculture.