16S RNA Research Articles

Aspirin inhibits atherosclerosis through macrophage pyroptosis by interacting with Lactobacillus johnsonii and its metabolite butyrate

Abstract Introduction Atherosclerotic cardiovascular disease (ASCVD) is a chronic progressive disease closely related to metabolism and inflammation. Aspirin inhibits cyclooxygenase (COX) and has antiplatelet aggregation effects, considered as the cornerstone of ASCVD treatment. Numerous studies have shown that gut microbiota (GM) and its metabolites affects host metabolism. Studies have also shown that people taking aspirin exhibit specific changes in the microbiota profile. However, whether the interaction of aspirin with GM and its metabolites affects the therapeutic efficacy of aspirin in treating atherosclerosis (AS) have not been reported. Purpose This study aimed to explore the interaction of aspirin with the GM and its metabolites in the treatment of AS, to reveal the specific mechanism of the GM-metabolite axis and provide potential new targets for the combined treatment of AS. Methods To establish the mouse model of atherosclerosis by high-fat diet, and the atherosclerotic plaque burden and composition were analyzed. The role of GM in aspirin anti-atherosclerosis was explored by antibiotics and fecal microbiota transplantation (FMT). The third generation 16S RNA sequencing was used to explore the effects of aspirin on species diversity and abundance of GM, and to screen differential microorganisms for intervention of AS mice. UHPLC-MS and GC-MS were used to explore the changes of intestinal metabolites induced by aspirin. The correlation between gut microbiota and metabolites was also investigated. Finally, in vitro and in vivo experiments were performed to confirm the effects and mechanisms of metabolites on macrophage pyroptosis and atherosclerosis. Results Aspirin has anti-atherosclerosis effect. After removing gut microbiota, the therapeutic effect of aspirin on atherosclerosis was decreased. Three generations of 16S rRNA gene sequencing results showed that aspirin supplementation alters the diversity of gut microbiota, and increased the relative abundance of Lactobacillus johnsonii(L.johnsonii) and Ligilactobacillus murinus(L.murinus). After gavage of L.johnsonii and L.murinus, the plaque burden and macrophage pyroptosis were significantly reduced in AS mice. Colonization with L.johnsonii and L.murinus significantly increased the abundance of probiotics and butyrate level in the feces of AS mice and L.johnsonii and L.murinus were positively correlated with butyrate. Supplementation of butyrate inhibited macrophage pyroptosis and atherosclerosis in vivo. In vitro, butyrate could inhibit the expression of NLRP3/Caspase-1/IL-1β and pyroptosome production, and this process mainly by activating butyrate receptors GPR41, GPR43 and GPR109A. Conclusions The gut microbiota may mediate the anti-AS effect of aspirin by promoting an increase in the abundance of L.johnsonii and L.murinus. Butyrate produced by Lactobacillus may mediate the anti-AS effect of aspirin, and inhibiting macrophage pyroptosis and the progression of AS.

Alterations of gut microbiome profiles as potential markers in patients developing acute coronary syndrome

Abstract Background Imbalanced gut microbiota or gut dysbiosis leads to systemic inflammation, one of key contributors to the development and progression of atherosclerosis. A recent study revealed the association of the gut microbiota and the severity of coronary artery lesions in patients with acute coronary syndrome (ACS). However, the gut microbiota profile in ACS patients in comparison with patients with high-risk cardiovascular disease (CVD) has not been thoroughly investigated. Purpose We aimed to compare the profiles of gut microbiome between patients with ACS and patients with high-risk CVD, as well as to determine the association between gut microbiota and CVD risk factors. Methods This cross-sectional study enrolled 24 stabilized ACS patients within 24 hrs of hospitalization and 59 outpatients in CVD clinics, as a control group. Echocardiography was done in those patients. Blood was collected for biochemical analysis, and fecal samples were collected for gut microbiome analysis via 16S RNA sequencing. Results The demographic data showed no significant differences between groups in CVD risk factors (age, levels of systolic and diastolic blood pressure, fasting glucose, high- and low-density cholesterol, and triglycerides). However, patients with ACS had greater cigarette use and alcohol consumption than the control group. For gut microbiome, both alpha and beta diversity levels of ACS group were significantly higher than those in a control group (Figure 1A-B). Differential abundance analysis by ANCOM-BC revealed significantly increased level of bacteria in the Atopobiaceae family in ACS patients, compared to controls (Figure 1C). Since Atopobiaceae was reported to be positively associated with percent atheroma volume (PAV), a marker of plaque deposit in the arteries, we found an increased number of Atopobiaceae which was positively associated with serum Troponin T level (Figure 1D), systemic inflammation (Figure 1E), and a trend to negatively correlated with LV ejection fraction. Conclusion Our findings suggested that alterations of gut microbiota occurred in ACS patients, and an increase in gut Atopobiaceae level could potentially be the predictive marker of the development of ACS in CVD patients.Figure 1

Toxic Effect of Heavy Metal Poisoning on Living Organisms in Water and Health Risk: A Central India Study

The main causes of this environmental catastrophe are pollutants such as iron, zinc, lead, nickel, and chromium that have entered the water system as a result of uncontrolled industrial effluent discharge in the area. This study finds resistant bacteria and shows the toxicity of heavy metals in industrial effluent near the steel industry. Five separate locations were used for water sampling, and 16s RNA sequencing of the microorganisms that were found was done along with physicochemical parameter analysis and atomic absorption spectrophotometer use. Different water samples’ conductivity, TDS, salinity, DO, turbidity, and pH levels indicate changes in the quality of the water. In addition to having higher values for each of these characteristics, Sample D3’s water samples had greater concentrations of heavy metals, suggesting contamination. Aspergillus niger and Aspergillus terreus were identified in all samples. Both Gram-negative and Gram-positive Bacilli’s resistance to heavy metals has been found to be a sign of microbial adaptation to exposure to heavy metals. 16s rRNA sequencing of microorganisms revealed their roles in heavy metal bioremediation processes. The delicate balance between the flora and fauna in the affected water bodies has been upset by the devastating losses in aquatic life. In this study, we presented the biological methods for eliminating heavy metals, which comprised both metabolically dependent and independent techniques.

Microbial and Transcriptomic Landscape Associated With Neutrophil Extracellular Traps in Perianal Fistulizing Crohn's Disease.

Perianal fistulizing Crohn's disease (pfCD) poses significant healing challenges, closely associated with neutrophil extracellular traps (NETs). This study aimed to investigate the microbe-host interactions influencing NETs in pfCD. From January 2019 to July 2022, patients with pfCD were screened at Ren Ji Hospital. Patients in remission following comprehensive treatment were recruited. We documented clinical characteristics, medication regimens, healing outcomes, and infliximab levels in fistula tissues. NET positivity was confirmed by positive results in citrullinated histone H3 (CitH3) enzyme-linked immunosorbent assay (ELISA) and dual immunofluorescence staining for myeloperoxidase and CitH3. Microbial and transcriptomic profiles from fistula tissues, obtained during surgery, were analyzed using 16S rRNA gene sequencing and RNA sequencing. Differences in microbiome and transcriptomic profiles were evaluated, and their relationships were assessed using Mantel's and Spearman's coefficients. Significant differences in microbial communities were found between groups (P = .007). Representatively differential microbes such as Prevotella bivia, Streptococcus gordonii, and Bacteroides dorei were enriched in NETs-positive fistulas (P < .05). Functional analysis of microbes revealed reduced ubiquinol biosynthesis and butanoate production in NETs-negative fistulas (P < .05). Transcriptomic analysis indicated increased neutrophil and monocyte infiltration in NETs-positive fistulas, associated with pathways involving bacterial response, neutrophil chemotaxis, secretory processes, and peptidase activity (P < .05). Species prevalent in NETs-positive fistulas correlated positively with immune responses and wound healing pathways, whereas bacteria in NETs-negative fistulas correlated negatively. NETs were negatively associated with tissue infliximab levels (P = .001) and healing outcomes (P = .025). Our findings reveal unique microbial and transcriptomic signatures associated with NETs in pfCD, highlighting their profound influence on clinical outcomes.

Developing Robust Probiotic Consortia: A Methodological Optimization Approach.

Developing effective probiotic consortia requires a comprehensive understanding of strain interactions. While traditional methods focus on direct interactions of the participating microbes, the role of microbial metabolites remains largely unexplored. Present study introduces a novel approach of evaluating the impact of strains as well as their secondary metabolites on compatibility during co-culture by assessing the antagonistic and synergistic attributes for multi-strain probiotic formulation. Assessment of antagonistic activity by spot method indicated suppressive nature of PIG1FD and PIG1IR on other strain's growth, hence not appropriate for consortia formulation. Findings of synergistic attribute demonstrated growth promoting role of cell supernatants from isolates PIG6IR and PIG5CI significantly, as it accelerated the entry of all other isolates into the log phase by 5-6h and 0-2h, respectively. By employing this methodology, we identified PIG5CI and PIG6IR (isolates identified as Bacillus spizizenii BAB 7915 and Bacillus subtilis BAB 7918 by 16S RNA sequencing method) as promising candidates for consortium formation due to their ability to enhance the growth of other strains through metabolite production. By attempting to elucidate the microbial interactions and metabolite-mediated effects, this research contributes to a more comprehensive understanding of probiotic consortia dynamics and offers valuable insights for future translational studies.

Screening for contamination with genetically modified organisms in food, feed and their additives obtained in retail and online shops in Latvia

The aim of the study was to screen for contamination of food and feed products with genetically modified organisms (GMO) in several sample groups obtained from retail and online shops. The total number of samples was 171, including 67 of food, 26 feed, 27 additive, and 51 samples of dried pollen for human consumption. Detection and quantification of GMO in food and feed was performed according to the approved quantitative real-time PCR methods. Fermentation product samples were analyzed using screening for antimicrobial resistance genes, 16S RNA and ITS1 sequencing, isolation of bacterial cultures and whole genome sequencing. In total, GMO contamination was found in 12 samples (in 10.45% of food and in 19.23% of feed samples). A lower proportion of GMO containing samples were from the European Union (10.26 %) vs. samples from outside (17.02%), but none with ingredients of both origins. Non-compliant were three food and five feed samples. Of the 27 samples of food and feed additives and food supplements, 10 samples were possibly non-compliant, as they contained live bacteria with antimicrobial resistance genes, and seven of them contained possibly recombinant DNA. The study indicates presence of GMO contamination that emphasizes the need for further monitoring.

Complete genome sequence analysis and Pks genes identification of Brevibacillus brevis FJAT-0809-GLX with a broad inhibitory spectrum against phytopathogens.

Brevibacillus brevis FJAT-0809-GLX has a broad spectrum of antimicrobial activity. Understanding the molecular basis of biocontrol ability of B. brevis will allow us to develop effective microbial agents for sustainable agriculture. In this study, we present the complete and annotated genome sequence of FJAT-0809-GLX. The complete genome size of B. brevis FJAT-0809-GLX was 6,137,019bp, with 5688 predicted coding sequences (CDS). The average GC content of 47.38%, and there were 44 copies of the rRNAs operon (16S, 23S and 5S RNA), and 127 tRNA genes. A total of 11,162 genes were functionally annotated with the COG, GO, and KEGG databases, and 123 genes belonged to CAZymes. Genomic secondary metabolite analysis indicated 13 clusters encoding potential new antimicrobials. FJAT-0809-GLX was designated as B. brevis according to average nucleotide polymorphism (ANI) and phylogenetic analysis. The pangenome consisted of 7141 homologous genes, and 4469 homologous genes shared by B. brevis FJAT-0809-GLX, B. brevis NBRC100599, B. brevis DSM30, and B. brevis NCTC2611. The number of unique homologous genes of B. brevis FJAT-0809-GLX (419 genes) and B. brevis NBRC100599 (480 genes) were much more than those in B. brevis DSM30 (13 genes), and B. brevis NCTC2611 (6 genes). Nine gene clusters encoding for secondary metabolite biosynthesis were compared in the genome of B. brevis FJAT-0809-GLX with those of B. brevis NBRC100599, B. brevis DSM30 and B. brevis NCTC2611, and the gene clusters encoding for lantipeptide and transatpks-otherks only existed in genome of B. brevis FJAT-0809-GLX. The 11 BbPks genes were included in the B. brevis FJAT-0809-GLX genome, which contained the conserved PS-DH domain. The relative expression of BbPksL, BbPksM2, BbPksM3, BbPksN3, BbPksN4 and BbPksN5 reached a maximum at 120h and then decreased at 144h. Our results provided detailed genomic and Pks genes information for the FJAT-0809-GLX strain, and lid a foundation for studying its biocontrol mechanisms.

Variability of the Microbiota in Chronic Rhinosinusitis: A Scoping Review.

Chronic rhinosinusitis (CRS) is characterized by a persistent inflammation of the nasal and paranasal sinus mucosa that could be potentially linked to a dysregulation between the microbiota and the immune system. We aim to explore general, methodological, and microbiological aspects of microbiota research in CRS compared to disease-free individuals. Embase, Ovid MEDLINE, PubMed, Scopus, and Web of Science. All studies comparing the composition of the resident microbiota of the sinonasal cavities in 2 groups: CRS and normal participants. We conducted systematic study selection, data extraction, and analysis first using the title and abstract, and then the full texts based on predefined inclusion and exclusion criteria. Compiled and presented findings include sampling site and technique, and microbiological results such as the relative abundance and the variability of the composition of the microbiota in both groups. Twenty-seven studies, using genomic identification with 16s RNA were analyzed. Case definitions primarily followed EPOS or AAO-HNS guidelines, with endoscopic swabs (82%), and middle meatus sampling (74%) being prevalent techniques. Despite relative abundance variability, patterns emerged across studies, indicating an increase in Haemophilus (19%) and Pseudomonas (11%), and decrease in Propionibacterium (15%) and Anaerococcus (11%). Another pattern was observed, showing a decreased alpha diversity (6/19; 22%) in CRS compared to normal individuals. While variations exist among studies, analysis of CRS microbiota suggests an association with dysbiosis, potentially contributing to chronic inflammation. Future research must prioritize standardized criteria for diagnostics and patient selection, fostering a more comprehensive understanding of CRS microbiota.

A Description of the THRIVE (“The Study of Host-Bacterial Relationships in Different Vaginal Environments”) Bacterial Vaginosis Observational Study

ObjectivesBacterial vaginosis (BV) contributes to poor reproductive health and is characterized by a displacement of Lactobacillus in the vaginal microbiome. However, treatment for BV is limited to antibiotics and half of the women treated experience recurrence within a year. THRIVE is a prospective study in XXXXX, which is designed to capture the daily variation of the microbiome and host mucosal immunity during treatment. The objective of this study is to identify host and bacterial factors that associate with vaginal microbiome stability to better inform therapeutic interventions. MethodsWomen treated for BV, and controls, are followed for 6 months collecting daily vaginal swabs and monthly questionnaires. Comprehensive mucosal sampling, including swabs, cytobrushes, biopsies, and blood are collected at baseline, months 1 and 6 post-enrolment. ResultsWe performed analysis on the first 52 participants, (19 BV+, 33 BV–). Molecular profiling by 16s RNA sequencing showed 20 women with non-Lactobacillus-dominant microbiomes and 32 with Lactobacillus-dominant microbiomes, with increased microbial diversity in non-Lactobacillus-dominant microbiomes (P = 3.1E-05). A pilot analysis in 2 participants demonstrates that multi-omics profiling of self-collected daily swabs provides high-quality data identifying 73 bacterial species, 1773 mucosal proteins and 117 metabolites. Initial flow cytometry analysis showed an increased cluster of differentiation (CD)4+ T cells and neutrophil activation (CD11b+CD62Lneg/dim) in the positive participant at baseline, while after treatment these shifted and resembled the control participant. ConclusionsThis study provides a framework to comprehensively investigate the kinetics of vaginal mucosal microbiome alterations, providing further insight into host and molecular features predicting BV recurrence.

Evaluating the Efficacy of Endophytic Bacteria in Controlling Rice Sheath Blight: In Vitro and In Vivo Studies

Rice production is highly susceptible to various pathogens, including Rhizoctonia solani, Curvularia lunata, and Epicoccum rostratum, which are major threats in Asia. Exploring biological control methods using endophytic bacteria offers promising opportunities to enhance rice resilience against these lethal diseases. Using 16S RNA sequencing, we identified four endophytic isolates of Bacillus spp. from rice roots, stems, and leaves. We evaluated the antagonistic activity of these endophytic bacterial isolates against rice pathogens both in vitro and in vivo. These isolates inhibited the growth of C. lunata by 82%, R. solani by 79%, and E. rostratum by 88% in vitro. The detached leaf assay for sheath blight (ShB) disease severity in strains ranged from 10.4% to 73.3%. In vivo results showed that B. amyloliquefaciens (R-19) exhibited the lowest disease intensity at 7.2% and the highest disease suppression at 78.8%. The fungicide propiconazole at 0.1% treatment showed the lowest disease intensity of 7.7% and the highest disease suppression of 73.4%, compared to the infected control. Besides biocontrol efficacy, endophytic isolates enhance plant growth parameters, including shoot height, root length, fresh and dry weights, number of tillers, and grains per tiller. Plant hormones abscisic acid (ABA) and gibberellic acids (GA3) increased by 35% and 53%, respectively, due to B. subtilis (R-20) and B. amyloliquefaciens (R-19), while flavonoid and indole acetic acid (IAA) concentrations surged by 30%–80%. Similarly, chlorophyll (a, b), carotenoids, antioxidant enzymatic activity, phenolic content, carbohydrates, and proline contents were higher compared to the control. This study provides a foundation for future studies on novel and eco-friendly biocontrol agents. In addition, our study recommends the integration of endophytic bacteria into sustainable agriculture for enhancing rice production and reducing disease impacts.

Exploring the Gut Microbiota Landscape in Cow Milk Protein Allergy: Clinical Insights and Diagnostic Implications in Pediatric Patients

Cow milk protein allergy (CMPA) is a significant health concern characterized by adverse immune reactions to cow milk proteins. Biomarkers for the accurate diagnosis and prognosis of CMPA are lacking. This study analyzed the clinical features of CMPA, and 16S RNA sequencing was used to investigate potential biomarkers through fecal microbiota profiling. Children with CMPA exhibit a range of clinical symptoms, including gastrointestinal (83% of patients), skin (53% of patients), and respiratory manifestations (26% of patients), highlighting the complexity of this condition. Laboratory analysis revealed significant differences in red cell distribution width (RDW) and inflammatory markers between the CMPA and control groups, suggesting immune activation and inflammatory responses in CMPA. Microbial diversity analysis revealed higher specific diversity indices in the CMPA group compared with those in control group, with significant differences at the genus and species levels. Bacteroides were more abundant in the CMPA group, whereas Bifidobacterium, Ruminococcus, Faecalibacterium, and Parabacteroides were less abundant. The control group exhibited a balanced microbial profile, with a predominant presence of Bifidobacterium bifidum and Akkermansia muciniphila. The significant abundance of Bifidobacterium in the control group (23.19% vs 9.89% in CMPA) was associated with improved growth metrics such as height and weight, suggesting its potential as a probiotic to prevent CMPA and enhance gut health. Correlation analysis linked specific microbial taxa such as Coprococcus and Bifidobacterium to clinical parameters such as family allergy history, weight and height, providing insights into CMPA pathogenesis. Significant differences in bacterial abundance suggested diagnostic potential, with a panel of 6 bacteria achieving high predictive accuracy (area under curve (AUC) = 0.8708). This study emphasizes the complex relationship between the gut microbiota and CMPA, offering valuable insights into disease mechanisms and diagnostic strategies.

Z-ligustilide alleviates atherosclerosis by reconstructing gut microbiota and sustaining gut barrier integrity through activation of cannabinoid receptor 2

BackgroundZ-Ligustilide (ZL) is an essential phthalide found in Ligusticum chuanxiong Hort, a commonly used traditional Chinese medicine for treating atherosclerosis (AS) clinically. ZL has been shown to be effective in treating AS. However, the underlying mechanism of ZL against AS and its potential targets remain elusive. PurposeThe purpose of this research was to assess the influence of ZL on AS and explore the role of the gut microbiome in mediating this effect. MethodsA well-established AS mouse model, apolipoprotein E deficient (ApoE-/-) mice was used to examine the effects of ZL on AS, inflammation, and the intestinal barrier. To analyze the changes in gut microbial community, we employed the 16S rRNA gene sequencing. Antibiotic cocktail and fecal microbiota transplantation (FMT) were employed to clarify the contribution of the gut microbiota to the anti-AS effects of ZL. The mechanism through which ZL provided protective effects on AS and the intestinal barrier was explored by untargeted metabolomics, as well as by validating the involvement of cannabinoid receptor 2 (CB2R) in mice and Caco-2 cells. ResultsOral administration of ZL inhibited the development of atherosclerotic lesions, improved plaque stability, inhibited the increase in serum and atherosclerotic inflammation, and improved intestinal barrier function. Fecal bacteria from ZL-treated mice induced similar beneficial effects on AS and the intestinal barrier. We used 16S RNA gene sequencing to reveal a significant increase in Rikenella abundance in both ZL-treated mice and ZL-FMT mice, which was associated with the beneficial effects of ZL. Further function prediction analysis of the gut microbiota and CB2R antagonist intervention experiment in mice and Caco-2 cells showed that the activation of CB2R resulted in the enhancement of the intestinal barrier by ZL. Furthermore, the analysis of metabolomic profiling revealed the enrichment of capsaicin upon ZL treatment, which induced the activation of CB2R in human colon epithelial cells. ConclusionOur study is the first to demonstrate that oral treatment with ZL has the potential to alleviate AS by reducing inflammation levels and enhancing the intestinal barrier function. This mechanism relies on the gut microbiota in a CB2R-dependent manner, suggesting promising strategies and ideas for managing AS. This study provides insights into a novel mechanism for treating AS with ZL.

Rhizosphere bacterial community influence on &lt;i&gt;Deschampsia antarctica&lt;/i&gt; È Desv. adaptability in context of temperature near plants in local spatial scales of Galindez Island, Argentine Islands (the maritime Antarctic)

The effect of rhizosphere bacterial community index (Irbi) influence on the nine populations of Antarctic hair grass (Deschampsia antarctica) adaptability was studied in the Galindez Island (summer season 2017/18). Moreover, the corresponding influence indices Irbi (i=1÷9) and Irbpi (p=1÷5 for the most common bacteria) were evaluated as well. The objective was to compare the Irbi and Irbpi series with the united temperature influence index on plant populations (It1i(z)) series and the united quality latent index of adaptability Iq1i. The study used data on the rhizosphere metagenome composition based on 16S RNA analysis. Methods determining the plant number in populations, and measuring the morphometric indices of D. antarctica populations were used. Reserve and protective seed proteins spectra were studied by polyacrylamide gel electrophoresis. Method of extreme grouping the spatial variables of these indices was applied for nine populations to obtain a Iq1I and It1i and Irbi, Irbpi. Sets of united indices were compared by regression technique. A comparative statistical analysis of the It1i and Irbi, Irbpi sets in this season was carried out. This possible influence appeared to be individual for each D. antarctica studied population. In each population, part of the plants reacted positively to the bacteria influence, while the other part either did not react or reacted negatively. Dependence of the plant adaptation indices on rhizospheric bacterial communities z(x) is shown in our data. This means that the rhizosphere bacterial community and temperature-dependent rhizosphere bacteria (x) can play an active role in plant adaptation of D. antarctica populations (z) to individual temperature conditions in the microscale of Galindez Island from a biological point of view.

Fecal microbiota transplantation as a new way for OVA-induced atopic dermatitis of juvenile mice

Children all over the world suffer from atopic dermatitis (AD), a prevalent condition that impairs their health. Corticosteroids, which have long-term negative effects, are frequently used to treat AD. There has been a growing body of research on the gut microbiota’s function in AD. Nevertheless, the function and underlying mechanisms of fecal microbiota transplantation (FMT) in AD children remain to be established. Therefore, in order to assess the preventive effects of FMT treatment on AD and investigate the mechanisms, we constructed an ovalbumin (OVA)-induced juvenile mouse AD model in this investigation. This study explored the role and mechanism of FMT treatment in AD through 16S RNA sequencing, pathological histological staining, molecular biology, and Flow cytometry. Results demonstrated that the FMT treatment improved the gut microbiota’s diversity and composition, bringing it back to a level similar to that of a close donor. Following FMT treatment, OVA-specific antibodies were inhibited, immunoglobulin (Ig) E production was decreased, the quantity of mast cells and eosinophils was decreased, and specific inflammatory markers in the skin and serum were decreased. Further mechanistic studies revealed that FMT treatment induced CD103+ DCs and programmed cell death ligand 1 (PD-L1)/programmed cell death 1 (PD-1) expression in skin-draining lymph nodes and promoted Treg production to induce immune tolerance and suppress skin inflammation. Meanwhile, changes in the gut microbiota were substantially correlated with Th2 cytokines, OVA-specific antibodies, and PD-L1/PD-1. In conclusion, FMT regulates the Th1/Th2 immunological balance and the gut microbiota. It may also inhibit AD-induced allergy responses through the PD-L1/PD-1 pathway, and providing a unique idea and possibly a fresh approach to the treatment of AD.

The reduction of imidazole propionate induced by intermittent fasting promotes recovery of peripheral nerve injury by enhancing migration of Schwann cells

Peripheral nerve injury (PNI) accompanied with sensory and motor dysfunction has serious effect on the quality of life of patients. Intermittent fasting (IF), as a dietary pattern, has rarely been reported to influence imidazole propionate (ImP), a microbial metabolite, in vivo. To date, the link between ImP and PNI is unknown. This study aimed to explore the impact of ImP on the recovery after PNI and determine whether IF could reduce the concentration of ImP in vivo. Sciatic nerve injury rat model and RSC96 cells were utilized with 16s RNA seq, HE staining, CCK-8 assay, Western blot (WB), Transmission electron microscopy (TEM), immunofluorescence, transwell and scratch wound healing assays as read outs. WB, TEM, transwell and wound healing assay showed an inhibitory effect of ImP on autophagy and migration of Schwann cells. This negative effect on migration was reversed by rapamycin. Detection of p-Erk and p-mTOR confirmed that the MAPK/Erk/mTOR pathway was involved in this process. In vivo, IF changed the composition of gut microbiome, including bacteria related to ImP production and reduced the concentration of ImP in serum. In sum, IF influenced the composition of gut microbiome and reduced the concentration of ImP in vivo. The reduction of ImP promoted migration of SCs through enhancing autophagy which involved MAPK/Erk/mTOR pathway.

PSLBII-13 Bioinformatics of rumen fluid from steers fed alfalfa-bermudagrass mixtures in the Deep South

Abstract When harvesting high-quality, high-water content forages like legumes, there is often a greater percentage of nutritive loss due to the drying process. Alternative feeding strategies like baleage provide a way to mitigate these losses. However, there is not much adoption of baleage in the Deep South. Therefore, our objective was to assess the influence of conserved forage type on rumen metabolomes of beef cattle systems in the Deep South. Three treatments including bermudagrass (Cynodon dactylon) hay, alfalfa (Medicago sativa) baleage, and alfalfa-bermudagrass baleage were supplied to four fistulated steers with a calculated daily forage allowance based on intake, body weight, and feed refusals. Each diet was allocated to one of three periods in which all four animals received the same diet due to potential feed spoilage. Each period had a 21-d adaptation period followed by a 5-d collection period to analyze rumen fluid, total fecal weight, feed intake, feed refusal, and total urine. This study integrated 16S RNA sequencing and LC-MS-based metabolomics to evaluate rumen bacterial diversity and metabolome of beef steers. Sequencing data from the rumen fluid samples were then analyzed using QIIME2. Bermudagrass hay had a reduced alpha diversity compared with alfalfa baleage (Shannon: H = 5.19, P = 0.02). Additionally, we saw a change in beta diversity (P &amp;lt; 0.001), measured using the unweighted UniFrac distance, between conserved forage types and distinct clustering in the PCoA analysis. The most abundant taxa in all microbial communities were from the orders Lachnospirales, Bacteroidales, and Oscillospirales. Previous analysis in this study evidenced that baleage had an increased dry matter digestibility (DMD; P = 0.02). The increase in DMD was associated with the increase in diversity of the metabolome which could influence animal health and performance. Thus, baleage can serve as a beneficial conserved forage type that mitigates the losses of high-quality forages and diversifies the gut microbiome of ruminant animals.

Si-Ni-San ameliorates cholestatic liver injury by favoring P. goldsteinii colonization

Ethnopharmacological relevanceCurrent treatment options for cholestatic liver diseases are limited, and addressing impaired intestinal barrier has emerged as a promising therapeutic approach. Si-Ni-San (SNS) is a Traditional Chinese Medicine (TCM) formula commonly utilized in the management of chronic liver diseases. Our previous studies have indicated that SNS effectively enhanced intestinal barrier function through the modulation of gut microbiota. Aim of the studyThis study aims to verify the therapeutic effects of SNS on cholestatic liver injury, focusing on elucidating the underlying mechanism involving the gut-liver axis. Materials and methodsThe 16s RNA gene sequencing, non-targeted metabolomics were used to investigate the effects of SNS on the gut microbiota dysbiosis. Fecal microbiota transplantation (FMT) was conducted to identify potential beneficial probiotics underlying the therapeutic effects of SNS. ResultsOur results demonstrated that SNS significantly ameliorated cholestatic liver injury induced by partial bile duct ligation (pBDL). Additionally, SNS effectively suppressed cholestasis-induced inflammation and barrier dysfunction in both the small intestine and colon. While SNS did not impact the intestinal FXR-FGF15-hepatic CYP7A1 axis, it notably improved gut microbiota dysbiosis and modulated the profile of microbial metabolites, including beneficial secondary bile acids and tryptophan derivatives. Furthermore, gut microbiota depletion experiments and FMT confirmed that the therapeutic benefits of SNS in cholestatic liver disease are dependent on gut microbiota modulation, particularly through the promotion of the growth of potential probiotic P. goldsteinii. Moreover, a synergistic improvement in cholestatic liver injury was observed with the co-administration of P. goldsteinii and SNS. ConclusionOur study underscores that SNS effectively alleviates cholestatic liver injury by addressing gut microbiota dysbiosis and enhancing intestinal barrier function, supporting its rational clinical utilization. Furthermore, we highlight P. goldsteinii as a promising probiotic candidate for the management of cholestatic liver diseases.

204. ALTERATIONS IN LOCAL OESOPHAGEAL MICROBIOTA AND OUTCOMES AFTER OESOPHAGECTOMY FOR OESOPHAGO-GASTRIC CANCER: A PILOT STUDY

Abstract Oesophageal cancer is a global health burden, with an estimated 600,000 new cases and 550,000 deaths per year. It is the 9th most common cancer yet is ranked fifth for cancer mortality. The current gold standard curative strategy includes oesophagectomy, which is a morbid procedure. In particular, anastomotic leaks are a feared complication postoperatively that result in significant morbidity. Studies of patients undergoing colorectal cancer surgery show that alterations in the local microbiota can contribute to complications including anastomotic leak. Furthermore, some pathogenic bacterial species have been implicated in shorter recurrence-free survival periods after curative oncologic surgery. Unlike bacterial culture, which requires viable bacteria to be preserved from the time of sampling through to processing, 16S RNA sequencing can be performed on both fresh and fixed tissues. However, there are few studies using either tissue source and to date, none that compare results from the same patient. The aims of this pilot study were to: 1. Assess the feasibility of testing archived histological specimens (i.e. formalin fixed) that in turn facilitates retrospective analysis of patients with known clinical outcomes (i.e. anastomotic leaks) 2. Identify any difference (variance, reduce or over-abundance) between the microbiota of patients who suffered anastomotic leak and those who did not 3. Generate preliminary data to inform sample sizes, statistical methods, workflow and cost of a future prospective trial Using an established Upper GI Cancer Surgery Database, we performed propensity score matching to identify 15 patients who had a clinically evident anastomotic leak to be matched with 15 patients who did not have an anastomotic leak. Known predictors of anastomotic leak (e.g. neoadjuvant radiotherapy, smoking status, COPD, chronic kidney disease, diabetes mellitus, chronic liver disease) have been controlled for. Fresh frozen and formalin-fixed samples for the same patients were available. The formalin-fixed tissue was comprised of the "anastomotic doughnuts" created at the time of the circular stapled anastomosis. This tissue was chosen because of its immediate proximity to the anastomosis. All samples were analysed using 16S RNA sequencing to obtain a full microbial profile. Sequencing data was analysed by scientific investigators blinded to the clinical outcome (i.e. anastomotic leak vs. no leak) using a pre-existing workflow and bioinformatics pipeline.

2-(3,4-dihydroxyphenyl)ethyl 3-hydroxybutanoate (HTHB) ameliorates cognitive dysfunction via modulating gut microbiota in aged senescence-accelerated mouse prone 8 (SAMP8) mice.

Numerous studies have indicated a close association between gut microbiota dysbiosis, inflammation, and cognitive impairment, highlighting their crucial role in the aging process. 2-(3,4-Dihydroxyphenyl)ethyl 3-hydroxybutanoate (HTHB), a novel derivative of hydroxytryrosol (HT), known for its metabolic and anti-inflammatory properties, was investigated for its effects on memory, inflammation, and gut microbiota in senescence-accelerated mouse prone 8 (SAMP8) mice. The study employed behavioral testing, biochemical detection and 16S RNA analysis. Results revealed that HTHB mitigated memory decline and lymphocyte aberrance, reduced inflammation in the brain cortex, intestine and peripheral system, and modulated gut microbiota dysbiosis. Interestingly, the cognitive function and serum inflammation of mice significantly correlated with differences in gut microbiota in SAMP8 mice. Furthermore, HTHB treatment exhibited an enhancement of gut barrier integrity in colon tissue in SAMP8 mice. In vitro experiments using HCT116 and DLD1 cells further evidenced that HTHB rescued the tight junction protein levels impaired by lipopolysaccharide (LPS). These finding demonstrate that HTHB effectively ameliorates cognitive dysfunction in aged mice, might by modulating gut microbiota, suppressing inflammation and promoting intestinal barrier integrity. This highlights the potential of HTHB as a therapeutic agent for age-related cognitive loss.

Laminaria japonica Polysaccharide Regulates Fatty Hepatosis Through Bile Acids and Gut Microbiota in Diabetes Rat.

In this study, we examined the effect of Laminaria japonica polysaccharide (fucoidan) on the regulation of lipid metabolism. A rat model of diabetes mellitus (DM) was established by a high-sugar and high-fat diet combined with streptozotocin. Changes in the rats' body weight and blood glucose level during the experiment were recorded. Before the end of the experiment, an automatic biochemical analyzer was used to detect the fasting blood glucose (FBG), lipid content in serum, and insulin content, and calculate the insulin resistance index. Oil red O staining was used to detect lipid deposition in the liver. H&E staining, Masson staining, and PASM staining were used to observe the pathological structural changes in the liver. 16s RNA sequencing and targeted metabolomics were used to detect intestinal microbiota and bile acid content. The results showed that fucoidan was able to inhibit weight loss in the DM rats and reduce the content of triglycerides (TG), cholesterol (TC), and low-density lipoprotein (LDL-C) in serum. Oil red O staining showed a decrease in liver fat accumulation after fucoidan treatment. 16s RNA sequencing demonstrated that fucoidan increased the abundance of Bacteroidia, Campylobacteria, Clostridia, Gammaproteobacteria, Negativicutes, and Verrucomicrobi. Fucoidan also increased the secretion of secondary bile acids (Nor-DCA, TLCA, β-UDCA) and alleviated lipid metabolism disorders. The expression of α-SMA was inhibited by fucoidan, whereas the expression of FXR and TGR5 was promoted. Fucoidan shows good activity in regulating lipid metabolism by regulating the expression of FXR and TGR5 and acting on the intestinal flora-bile acid axis.