Microbiota-derived butyrate dynamically regulates intestinal homeostasis through regulation of actin-associated protein synaptopodin

Butyrylated modification of corn starch alleviates autism-like behaviors by modulating 5-hydroxytryptamine metabolism and gut-brain neural activity

This study was conducted to elucidate the effects of different degrees of substitution (DS) on the properties of propionylated and butyrylated starches and to investigate their efficacy and mechanisms in ameliorating autism-like phenotypes. Fourier transform infrared spectra of propionylated and butyrylated starches revealed the presence of the CO absorption peak at 1730 cm-1. Additionally, as the DS increased, the surface of the starch granules became rougher, and the crystallinity decreased. Moreover, in vitro digestion tests demonstrated that propionylated and butyrylated starches with a DS of approximately 0.25 exhibited enhanced resistance to digestion. Animal experiments indicated that butyrylated starch significantly improved abnormal behaviors in autism-like rats and increased butyrate accumulation in the colon. Furthermore, butyrylated starch normalized aberrant expression of G protein-coupled receptor 41 and tryptophan hydroxylase 1 in the colon, promoting 5-hydroxytryptamine metabolism and suppressing the expression of ionized calcium binding adaptor molecule 1 and glial fibrillary acidic protein in the gut and brain. These findings demonstrate that butyrylated starch effectively alleviates autism-like phenotypes in rats, supporting strategies to mitigate autism and develop new applications for natural corn starch.

Bacteria-tumor symbiosis destructible novel nanocatalysis drug delivery systems for effective tumor therapy

Colorectal cancer (CRC) is a significant threat to human health. The dynamic equilibrium between probiotics and pathogenic bacteria within the gut microbiota is crucial in mitigating the risk of CRC. An overgrowth of harmful microorganisms in the gastrointestinal tract can result in an excessive accumulation of bacterial toxins and carcinogenic metabolites, thereby disrupting the delicate balance of the microbiota. This disruption may lead to alterations in microbial composition, impairment of mucosal barrier function, potential promotion of abnormal cell proliferation, and ultimately contribute to the progression of CRC. Recently, research has indicated that intestinal presence of Fusobacterium nucleatum (Fn) significantly influences the onset, progression, and metastasis of CRC. Consequently, disrupting the interaction between CRC cells and Fn presents a promising strategy against CRC. Nanomaterials have been extensively utilized in cancer therapy and bacterial infection control, demonstrating substantial potential in treating bacteria-associated tumors. This review begins by elucidating the mechanisms of gut microbiota and the occurrence and progression of CRC, with a particular emphasis on clarifying the intricate relationship between Fn and CRC. Subsequently, we highlight strategies that utilize nanomaterials to disrupt the association between Fn and CRC. Overall, this review offers valuable insight and guidance for leveraging nanomaterials in CRC therapy.

Synergistic interactions between gut microbiota and short chain fatty acids: Pioneering therapeutic frontiers in chronic disease management

Microorganisms in the gut play a pivotal role in human health, influencing various pathophysiological processes. Certain microorganisms are particularly essential for maintaining intestinal homeostasis, reducing inflammation, supporting nervous system function, and regulating metabolic processes. Short-chain fatty acids (SCFAs) are a subset of fatty acids produced by the gut microbiota (GM) during the fermentation of indigestible polysaccharides. The interaction between GM and SCFAs is inherently bidirectional: the GM not only shapes SCFAs composition and metabolism but SCFAs also modulate microbiota's diversity, stability, growth, proliferation, and metabolism. Recent research has shown that GM and SCFAs communicate through various pathways, mainly involving mechanisms related to inflammation and immune responses, intestinal barrier function, the gut-brain axis, and metabolic regulation. An imbalance in GM and SCFA homeostasis can lead to the development of several chronic diseases, including inflammatory bowel disease, colorectal cancer, systemic lupus erythematosus, Alzheimer's disease, and type 2 diabetes mellitus. This review explores the synergistic interactions between GM and SCFAs, and how these interactions directly or indirectly influence the onset and progression of various diseases through the regulation of the mechanisms mentioned above.

Short-Chain Fatty Acids: Promising Therapeutic Targets for Respiratory Syncytial Virus Infection

The intestinal microbiota is a complex community of organisms present in the human gastrointestinal tract, some of which can produce short-chain fatty acids (SCFAs) through the fermentation of dietary fiber. SCFAs play a major role in mediating the intestinal microbiota's regulation of host immunity and intestinal homeostasis. Respiratory syncytial virus (RSV) can cause an imbalance between anti-inflammatory and proinflammatory responses in the host. In addition, changes in SCFA levels and the structure of the intestinal microbiota have been observed after RSV infection. Therefore, there may be a link between SCFAs and RSV infection, and SCFAs are expected to be therapeutic targets for RSV infection.

Host-microbe computational proteomic landscape in oral cancer revealed key functional and metabolic pathways between Fusobacterium nucleatum and cancer progression

Oral squamous cell carcinoma (OSCC) is the most common manifestation of oral cancer. It has been proposed that periodontal pathogens contribute to OSCC progression, mainly by their virulence factors. However, the main periodontal pathogen and its mechanism to modulate OSCC cells remains not fully understood. In this study we investigate the main host-pathogen pathways in OSCC by computational proteomics and the mechanism behind cancer progression by the oral microbiome. The main host-pathogen pathways were analyzed in the secretome of biopsies from patients with OSCC and healthy controls by mass spectrometry. Then, functional assays were performed to evaluate the host-pathogen pathways highlighted in oral cancer. Host proteins associated with LPS response, cell migration/adhesion, and metabolism of amino acids were significantly upregulated in the human cancer proteome, whereas the complement cascade was downregulated in malignant samples. Then, the microbiome analysis revealed large number and variety of peptides from Fusobacterium nucleatum (F. nucleatum) in OSCC samples, from which several enzymes from the L-glutamate degradation pathway were found, indicating that L-glutamate from cancer cells is used as an energy source, and catabolized into butyrate by the bacteria. In fact, we observed that F. nucleatum modulates the cystine/glutamate antiporter in an OSCC cell line by increasing SLC7A11 expression, promoting L-glutamate efflux and favoring bacterial infection. Finally, our results showed that F. nucleatum and its metabolic derivates promote tumor spheroids growth, spheroids-derived cell detachment, epithelial-mesenchymal transition and Galectin-9 upregulation. Altogether, F. nucleatum promotes pro-tumoral mechanism in oral cancer.

Relieving Effect of Artemisia ordosica Krasch Extract on DSS-Induced Colitis by Regulating Immunity, Antioxidant Function, Gut Microbiota, and Bile Acid Metabolism in Mice

Artemisia ordosica Krasch, a traditional Chinese herbal medicine, possesses antibacterial, antiviral, and anti-inflammatory properties. The aim of this experiment was to investigate the therapeutic effect of Artemisia ordosica Krasch extraction (AOE) in treating colitis induced by dextran sulfate sodium (DSS) in mice. The in vitro antioxidant activity of AOE was evaluated by assessing its iron reduction capacity and scavenging capacity towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals (·OH). The protective effect of AOE on colitis in mice was determined by monitoring key indicators such as body weight, colon length, and survival rate in mice, as well as by assessing the expression of colon-related genes and cytokine levels. We evaluated the impact of AOE on intestinal microbiota by measuring the 16s sequencing of cecal contents and bile acid metabolism. The results showed that the iron reduction capacity of AOE was positively correlated with its concentration. The half-maximal inhibitory concentrations (IC50) for scavenging DPPH and hydroxyl radicals were 3.126 mg/mL and 6.139 mg/mL, with a 95% confidence interval of 95%. In vivo studies demonstrated that AOE reduced DSS-induced colitis in mice by increasing the colon length, enhancing antioxidant enzyme activity, inhibiting inflammatory cell infiltration, suppressing the formation of TNF-α and IL-6, and reducing malondialdehyde (MDA) levels. qPCR analysis revealed that AOE reversed the down-regulation of Claudin mRNA expression, and altered the composition of cecal microbiota, thus mitigating DSS-induced colitis. AOE plays a crucial role in alleviating colitis in mice and effectively improves DSS-induced colitis, highlighting its potential as a therapeutic agent for inflammatory bowel diseases.

The Gut-Lung Axis During Ethanol Exposure and a Pseudomonas aeruginosa Bacterial Challenge

Background: Susceptibility to and severity of pulmonary infections increase with ethanol consumption. We have previously shown that ethanol-induced changes in the gut microbiome disrupt gut homeostasis, allowing for the translocation of proinflammatory mediators into the circulation and eliciting an immune response in the lung. Additionally, targeting the gut with butyrate supplementation not only rescues ethanol-induced disruptions to gut health but also reverses aspects of immune dysregulation in the lungs. Here, we assessed the impact of this connection on a subsequent infectious challenge. Methods: To assess if ethanol-induced alterations to the gut microbiome could also impact the host response to a pulmonary infectious challenge, we employed a chronic-binge ethanol-feeding mouse model followed by a nasal instillation of Pseudomonas aeruginosa. Results: In addition to altering gut microbiome composition and metabolism, ethanol consumption also disrupted the local immune response as demonstrated by suppressed cecal SIgA levels, a decreased presence of CD3+CD8a+ cytotoxic T cells in the proximal colon mucosa, and depleted CD3+CD8a+ T cells and CD11c+CD8a+ dendritic cells in the mesenteric lymph nodes. Circulatory Ly6G+CD11b+ neutrophils increased, indicating a systemic change in immune-cell presence with ethanol exposure. Ethanol exposure increased CD11c+CD64+ macrophages and Ly6G+CD11b+ neutrophils in the lungs, with neutrophil populations being further exacerbated during a bacterial challenge with Pseudomonas aeruginosa. Lipocalin 2, a marker of oxidative stress, was also elevated with ethanol consumption, though not with infection. Conclusions: These data suggest that ethanol-induced changes in the gut microbiome and immune environment are linked to dysfunctional immune responses in the intestine, blood, and the lungs, compromising the pulmonary immune response during an infectious challenge in mice.

Regulation of Milk Fat Synthesis: Key Genes and Microbial Functions

Milk is rich in a variety of essential nutrients, including fats, proteins, and trace elements that are important for human health. In particular, milk fat has an alleviating effect on diseases such as heart disease and diabetes. Fatty acids, the basic units of milk fat, play an important role in many biological reactions in the body, including the involvement of glycerophospholipids and sphingolipids in the formation of cell membranes. However, milk fat synthesis is a complex biological process involving multiple organs and tissues, and how to improve milk fat of dairy cows has been a hot research issue in the industry. There exists a close relationship between milk fat synthesis, genes, and microbial functions, as a result of the organic integration between the different tissues of the cow's organism and the external environment. This review paper aims (1) to highlight the synthesis and regulation of milk fat by the first and second genomes (gastrointestinal microbial genome) and (2) to discuss the effects of ruminal microorganisms and host metabolites on milk fat synthesis. Through exploring the interactions between the first and second genomes, and discovering the relationship between microbial and host metabolite in the milk fat synthesis pathway, it may become a new direction for future research on the mechanism of milk fat synthesis in dairy cows.

Underneath the Gut-Brain Axis in IBD-Evidence of the Non-Obvious

The gut-brain axis (GBA) plays a pivotal role in human health and wellness by orchestrating complex bidirectional regulation and influencing numerous critical processes within the body. Over the past decade, research has increasingly focused on the GBA in the context of inflammatory bowel disease (IBD). Beyond its well-documented effects on the GBA-enteric nervous system and vagus nerve dysregulation, and gut microbiota misbalance-IBD also leads to impairments in the metabolic and cellular functions: metabolic dysregulation, mitochondrial dysfunction, cationic transport, and cytoskeleton dysregulation. These systemic effects are currently underexplored in relation to the GBA; however, they are crucial for the nervous system cells' functioning. This review summarizes the studies on the particular mechanisms of metabolic dysregulation, mitochondrial dysfunction, cationic transport, and cytoskeleton impairments in IBD. Understanding the involvement of these processes in the GBA may help find new therapeutic targets and develop systemic approaches to improve the quality of life in IBD patients.

Butyrate Inhibits the HDAC8/NF-κB Pathway to Enhance Slc26a3 Expression and Improve the Intestinal Epithelial Barrier to Relieve Colitis

Dietary fiber is known to promote the production of short-chain fatty acids (SCFAs) by gut bacteria, which can enhance intestinal epithelial barrier function and ameliorate intestinal inflammation in patients with inflammatory bowel disease (IBD). Interestingly, some IBD patients show reduced expression of solute carrier family member 3 (Slc26a3) in intestinal epithelial cells. The objective of this research was to investigate the interaction between SCFAs and Slc26a3 during colitis and assess how this interaction affects intestinal epithelial barrier function. We showed that butyrate alleviated colonic inflammation in a dose-dependent manner in a dextran sulfate sodium salt (DSS)-induced colitis model. Consistent with this, butyrate increased Slc26a3 and tight junction protein levels. In addition, butyrate inhibited histone deacetylase (HDAC) levels and significantly increased the expression of Slc26a3 by the acetylation of histones in Caco-2BBe cells. The utilization of a pan-HDAC inhibitor or inhibitors specific to certain classes of HDACs revealed that butyrate primarily suppressed HDAC8 to blunt the NF-κB pathways and enhance the expression of Slc26a3. Notably, we demonstrated that HDAC8 activation counteracted the beneficial effect of butyrate in DSS-induced colitis. Therefore, we concluded that butyrate improves the expression of Slc26a3 via inhibition of the HDAC8/NF-κB pathway, leading to increased intestinal epithelial barrier function.

Microbiota-derived succinic acid mediates attenuating effect of dietary tomato juice supplementation on steatohepatitis through enhancing intestinal barrier

The hepatoprotective potential of tomato juice (TJ) has been reported in chronic liver models, and its potential prebiotic properties may be key to its preventative effects. However, the mechanistic role of the gut microbiota and its derived metabolites in ameliorating nonalcoholic steatohepatitis (NASH) via TJ remains unclear. In this study, we explored how TJ regulates gut microbiota and succinic acid (SA) to restore intestinal barrier function and thus suppress NASH progression. TJ supplementation effectively reduced serum lipid concentrations, alleviated endotoxin levels, and suppressed activation of the endotoxin-TLR4-NF-κB pathway in methionine-choline-deficient (MCD) diet-induced NASH mice. TJ restored the MCD diet-induced gut microbiota dysbiosis, increased the abundance of short-chain fatty acid and SA-producing bacteria (Bifidobacterium, Ileibacterium, Odoribacter, and Parasutterella) and enhanced the expression of intestinal barrier-associated proteins (E-cadherin, Claudin-1, MUC-2, and ZO-1). The hepatoprotective and enteroprotective effects of TJ were abolished in an antibiotic-treated mouse model, underscoring the pivotal role of the gut microbiota in the beneficial effects of TJ on NASH. Fecal metabolomics demonstrated that TJ significantly upregulated the tricarboxylic acid cycle, pyruvate metabolism, and butanoate metabolism pathways, increasing levels of butyric acid (BA) and SA-metabolites associated with reduced hepatic steatosis and intestinal damage. We further found that the physiological concentration of SA, rather than BA, could reduce pro-inflammatory cytokines (TNF-α and IL-6) levels and enhance mucin proteins and tight junction markers in the LPS-induced colon cell line LS174T. This study uncovers new mechanisms by which TJ prevents NASH, highlighting the potential of TJ and SA as effective dietary supplements for patients with chronic liver diseases.

Dietary nitrate maintains intestinal epithelia homeostasis in aged mice

The intestinal tract, which is the primary site of digestion and absorption of nutrients, is one of the most vulnerable organs during aging. Dietary nitrate, which is mainly derived from the diet and absorbed in the intestinal tract, is a key messenger that connecting oral and general health. However, whether dietary nitrate regulates intestinal tract homeostasis remains unclear. Our data revealed that the serum and salivary nitrate levels decreased during mice aging. The functional proteins of the epithelial barrier (E-cadherin, Claudin-1 and Zonula Occludens-1) in the colon tissues decreased during the aging process. Long-term nitrate supplement in drinking water restored the serum and salivary nitrate levels and increased the functional proteins expression of the colon epithelial barrier. Dietary nitrates increase the relative abundance of some intestinal probiotics, particularly those associated with the production of short-chain fatty acids, such as Blautia, Alloprevotella, Butyricicoccus, and Ruminococcaceae, while promoting the butyric acid production in the colon. Moreover, the expression of Sialin (encoded by Slc17a5), which is a nitrate transporter, increased in the colon epithelial cells by nitrate supplementation. The epithelial cell-conditional Slc17a5-knockout mutant mice (K14-cre; Slc17a5fl/fl) revealed that the functional proteins expression of the colon epithelial barrier and the proliferation of PCNA-positive intestinal epithelial cells in the colon crypts was significantly decreased compared with those of the K14-cre; Slc17a5fl/+ mice. Taken together, our findings suggested that nitrate supplementations were associated with the increased expression of colonic epithelial barriers-related proteins and the increased Sialin expression. Nitrate may serve as a potential therapeutic approach in maintaining aged colonic homeostasis.

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

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

Gut microbiota-related modulation of immune mechanisms in post-infarction remodelling and heart failure

The immune system has long been recognized as a key driver in the progression of heart failure (HF). However, clinical trials targeting immune effectors have consistently failed to improve patient outcome across different HF aetiologies. The activation of the immune system in HF is complex, involving a broad network of pro-inflammatory and immune-modulating components, which complicates the identification of specific immune pathways suitable for therapeutic targeting. Increasing attention has been devoted to identifying gut microbial pathways that affect cardiac remodelling and metabolism and, thereby impacting the development of HF. In particular, gut microbiota-derived metabolites, absorbed by the host and transported to the peripheral circulation, can act as signalling molecules, influencing metabolism and immune homeostasis. Recent reports suggest that the gut microbiota plays a crucial role in modulating immune processes involved in HF. Here, we summarize recent advances in understanding the contributory role of gut microbiota in (auto-)immune pathways that critically determine the progression or alleviation of HF. We also thoroughly discuss potential gut microbiota-based intervention strategies to treat or decelerate HF progression.

Gut bacteria: an etiological agent in human pathological conditions

Through complex interactions with the host's immune and physiological systems, gut bacteria play a critical role as etiological agents in a variety of human diseases, having an impact that extends beyond their mere presence and affects the onset, progression, and severity of the disease. Gaining a comprehensive understanding of these microbial interactions is crucial to improving our understanding of disease pathogenesis and creating tailored treatment methods. Correcting microbial imbalances may open new avenues for disease prevention and treatment approaches, according to preliminary data. The gut microbiota exerts an integral part in the pathogenesis of numerous health conditions, including metabolic, neurological, renal, cardiovascular, and gastrointestinal problems as well as COVID-19, according to recent studies. The crucial significance of the microbiome in disease pathogenesis is highlighted by this role, which is comparable to that of hereditary variables. This review investigates the etiological contributions of the gut microbiome to human diseases, its interactions with the host, and the development of prospective therapeutic approaches. To fully harness the benefits of gut microbiome dynamics for improving human health, future research should address existing methodological challenges and deepen our knowledge of microbial interactions.

Physiologic hypoxia in the intestinal mucosa: a central role for short-chain fatty acids

The intestinal mucosa is a dynamic surface that facilitates interactions between the host and an outside world that includes trillions of microbes, collectively termed the microbiota. This fine balance is regulated by an energetically demanding physical and biochemical barrier that is formed by the intestinal epithelial cells. In addition, this homeostasis exists at an interface between the anaerobic colonic lumen and a highly oxygenated, vascularized lamina propria. The resultant oxygen gradient within the intestine establishes "physiologic hypoxia" as a central metabolic feature of the mucosa. Although oxygen is vital for energy production to meet cellular metabolism needs, the availability of oxygen has far-reaching influences beyond just energy provision. Recent studies have shown that the intestinal mucosa has purposefully adapted to use differential oxygen levels largely through the presence of short-chain fatty acids (SCFAs), particularly butyrate (BA). Intestinal epithelial cells use butyrate for a multitude of functions that promote mucosal homeostasis. In this review, we explore how the physiologic hypoxia profile interfaces with SCFAs to benefit host mucosal tissues.

Xylooligosaccharides alleviate the carbohydrate-enriched diet-induced intestinal barrier dysfunction in carp Megalobrama amblycephala by promoting intestinal development, immunity and gut microbiota

To date, although the high-carbohydrate (HC) feed has been extensively adopted in the aquaculture industry, its effects on the intestinal function and development of aquatic animals still remain unclear. In addition, the corresponding nutritional intervention is still barely reported. This study aimed to evaluate the influence of xylooligosaccharides (XOS) on the intestinal health of Megalobrama amblycephala subjected to a HC feeding. Fish (average weight: 44.55 ± 0.15 g) were randomly offered 3 diets, including a control one (29 % carbohydrate), a HC one (41 % carbohydrate), and a XOS supplemented one (HC + 1.0 % XOS, HCX) respectively for 12 weeks. The HC feeding caused morphological abnormalities of intestine, an increased intestinal permeability, and the intestinal immunosuppression, all of which were markedly reversed by XOS administration. In addition, compared with the HC group, HCX feeding remarkably promoted the intestinal activities of digestive and brush border enzymes, and the expressions of cell proliferation-related proteins (Wnt10b and Cyclin D1). The 16s rDNA sequencing also revealed that XOS administration increased the abundance of beneficial bacteria, and decreased that of pathogenic ones. In conclusion, dietary supplementation of XOS improved the intestinal histomorphology, barrier function, cell proliferation and bacterial communities of carbohydrate-overloaded fish Megalobrama amblycephala.

Bacteria and Allergic Diseases

Microorganisms colonize all barrier tissues and are present on the skin and all mucous membranes from birth. Bacteria have many ways of influencing the host organism, including activation of innate immunity receptors by pathogen-associated molecular patterns and synthesis of various chemical compounds, such as vitamins, short-chain fatty acids, bacteriocins, toxins. Bacteria, using extracellular vesicles, can also introduce high-molecular compounds, such as proteins and nucleic acids, into the cell, regulating the metabolic pathways of the host cells. Epithelial cells and immune cells recognize bacterial bioregulators and, depending on the microenvironment and context, determine the direction and intensity of the immune response. A large number of factors influence the maintenance of symbiotic microflora, the diversity of which protects hosts against pathogen colonization. Reduced bacterial diversity is associated with pathogen dominance and allergic diseases of the skin, gastrointestinal tract, and upper and lower respiratory tract, as seen in atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, food allergies, and asthma. Understanding the multifactorial influence of microflora on maintaining health and disease determines the effectiveness of therapy and disease prevention and changes our food preferences and lifestyle to maintain health and active longevity.

The alleviative effects of viable and inactive Lactobacillus paracasei CCFM1120 against alcoholic liver disease via modulation of gut microbiota and the Nrf2/HO-1 and TLR4/MyD88/NF-κB pathways

Probiotics can alleviate alcoholic liver disease. However, whether inactive counterparts can produce similar outcomes requires further investigation. We investigated the effects of viable (V) and dead (D) Lactobacillus paracasei CCFM1120 on alcohol-induced ALD mice. The results showed that CCFM1120V and D ameliorated the disease symptoms and intestinal injury. Specifically, these interventions strengthened the intestinal barrier, as evidenced by the increased expression of ZO-1 (zonula occludens 1), occludin, and claudin-1 in the colon and the restored ileal microstructure, including the villi and crypts. In addition, they enhanced the antioxidant capacity of the liver by reducing the production of malondialdehyde and increasing the levels of glutathione and superoxide dismutase. The activation of Nrf2 and HO-1 may be responsible for recovering the antioxidant capacity. Interventions can decrease mouse TNF-α, IL-6 and IL-1β content in serum, probably through the TLR4/MyD88/NF-κB pathway. Furthermore, they possess the ability to restore the quantities of bacteria responsible for producing butyric acid, such as Lactobacillus, Blautia, Bifidobacterium, Ruminococcaceae, Faecalibaculum and Lachnospiraceae. Taken together, CCFM1120V and D apparently can modify the composition of the gut microbiota, foster the gastrointestinal equilibrium, fortify the intestinal barrier, augment the antioxidant capacity of the liver, and effectively shield it from ethanol-induced injury.

Postbiotics-peptidoglycan, lipoteichoic acid, exopolysaccharides, surface layer protein and pili proteins-Structure, activity in wounds and their delivery systems

Chronic wound healing is a pressing global public health concern. Abuse and drug resistance of antibiotics are the key problems in the treatment of chronic wounds at present. Postbiotics are a novel promising strategy. Previous studies have reported that postbiotics have a wide range of biological activities including antimicrobial, immunomodulatory, antioxidant and anti-inflammatory abilities. However, several aspects related to these postbiotic activities remain unexplored or poorly known. Therefore, this work aims to outline general aspects and emerging trends in the use of postbiotics for wound healing, such as the production, characterization, biological activities and delivery strategies of postbiotics. In this review, a comprehensive overview of the physiological activities and structures of postbiotic biomolecules that contribute to wound healing is provided, such as peptidoglycan, lipoteichoic acid, bacteriocins, exopolysaccharides, surface layer proteins, pili proteins, and secretory proteins (p40 and p75 proteins). Considering the presence of readily degradable components in postbiotics, potential natural polymer delivery materials and delivery systems are emphasized, followed by the potential applications and commercialization prospects of postbiotics. These findings suggest that the treatment of chronic wounds with postbiotic ingredients will help provide new insights into wound healing and better guidance for the development of postbiotic products.

In vitro fecal fermentation of acylated porous Canna edulis starch and corresponding stabilized Pickering emulsions

In this study, acylated porous Canna edulis starch with varying degrees of substitution (DS) were prepared and employed for stabilizing Pickering emulsions. Subsequently, the fermentation characteristics of them were investigated. Enzymatically produced porous starch (PS) was esterified with acetic, propionic, butyric, or valeric anhydrides, yielding acetylated (PSA-0.116), propionylated (PSP-0.163), butyrylated (PSB-0.304), and valerylated PS (PSV-0.462) with different DS. Scanning electron microscopy revealed the presence of pores and surface micro-particles in the modified PS, confirming successful esterification through characteristic peaks in 1H NMR and a CO peak at 1736 cm-1 in the FT-IR spectrum. With increasing DS, starch exhibited reduced crystallinity (PSV, 26.61 %), elevated resistant starch content (PSV, 91.63 %), and a higher contact angle (PSV, 87.13°). Acylated PS particles effectively stabilized Pickering emulsions. Pickering emulsions stabilized by acylated PS with higher DS exhibited higher emulsification index and smaller droplet sizes. In vitro fermentation of acylated PS and corresponding stabilized Pickering emulsions fostered short-chain fatty acid production, boosted the relative abundance of beneficial bacteria (Bifidobacterium, Prevotella, etc.) while inhibited the growth of harmful bacteria (Escherichia-Shigella, Comamonas, etc.), maintaining the intestinal microbiota balance. These findings support the potential applications of acylated PS and corresponding stabilized Pickering emulsions in functional foods and drug delivery.

Gut microbiota and metabolic changes in children with idiopathic short stature

BACKGROUND

Idiopathic short stature (ISS) is characterized by short stature with unknown causes. Recent studies showed different gut microbiota flora and reduced fecal short-chain fatty acids in ISS children. However, the roles of the microbiome and metabolites in the pathogenesis of ISS remains largely unknown.

METHODS

We recruited 51 Chinese subjects, comprising 26 ISS children and 25 normal-height control individuals. Untargeted metabolomics was performed to explore the fecal metabolic profiles between groups. A shotgun metagenomic sequencing approach was used to investigate the microbiome at the strains level. Mediation analyses were done to reveal correlations between the height standard deviation (SD) value, the gut microbiome and metabolites.

RESULTS

We detected marked differences in the composition of fecal metabolites in the ISS group, particularly a significant increase in erucic acid and a decrease in spermidine, adenosine and L-5-Hydroxytryptophan, when compared to those of controls. We further identified specific groups of bacterial strains to be associated with the different metabolic profile. Through mediation analysis, 50 linkages were established. KEGG pathway analysis of microbiota and metabolites indicated nutritional disturbances. 13 selected features were able to accurately distinguish the ISS children from the controls (AUC = 0.933 [95%CI, 79.9-100%]) by receiver operating characteristic (ROC) analysis.

CONCLUSION

Our study suggests that the microbiome and the microbial-derived metabolites play certain roles in children's growth. These findings provide a new research direction for better understanding the mechanism(s) underlying ISS.

In vitro digestion and fermentation characteristics of eight kinds of pulses and suggestions for different populations

Pulse-based diets are attracting attention for their potential in combating diet-related non-communicable diseases. However, limited research studies have focused on the digestive and fermentative properties of pulses, which are crucial for exerting benefits. Here, we investigated the in vitro digestibility of starch/protein, along with the fermentation characteristics, of eight pulses and their pastes, including white kidney beans, adzuki beans, cowpeas, broad beans, mung beans, chickpeas, white lentils, and yellow peas. The findings indicated that pulse flours and pastes were low GL food (estimated GL < 10) and had a low degree of protein hydrolysis during simulated gastrointestinal digestion. During in vitro fermentation, pulses flours and pastes decreased the fermentation pH, increased the level of short-chain fatty acids (mainly consisting of valeric acid, followed by acetic acid, propionic acid, butyric acid, isobutyric acid, and isovaleric acid), and positively modulated the microbiota composition over time, specifically reducing the ratio of Firmicutes to Bacteroidetes. In addition, we found that boiling could affect the in vitro digestion and fermentation characteristics of pulses, possibly depending on their intrinsic nutrient characteristics. This research could provide a comprehensive summary of the nutrient content, digestibility, and fermentation of eight pulses and their pastes. Guided by factor analysis, for different individuals' consumption, pulses, cowpeas, broad beans, white lentils, and white kidney beans were preferred for diabetic individuals, yellow peas and white lentils were preferred for intestinal homeostasis disorders, and white lentils, broad beans, white kidney beans, and cowpeas were suitable for obese individuals, in which white lentils were considered healthier and suggested for healthy adults.

Gut microbiota-derived metabolites tune host homeostasis fate

The gut microbiota, housing trillions of microorganisms within the gastrointestinal tract, has emerged as a critical regulator of host health and homeostasis. Through complex metabolic interactions, these microorganisms produce a diverse range of metabolites that substantially impact various physiological processes within the host. This review aims to delve into the intricate relationships of gut microbiota-derived metabolites and their influence on the host homeostasis. We will explore how these metabolites affect crucial aspects of host physiology, including metabolism, mucosal integrity, and communication among gut tissues. Moreover, we will spotlight the potential therapeutic applications of targeting these metabolites to restore and sustain host equilibrium. Understanding the intricate interplay between gut microbiota and their metabolites is crucial for developing innovative strategies to promote wellbeing and improve outcomes of chronic diseases.

Microbial metabolite sodium butyrate enhances the anti-tumor efficacy of 5-fluorouracil against colorectal cancer by modulating PINK1/Parkin signaling and intestinal flora

Colorectal cancer (CRC) is a prevalent global health issue, with 5-fluorouracil (5-FU) being a commonly used chemotherapeutic agent for its treatment. However, the efficacy of 5-FU is often hindered by drug tolerance. Sodium butyrate (NaB), a derivative of intestinal flora, has demonstrated anti-cancer properties both in vitro and in vivo through pro-apoptotic effects and has shown promise in improving outcomes when used in conjunction with traditional chemotherapy agents. This study seeks to evaluate the impact and potential mechanisms of NaB in combination with 5-FU on CRC. We employed a comprehensive set of assays, including CCK-8, EdU staining, Hoechst 33258 staining, flow cytometry, ROS assay, MMP assay, immunofluorescence, and mitophagy assay, to detect the effect of NaB on the biological function of CRC cells in vitro. Western blotting and immunohistochemistry were used to verify the above experimental results. The xenograft tumor model was established to evaluate the in vivo anti-CRC activity of NaB. Subsequently, 16S rRNA gene sequencing was used to analyze the intestinal flora. The findings of our study demonstrate that sodium butyrate (NaB) exerts inhibitory effects on tumor cell proliferation and promotes tumor cell apoptosis in vitro, while also impeding tumor progression in vivo through the enhancement of the mitophagy pathway. Furthermore, the combined treatment of NaB and 5-fluorouracil (5-FU) yielded superior therapeutic outcomes compared to monotherapy with either agent. Moreover, this combination therapy resulted in the specific enrichment of Bacteroides, LigiLactobacillus, butyric acid-producing bacteria, and acetic acid-producing bacteria in the intestinal microbiota. The improvement in the intestinal microbiota contributed to enhanced therapeutic outcomes and reduced the adverse effects of 5-FU. Taken together, these findings indicate that NaB, a histone acetylation inhibitor synthesized through intestinal flora fermentation, has the potential to significantly enhance the therapeutic efficacy of 5-FU in CRC treatment and improve the prognosis of CRC patients.

Dietary nutrition, intestinal microbiota dysbiosis and post-weaning diarrhea in piglets

Weaning is a critical transitional point in the life cycle of piglets. Early weaning can lead to post-weaning syndrome, destroy the intestinal barrier function and microbiota homeostasis, cause diarrhea and threaten the health of piglets. The nutritional components of milk and solid foods consumed by newborn animals can affect the diversity and structure of their intestinal microbiota, and regulate post-weaning diarrhea in piglets. Therefore, this paper reviews the effects and mechanisms of different nutrients, including protein, dietary fiber, dietary fatty acids and dietary electrolyte balance, on diarrhea and health of piglets by regulating intestinal function. Protein is an essential nutrient for the growth of piglets; however, excessive intake will cause many harmful effects, such as allergic reactions, intestinal barrier dysfunction and pathogenic growth, eventually aggravating piglet diarrhea. Dietary fiber is a nutrient that alleviates post-weaning diarrhea in piglets, which is related to its promotion of intestinal epithelial integrity, microbial homeostasis and the production of short-chain fatty acids. In addition, dietary fatty acids and dietary electrolyte balance can also facilitate the growth, function and health of piglets by regulating intestinal epithelial function, immune system and microbiota. Thus, a targeted control of dietary components to promote the establishment of a healthy bacterial community is a significant method for preventing nutritional diarrhea in weaned piglets.

Short-duration selective decontamination of the digestive tract infection control does not contribute to increased antimicrobial resistance burden in a pilot cluster randomised trial (the ARCTIC Study)

OBJECTIVE

Selective decontamination of the digestive tract (SDD) is a well-studied but hotly contested medical intervention of enhanced infection control. Here, we aim to characterise the changes to the microbiome and antimicrobial resistance (AMR) gene profiles in critically ill children treated with SDD-enhanced infection control compared with conventional infection control.

DESIGN

We conducted shotgun metagenomic microbiome and resistome analysis on serial oropharyngeal and faecal samples collected from critically ill, mechanically ventilated patients in a pilot multicentre cluster randomised trial of SDD. The microbiome and AMR profiles were compared for longitudinal and intergroup changes. Of consented patients, faecal microbiome baseline samples were obtained in 89 critically ill children. Additionally, samples collected during and after critical illness were collected in 17 children treated with SDD-enhanced infection control and 19 children who received standard care.

RESULTS

SDD affected the alpha and beta diversity of critically ill children to a greater degree than standard care. At cessation of treatment, the microbiome of SDD patients was dominated by Actinomycetota, specifically Bifidobacterium, at the end of mechanical ventilation. Altered gut microbiota was evident in a subset of SDD-treated children who returned late longitudinal samples compared with children receiving standard care. Clinically relevant AMR gene burden was unaffected by the administration of SDD-enhanced infection control compared with standard care. SDD did not affect the composition of the oral microbiome compared with standard treatment.

CONCLUSION

Short interventions of SDD caused a shift in the microbiome but not of the AMR gene pool in critically ill children at the end mechanical ventilation, compared with standard antimicrobial therapy.

Intermittent fasting modulates human gut microbiota diversity in a phenotype-dependent manner: a systematic review

Cumulative evidence suggests that intermittent fasting (IF) has beneficial effects on human metabolic health. It has been indicated that its impact on the gut microbiota may mediate these beneficial effects. As a result, we hypothesized that IF may impact the human gut microbiota. A systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol using the PubMed, Scopus, and CINAHL databases. We registered our systematic review protocol in PROSPERO under registration number CRD42021270050. Human intervention studies published until April 30, 2023, were included. The quality of the included studies was assessed using National Institutes of Health (NIH) quality assessment study tools for intervention studies. The search in the database returned 166 studies, of which 13 matched all criteria for the final qualitative analysis. The body of evidence suggests that IF modulates human gut microbiota alpha and beta diversity in lean (relatively healthy) and relatively healthy overweight/obese individuals but not in individuals with metabolic syndrome. Furthermore, IF also alters human gut microbiota composition in all phenotypes. Of interest, the gut microbiota taxa or microbial metabolites after an IF intervention are associated with metabolic markers. According to this review, IF influences the diversity and taxonomic levels of the human gut microbiota. Individual metabolic phenotypes may alter the effect of IF on the diversity and taxonomic levels of the gut microbiota.

Probiotic Pediococcus pentosaceus restored gossypol-induced intestinal barrier injury by increasing propionate content in Nile tilapia

BACKGROUND

Intestinal barrier is a dynamic interface between the body and the ingested food components, however, dietary components or xenobiotics could compromise intestinal integrity, causing health risks to the host. Gossypol, a toxic component in cottonseed meal (CSM), caused intestinal injury in fish or other monogastric animals. It has been demonstrated that probiotics administration benefits the intestinal barrier integrity, but the efficacy of probiotics in maintaining intestinal health when the host is exposed to gossypol remains unclear. Here, a strain (YC) affiliated to Pediococcus pentosaceus was isolated from the gut of Nile tilapia (Oreochromis niloticus) and its potential to repair gossypol-induced intestinal damage was evaluated.

RESULTS

A total of 270 Nile tilapia (2.20 ± 0.02 g) were allotted in 3 groups with 3 tanks each and fed with 3 diets including CON (control diet), GOS (control diet containing 300 mg/kg gossypol) and GP (control diet containing 300 mg/kg gossypol and 108 colony-forming unit (CFU)/g P. pentosaceus YC), respectively. After 10 weeks, addition of P. pentosaceus YC restored growth retardation and intestinal injury induced by gossypol in Nile tilapia. Transcriptome analysis and siRNA interference experiments demonstrated that NOD-like receptors (NLR) family caspase recruitment domain (CARD) domain containing 3 (Nlrc3) inhibition might promote intestinal stem cell (ISC) proliferation, as well as maintaining gut barrier integrity. 16S rRNA sequencing and gas chromatography-mass spectrometry (GC-MS) revealed that addition of P. pentosaceus YC altered the composition of gut microbiota and increased the content of propionate in fish gut. In vitro studies on propionate's function demonstrated that it suppressed nlrc3 expression and promoted wound healing in Caco-2 cell model.

CONCLUSIONS

The present study reveals that P. pentosaceus YC has the capacity to ameliorate intestinal barrier injury by modulating gut microbiota composition and elevating propionate level. This finding offers a promising strategy for the feed industry to incorporate cottonseed meal into fish feed formulations.

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

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

Inflammatory response in dairy cows caused by heat stress and biological mechanisms for maintaining homeostasis

Climate change increases global temperatures, which is lethal to both livestock and humans. Heat stress is known as one of the various livestock stresses, and dairy cows react sensitively to high-temperature stress. We aimed to better understand the effects of heat stress on the health of dairy cows and observing biological changes. Individual cows were divided into normal (21-22 °C, 50-60% humidity) and high temperature (31-32 °C, 80-95% humidity), respectively, for 7-days. We performed metabolomic and transcriptome analyses of the blood and gut microbiomes of feces. In the high-temperature group, nine metabolites including linoleic acid and fructose were downregulated, and 154 upregulated and 72 downregulated DEGs (Differentially Expressed Genes) were identified, and eighteen microbes including Intestinimonas and Pseudoflavonifractor in genus level were significantly different from normal group. Linoleic acid and fructose have confirmed that associated with various stresses, and functional analysis of DEG and microorganisms showing significant differences confirmed that high-temperature stress is related to the inflammatory response, immune system, cellular energy mechanism, and microbial butyrate production. These biological changes were likely to withstand high-temperature stress. Immune and inflammatory responses are known to be induced by heat stress, which has been identified to maintain homeostasis through modulation at metabolome, transcriptome and microbiome levels. In these findings, heat stress condition can trigger alteration of immune system and cellular energy metabolism, which is shown as reduced metabolites, pathway enrichment and differential microbes. As results of this study did not include direct phenotypic data, we believe that additional validation is required in the future. In conclusion, high-temperature stress contributed to the reduction of metabolites, changes in gene expression patterns and composition of gut microbiota, which are thought to support dairy cows in withstanding high-temperature stress via modulating immune-related genes, and cellular energy metabolism to maintain homeostasis.

Vitamin D and celiac disease

Celiac disease (CD) is an immune-mediated condition affecting the small intestine. Its reported global prevalence falls within the range of 0.7% to 1.4%. Notably, historically, higher rates, reaching 1% in Western Ireland, have been documented. Recent research has even revealed prevalence rates as elevated as 2% in northern Europe. These findings underscore the urgency for swift and cost-effective diagnosis, especially in individuals identified through screening efforts. At present, the diagnosis of CD relies on a multifaceted approach involving positive serological markers such as IgA anti-tissue transglutaminase (anti-TTG) and anti-endomysial antibodies (anti-EMA). These serological findings are assessed in conjunction with classical histological alterations, as outlined in the Marsh classification. CD is an inflammatory condition triggered by the consumption of gluten, resulting from intricate interactions between genetic, immunological, and environmental factors. CD is linked to malabsorption, leading to nutritional deficiencies. Individuals with CD are required to adhere to a gluten-free diet, which itself can lead to nutrient deficiencies. One such deficiency includes vitamin D, and there is substantial experimental evidence supporting the notion of a bidirectional relationship between CD and vitamin D status. A low level of vitamin D has a detrimental impact on the clinical course of the disease. Here we summarize the key characteristics of CD and explore the prominent roles of vitamin D in individuals with CD.

Potential for the development of Taraxacum mongolicum aqueous extract as a phytogenic feed additive for poultry

Introduction

Taraxacum mongolicum (TM) is a kind of medicinal and edible homologous plant which is included in the catalogue of feed raw materials in China. It is rich in polyphenols, flavonoids, polysaccharides and other active substances, and shows many benefits to livestock, poultry and aquatic products. The study aimed to assess the potential of TM aqueous extract (TMAE) as a substitute for poultry AGPs.

Methods

A total of 240 one-day-old Arbor Acker broilers were randomly assigned to four groups and fed a basal diet (Con) supplemented with 500, 1000, and 2000 mg/kg TMAE (Low, Medium, and High groups). The growth performance of the broilers was measured on day 21 and day 42. At the end of the trial, the researchers measured slaughter performance and collected serum, liver, spleen, ileum, and intestinal contents to investigate the effects of TMAE on serum biochemistry, antioxidant capacity, immune function, organ coefficient, intestinal morphology, flora composition, and short-chain fatty acids (SCFAs).

Results

The results showed that broilers treated with TMAE had a significantly higher average daily gain from 22 to 42 days old compared to the Con group. Various doses of TMAE resulted in different levels of improvement in serum chemistry. High doses increased serum alkaline phosphatase and decreased creatinine. TMAE also increased the antioxidant capacity of serum, liver, and ileum in broilers. Additionally, middle and high doses of TMAE enhanced the innate immune function of the liver (IL-10) and ileum (Occludin) in broilers. Compared to the control group, the TMAE treatment group exhibited an increase in the ratio of villi length to villi crypt in the duodenum. TMAE increased the abundance of beneficial bacteria, such as Alistipes and Lactobacillus, while reducing the accumulation of harmful bacteria, such as Colidextracter and Sellimonas. The cecum's SCFAs content increased with a medium dose of TMAE. Supplementing broiler diets with TMAE at varying doses enhanced growth performance and overall health. The most significant benefits were observed at a dose of 1000 mg/kg, including improved serum biochemical parameters, intestinal morphology, antioxidant capacity of the liver and ileum, immune function of the liver and ileum, and increased SCFAs content. Lactobacillus aviarius, norank_f_norank_o__Clostridia_UCG-014, and Flavonifractor are potentially dominant members of the intestinal microflora.

Conclusion

In conclusion, TMAE is a promising poultry feed additive and 1000 mg/kg is an effective reference dose.

Border Control: The Role of the Microbiome in Regulating Epithelial Barrier Function

The gut mucosal epithelium is one of the largest organs in the body and plays a critical role in regulating the crosstalk between the resident microbiome and the host. To this effect, the tight control of what is permitted through this barrier is of high importance. There should be restricted passage of harmful microorganisms and antigens while at the same time allowing the absorption of nutrients and water. An increased gut permeability, or "leaky gut", has been associated with a variety of diseases ranging from infections, metabolic diseases, and inflammatory and autoimmune diseases to neurological conditions. Several factors can affect gut permeability, including cytokines, dietary components, and the gut microbiome. Here, we discuss how the gut microbiome impacts the permeability of the gut epithelial barrier and how this can be harnessed for therapeutic purposes.

Dietary xylo-oligosaccharides and arabinoxylans improved growth efficiency by reducing gut epithelial cell turnover in broiler chickens

BACKGROUND

One of the main roles of the intestinal mucosa is to protect against environmental hazards. Supplementation of xylo-oligosaccharides (XOS) is known to selectively stimulate the growth of beneficial intestinal bacteria and improve gut health and function in chickens. XOS may have an impact on the integrity of the intestinal epithelia where cell turnover is critical to maintain the compatibility between the digestive and barrier functions. The aim of the study was to evaluate the effect of XOS and an arabinoxylan-rich fraction (AXRF) supplementation on gut function and epithelial integrity in broiler chickens.

METHODS

A total of 128 broiler chickens (Ross 308) were assigned into one of two different dietary treatments for a period of 42 d: 1) control diet consisting of a corn/soybean meal-based diet; or 2) a control diet supplemented with 0.5% XOS and 1% AXRF. Each treatment was randomly distributed across 8 pens (n = 8) with 8 chickens each. Feed intake and body weight were recorded weekly. On d 42, one male chicken per pen was selected based on average weight and euthanized, jejunum samples were collected for proteomics analysis.

RESULTS

Dietary XOS/AXRF supplementation improved feed efficiency (P < 0.05) from d 1 to 42 compared to the control group. Proteomic analysis was used to understand the mechanism of improved efficiency uncovering 346 differentially abundant proteins (DAP) (Padj < 0.00001) in supplemented chickens compared to the non-supplemented group. In the jejunum, the DAP translated into decreased ATP production indicating lower energy expenditure by the tissue (e.g., inhibition of glycolysis and tricarboxylic acid cycle pathways). In addition, DAP were associated with decreased epithelial cell differentiation, and migration by reducing the actin polymerization pathway. Putting the two main pathways together, XOS/AXRF supplementation may decrease around 19% the energy required for the maintenance of the gastrointestinal tract.

CONCLUSIONS

Dietary XOS/AXRF supplementation improved growth efficiency by reducing epithelial cell migration and differentiation (hence, turnover), actin polymerization, and consequently energy requirement for maintenance of the jejunum of broiler chickens.

Adenosine in Intestinal Epithelial Barrier Function

At the intestinal front, several lines of defense are in place to resist infection and injury, the mucus layer, gut microbiome and strong epithelial junctions, to name a few. Their collaboration creates a resilient barrier. In intestinal disorders, such as inflammatory bowel disease (IBD), barrier function is compromised, which results in rampant inflammation and tissue injury. In response to the destruction, the intestinal epithelium releases adenosine, a small but powerful nucleoside that functions as an alarm signal. Amidst the chaos of inflammation, adenosine aims to restore order. Within the scope of its effects is the ability to regulate intestinal epithelial barrier integrity. This review aims to define the contributions of adenosine to mucus production, microbiome-dependent barrier protection, tight junction dynamics, chloride secretion and acid-base balance to reinforce its importance in the intestinal epithelial barrier.

Microbiota-gut-brain axis and its therapeutic applications in neurodegenerative diseases

The human gastrointestinal tract is populated with a diverse microbial community. The vast genetic and metabolic potential of the gut microbiome underpins its ubiquity in nearly every aspect of human biology, including health maintenance, development, aging, and disease. The advent of new sequencing technologies and culture-independent methods has allowed researchers to move beyond correlative studies toward mechanistic explorations to shed light on microbiome-host interactions. Evidence has unveiled the bidirectional communication between the gut microbiome and the central nervous system, referred to as the "microbiota-gut-brain axis". The microbiota-gut-brain axis represents an important regulator of glial functions, making it an actionable target to ameliorate the development and progression of neurodegenerative diseases. In this review, we discuss the mechanisms of the microbiota-gut-brain axis in neurodegenerative diseases. As the gut microbiome provides essential cues to microglia, astrocytes, and oligodendrocytes, we examine the communications between gut microbiota and these glial cells during healthy states and neurodegenerative diseases. Subsequently, we discuss the mechanisms of the microbiota-gut-brain axis in neurodegenerative diseases using a metabolite-centric approach, while also examining the role of gut microbiota-related neurotransmitters and gut hormones. Next, we examine the potential of targeting the intestinal barrier, blood-brain barrier, meninges, and peripheral immune system to counteract glial dysfunction in neurodegeneration. Finally, we conclude by assessing the pre-clinical and clinical evidence of probiotics, prebiotics, and fecal microbiota transplantation in neurodegenerative diseases. A thorough comprehension of the microbiota-gut-brain axis will foster the development of effective therapeutic interventions for the management of neurodegenerative diseases.

When inflammatory stressors dramatically change, disease phenotypes may transform between autoimmune hematopoietic failure and myeloid neoplasms

Aplastic anemia (AA) and hypoplastic myelodysplastic syndrome are paradigms of autoimmune hematopoietic failure (AHF). Myelodysplastic syndrome and acute myeloid leukemia are unequivocal myeloid neoplasms (MNs). Currently, AA is also known to be a clonal hematological disease. Genetic aberrations typically observed in MNs are detected in approximately one-third of AA patients. In AA patients harboring MN-related genetic aberrations, a poor response to immunosuppressive therapy (IST) and an increased risk of transformation to MNs occurring either naturally or after IST are predicted. Approximately 10%-15% of patients with severe AA transform the disease phenotype to MNs following IST, and in some patients, leukemic transformation emerges during or shortly after IST. Phenotypic transformations between AHF and MNs can occur reciprocally. A fraction of advanced MN patients experience an aplastic crisis during which leukemic blasts are repressed. The switch that shapes the disease phenotype is a change in the strength of extramedullary inflammation. Both AHF and MNs have an immune-active bone marrow (BM) environment (BME). In AHF patients, an inflamed BME can be evoked by infiltrated immune cells targeting neoplastic molecules, which contributes to the BM-specific autoimmune impairment. Autoimmune responses in AHF may represent an antileukemic mechanism, and inflammatory stressors strengthen antileukemic immunity, at least in a significant proportion of patients who have MN-related genetic aberrations. During active inflammatory episodes, normal and leukemic hematopoieses are suppressed, which leads to the occurrence of aplastic cytopenia and leukemic cell regression. The successful treatment of underlying infections mitigates inflammatory stress-related antileukemic activities and promotes the penetration of leukemic hematopoiesis. The effect of IST is similar to that of treating underlying infections. Investigating inflammatory stress-powered antileukemic immunity is highly important in theoretical studies and clinical practice, especially given the wide application of immune-activating agents and immune checkpoint inhibitors in the treatment of hematological neoplasms.

Gut Microbiota-mediated Alleviation of Dextran Sulfate Sodium-induced Colitis in Mice

Background and Aims

Gut dysbiosis characterized by an imbalanced microbiota is closely involved in the pathogenesis of a widespread gastrointestinal inflammatory disorder, inflammatory bowel disease. However, it is unclear how the complex intestinal microbiota affects development or resistant of mucosal inflammation. Our aim was to investigate the impact of the gut microbiota on susceptibility in a mouse model of ulcerative colitis.

Methods

We compared the susceptibility to dextran sulfate sodium (DSS)-induced colitis of inbred BALB/c mice obtained from the 3 main distributors of laboratory animals in Japan. Clinical symptoms of the colitis and the faecal microbiota were assessed. Cohousing approach was used to identify whether the gut microbiota is a primary factor determining disease susceptibility.

Results

Here, we showed differences in the susceptibility of BALB/c mice from the vendors to DSS colitis. Analysis of the gut microbiota using 16S ribosomal RNA sequencing revealed clear separation of the gut microbial composition among mice from the vendors. Notably, the abundance of the phylum Actinobacteriota was strongly associated with disease activity. We also observed the expansion of butyrate-producing Roseburia species in mice with decreased susceptibility of the disease. Further cohousing experiments showed that variation in clinical outcomes was more correlated with the gut microbiota than genetic variants among substrains from different suppliers.

Conclusion

A BALB/c substrain that was resistant to DSS-induced colitis was observed, and the severity of DSS-induced colitis was mainly influenced by the gut microbiota. Targeting butyrate-producing bacteria could have therapeutic potential for ulcerative colitis.

Brain-Gut-Microbiota Axis in Amyotrophic Lateral Sclerosis: A Historical Overview and Future Directions

Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disease which is strongly associated with age. The incidence of ALS increases from the age of 40 and peaks between the ages of 65 and 70. Most patients die of respiratory muscle paralysis or lung infections within three to five years of the appearance of symptoms, dealing a huge blow to patients and their families. With aging populations, improved diagnostic methods and changes in reporting criteria, the incidence of ALS is likely to show an upward trend in the coming decades. Despite extensive researches have been done, the cause and pathogenesis of ALS remains unclear. In recent decades, large quantities of studies focusing on gut microbiota have shown that gut microbiota and its metabolites seem to change the evolvement of ALS through the brain-gut-microbiota axis, and in turn, the progression of ALS will exacerbate the imbalance of gut microbiota, thereby forming a vicious cycle. This suggests that further exploration and identification of the function of gut microbiota in ALS may be crucial to break the bottleneck in the diagnosis and treatment of this disease. Hence, the current review summarizes and discusses the latest research advancement and future directions of ALS and brain-gut-microbiota axis, so as to help relevant researchers gain correlative information instantly.

Liver Bacterial Colonization in Patients with Obesity and Gut Dysbiosis

PURPOSE

Recently, the link between gut microbiota, liver inflammation, and obesity has become an interesting focus of research. The aim of this study is to show the possible relation between gut microbiota dysbiosis in patients with obesity and the presence of bacterial genomes in their liver biopsies.

MATERIALS AND METHODS

A prospective study on patients undergoing bariatric surgery was carried out. Anthropometric and metabolic data, comorbidities, stool samples, and hepatic biopsies were collected and analyzed at the time of surgery. The V3-16S rRNA region was sequenced using the Ion Torrent new-generation sequencing platform.

RESULTS

In each of the 23 patients enrolled, the bacterial population was analyzed both in the stools and liver. In eight patients (34.7%), Prevotella (62.5%), Bacteroides (50%), Streptococcus (12.5%), and Dalister (12.5%) were found in both samples, simultaneously; in 15 cases, the liver was free from colonization. The statistically significant difference between groups was a Roseburia intestinalis reduction in fecal samples of patients with liver biopsies colonized by bacteria (1% vs 3%; p = 0.0339).

CONCLUSION

To the best of our knowledge, this is the first study reporting the presence of bacterial genome in a liver biopsy on bariatric patients, instead of the microbe-associated molecular patterns. Notably, in literature, the presence of Roseburia intestinalis in stool samples has been shown to prevent intestinal inflammation playing its role in the gut barrier integrity. In our population, the Roseburia reduction was associated with the presence of bacterial genome in the liver, probably related to a greater permeability of the gut and vascular barriers.

Electroacupuncture at ST36 modulates the intestinal microecology and may help repair the intestinal barrier in the rat model of severe acute pancreatitis

Severe acute pancreatitis (SAP) onset and development are closely associated with intestinal barrier injury. Evidence from clinical practice and research has shown that electroacupuncture (EA) at the Zusanli (ST36) acupoint can improve intestinal barrier function and abdominal symptoms in patients with SAP; however, the specific mechanisms of action remain unclear. This study aimed to observe the changes in the intestinal microbiota and metabolites in SAP rats and to explore the effect of EA at ST36 on intestinal barrier injury in SAP rats. 16S rRNA gene sequencing combined with microbial diversity analysis, short-chain fatty acids (SCFAs)-targeted metabolomics, immunohistochemistry, immunofluorescence, western blotting, and other techniques were used to explore the mechanism of EA at bilateral ST36 acupoints on SAP-related intestinal barrier injury. Our results showed that EA at ST36 could repair intestinal barrier injury by modulating intestinal microecology, thereby reducing intestinal inflammation, restoring intestinal function, and ultimately alleviating the prognosis of SAP. Our study provides new insights into the mechanisms and treatment of intestinal barrier injury in patients with SAP from the perspectives of microbiota and SCFAs regulation.

An Engineered Butyrate-Derived Polymer Nanoplatform as a Mucosa-Healing Enhancer Potentiates the Therapeutic Effect of Magnolol in Inflammatory Bowel Disease

Colonic epithelial damage and dysregulated immune response are crucial factors in the progression and exacerbation of inflammatory bowel disease (IBD). Nanoenabled targeted drug delivery to the inflamed intestinal mucosa has shown promise in inducing and maintaining colitis remission, while minimizing side effects. Inspired by the excellent antioxidative and anti-inflammatory efficacy of naturally derived magnolol (Mag) and gut homeostasis regulation of microbiota-derived butyrate, we developed a pH/redox dual-responsive butyrate-rich polymer nanoparticle (PSBA) as an oral Mag delivery system for combinational therapy of IBD. PSBA showed a high butyrate content of 22% and effectively encapsulated Mag. The Mag-loaded nanoparticles (PSBA@Mag) demonstrated colonic pH and reduction-responsive drug release, ensuring efficient retention and adhesion in the colon of colitis mice. PSBA@Mag not only normalized the level of reactive oxygen species and inflammatory effectors in inflamed colonic mucosa but also restored the epithelial barrier function in both ulcerative colitis and Crohn's disease mouse models. Importantly, PSBA promoted the migration and healing ability of intestinal epithelial cells in vitro and in vivo, sensitizing the therapeutic efficacy of Mag in animal models. Moreover, transcriptomics and metabolism analyses revealed that PSBA@Mag mitigated inflammation by suppressing the production of pro-inflammatory cytokines and chemokines and restoring the lipid metabolism. Additionally, this nanomedicine modulated the gut microbiota by inhibiting pathogenic Proteus and Escherichia-Shigella and promoting the proliferation of beneficial probiotics, including Lachnoclostridium, Lachnospiraceae_NK4A136_group and norank_f_Ruminococcaceae. Overall, our findings highlight the potential of butyrate-functionalized polymethacrylates as versatile and effective nanoplatforms for colonic drug delivery and mucosa repair in combating IBD and other gastrointestinal disorders.

The improvement of immunity and activation of TLR2/NF-κB signaling pathway by Romboutsia ilealis in broilers

This study was conducted to investigate the effects of Romboutsia ilealis on the immune function of broilers and the underlying mechanisms. A total of 48 one-day-old Arbor Acres broilers were allocated to 4 groups as follows: broilers treated daily with 1 mL live R. ilealis in general anaerobic medium broth media (0, 1 × 104, 1 × 106, and 1 × 108 CFU/mL) from days 1 to 7. Samples were collected on days 8 and 14. The results showed that R. ilealis had no negative effect on the body weight of broilers (P > 0.05). R. ilealis significantly increased the levels of lysozyme, IFN-γ, IFN-γ/IL-4, and IgG in the serum (P < 0.05). R. ilealis significantly increased the levels of IL-4, IFN-γ, sIgA, lysozyme, and iNOS in the ileal mucosa (P < 0.05). R. ilealis significantly increased the mRNA levels of TLR2, TLR4, NF-κB, IL-1β, TNF-α, IFN-γ, IgA, pIgR, iNOS, and MHC-II in the ileum (P < 0.05). R. ilealis significantly increased the relative abundance of Enterococcus and Paracoccus in the jejunum and ileum, ileal Candidatus Arthromitus, and cecal Romboutsia and Intestinimonas (P < 0.05). Correlation analysis showed that Enterococcus, Paracoccus, Romboutsia, and Intestinimonas were significantly positively correlated with humoral immune function (P < 0.05). In conclusion, R. ilealis boosted the immune system, activated the intestinal TLR2/NF-κB signaling pathway, and improved the gut microbiota in broilers.

Decreased YB-1 expression denervates brown adipose tissue and contributes to age-related metabolic dysfunction

Thermogenesis in brown adipose tissue (BAT) declines with aging, however, the underlying mechanism remains unclear. Here, we show that the expression of Y-box binding protein 1 (YB-1), a critical DNA/RNA binding protein, decreased in the BAT of aged mice due to the reduction of microbial metabolite butyrate. Genetic ablation of YB-1 in the BAT accelerated diet-induced obesity and BAT thermogenic dysfunction. In contrast, overexpression of YB-1 in the BAT of aged mice was sufficient to promote BAT thermogenesis, thus alleviating diet-induced obesity and insulin resistance. Interestingly, YB-1 had no direct effect on adipose UCP1 expression. Instead, YB-1 promoted axon guidance of BAT via regulating the expression of Slit2, thus potentiating sympathetic innervation and thermogenesis. Moreover, we have identified that a natural compound Sciadopitysin, which promotes YB-1 protein stability and nuclear translocation, alleviated BAT aging and metabolic disorders. Together, we reveal a novel fat-sympathetic nerve unit in regulating BAT senescence and provide a promising strategy against age-related metabolic disorders.

Gut/rumen-mammary gland axis in mastitis: Gut/rumen microbiota-mediated "gastroenterogenic mastitis"

BACKGROUND

Mastitis is an inflammatory response in the mammary gland that results in huge economic losses in the breeding industry. The aetiology of mastitis is complex, and the pathogenesis has not been fully elucidated. It is commonly believed that mastitis is induced by pathogen infection of the mammary gland and induces a local inflammatory response. However, in the clinic, mastitis is often comorbid or secondary to gastric disease, and local control effects targeting the mammary gland are limited. In addition, recent studies have found that the gut/rumen microbiota contributes to the development of mastitis and proposed the gut/rumen-mammary gland axis. Combined with studies indicating that gut/rumen microbiota disturbance can damage the gut mucosa barrier, gut/rumen bacteria and their metabolites can migrate to distal extraintestinal organs. It is believed that the occurrence of mastitis is related not only to the infection of the mammary gland by external pathogenic microorganisms but also to a gastroenterogennic pathogenic pathway.

AIM OF REVIEW

We propose the pathological concept of "gastroenterogennic mastitis" and believe that the gut/rumen-mammary gland axis-mediated pathway is the pathological mechanism of "gastroenterogennic mastitis".

KEY SCIENTIFIC CONCEPTS OF REVIEW

To clarify the concept of "gastroenterogennic mastitis" by summarizing reports on the effect of the gut/rumen microbiota on mastitis and the gut/rumen-mammary gland axis-mediated pathway to provide a research basis and direction for further understanding and solving the pathogenesis and difficulties encountered in the prevention of mastitis.

Bacteria and bacteriophage consortia are associated with protective intestinal metabolites in patients receiving stem cell transplantation

The microbiome is a predictor of clinical outcome in patients receiving allogeneic hematopoietic stem cell transplantation (allo-SCT). Microbiota-derived metabolites can modulate these outcomes. How bacteria, fungi and viruses contribute to the production of intestinal metabolites is still unclear. We combined amplicon sequencing, viral metagenomics and targeted metabolomics from stool samples of patients receiving allo-SCT (n = 78) and uncovered a microbiome signature of Lachnospiraceae and Oscillospiraceae and their associated bacteriophages, correlating with the production of immunomodulatory metabolites (IMMs). Moreover, we established the IMM risk index (IMM-RI), which was associated with improved survival and reduced relapse. A high abundance of short-chain fatty acid-biosynthesis pathways, specifically butyric acid via butyryl-coenzyme A (CoA):acetate CoA-transferase (BCoAT, which catalyzes EC 2.8.3.8) was detected in IMM-RI low-risk patients, and virome genome assembly identified two bacteriophages encoding BCoAT as an auxiliary metabolic gene. In conclusion, our study identifies a microbiome signature associated with protective IMMs and provides a rationale for considering metabolite-producing consortia and metabolite formulations as microbiome-based therapies.

The Role of Gut Microbiota and Associated Compounds in Cardiovascular Health and its Therapeutic Implications

It is possible that gut bacteria may have a beneficial effect on cardiovascular health in humans. It may play a major role in the progression of a variety of cardiovascular diseases, including Heart Failure (HF), Atherosclerosis, Coronary Arterial Disease (CAD), Ischemic Heart Disease (IHD), and Others. Dysbiosis of the gut microbiota, along with its direct and indirect impact on gut health, may induce cardiovascular disorders. Although advanced studies have demonstrated the relationship of various metabolites to cardiovascular diseases (CVD) in animals, translating their functional capacity to humans remains a significant area of research. This paper simplifies the demonstration of some compounds, pathways, and components like Trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs), and butyrate production. It demonstrates how a change in eating habits causes TMAO and how the impact of different drugs on gut microbiota species and high consumption of Westernized food causes several heartrelated problems, such as atherosclerosis and inflammation that can even become the cause of heart failure. Modulation of the gut microbiome, on the other hand, is a novel therapeutic measure because it can be easily altered through diet and other lifestyle changes. It could then be used to lower the risk of several CVDs.

Response of growth performance and cecum microbial community to cyclic heat stress in broilers

Heat stress (HS) can affect growth performance through alterations in specific gut microbiota, which greatly threatens poultry production. How HS affects the mechanisms of microbial changes in the poultry cecum and the complex interactions between cecal microbial changes and growth performance have not yet been well evaluated. This study was conducted to examine the changes in growth performance and cecal microbiotal community in cyclic heat stress (CHS)-treated broilers. A total of 200 twenty-eight-day-old female Arbor Acres (AA) broilers were equally allotted into neutral ambient temperature group (TN group, 24 ± 1°C, 24 h/day) and CHS group (33 ± 1°C, 8 h/day) with five replicates of 10 broilers each, respectively. Growth performance, cecum microbial diversity, flora composition, and community structure were analyzed on days 35 and 42. The decreased average daily feed intake (ADFI), average daily gain (ADG), and the increased feed/gain ratio (F:G) were observed in heat-stressed broilers on days 35 and 42. The alpha and beta diversity index had no significant changes at the two experimental periods (P > 0.05). At the genus level, CHS significantly increased the relative abundance of Enterococcus at 42 days (P < 0.05). Based on the analysis of linear effect size feature selection, CHS made an enriched Reyranella and a reduced Romboutsia and Ruminiclostridium at 35 days of age (P < 0.05). CHS made an enriched Weissella and Enterococcus at 42 days of age (P < 0.05). The present study revealed that CHS reduces broiler growth performance and alters the microbial community of the cecum microbiota and the abundance of species. These findings are of critical importance to alleviate the negative effects of CHS on broiler chickens' growth performance by maintaining gut microbial balance.

Mimicry of microbially-derived butyrate reveals templates for potent intestinal epithelial HIF stabilizers

Microbiota-derived short-chain fatty acids, including butyrate (BA), have multiple beneficial health effects. In the colon, BA concentrations range from 10 to 20 mM and up to 95% is utilized as energy by the mucosa. BA plays a key role in epithelial-barrier regulation and anti-inflammation, and regulates cell growth and differentiation, at least in part, due to its direct influence on stabilization of the transcription factor hypoxia-inducible factor (HIF). It remains unclear whether BA is the optimal metabolite for such a response. In this study, we explored metabolite mimicry as an attractive strategy for the biological response to HIF. We discovered that 4-mercapto butyrate (MBA) stabilizes HIF more potently and has a longer biological half-life than BA in intestinal epithelial cells (IECs). We validated the MBA-mediated HIF transcriptional activity through the induction of classic HIF gene targets in IECs and enhanced epithelial barrier formation in vitro. In-vivo studies with MBA revealed systemic HIF stabilization in mice, which was more potent than its parent BA metabolite. Mechanistically, we found that MBA enhances oxygen consumption and that the sulfhydryl group is essential for HIF stabilization, but exclusively as a four-carbon SCFA. These findings reveal a combined biochemical mechanism for HIF stabilization and provide a foundation for the discovery of potent metabolite-like scaffolds.