Gut microbiota-derived short-chain Fatty acids, T cells, and inflammation

Microbiota-centered interventions to boost immune checkpoint blockade therapies

Immune checkpoint blockade therapies have markedly advanced cancer treatment by invigorating antitumor immunity and extending patient survival. However, therapeutic resistance and immune-related toxicities remain major concerns. Emerging evidence indicates that microbial dysbiosis diminishes therapeutic response rates, while a diverse gut ecology and key beneficial taxa correlate with improved treatment outcomes. Therefore, there is a growing understanding that manipulating the gut microbiota could boost therapy efficacy. This review examines burgeoning methods that target the gut microbiome to optimize therapy and innovative diagnostic tools to detect dysbiosis, and highlights challenges that remain to be addressed in the field.

Unraveling Spinal Cord Injury Nutrition: Effects of Diet on the Host and Microbiome

Spinal cord injury (SCI) leads to severe neurological dysfunction with significant nutritional alterations. These alterations are closely associated with gut dysbiosis and neurogenic gut dysfunction after SCI, creating complex interactions that further exacerbate metabolic disturbances and impede neurological recovery. In the context of SCI, diet not only fulfills basic nutritional needs but also serves as an important therapeutic tool to modulate these interactions. This review provides a broad overview of existing research findings, analyzes the impact of existing dietary interventions on SCI, and attempts to clarify the complex relationship between diet and host and gut microbiota. We hope to provide a clear direction for future research and a scientific basis for the development of personalized dietary interventions to improve the nutritional status of SCI patients, reduce the incidence of complications such as metabolic disorders, and promote the recovery of neurological function and overall quality of life of SCI patients. STATEMENT OF SIGNIFICANCE: This review evaluates the nutritional changes in patients with spinal cord injury, comprehensively elucidating the effects of dietary interventions on SCI patients from both the host and gut microbiota perspectives. By revealing the complex interactions among them, it lays the foundation for developing personalized nutritional intervention strategies to optimize recovery and improve long-term health outcomes in the future.

Microbiota-derived metabolites in tumorigenesis: mechanistic insights and therapeutic implications

Intestinal microbiota is a complex ecosystem of microorganisms that perform diverse metabolic activities to maintain gastrointestinal homeostasis. These microorganisms provide energy and nutrients for growth and reproduction while producing numerous metabolites including lipopolysaccharides (LPS), Bacteroides fragilis toxin (BFT), bile acids (BAs), polyamines (PAs), and short-chain fatty acids (SCFAs). These metabolites are linked to inflammation and various metabolic diseases, such as obesity, type-2 diabetes, non-alcoholic fatty liver disease, cardiometabolic disease, and malnutrition. In addition, they may contribute to tumorigenesis. Evidence suggests that these microbes can increase the susceptibility to certain cancers and affect treatment responses. In this review, we discuss the current knowledge on how the gut microbiome and its metabolites influence tumorigenesis, highlighting the potential molecular mechanisms and prospects for basic and translational research in this emerging field.

Multi-omics analyses reveal differences in intestinal flora composition and serum metabolites in Cherry Valley broiler ducks of different body weights

Fledgling broiler ducks vary in body weight and growth rate. The aim of this study was to investigate the relationship between serum metabolites and the intestinal microbiota in Cherry Valley broiler ducks with different finishing weights and to reveal differences in their metabolic regulation and microbial composition. Serum and cecum content samples were collected from Cherry Valley broiler ducks of different finishing weights. Metabolites were identified and compared using untargeted metabolomics, 16S rRNA gene sequencing, multivariate statistics and bioinformatics. Six key findings emerged. First, serum biochemical parameters showed that AST and ALT levels were significantly lower in the high weight group (Group H) than in the low weight group (Group L), and serum immunoglobulin IgG levels were significantly higher in group H. Second, the chorionic height to crypt depth ratio of the duodenum was significantly higher in group H than in group L. Third, the gut microbial community diversity or abundance was lower in broiler ducks in group L. Fourth, LEfSe analysis showed that the biomarker for group L was Streptococcus, whereas for group H it was Faecalibacterium. Fifth, a total of 127 differential metabolites were identified (49 up-regulated and 78 down-regulated). Finally, Spearman's correlation analysis showed that Spearman's correlation analyses showed that the Lipid-related serum metabolites were higher in low-body recombinant broiler ducks, mainly Lathosterol, Cholesterol, Cynaratriol and Leukotriene B4. In addition to lipid-associated serum metabolites in high-body recombination, The water-soluble vitamin-like metabolite Pantothenate and the antibiotic-like metabolite Tylosin were high. The cecum microbiota is strongly associated with metabolites, especially Faecalibacterium, unclassified Tannerellaceae, Subdoligranulum, Alistipes, and [Ruminococcus] torques_group, with which it exhibits strong Correlation. Broiler ducks with higher body weights have a better intestinal villous structure, enhanced digestion and absorption, higher levels of immunoglobulin secretion and superior growth performance. Broiler ducks with different body weights differed in plasma metabolites and cecum flora. Spearman's correlation analyses showed that the Correlation between differential metabolites and differential gut microbial genera.

The efficacy and underlying mechanisms of berberine in the treatment of recurrent Clostridioides difficile infection

Recurrent Clostridioides difficile infection (rCDI) is a global health threat that has received considerable attention. Berberine (BBR), a natural pentacyclic isoquinoline alkaloid, has been used as a cost-effective treatment for intestinal infections in Asia for many years. However, the effect of BBR on rCDI is not clear. The efficacy and underlying mechanisms of BBR were evaluated in a vancomycin-dependent rCDI mouse model and an intestinal organoids model. The study findings showed that BBR treatment alleviated the severity of infection and increased survival rate in rCDI mice. Mechanistically, BBR alleviated intestinal epithelial damage with higher Occludin expression, suppressed some inflammatory pathways and reduced the level of inflammatory factors in both the caecum and serum. Moreover, 16S rRNA sequencing analysis indicated that BBR reshaped the gut microbiota by increasing the abundance of Firmicutes and reducing the abundance of Proteobacteria. At genus level, BBR treatment increased levels of Blautia and Bilophila, and reduced levels of Proteus. In addition, acetic acid, one of the short-chain fatty acids (SCFAs), was also increased after BBR treatment in rCDI mice. Collectively, BBR exerted a protective effect in rCDI via multiple underlying mechanisms and is a potential drug candidate for alleviating rCDI, but further research is needed in this area.

Dysbiosis in the Gut Microbiome of Pembrolizumab-Treated Non-Small Lung Cancer Patients Compared to Healthy Controls Characterized Through Opportunistic Sampling

BACKGROUND

The gut microbiome influences the host immune system, cancer development and progression, as well as the response to immunotherapy during cancer treatment. Here, we analyse the composition of the gut bacteriome in metastatic Non-Small Cell Lung Cancer (NSCLC) patients receiving Pembrolizumab immunotherapy within a prospective maintenance trial through opportunistic sampling during treatment.

METHODS

The gut microbiome profiles of NSCLC patients were obtained from stool samples collected during Pembrolizumab treatment and analysed with 16S rRNA metagenomics sequencing. Patient profiles were compared to a group of healthy individuals of matching ethnic group, age, sex, BMI and comorbidities.

RESULTS

A significant decrease in the treated patients was observed in two prominent bacterial families of the phylum Firmicutes, Lachnospiraceae and Ruminoccocaceae, which comprised 31.6% and 21.8% of the bacteriome in the healthy group but only 10.9% and 14.2% in the treated patient group, respectively. Species within the Lachnospiraceae and Ruminococcaceae families are known to break down undigested carbohydrates generating short chain fatty acids (SCFA), such as butyrate, acetate and propionate as their major fermentation end-products, which have been implicated in modifying host immune responses. In addition, a significant increase of the Bacteroidacaeae family (Bacteroidetes phylum) was observed from 10.7% in the healthy group to 23.3% in the treated patient group. Moreover, and in agreement with previous studies, a decrease in the Firmicutes to Bacteroidetes ratio in the metastatic NSCLC Pembrolizumab-treated patients was observed.

CONCLUSION

The observed differences indicate dysbiosis and a compromised intestinal health status in the metastatic NSCLC Pembrolizumab-treated patients. This data could inform future studies of immunotherapy treatment responses and modulation of the gut microbiome to minimise dysbiosis prior or concurrent to treatment.

TRIAL REGISTRATION

SWIPE Trial (NCT02705820).

Short-Chain Fatty Acids Modulate Anti-ROR1 CAR T-Cell Function and Exhaustion in an Intestinal Adenocarcinoma-on-Chip Model

Chimeric antigen receptor (CAR) T-cell therapy represents a promising approach for cancer treatment, with receptor tyrosine kinase-like orphan receptor 1 (ROR1) emerging as a novel target in malignancies. This study investigates how short-chain fatty acids (SCFAs), key microbiota-derived metabolites, modulate anti-ROR1 CAR T-cell efficacy using a physiologically relevant intestinal adenocarcinoma-on-chip model that replicates the human intestinal microenvironment. The findings demonstrate that propionate and butyrate inhibit anti-ROR1 CAR T-cell function by reducing infiltration, cytotoxicity, and cytokine release while preserving junctional integrity within the tumor model. Mechanistically, these SCFAs inhibit histone deacetylase activity and promote a phenotype switch toward regulatory T-cells, as indicated by increased expression of FoxP3 and RORγt. Additionally, propionate and butyrate upregulate PD-1 and TIM-3, markers of T-cell exhaustion and immune tolerance, and induce a dose- and time-dependent reduction in proinflammatory cytokines. In contrast, acetate and pentanoate promote a proinflammatory T helper 17 phenotype. These results highlight the immunomodulatory effects of SCFAs on CAR T-cell function, emphasizing the need to consider microbiota-derived metabolites in CAR T-cell therapies.

Short-chain fatty acids-a key link between the gut microbiome and T-lymphocytes in neonates?

Infancy is a vulnerable and critical phase in the acquisition of the gut microbiome and the establishment of immune function. Short-chain fatty acids (SCFAs), such as acetate, propionate and butyrate, are compounds mostly produced by the microbiome through various metabolic pathways and play an indispensable role in connecting the microbiome and the adaptive immune system. This review aims to summarise recent findings regarding the intricate relationship between SCFAs, the gut microbiome, and T lymphocytes with a focus on early life interactions. The paper discusses factors affecting the establishment of the neonatal microbiome, especially human milk versus formula milk, and how these influence SCFA concentrations in feces, which in turn directly impact T cell development and function. Despite recent advances in understanding the role of gut microbiome derived SCFAs in adults, a significant knowledge gap remains in translating these findings to neonates and exploring the utility of SCFAs as a potential therapeutic intervention in inflammatory complications of preterm and term neonates. IMPACT: This review highlights potential therapeutic applications of short-chain fatty acids (SCFAs) in neonatal care, particularly in preventing and treating inflammatory conditions. This could lead to new treatment strategies for conditions like NEC and other immune-mediated disorders in neonates. By identifying significant knowledge gaps in neonatal SCFA research, this review helps future investigations toward understanding SCFA mechanisms specifically in neonates, potentially leading to age-appropriate therapeutic interventions. Understanding the relationship between early-life factors (such as feeding methods and microbiome development) and immune system development through SCFAs could inform public health policies and recommendations for infant nutrition and care practices.

Microbiome dysbiosis in SARS-CoV-2 infection: implication for pathophysiology and management strategies of COVID-19

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), in late 2019 initiated a global health crisis marked by widespread infection, significant mortality, and long-term health implications. While SARS-CoV-2 primarily targets the respiratory system, recent findings indicate that it also significantly disrupts the human microbiome, particularly the gut microbiota, contributing to disease severity, systemic inflammation, immune dysregulation, and increased susceptibility to secondary infections and chronic conditions. Dysbiosis, or microbial imbalance, exacerbates the clinical outcomes of COVID-19 and has been linked to long-COVID, a condition affecting a significant proportion of survivors and manifesting with over 200 symptoms across multiple organ systems. Despite the growing recognition of microbiome alterations in COVID-19, the precise mechanisms by which SARS-CoV-2 interacts with the microbiome and influences disease progression remain poorly understood. This narrative review investigates the impact of SARS-CoV-2 on host-microbiota dynamics and evaluates its implications in disease severity and for developing personalized therapeutic strategies for COVID-19. Furthermore, it highlights the dual role of the microbiome in modulating disease progression, and as a promising target for advancing diagnostic, prognostic, and therapeutic approaches in managing COVID-19.

Critical Care Nutrition from a Metabolic Point of View: A Narrative Review

Background: Critical illness induces profound metabolic alterations, characterized by a hypermetabolic state, insulin resistance, protein catabolism, and gut barrier dysfunction, which contribute to increased morbidity and mortality. Emerging evidence highlights the role of the gut microbiome and its metabolites in modulating systemic inflammation and immune responses during critical illness. This narrative review explores the metabolic evolution of critically ill patients, the impact of gut dysbiosis on disease progression, and the potential role of nutrition in modulating metabolism and improving patient outcomes. Methods: A comprehensive literature search was conducted across PubMed and Google Scholar for articles published up to February 2025. Search terms included "critical illness", "metabolism", "gut microbiota", "nutrition", and related keywords. Articles published in English addressing metabolic alterations, microbiome changes, and nutritional strategies in critically ill patients were included. After screening for eligibility, relevant articles were synthesized to outline current knowledge and identify gaps. Results: Metabolic changes in critical illness progress through distinct phases, from catabolism-driven hypermetabolism to gradual recovery. Gut dysbiosis, characterized by a loss of microbial diversity and increased gut permeability, contributes to systemic inflammation and organ dysfunction. Nutritional strategies, including enteral nutrition, probiotics, prebiotics, and metabolomics-driven interventions, may help restore microbial balance, preserve gut barrier integrity, and modulate immune and metabolic responses. Future nutrition therapy should focus on metabolic modulation rather than solely addressing nutrient deficits. Conclusions: Advances in gut microbiome research and metabolomics offer new avenues for personalized nutrition strategies tailored to the metabolic demands of critically ill patients. Integrating these approaches may improve clinical and functional recovery while mitigating the long-term consequences of critical illness.

A comprehensive review on the implications of Yogic/Sattvic diet in reducing inflammation in type 2 diabetes

Chronic inflammation in type 2 diabetes (T2D), characterized by constitutively activated immune cells and elevated pro-inflammatory mediators along with hyperglycaemia and increased free fatty acids and branched chain amino acid levels, significantly alters the immuno-metabolic axis. Over the years, dietary intervention has been explored as an effective strategy for managing T2D. Evidence from experimental and clinical studies indicates that various diets, including Mediterranean, Nordic, Palaeolithic and ketogenic diets, increase insulin sensitivity, decrease gluconeogenesis, and adiposity, and exert anti-inflammatory effects, thus preserving immuno-metabolic homeostasis in individuals with T2D. Indian dietary sources are categorized as Sattvic, Rajasic, and Tamasic, depending on their impact on health and behaviour. The Yogic diet, commonly recommended during yoga practice, is predominantly Sattvic, emphasizing plant-based whole foods while limiting processed and high-glycaemic-index items. Yogic diet is also recommended for Mitahara, emphasizing mindful eating, which is attributed to calorie restriction. Adopting a Yogic diet, featuring low-fat vegetarian principles, strongly reduces inflammatory mediator levels. This diet not only ameliorates insulin resistance and maintains a healthy body weight but also regulates immunomodulation, enhances gut microbiome diversity and provides essential phytonutrients, collectively preventing inflammation. Although, preliminary studies show aforementioned beneficial role of Yogic diet in improving diabetes associated metabolic and inflammatory changes, precise cellular and molecular mechanisms are not yet understood. Hence, further studies are warranted to decipher the mechanisms. This review summarizes the multiple roles of Yogic diet and related dietary components in mitigating inflammation and enhancing glycaemic control in T2D.

Zinc Glycine supplementation improves bone quality in meat geese by modulating gut microbiota, SCFA's, and gut barrier function through Wnt10b/NF-κB axis

Bone disorders are characterized by leg abnormalities and alterations in gut microbiota, which are linked with destruction of bone structure and increased risk of fractures. Zinc (Zn) plays a crucial role in normal bone homeostasis and has been proven to be highly effective against leg problems. The effects of different Zn sources on bone quality were evaluated in this study. A total of 300 one-d-old Wanpu mixed-sexed geese fed 2 basal diets added with best suited levels of 80 mg/kg inorganic zinc (ZnSO4), and 80 mg/kg Organic zinc (Zn-Glycine) for 60 d. Tibia bone mineral density (BMD), ash percentage, and tibia length increased with dietary Zn source (P < 0.05). Micro-computed tomography analysis revealed that Zn-Glycine improved bone mass, potentially due to an increased abundance of Firmicutes and higher SCFA production in the cecum. Dietary Zn Glycine addition reduced intestinal permeability, upregulated the protein expression of tight junction protein (Zonula Occludens-1, Claudin-1), downregulated diamine oxidase (DAO) levels, and increased the abundance of Lactobacillus and Bifidobacterium, which was accompanied by a reduction in inflammatory cytokines levels in the serum, tibia, and cecum. In terms of bone turnover, Zn-Glycine increased alkaline phosphatase (ALP) and other bone markers (Runt-related transcription factor 2- Runx2, Osteoprotegerin- OPG, Osteocalcin- OCN, Suppressor of mother against decapentaplegic- SMAD) expression, resulting in a decrease in osteoclast number and a reduction in serum bone resorption biomarkers, including serum tartrate-resistant acid phosphatase activity and tibia nuclear factor of activated T-cells (NFATC1) and tumor necrosis factor receptor associated factor 6 (TRAF-6) (P < 0.05). Zn-Glycine also enhanced antioxidant capacity by increasing catalase (CAT) and glutathione peroxidase (GSH-PX), resulting in reduced reactive oxygen species (ROS) and malondialdehyde (MDA) production (P<0.05). Zn-Glycine at 80mg/kg in the diet actively reduced (P<0.05) the expression of cell-death-associated proteins (Beclin-1, Caspase-3). Additionally, Zn-Glycine improved intestinal morphology (villus height, villus-to-crypt ratio), supporting efficient nutrient absorption. Immunofluorescence analysis of tibia showed higher expression of wingless type-10b (Wnt-10b) and reduced expression of nuclear factor-kappa B (NF-κB) in Zn-Glycine group compared to ZnSO4 group. These findings underscore the significance of the gut-bone axis and provide new insights into the effect of Zn-Glycine on bone health in meat geese through a key signaling pathway.

Impact of Nutrition on the Gut Microbiota: Implications for Parkinson's Disease

Parkinson's disease (PD) is a multifactorial neurodegenerative disease that is characterized by the degeneration of dopaminergic neurons in the substantia nigra pars compacta and by the anomalous accumulation of α-synuclein aggregates into Lewy bodies and Lewy neurites. Research suggests 2 distinct subtypes of PD: the brain-first subtype if the pathology arises from the brain and then spreads to the peripheral nervous system (PNS) and the body-first subtype, where the pathological process begins in the PNS and then spreads to the central nervous system. This review primarily focuses on the body-first subtype. The influence of the gut microbiota on the development of PD has been the subject of growing interest among researchers. It has been suggested that gut inflammation may be closely associated with pathogenesis in PD, therefore leading to the hypothesis that gut microbiota modulation could play a significant role in this process. Nutrition can influence gut health and alter the risk and progression of PD by altering inflammatory markers. This review provides an overview of recent research that correlates variations in gut microbiota composition between patients with PD and healthy individuals with the impact of certain nutrients and dietary patterns, including the Mediterranean diet, the Western diet, and the ketogenic diet. It explores how these diets influence gut microbiota composition and, consequently, the risk of PD. Last, it examines fecal transplantation and the use of prebiotics, probiotics, or synbiotics as potential therapeutic strategies to balance the gut microbiome, aiming to reduce the risk or delay the progression of PD.

Exploring blood immune cells in the protective effects of gut microbiota on rheumatic heart disease based on Mendelian randomization analysis

Rheumatic Heart Disease (RHD) remains a significant health burden, particularly in regions with scarce healthcare resources, research on its immunological aspects remains insufficient. This study employed a two-sample Mendelian Randomization approach, utilizing GWAS data from the largest available datasets for gut microbiota and immune cells as exposures, with outcome data for Rheumatic Valve Diseases (RVD) and Rheumatic Heart Disease affecting other parts of the heart (RHD-other) obtained from the FinnGen study. The primary analytical method was the Inverse Variance Weighted (IVW) approach, complemented by heterogeneity analyses and MR-Egger regression to assess horizontal pleiotropy. Furthermore, a two-step mediation analysis was conducted to investigate the potential mediating role of immune cells in the association between gut microbiota and RHD. This study revealed significant inverse associations between gut microbiota abundance and Rheumatic Heart Disease (RHD) risk. Specifically, the gut abundance of genus Blautia was negatively correlated with RHD-other risk (P_IVW: 0.00932, OR [95%CI]: 0.000734[3.22e-06, 0.16937]), and genus Ruminococcaceae UCG005 showed a similar negative association (P_IVW: 0.038, OR [95%CI]: 0.165[0.02994, 0.90811]). Additionally, the proportions of CD4-CD8- T cell %leukocyte and CD4-CD8- T cell %T cell were inversely related to RHD-other risk (P_IVW: 0.02222, OR [95%CI]: 5.08027 [1.26133, 20.46191] and P: 0.01601, OR[95%CI]: 6.55576 [1.4196, 30.27582], respectively). Moreover, IgD on IgD + CD24 + B cells was found to be negatively correlated with RHD-other risk (P_IVW: 0.01867, OR [95%CI]: 2.17171 [1.1380, 4.14443]). The study also highlighted the protective effects of gut microbiota through mediation analyses: Blautia's impact via IgD on IgD + CD24 + B cells showed a mediation proportion of 8.62514%; Ruminococcaceae UCG005's influence via CD4-CD8- T cell %T cell and CD4-CD8- T cell %leukocyte resulted in mediation proportions of 35.25817% and 30.86827%, respectively. Significant inverse associations were observed between gut microbiota abundance and risk of Rheumatic Heart Disease (RHD), with specific findings for Rheumatic Valve Disease (RVD) and RHD affecting other parts of the heart (RHD-other). For RHD-other, higher abundance of Blautia (OR: 0.0007, 95% CI: 3.22e-06 to 0.169, p = 0.009) and Ruminococcaceae UCG005 (OR: 0.165, 95% CI: 0.030 to 0.908, p = 0.038) were associated with lower risk. Additionally, lower proportions of CD4-CD8- T cells (%leukocyte and %T cell) and IgD on IgD + CD24 + B cells were inversely related to RHD-other risk (ORs: 5.08 and 6.56, p = 0.022 and p = 0.016, respectively). For RVD, higher abundance of Candidatus Soleaferrea was protective (OR: 0.670, 95% CI: 0.460 to 0.976, p = 0.037), while higher levels of CD11c on granulocytes were associated with increased risk (OR: 1.310, 95% CI: 1.023 to 1.679, p = 0.032). Mediation analyses indicated that gut microbiota influence RHD risk through distinct immune pathways, with Blautia affecting RHD-other via IgD on B cells (8.62% mediation), Ruminococcaceae UCG005 via CD4-CD8- T cells (%T cell: 35.26%, %leukocyte: 30.87%). Genus Candidatus Soleaferrea affecting RVD through CD11c on granulocyte (15.01% mediation). The study concludes that higher gut abundance of Candidatus Soleaferrea protects against RVD through the mechanism involving CD11c on granulocytes. Additionally, Blautia exerts a protective effect against RHD-other through its influence on IgD on IgD + CD24 + B cells. Similarly, the abundance of genus Ruminococcaceae UCG005 provides protection against RHD-other by influencing CD4-CD8- T cell %T cell and CD4-CD8- T cell %leukocyte.

Fu Brick Tea Protects the Intestinal Barrier and Ameliorates Colitis in Mice by Regulating Gut Microbiota

Ulcerative colitis (UC) pathogenesis is strongly linked to gut microbiota dysbiosis and compromised intestinal barrier integrity. Emerging evidence suggests that targeted dietary interventions may restore microbial homeostasis and ameliorate colitis progression. In this study, we evaluated the therapeutic potential of Fu Brick tea (FBT) using a dextran sulfate sodium (DSS)-induced murine colitis model. The results indicated that oral administration of FBT extract significantly improved the disease index, reduced inflammatory response, protected intestinal barrier protein (e.g., ZO-1), and maintained intestinal structure integrity. Furthermore, FBT intake increased the diversity of gut microbiota, promoted the growth of beneficial bacteria (e.g., Akkermansia), inhibited the proliferation of harmful bacteria (e.g., Desulfovibrioceae, Escherichia, and Helicobacter), restored intestinal homeostasis, and alleviated colitis symptoms including diarrhea. These findings position FBT as a promising nutraceutical candidate for UC management via multi-target modulation of mucosal immunity and microbial ecology.

Teratogenic effect evaluation of Monascus red oral exposure to pregnant rats and their gut microbiota

Monascus red (MR) is widely used as a natural food colorant and preservative in East Asia. However, the potential effects of MR during pregnancy remains unknown. In this study, MR was administrated to Sprague-Dawley (SD) rats at doses of 0, 0.50, 1.58, and 5.00 g/kg bw on gestational days 6-15 by oral gavage. In the maternal and embryo-fetal examinations, there were no marked toxicities in terms of general clinical signs, body weight, food consumption, serum endocrine indices, organ weights, thyroid histopathology, examinations of uterine contents and fetuses. In the gut microbiota analysis, the 5.00 g/kg bw dose of MR decreased the α diversity and slightly changed their community structure at the genus level. Yet no marked toxicities in maternal animals or embryo-fetal development were observed. The no-observed-adverse-effect-level (NOAEL) of the maternal and developmental toxicity through oral exposure to MR was 5.00 g/kg bw, the highest dose tested in rats.

The Kynurenine Pathway and Indole Pathway in Tryptophan Metabolism Influence Tumor Progression

Tryptophan (Trp), an essential amino acid, is solely acquired through dietary intake. It is vital for protein biosynthesis and acts as a precursor for numerous key bioactive compounds. The Kynurenine Pathway and the Indole Pathway are the main metabolic routes and are extensively involved in the occurrence and progression of diseases in the digestive, nervous, and urinary systems. In the Kynurenine Pathway, enzymes crucial to tryptophan metabolism, indoleamine-2,3-dioxygenase 1 (IDO1), IDO2, and Trp-2,3-dioxygenase (TDO), trigger tumor immune resistance within the tumor microenvironment and nearby lymph nodes by depleting Trp or by activating the Aromatic Hydrocarbon Receptor (AhR) through its metabolites. Furthermore, IDO1 can influence immune responses via non-enzymatic pathways. The Kynurenine Pathway exerts its effects on tumor growth through various mechanisms, including NAD+ regulation, angiogenesis promotion, tumor metastasis enhancement, and the inhibition of tumor ferroptosis. In the Indole Pathway, indole and its related metabolites are involved in gastrointestinal homeostasis, tumor immunity, and drug resistance. The gut microbiota related to indole metabolism plays a critical role in determining the effectiveness of tumor treatment strategies and can influence the efficacy of immunochemotherapy. It is worth noting that there are conflicting effects of the Kynurenine Pathway and the Indole Pathway on the same tumor phenotype. For example, different tryptophan metabolites affect the cell cycle differently, and indole metabolism has inconsistent protective effects on tumors in different regions. These differences may hold potential for enhancing therapeutic efficacy.

Therapeutic role of gut microbiota in lung injury-related cognitive impairment

Lung injury can lead to specific neurocognitive dysfunction, and the "triple-hit" phenomenon may be the key theoretical mechanism for the progressive impairment of lung injury-related cognitive impairment. The lung and brain can communicate biologically through immune regulation pathway, hypoxic pathway, neural circuit, mitochondrial dysfunction, and microbial influence, which is called the "lung-brain axis." The gut microbiota is a highly complex community of microorganisms that reside in the gut and communicate with the lung via the "gut-lung axis." The dysregulation of gut microbiota may lead to the migration of pathogenic bacteria to the lung, and directly or indirectly regulate the lung immune response through their metabolites, which may cause or aggravate lung injury. The gut microbiota and the brain interact through the "gut-brain axis." The gut microbiota can influence and regulate cognitive function and behavior of the brain through neural pathway mechanisms, immune regulation pathway and hypothalamic-pituitary-adrenal (HPA) axis regulation. Based on the gut microbiota regulation mechanism of the "gut-lung axis" and "gut-brain axis," combined with the mechanisms of cognitive impairment caused by lung injury, we proposed the "triple-hit" hypothesis. It states that the pathophysiological changes of lung injury trigger a series of events such as immune disorder, inflammatory responses, and microbiota changes, which activate the "lung-gut axis," thus forming a "triple-hit" that leads to the development or deterioration of cognitive impairment. This hypothesis provides a more comprehensive framework for studying and understanding brain dysfunction in the context of lung injury. This review proposes the existence of an interactive tandem network for information exchange among the gut, lung, and brain, referred to as the "gut-lung-brain axis." It further explores the potential mechanism of lung injury-related cognitive impairment caused by multiple interactions of gut microbiota in the "gut-lung-brain axis." We found that there are many numerous pathophysiological factors that influence the interaction within the "gut-lung-brain axis." The impact of gut microbiota on cognitive functions related to lung injury may be mediated through mechanisms such as the "triple-hit" hypothesis, direct translocation of microbes and their metabolites, hypoxic pathway, immune modulation, vagal nerve activity, and the HPA axis regulation, among others. As the research deepens, based on the "triple-hit" hypothesis of lung injury, it is further discovered that gut microbial therapy can significantly change the pathogenesis of the inflammatory process on the "gut-lung-brain axis." It can also relieve lung injury and therapeutically modulate brain function and behavior. This perspective provides a new idea for the follow-up treatment of lung injury-related cognitive impairment caused by dysregulation of gut microbiota.

Porcine Bile Acids Improve Antioxidant Status and Immune Function by Increasing Hungatella Abundance with Different Protein Level Diets in Late-Laying Hens

The modern livestock industry faces significant challenges due to the extension of production cycles and a growing shortage of feed resources. Low-protein (LP) diets offer potential environmental advantages whereas damage intestinal integrity and increase pro-inflammatory cytokines. Bile acids (BAs), metabolic products of cholesterol in the liver, possess strong antioxidative and immune properties. This study evaluated the effects of dietary porcine BA supplementation at different protein levels on the antioxidant status, immune function, and gut microbiota of late-laying hens. A 2 × 2 factorial design was employed with 198 Hy-Line Brown laying hens (62 weeks old), randomly divided into one of four treatment groups with 8 replicates for each treatment. Diets included normal (16.42%) or low-protein (15.35%) levels, with porcine BAs supplemented at 0 or 120 mg/kg (62-69 weeks) and 0 or 200 mg/kg (70-75 weeks) over 14 weeks. Dietary protein levels and bile acids had no effect on organ development in laying hens. Low-protein diets increased serum anti-inflammatory cytokines IL-4 and IL-10 but elevated pro-inflammatory cytokines IL-1β (p < 0.05), corroborated by higher IL-10 gene expression in the ileum mucosa (p < 0.05). The supplementation of bile acids improved immune function by increasing serum IL-4 and TGF-β while decreasing IL-6 levels (p < 0.05). Moreover, bile acids treatments upregulated IL-10, TGF-β and ZO-1 gene expression in the ileum mucosa (p < 0.05) and alleviated oxidative stress by enhancing serum GSH-Px activity (p < 0.05). Additionally, both low-protein diets and bile acids enriched beneficial cecal bacteria, including Hungatella and Blautia, primarily linked to immune function. These findings demonstrate that porcine bile acids administration improve antioxidant capacity, immune function and gut microbiota dysbiosis. These beneficial effects were associated with Hungatella and Blautia levels, which may be responsible for the porcine bile acids efficacy in poultry nutrition.

Effects of dietary supplementation with butyrate glycerides on lipid metabolism, intestinal morphology, and microbiota population in laying hens

The present study investigated the impact of butyrate glycerides (BG) on lipid metabolism, intestinal morphology, and microbiota of laying hens. Four hundred eighty 54-week-old Hy-line Brown laying hens were randomly selected and divided into five groups. The control group (ND) was fed a basal diet. Meanwhile, the remaining groups were given a basal supplemented with 0.5, 1, 2, and 4 g/kg of the product containing BG and were designated as BG-0.5, BG-1, BG-2, and BG-4 groups, respectively. The findings showed that: (1) BG supplementation significantly decreased (P < 0.001) the blood Glu levels (BG-0.5, BG-1, BG-2, and BG-4) and increased (P < 0.001) the serum HDL-C levels (BG-2, and BG-4). (2) The BG-2 and BG-4 groups showed an increase (P < 0.01) in abdominal lipid HSL activity. (3) The levels of hepatic TC and TG in all BG groups were significantly decreased (P < 0.05). (4) The addition of BG resulted in a significant reduction in the mRNA expression of the liver X receptor alpha (LXRα) (P < 0.05). (5) All BG groups presented a substantial reduction in duodenal crypt depth and a notable increase in the ratio of villus height to crypt depth (V/C) (P < 0.01). Additionally, all BG groups exhibited a significant increase in villus height in the ileum (P < 0.001). (6) Both the BG-1 and BG-4 groups exhibited a significant reduction in the amounts of n-butyric and n-glutaric acids in the cecum contents (P < 0.05). (7) The inclusion of BG did not substantially impact the diversity of cecal microbiota in laying hens. However, it dramatically boosted the proportion of the beneficial bacterium Alistipes (P < 0.05) and reduced the abundance of the harmful bacterium Verrucomicrobiota (P < 0.05). Overall, incorporating BG with glycerol monobutyrate as the diet's primary active component reduces fat accumulation in laying hens' blood and liver. It potentially regulates lipid metabolism via the PPARγ-LXRα-SREBP1c pathway. Additionally, BG has the potential to enhance the structure of the small intestine's mucous membrane and increase the presence of beneficial bacteria. Under the experimental conditions, late-laying hens supplemented with 4 g/kg BG performed best overall.

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

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

Gut-brain axis and brain health: modulating neuroinflammation, cognitive decline, and neurodegeneration

The microbiota-gut-brain axis is a pivotal medium of crosstalk between the central nervous system (CNS) and the gastrointestinal tract. It is an intricate network of synergistic molecular pathways that exert their effects far beyond their local vicinity and even affect the systemic functioning of the body. The current review explores the involvement of the gut-brain axis (GBA) in the functioning of the nervous system, with a special emphasis on the neurodegeneration, cognitive decline, and neuroinflammation that occur in Alzheimer's disease (AD) and Parkinson's disease (PD). Gut-derived microbial metabolites play an important role in facilitating this interaction. We also highlighted the complex interaction between gut-derived metabolites and CNS processes, demonstrating how microbial dysbiosis might result in clinical disorders. Short-chain fatty acids have neuroprotective properties, whereas branched-chain amino acids, trimethylamine-N-oxide (TMAO), and tryptophan derivatives such as indole have negative effects at high concentrations. Furthermore, we cover pharmaceutical and nonpharmacological approaches for restoring the gut microbial balance and promoting neurological health. We further expanded on nutritional therapies and lifestyle changes, such as the Mediterranean diet and exercise. Next, we focused on food-controlling habits such as caloric restriction and intermittent fasting. Moreover, interventional techniques such as prebiotics, probiotics, and pharmacological medications have also been utilized to modify the GBA. Historical microbiome research from early discoveries to recent studies linking gut health to cognitive and emotional well-being has increased our understanding of the GBA.

In Vitro Evaluation of Probiotic Activities and Anti-Obesity Effects of Enterococcus faecalis EF-1 in Mice Fed a High-Fat Diet

This research sought to assess the anti-obesity potential of Enterococcus faecalis EF-1. An extensive and robust in vitro methodology confirmed EF-1's significant potential in combating obesity, probably due to its excellent gastrointestinal tract adaptability, cholesterol-lowering property, bile salt hydrolase activity, α-glucosidase inhibition, and fatty acid absorption ability. Moreover, EF-1 exhibited antimicrobial activity against several pathogenic strains, lacked hemolytic activity, and was sensitive to all antibiotics tested. To further investigate EF-1's anti-obesity properties in vivo, a high-fat diet (HFD) was used to induce obesity in C57BL/6J mice. Treatment with EF-1 (2 × 109 CFU/day) mitigated HFD-induced body weight gain, reduced adipose tissue weight, and preserved liver function. EF-1 also ameliorated obesity-associated microbiota imbalances, such as decreasing the Firmicutes/Bacteroidetes ratio and boosting the levels of bacteria (Faecalibacterium, Mucispirillum, Desulfovibrio, Bacteroides, and Lachnospiraceae_NK4A136_group), which are responsible for the generation of short-chain fatty acids (SCFAs). Concurrently, the levels of total SCFAs were elevated. Thus, following comprehensive safety and efficacy assessments in vitro and in vivo, our results demonstrate that E. faecalis EF-1 inhibits HFD-induced obesity through the regulation of gut microbiota and enhancing SCFA production. This strain appears to be a highly promising candidate for anti-obesity therapeutics or functional foods.

Exploring the causal connection: insights into diabetic nephropathy and gut microbiota from whole-genome sequencing databases

Over recent years, the prevalence of diabetes has been on the rise, paralleling improvements in living standards. Diabetic nephropathy (DN), a prevalent complication of diabetes, has also exhibited a growing incidence. While some clinical studies and reviews have hinted at a link between diabetic nephropathy and gut microbiota (GM), the nature of this connection, specifically its causative nature, remains uncertain. Investigating the causal relationship between diabetic nephropathy and gut microbiota holds the promise of aiding in disease screening and identifying novel biomarkers. In this study, we employed a two-sample Mendelian randomization analysis. Our dataset encompassed 4,111 DN patients from the GWAS database, juxtaposed with 308,539 members forming a control group. The aim was to pinpoint specific categories within the vast spectrum of the 211 known gut microbiota types that may have a direct causal relationship with diabetic nephropathy. Rigorous measures, including extensive heterogeneity and sensitivity analyses, were implemented to mitigate the influence of confounding variables on our experimental outcomes. Ultimately, our comprehensive analysis revealed 15 distinct categories of gut microbiota that exhibit a causal association with diabetic nephropathy. In summary, the phyla Bacteroidota and Verrucomicrobiae, the families Peptostreptococcaceae and Veillonellaceae, the genus Akkermansia, and the species Catenibacterium, Lachnoclostridium, Parasutterella, along with the orders Bacteroidales and Verrucomicrobiales, and the class Bacteroidetes were identified as correlates of increased risk for DN. Conversely, the family Victivallaceae, the species Eubacterium coprostanoligenes, and the Clostridium sensu stricto 1 group were found to be associated with a protective effect against the development of DN.These findings not only provide valuable insights but also open up novel avenues for clinical research, offering fresh directions for potential treatments.

Relevance of Indian Traditional Herbal Brews for Gut Microbiota Balance

The considerable changes in lifestyle patterns primarily affect the human gut microbiota and result in obesity, diabetes, dyslipidemia, renal complications, etc. though there are few traditional safeguards such as herbal brews to maintain the ecological stability under intestinal dysbiosis. The present article is designed to collect all the scientific facts in a place to decipher the role of the Indian traditional herbal brews used to balance gut health for centuries. Computerized databases, commercial search engines, research papers, articles, and books were used to search by using different keywords to select the most appropriate published articles from 2000 onward to September 2023. A total of 1907 articles were scrutinized, 46 articles were finally selected from the 254 screened, and targeted information was compiled. Interaction of herbal brews to the gut microflora and resulting metabolites act as prebiotics due to antimicrobial, anti-inflammatory, and antioxidant properties, and modulate the pH of the gut. The effect of brews on gut microbiota has a drastic impact on various gut-related diseases and has gained popularity as an alternative to antibiotics against bacteria, fungi, viruses, parasites, and boosting the immune system and strengthening the intestinal barrier. Berberine, kaempferol, piperine, and quercetin have been found in more than one brew discussed in the present article. Practically, these brews balance the gut microbiota, prevent chronic and degenerative diseases, and reduce organ inflammation, though, there is a knowledge gap on the molecular mechanism to explain their efficacy. Indian traditional herbal brews used to reboot and heal the gut microbiota since centuries-old practice with successful history without toxicity. The systematic consumption of these brews under specific dietary prescriptions has a hope of arrays for a healthy human gut microbiome in the present hasty lifestyle with overall health and well-being.

Graphical Abstract

Sodium houttuyfonate modulates the lung Th1/Th2 balance and gut microbiota to protect against pathological changes in lung of ovalbumin-induced asthmatic mice

OBJECTIVE

The gut-lung axis involves microbial and product interactions between the lung and intestine. Antibiotics for chronic asthma can cause intestinal dysbiosis, disrupting this axis. Sodium houttuyfonate (SH) has diverse biological activities, including modifying gut microbiota, antibacterial, and anti-inflammatory. This study aims to explore the relationship between SH, CD4+ T cells, and gut microbiota.

METHODS

Allergic asthma was experimentally induced in mice through injection and inhalation of ovalbumin. After the administration of different amounts of SH, ELISA was utilized to ascertain the levels of inflammatory cytokines in the serum, flow cytometry was used to examine the levels of Th1/Th2 cytokines in CD4+ cells from lung tissues. The expression of T-bet and GATA3 in lung tissue was determined by Western blotting and quantitative real-time PCR assay. Gut microbiota was determined by 16S rRNA gene sequencing.

RESULTS

The results showed that SH can alleviate pulmonary injury in asthmatic mice, reducing serum levels of IL-4, IL-5, and IL-13 while simultaneously increasing IFN-γ. Furthermore, SH has been observed to modulate the balance of Th1/Th2 cells by up-regulating the mRNA and protein expression of T-bet but down-regulating GATA3 in the lung tissues of asthmatic mice, thereby promoting the differentiation of Th1 cells. Additionally, SH can regulate the variety and composition of gut microbiota especially genus Akkermansia in asthmatic mice.

CONCLUSION

SH can alleviate asthma through the regulation of Th1/Th2 cells and gut microbiota.

Investigating the Causal Relationship Between Gut Microbiota and Allergic Conjunctivitis: A Two-Sample Mendelian Randomization Study

PURPOSE

To investigate the causal association between gut microbiota and allergic conjunctivitis.

METHODS

A two-sample Mendelian randomization (MR) analysis was performed using the summary statistics of gut microbiota (18,340) from MiBio-Gen consortium and allergic conjunctivitis data (n = 218,792) obtained from the IEU Open GWAS project. F-statistics and sensitivity analyses were used to address potential biases and ensure the reliability of our findings. Reverse MR analysis was conducted to assess the possible of reverse causal relationships.

RESULTS

The inverse variance weighted estimates revealed the protective potential of the phylum Euryarchaeota against allergic conjunctivitis (OR = 0.87, p = 6.17 × 10-4). On the other hand, the genus Christensenellaceae R.7 group (OR = 0.75, p = 2.89 × 10-3), family Peptostreptococcaceae (OR = 0.83, p = 6.22 × 10-3), genus Lachnospiraceae FCS020 group (OR = 0.82, p = 0.02) all showed a suggestive protective association with allergic conjunctivitis. Additionally, sensitivity analysis confirmed the robustness of the above associations. In the reverse MR analysis, no significant causal association was found between gut microbiota and allergic conjunctivitis.

CONCLUSION

This study has revealed a potential causal correlation between the phylum Euryarchaeota and allergic conjunctivitis, offering new insights to improve prevention and treatment of this condition.

Rifaximin alleviates irinotecan-induced diarrhea in mice model

BACKGROUND

Irinotecan is a chemotherapeutic drug widely used to treat solid tumors. However, its effectiveness is limited by the severely delayed onset of diarrhea. This study aimed to confirm the protective effects of the non-systemic oral antibiotic rifaximin on irinotecan-induced mucositis in mice model.

MATERIALS AND METHODS

Six to eight week-old BALB/c mice were treated with saline, irinotecan (50 mg/kg, i.p. once daily), rifaximin (50 mg/kg, p.o. twice daily), or irinotecan + rifaximin for 9 consecutive days. Signs of diarrhea, bloody diarrhea, and body weight were monitored daily. Intestinal tissues were harvested for histopathological analysis and quantitative PCR. SN38 and SN38G concentration in intestine were detected using LC-MS analysis. Intestinal bacteria β-glucuronidase (BGUS) activity was detected using mouse feces. We performed 16S rRNA sequencing to investigate the gut microbiota composition. Gut permeability was tested in vivo by measuring the fluorescein isothiocyanate-dextran intensity in the serum.

RESULTS

Rifaximin reduced the frequency of delayed diarrhea and attenuated the severity of diarrhea caused by irinotecan in mice. Rifaximin significantly inhibited SN38 exposure in intestine and irinotecan-induced increase in BGUS activity. Rifaximin alleviated intestinal mucosal inflammation, prevented intestinal epithelial damage caused by irinotecan, and maintained gut barrier function. Moreover, the consecutive use of rifaximin did not cause a disorder in gut microbiota and reduced irinotecan-induced Firmicutes expansion. More importantly, rifaximin inhibited the expansion of some microbiota (such as Blautia, Eggerthella, and f_Enterobacteriaceae) and promoted an increase in beneficial microbiota (such as Lactobacillus intestinalis, Lachnospiraceae NK4A136 group, and f_Oscillospiraceae).

CONCLUSIONS

Preventive use of rifaximin is a feasible method to protect against irinotecan-induced diarrhea.

Short-chain fatty acids are a key mediator of gut microbial regulation of T cell trafficking and differentiation after traumatic brain injury

The gut microbiota has emerged as a pivotal regulator of host inflammatory processes after traumatic brain injury (TBI). However, the mechanisms by which the gut microbiota communicates to the brain in TBI are still under investigation. We previously reported that gut microbiota depletion (GMD) using antibiotics after TBI resulted in increased microglial activation, reduced neurogenesis, and reduced T cell infiltration. In the present study, we have demonstrated that intestinal T cells contribute to the pool of cells infiltrating the brain after TBI. Depletion or genetic deletion of T cells before injury reversed GMD induced reductions in post-TBI neurogenesis. Short-chain fatty acid supplementation increased T regulatory and T helper1 cell infiltration to the brain along with restoring neurogenesis and microglia activation after TBI with GMD. These data suggest that T cell subsets are essential cellular mediators by which the gut microbiota modulates TBI pathogenesis, a finding with important therapeutic implications.

A cross-section study of the comparison of plasma inflammatory cytokines and short-chain fatty acid in patients with depression and schizophrenia

BACKGROUND

Major depressive disorder (MDD) and schizophrenia (SCH) are common and severe mental disorders that are mainly diagnosed depending on the subjective identification by psychiatrists. Finding potential objective biomarkers that can distinguish these two diseases is still meaningful.

METHODS

In the present study, we investigate the differences in plasma inflammatory cytokines and short-chain fatty acids (SCFAs) among patients with MDD (n = 24) and SCH (n = 24), and gender- and age-matched healthy controls (HC, n = 27) and identify potential plasma biomarkers.

RESULTS

We found that the concentrations of pro-inflammatory cytokines were increased, whereas the anti-inflammatory cytokines were decreased in both MDD and SCH. Meanwhile, except for an increase in 4-Methylvaleric acid, other SCFAs with statistical differences were reduced in both MDD and SCH. Moreover, potential biomarker panels were developed that can effectively discriminate MDD from HC (AUC = 0.997), SCH from HC (AUC = 0.999), and from each other (MDD from SCH, AUC = 0.983).

CONCLUSIONS

These data suggest that alterations in plasma cytokines and SCFAs might be one of the potential features for distinguishing MDD and SCH.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2100051243, registration date: 2021/09/16.

Research advancements on the diversity and host interaction of gut microbiota in chickens

The maintenance of host health and immune function is heavily dependent on the gut microbiota. However, the precise contribution of individual microbial taxa to regulating the overall functionality of the gut microbiome remains inadequately investigated. Chickens are commonly used as models for studying poultry gut microbiota, with high-throughput 16S rRNA sequencing has emerged as a valuable tool for assessing both its composition and functionality. The interactions between the gut's microbial community and its host significantly influence health outcomes, disease susceptibility, and various mechanisms affecting gastrointestinal function. Despite substantial research efforts, the dynamic nature of this microbial ecosystem has led to inconsistencies in findings related to chicken gut microbiota, which is largely attributed to variations in rearing conditions. Consequently, the interaction between the chickens' gut microflora and its host remains inadequately explored. This review highlights recent advances in understanding these relationships, with a specific focus on microbial composition, diversity, functional mechanisms, and their potential implications for improving poultry production.

Ageing, proteostasis, and the gut: Insights into neurological health and disease

Recent research has illuminated the profound bidirectional communication between the gastrointestinal tract and the brain, furthering our understanding of neurological ailments facilitating possible therapeutic strategies. Technological advancements in high-throughput sequencing and multi-omics have unveiled significant alterations in gut microbiota and their metabolites in various neurological disorders. This review provides a thorough analysis of the role of microbiome-gut-brain axis in neurodegenerative disease pathology, linking it to reduced age-associated proteostasis. We discuss evidences that substantiate the existence of a gut-brain cross talk ranging from early clinical accounts of James Parkinson to Braak's hypothesis. In addition to understanding of microbes, the review particularly entails specific metabolites which are altered in neurodegenerative diseases. The regulatory effects of microbial metabolites on protein clearance mechanisms, proposing their potential therapeutic implications, are also discussed. By integrating this information, we advocate for a combinatory therapeutic strategy that targets early intervention, aiming to restore proteostasis and ameliorate disease progression. This approach not only provides a new perspective on the pathogenesis of neurodegenerative diseases but also highlights innovative strategies to combat the increasing burden of these age-related disorders.

Altered Microbiome Promotes Pro-Inflammatory Pathways in Oesophago-Gastric Tumourigenesis

INTRODUCTION

The upper gastrointestinal microbiome is a dynamic entity that is involved in numerous processes including digestion, production of vitamins and protection against pathogens. Many external and intrinsic factors may cause changes in the proportions of bacteria within the microbial community, termed 'dysbiosis'. A number of these have been identified as risk factors for a range of diseases, including oesophago-gastric carcinoma.

MATERIALS AND METHODS

A narrative review was conducted to elucidate the current evidence on the role of the microbiome in promoting oesophago-gastric tumourigenesis. Significant causes of dysbiosis including age, medications and GORD were examined and key pro-inflammatory pathways implicated in tumourigenesis and their interaction with the microbiome were described.

RESULTS AND DISCUSSION

An association between microbial dysbiosis and development of oesophago-gastric cancer may be mediated via activation of pro-inflammatory pathways, the inflammasome and the innate immune system. Advances in sequencing technology allow microbial communities to be fingerprinted by sequencing the 16S rRNA gene, enabling a deeper understanding of the genera that may be implicated in driving tumourigenesis.

CONCLUSIONS

Developing a greater understanding of the influence of the microbiota on oesophago-gastric tumourigenesis may enable advances to be made in the early detection of malignancy and in the development of novel systemic therapies, leading to improved rates of survival.

Branched Short-Chain Fatty Acid-Rich Fermented Protein Food Improves the Growth and Intestinal Health by Regulating Gut Microbiota and Metabolites in Young Pigs

The diet in early life is essential for the growth and intestinal health later in life. However, beneficial effects of a diet enriched in branched short-chain fatty acids (BSCFAs) for infants are ambiguous. This study aimed to develop a novel fermented protein food, enriched with BSCFAs and assess the effects of dry and wet ferment products on young pig development, nutrient absorption, intestinal barrier function, and gut microbiota and metabolites. A total of 18 young pigs were randomly assigned to three groups. The dry corn gluten-wheat bran mixture (DFCGW) and wet corn gluten-wheat bran mixture (WFCGW) were utilized as replacements for 10% soybean meal in the basal diet. Our results exhibited that the WFCGW diet significantly increased the growth performance of young pigs, enhanced the expression of tight junction proteins, and regulated associated cytokines expression in the colonic mucosa. Simultaneously, the WFCGW diet led to elevated levels of colonic isobutyric and isovaleric acid, as well as the activation of GPR41 and GPR109A. Furthermore, more potential probiotics including Lactobacillus, Megasphaera, and Lachnospiraceae_ND3007_group were enriched in the WFCGW group and positively associated with the beneficial metabolites such as 5-hydroxyindole-3-acetic acid. Differential metabolite KEGG pathway analysis suggested that WFCGW might exert gut health benefits by modulating tryptophan metabolism. In addition, the WFCGW diet significantly increased ghrelin concentrations in serum and hypothalamus and promoted the appetite of young pigs by activating hypothalamic NPY/AGRP neurons. This study extends the knowledge of BSCFAs and provides a reference for the fermented food application in the infant diet.

Hydrogen inhalation: A novel approach to alleviating allergic rhinitis symptoms by modulating nasal flora

Background

Allergic rhinitis (AR) is an allergic reaction dominated by the Th2 immune response in the nasal mucosa. The bacterial infection process affects the balance between Th1 and Th2 immune responses, and the level of exposure to environmental flora is closely related to the development of AR. Hydrogen (H2) is a medical molecule with anti-inflammatory and antioxidant properties. This study aimed to explore the possible mechanism of action of H2 on AR through its ability to regulate the balance of nasal flora.

Methods

Serum eosinophil count (EOS), immunoglobulin E (IgE) concentration, visual analog scale (VAS), total nasal symptom score (TNSS), and rhinoconjunctivitis quality of life questionnaire (RQLQ) were observed before and after hydrogen inhalation in AR patients. Skin prick test (SPT) was used to determine allergen sensitisation. Community composition and relative abundance of nasal flora were examined before and after hydrogen inhalation and in normal subjects using 16S rRNA gene sequencing.

Results

There were no adverse reactions during and after hydrogen inhalation in AR patients, with a favorable safety profile and significant improvements in VAS, TNSS, EOS, and IgE (P < 0.05). Cavity flora 16S rRNA gene sequencing showed higher abundance of Ruminococcus and Erysipelotrichaceae flora in the nasal cavity of AR patients than in normal subjects, and their abundance could be down-regulated after H2 inhalation. H2 significantly increased the abundance of Blautia_faecis and negatively correlated with VAS, TNSS, EOS, and IgE.

Conclusions

H2 may improve symptoms in AR patients by modulating the distribution of nasal flora. Trials with larger sample sizes are required to further test this hypothesis.

Trial registration

This trial was registered in the China Clinical Trial Registry (Registration No. ChiCTR2200062253).

A New Strategy for Dietary Nutrition to Improve Intestinal Homeostasis in Diarrheal Irritable Bowel Syndrome: A Perspective on Intestinal Flora and Intestinal Epithelial Interaction

BACKGROUND AND OBJECTIVES

Although a reasonable diet is essential for promoting human health, precise nutritional regulation presents a challenge for different physiological conditions. Irritable Bowel Syndrome (IBS) is characterized by recurrent abdominal pain and abnormal bowel habits, and diarrheal IBS (IBS-D) is the most common, seriously affecting patients' quality of life. Therefore, the implementation of precise nutritional interventions for IBS-D has become an urgent challenge in the fields of nutrition and food science. IBS-D intestinal homeostatic imbalance involves intestinal flora disorganization and impaired intestinal epithelial barrier function. A familiar interaction is evident between intestinal flora and intestinal epithelial cells (IECs), which together maintain intestinal homeostasis and health. Dietary patterns, such as the Mediterranean diet, have been shown to regulate gut flora, which in turn improves the body's health by influencing the immune system, the hormonal system, and other metabolic pathways.

METHODS

This review summarized the relationship between intestinal flora, IECs, and IBS-D. It analyzed the mechanism behind IBS-D intestinal homeostatic imbalance by examining the interactions between intestinal flora and IECs, and proposed a precise dietary nutrient intervention strategy.

RESULTS AND CONCLUSION

This increases the understanding of the IBS-D-targeted regulation pathways and provides guidance for designing related nutritional intervention strategies.

Appraisal of postbiotics in cancer therapy

Cancer remains a multifactorial disease with an increased mortality rate around the world for the past several decades. Despite advancements in treatment strategies, lower survival rates, drug-associated side effects, and drug resistance create a need for novel anticancer agents. Ample evidence shows that imbalances in the gut microbiota are associated with the formation of cancer and its progression. Altering the gut microbiota via probiotics and their metabolites has gained attention among the research community as an alternative therapy to treat cancer. Probiotics exhibit health benefits as well as modulate the immunological and cellular responses in the host. Apart from probiotics, their secreted products like bacteriocins, exopolysaccharides, short-chain fatty acids, conjugated linoleic acid, peptidoglycan, and other metabolites are found to possess anticancer activity. The beneficiary role of these postbiotic compounds is widely studied for characterizing their mechanism and mode of action that reduces cancer growth. The present review mainly focuses on the postbiotic components that are employed against cancer with their reported mechanism of action. It also describes recent research works carried out so far with specific strain and anticancer activity of derived compounds both in vitro and in vivo, validating that the probiotic approach would pave an alternative way to reduce the burden of cancer.

Lactiplantibacillus argentoratensis AGMB00912 protects weaning mice from ETEC infection and enhances gut health

Maintaining a healthy intestinal environment, optimal epithelial barrier integrity, and balanced gut microbiota composition are essential for the growth performance of weaning pigs. We identified Lactiplantibacillus argentoratensis AGMB00912 (LA) in healthy porcine feces as having antimicrobial activity against pathogens and enhanced short-chain fatty acid (SCFA) production. Herein, we assess the protective role of LA using a weaning mouse model with enterotoxigenic Escherichia coli (ETEC) infection. LA treatment improves feed intake and weight gain and alleviates colon shortening. Furthermore, LA inhibits intestinal damage, increases the small intestine villus height compared with the ETEC group, and enhances SCFA production. Using the Kyoto Encyclopedia of Genes and Genomes and other bioinformatic tools, including InterProScan and COGNIZER, we validated the presence of SCFA-producing pathways of LA and Lactiplantibacillus after whole genome sequencing. LA mitigates ETEC-induced shifts in the gut microbiota, decreasing the proportion of Escherichia and Enterococcus and increasing SCFA-producing bacteria, including Kineothrix, Lachnoclostridium, Roseuburia, Lacrimispora, Jutongia, and Blautia. Metabolic functional prediction analysis revealed enhanced functions linked to carbohydrate, amino acid, and vitamin biosynthesis, along with decreased functions associated with infectious bacterial diseases compared to the ETEC group. LA mitigates the adverse effects of ETEC infection in weaning mice, enhances growth performance and intestinal integrity, rebalances gut microbiota, and promotes beneficial metabolic functions. These findings validate the functionality of LA in a small animal model, supporting its potential application in improving the health and growth performance of weaning pigs.

Deciphering the microbial map and its implications in the therapeutics of neurodegenerative disorder

Every facet of biological anthropology, including development, ageing, diseases, and even health maintenance, is influenced by gut microbiota's significant genetic and metabolic capabilities. With current advancements in sequencing technology and with new culture-independent approaches, researchers can surpass older correlative studies and develop mechanism-based studies on microbiome-host interactions. The microbiota-gut-brain axis (MGBA) regulates glial functioning, making it a possible target for the improvement of development and advancement of treatments for neurodegenerative diseases (NDDs). The gut-brain axis (GBA) is accountable for the reciprocal communication between the gastrointestinal and central nervous system, which plays an essential role in the regulation of physiological processes like controlling hunger, metabolism, and various gastrointestinal functions. Lately, studies have discovered the function of the gut microbiome for brain health-different microbiota through different pathways such as immunological, neurological and metabolic pathways. Additionally, we review the involvement of the neurotransmitters and the gut hormones related to gut microbiota. We also explore the MGBA in neurodegenerative disorders by focusing on metabolites. Further, targeting the blood-brain barrier (BBB), intestinal barrier, meninges, and peripheral immune system is investigated. Lastly, we discuss the therapeutics approach and evaluate the pre-clinical and clinical trial data regarding using prebiotics, probiotics, paraprobiotics, fecal microbiota transplantation, personalised medicine, and natural food bioactive in NDDs. A comprehensive study of the GBA will felicitate the creation of efficient therapeutic approaches for treating different NDDs.

Skin microbiome and causal relationships in three dermatological diseases: Evidence from Mendelian randomization and Bayesian weighting

BACKGROUND

Atopic dermatitis (AD), psoriasis (PSO), rosacea, and other related immune skin diseases are affected by multiple complex factors such as genetic and microbial components. This research investigates the causal relationships between specific skin microbiota and these diseases by using Mendelian randomization (MR), and Bayesian weighted Mendelian randomization (BWMR).

METHODS

We utilized genome-wide association study (GWAS) data to analyze the associations between various skin bacteria and three dermatological diseases. Single nucleotide polymorphisms (SNPs) served as instrumental variables (IVs) in MR methods, including inverse variance weighted (IVW), and MR Egger. BWMR was employed to validate results and address pleiotropy.

RESULTS

The IVW analysis identified significant associations between specific skin microbiota and dermatological diseases. ASV006_Dry, ASV076_Dry, and Haemophilus_Dry were significantly positively associated with AD, whereas Kocuria_Dry was negatively associated. In PSO, ASV005_Dry was negatively associated, whereas ASV004_Dry, Rothia_Dry, and Streptococcus_Moist showed positive associations. For rosacea, ASV023_Dry was significantly positively associated, while ASV016_Moist, Finegoldia_Dry, and Rhodobacteraceae_Moist were significantly negatively associated. These results were corroborated by BWMR analysis.

CONCLUSION

Bacterial species such as Finegoldia, Rothia, and Streptococcus play crucial roles in the pathogenesis of AD, PSO, and rosacea. Understanding these microbial interactions can aid in developing targeted treatments and preventive strategies, enhancing patient outcomes and quality of life.

Complex Interactions between the Human Major Histocompatibility Complex (MHC) and Microbiota: Their Roles in Disease Pathogenesis and Immune System Regulation

The relationship between microbiota and the immune system is complex and characterized by the ways in which microbiota directs immune function interactions, both innate and acquired and also keeps activating the immune system throughout an individual's life. In this respect, the human Major Histocompatibility Complex (MHC, referred to as HLA in humans) plays a crucial role and is also established in self-defense against microbes by presenting microbial-derived peptides to the immune cells. However, this assumption has some unclear aspects that should be investigated. For example, how is the microbiota shaped by microbe species diversity, quantity and functions of the immune system, as well as the role and molecular mechanisms of the HLA complex during this process. There are autoimmune diseases related to both HLA and specific microbiota changes or alterations, many of which are mentioned in the present review. In addition, the HLA peptide presenting function should be put in a framework together with its linkage to diseases and also with HLA compatibility necessary for transplants to be successful. These are still quite an enigmatically statistical and phenomenological approach, but no firm pathogenic mechanisms have been described; thus, HLA's real functioning is still to be fully unveiled. After many years of HLA single-genes studies, firm pathogenesis mechanisms underlying disease linkage have been discovered. Finally, microbiota has been defined as conformed by bacteria, protozoa, archaea, fungi, and viruses; notwithstanding, endogenous viral sequences integrated into the human genome and other viral particles (obelisks) recently found in the digestive mucosa should be taken into account because they may influence both the microbiome and the immune system and their interactions. In this context, we propose to integrate these microbial-genetic particle components into the microbiome concept and designate it as "microgenobiota".

Gut redox and microbiome: charting the roadmap to T-cell regulation

The gastrointestinal (GI) tract redox environment, influenced by commensal microbiota and bacterial-derived metabolites, is crucial in shaping T-cell responses. Specifically, metabolites from gut microbiota (GM) exhibit robust anti-inflammatory effects, fostering the differentiation and regulation of CD8+ tissue-resident memory (TRM) cells, mucosal-associated invariant T (MAIT) cells, and stabilizing gut-resident Treg cells. Nitric oxide (NO), a pivotal redox mediator, emerges as a central regulator of T-cell functions and gut inflammation. NO impacts the composition of the gut microbiome, driving the differentiation of pro-inflammatory Th17 cells and exacerbating intestinal inflammation, and supports Treg expansion, showcasing its dual role in immune homeostasis. This review delves into the complex interplay between GI redox balance and GM metabolites, elucidating their profound impact on T-cell regulation. Additionally, it comprehensively emphasizes the critical role of GI redox, particularly reactive oxygen species (ROS) and NO, in shaping T-cell phenotype and functions. These insights offer valuable perspectives on disease mechanisms and potential therapeutic strategies for conditions associated with oxidative stress. Understanding the complex cross-talk between GI redox, GM metabolites, and T-cell responses provides valuable insights into potential therapeutic avenues for immune-mediated diseases, underscoring the significance of maintaining GI redox balance for optimal immune health.

Effects of Acremonium terricola Culture on Lactation Performance, Immune Function, Antioxidant Capacity, and Intestinal Flora of Sows

This study aimed to determine the effects of different doses of Acremonium terricola culture (ATC) on lactation performance, immune function, antioxidant capacity, and intestinal flora of sows. Forty-five Landrace sows (3-6 parity) were randomly assigned to the following three treatments from 85 days of gestation to 21 days after farrowing: a control diet (CON, basal diet), a low-dose Acremonium terricola culture diet (0.2% ATC, basal diet + 0.2% ATC), and a high-dose Acremonium terricola culture diet (0.4% ATC, basal diet + 0.4% ATC). Compared with the CON group, the supplementation of 0.2% ATC increased the average daily milk yield of sows by 4.98%, increased milk fat, total solids, and freezing point depression on day 1 postpartum (p < 0.05), increased serum concentration of Triiodothyronine, Thyroxin, and Estradiol on day 21 postpartum (p < 0.05). Compared with the CON group, the supplementation of 0.4% ATC increased the average daily milk yield of sows by 9.38% (p < 0.05). Furthermore, the supplementation of 0.2% ATC increased serum concentration of IgG, IgM, and IFN-γ, CD4 on day 1 postpartum (p < 0.05) and increased serum concentration of immunoglobulin A ( IgA), immunoglobulin G (IgG), immunoglobulin M ( IgM), complement 3 (C3), cluster of differentiation 4 (CD4), cluster of differentiation 8 (CD8), interferon-γ (IFN-γ) on day 21 postpartum (p < 0.05), while the supplementation of 0.4% ATC reduced serum concentration of IL-2 on day 21 postpartum (p < 0.05). Moreover, the supplementation of 0.4% ATC significantly increased serum concentration of catalase (CAT) (p < 0.05). Additionally, the supplementation of ATC affected the relative abundance of the intestinal flora at different taxonomic levels in sows and increased the abundance of beneficial bacteria such as in the norank_f__Eubacterium_coprostanoligenes group, Eubacterium_coprostanoligenes group, and Lachnospiraceae_XPB1014 group of sows, while reducing the abundance of harmful bacteria such as Phascolarctobacterium and Clostridium_sensu_stricto_1. These data revealed that the supplementation of ATC during late gestation and lactation can improve lactation performance, immune function, antioxidant capacity, and the gut microbiota. Compared with supplementation of 0.4% ATC, 0.2% ATC enhances the levels of thyroid-related hormones, specific antibodies, and cytokines in serum, promotes the diversity of beneficial gut microbiota, beneficial bacteria in the intestine, reduces the population of harmful bacteria, and thereby bolsters the immunity of sows. Hence, 0.2% ATC is deemed a more optimal concentration.

Feeding gut microbes to nourish the brain: unravelling the diet-microbiota-gut-brain axis

The prevalence of brain disorders, including stress-related neuropsychiatric disorders and conditions with cognitive dysfunction, is rising. Poor dietary habits contribute substantially to this accelerating trend. Conversely, healthy dietary intake supports mood and cognitive performance. Recently, the communication between the microorganisms within the gastrointestinal tract and the brain along the gut-brain axis has gained prominence as a potential tractable target to modulate brain health. The composition and function of the gut microbiota is robustly influenced by dietary factors to alter gut-brain signalling. To reflect this interconnection between diet, gut microbiota and brain functioning, we propose that a diet-microbiota-gut-brain axis exists that underpins health and well-being. In this Review, we provide a comprehensive overview of the interplay between diet and gut microbiota composition and function and the implications for cognition and emotional functioning. Important diet-induced effects on the gut microbiota for the development, prevention and maintenance of neuropsychiatric disorders are described. The diet-microbiota-gut-brain axis represents an uncharted frontier for brain health diagnostics and therapeutics across the lifespan.

Gut microbiota and sleep: Interaction mechanisms and therapeutic prospects

Sleep is crucial for wellness, and emerging research reveals a profound connection to gut microbiota. This review explores the bidirectional relationship between gut microbiota and sleep, exploring the mechanisms involved and the therapeutic opportunities it presents. The gut-brain axis serves as a conduit for the crosstalk between gut microbiota and the central nervous system, with dysbiosis in the microbiota impairing sleep quality and vice versa. Diet, circadian rhythms, and immune modulation all play a part. Specific gut bacteria, like Lactobacillus and Bifidobacterium, enhance sleep through serotonin and gamma-aminobutyric acid production, exemplifying direct microbiome influence. Conversely, sleep deprivation reduces beneficial bacteria, exacerbating dysbiosis. Probiotics, prebiotics, postbiotics, and fecal transplants show therapeutic potential, backed by animal and human research, yet require further study on safety and long-term effects. Unraveling this intricate link paves the way for tailored sleep therapies, utilizing microbiome manipulation to improve sleep and health. Accelerated research is essential to fully tap into this promising field for sleep disorder management.

Gut-brain axis: A cutting-edge approach to target neurological disorders and potential synbiotic application

The microbiota-gut-brain axis (MGBA) represents a sophisticated communication network between the brain and the gut, involving immunological, endocrinological, and neural mediators. This bidirectional interaction is facilitated through the vagus nerve, sympathetic and parasympathetic fibers, and is regulated by the hypothalamic-pituitary-adrenal (HPA) axis. Evidence shows that alterations in gut microbiota composition, or dysbiosis, significantly impact neurological disorders (NDs) like anxiety, depression, autism, Parkinson's disease (PD), and Alzheimer's disease (AD). Dysbiosis can affect the central nervous system (CNS) via neuroinflammation and microglial activation, highlighting the importance of the microbiota-gut-brain axis (MGBA) in disease pathogenesis. The microbiota influences the immune system by modulating chemokines and cytokines, impacting neuronal health. Synbiotics have shown promise in treating NDs by enhancing cognitive function and reducing inflammation. The gut microbiota's role in producing neurotransmitters and neuroactive compounds, such as short-chain fatty acids (SCFAs), is critical for CNS homeostasis. Therapeutic interventions targeting the MGBA, including dietary modulation and synbiotic supplementation, offer potential benefits for managing neurodegenerative disorders. However, more in-depth clinical studies are necessary to fully understand and harness the therapeutic potential of the MGBA in neurological health and disease.

Colonization of microbiota derived from Macaca fascicularis, Bama miniature pigs, beagle dogs, and C57BL/6J mice alleviates DSS-induced colitis in germ-free mice

Fecal microbiota transplantation (FMT) is an innovative and promising treatment for inflammatory bowel disease (IBD), which is related to the capability of FMT to supply functional microorganisms to improve recipient gut health. Numerous studies have highlighted considerable variability in the efficacy of FMT interventions for IBD. Several factors, including the composition of the donor microorganisms, significantly affect the efficacy of FMT in the treatment of IBD. Consequently, identifying the functional microorganisms in the donor is crucial for enhancing the efficacy of FMT. To explore potential common anti-inflammatory bacteria with therapeutic implications for IBD, germ-free (GF) BALB/c mice were pre-colonized with fecal microbiota obtained from diverse donors, including Macaca fascicularis (MCC_FMT), Bama miniature pigs (BP_FMT), beagle dogs (BD_FMT), and C57BL/6 J mice (Mice_FMT). Subsequently, mice were treated with dextran sodium sulfate (DSS). As expected, the symptoms of colitis were alleviated by MCC_FMT, BP_FMT, BD_FMT, and Mice_FMT, as demonstrated by the prevention of an elevated disease activity index in mice. Additionally, the utilization of distinct donors protected the intestinal barrier and contributed to the regulation of cytokine homeostasis. Metagenomic sequencing data showed that the microbial community structure and dominant species were significantly different among the four groups, which may be linked to variations in the anti-inflammatory efficacy observed in the respective groups. Notably, Lactobacillus reuteri and Flavonifractor plautii were consistently present in all four groups. L. reuteri exhibited a significant negative correlation with IL-1β, and animal studies further confirmed its efficacy in alleviating IBD, suggesting the presence of common functional bacteria across different donors that exert anti-inflammatory effects. This study provides essential foundational data for the potential clinical applications of FMT.IMPORTANCEDespite variations in efficacy observed among donors, numerous studies have underscored the potential of fecal microbiota transplantation (FMT) for managing inflammatory bowel disease (IBD), indicating the presence of shared anti-IBD bacterial species. In the present study, the collective anti-inflammatory efficacy observed across all four donor groups prompted the identification of two common bacterial species using metagenomics. A significant negative correlation between Lactobacillus reuteri and IL-1β was revealed. Furthermore, mice gavaged with L. reuteri successfully managed the colitis challenge induced by dextran sodium sulfate (DSS), suggesting that L. reuteri may act as an efficacious bacterium mediating shared anti-inflammatory effects among variable donors. This finding highlights the utilization of variable donors to screen FMT core bacteria, which may be a novel strategy for developing FMT applications.

Effects of xylo-oligosaccharide on gut microbiota, brain protein expression, and lipid profile induced by high-fat diet

Midlife overweight and obesity are risk factors of cognitive decline and Alzheimer' s disease (AD) in late life. In addition to increasing risk of obesity and cognitive dysfunction, diets rich in fats also contributes to an imbalance of gut microbiota. Xylo-oligosaccharides (XOS) are a kind of prebiotic with several biological advantages, and can selectively promote the growth of beneficial microorganisms in the gut. To explore whether XOS can alleviate cognitive decline induced by high-fat diet (HFD) through improving gut microbiota composition, mice were fed with normal control or 60% HFD for 9 weeks to induce obesity. After that, mice were supplemented with XOS (30 g or 60 g/kg-diet) or without, respectively, for 12 weeks. The results showed that XOS inhibited weight gain, decreased epidydimal fat weight, and improved fasting blood sugar and blood lipids in mice. Additionally, XOS elevated spatial learning and memory function, decreased amyloid plaques accumulation, increased brain-derived neurotrophic factor levels, and improved neuroinflammation status in hippocampus. Changes in glycerolipids metabolism-associated lipid compounds caused by HFD in hippocampus were reversed after XOS intervention. On the other hand, after XOS intervention, increase in immune-mediated bacteria, Faecalibacterium was observed. In conclusion, XOS improved gut dysbiosis and ameliorated spatial learning and memory dysfunction caused by HFD by decreasing cognitive decline-associated biomarkers and changing lipid composition in hippocampus.

Causal relationship between gut microbiota and Behçet's disease: a Mendelian randomization study

Background

While observational epidemiological studies have suggested an association between gut microbiota and Behçet's disease (BD), the causal relationship between the two remains uncertain.

Methods

Statistical data were obtained from gut microbiome Genome-Wide Association Studies (GWAS) published by the MiBioGen consortium, and genetic variation points were screened as instrumental variables (IV). Mendelian randomization (MR) study was performed using inverse variance weighted (IVW), weighted median, MR-Egger regression, simple mode, and weighted mode methods to evaluate the causal relationship between gut microbiota (18,340 individuals) and BD (317,252 individuals). IVW was the main method of analysis. The stability and reliability of the results were verified using the leave-one-out method, heterogeneity test, and horizontal genetic pleiotropy test. Finally, a reverse MR analysis was performed to explore reverse causality.

Results

Inverse variance weighted (IVW) results showed that the genus Parasutterella (OR = 0.203, 95%CI 0.055-0.747, p = 0.016), Lachnospiraceae NC2004 group (OR = 0.101, 95%CI 0.015-0.666, p = 0.017), Turicibacter (OR = 0.043, 95%CI 0.007-0.273, p = 0.001), and Erysipelatoclostridium (OR = 0.194, 95%CI 0.040-0.926, p = 0.040) were protective factors against BD, while Intestinibacter (OR = 7.589, 95%CI 1.340-42.978, p = 0.022) might be a risk factor for BD.

Conclusion

Our study revealed the causal relationship between gut microbiota and BD. The microbiota that related to BD may become new biomarkers; provide new potential indicators and targets for the prevention and treatment of BD.