Gut-organ axis: a microbial outreach and networking

Recent drug delivery systems targeting the gut-brain-microbiome axis for the management of chronic diseases

In recent years, the study of microorganisms and the brain has become increasingly connected. The gut-brain-microbiome axis (GBMA), a bi-directional communication system, is the key part of how the body's bacteria and the brain interact. This system can influence the brain and behaviour. Changes in this relationship have been linked to various mental and physical health conditions. The immune system, tryptophan metabolism, the vagus nerve, and the enteric nervous system all facilitate connections between the gut and brain. Microbes produce Peptidoglycans, branched-chain amino acids, and short-chain fatty acids, which are involved in this communication. Studies suggest the gut microbiome may be involved in conditions like autism, anxiety, obesity, schizophrenia, Parkinson's disease, and Alzheimer's disease. Researchers are exploring the gut-brain connection to cure a variety of disorders, such as neurological disorders, cancers, metabolic problems, and liver diseases. Developing novel drug delivery systems is a key focus in GBMA for therapeutic targeting at various disease pathways. Notable platforms attracting significant interest include silica nanoparticle-based delivery systems for probiotic spores, composite hydrogels formulated from protein isolates and citrus pectin, and biomimetic nanosystems designed for targeted therapeutic delivery. This review summarizes different methods of delivering drugs and using dietary interventions to target the GBMA and treat these conditions in a less invasive way. By understanding how the gut and brain communicate, scientists aim to develop new and more effective therapies for these complex chronic diseases.

Di (2-ethylhexyl) Phthalate decrease pregnancy rate via disrupting the microbe-gut-hypothalamic-pituitary-ovarian axis in mice

Di (2-ethylhexyl) Phthalate (DEHP), a widely used plasticizer and endocrine disruptor, poses risks to human health, particularly reproductive function. Using a mouse model, we investigated how DEHP exposure impacts the hypothalamic-pituitary-ovarian (HPO) axis through gut microbiome disruption. DEHP decreased pregnancy rates by impairing ovarian function, activating hypothalamic astrocytes, and increasing neuregulin 1 (NRG1) expression. NRG1 binding to astrocyte ErbB2 receptors elevated prostaglandin E2 (PGE2) and gonadotropin-releasing hormone (GnRH), disrupting HPO axis homeostasis. Additionally, DEHP altered gut microbiota, destabilized microbial networks, and impacted β-glucuronidase-related taxa, leading to hormone fluctuations and reduced fertility. This study highlights gut microbiome perturbations as a novel mechanism linking DEHP exposure to reproductive dysfunction. Our study provides novel insights concerning perturbations of the gut microbiome and HPO axis and their functions as a potential new mechanism by which DEHP exposes interferes with the reproductive function-related human health.

Healthy lifestyle, daytime sleepiness, and gut microbiome composition are determinants of functional strength in humans: a cross-sectional study

Age, metabolic inflammation, sleep patterns, lifestyle choices, and gut microbiome composition were investigated as factors influencing functional strength. The Northern German FoCus cohort subgroup (394 women, 233 men) was categorized into six groups based on weekly sports activity and handgrip strength (HGS) measurements. The analyses included anthropometric data, clinical biochemistry, medication, sleep duration, healthy lifestyle score (HLS), 16 S rRNA gut microbiota, serum and urine metabolomics, bile acids, and an adapted dietary inflammatory index (ADII) score. Associations were found between age, inflammation, and low functional strength, with sleep duration increasing the odds and a healthy lifestyle decreasing the risk. Urine metabolomics revealed differences in enrichment analyses. No significant differences were observed in the Chao1 and InVSimpson indices between the groups. At the genus level, some species were associated with daily sports activity, whereas others were associated with HGS measurements. Clostridium XIVa was found only in high- and medium-HGS groups, while Alistipes, Odoribacter, and Streptococcus decreased with activity. Thus, tailored lifestyle interventions may reduce the risk of poor functional strength.

Impact of probiotic Lactobacillus plantarum GKM3 on gastrointestinal health in overweight and obese individuals: A randomized clinical trial

BACKGROUND & AIMS

Overweight and obesity, usually resulting from excess calorie intake, pose significant health challenges in modern societies and contribute to the development of chronic metabolic disorders. Gut microbes have been recognized as key regulators of energy utilization and gastrointestinal health. In this study, we investigated the effects of probiotics Lactobacillus plantarum strain GKM3 on overweight and obese subjects in a double-blind, randomized, placebo-controlled clinical trial.

METHODS

Participants, aged 20-40 with body mass index between 25.0 and 29.9 and body fat percentages over 25 % for males and 30 % for females, were divided into a placebo group (n = 19) and a probioitcs group (n = 40), receiving capsules containing either a placebo or the probiotics GKM3 for four weeks.

RESULTS

Our findings demonstrated that supplementation with strain GKM3 at 1 g per day over the 4-week period significantly increased bowel movement frequency and alleviated symptoms such as gastroesophageal reflux, nausea, abdominal pain, and constipation. Fecal lipid analysis revealed elevated levels of triglycerides and total cholesterol compared to the placebo group. Microbiota analysis showed a significant reduction in obesity-associated taxa (Alcaligenaceae, Fusobacteriaceae, Acidaminococcus, Fusobacterium, and Megamonas) and an increase in beneficial genera (Akkermansia and Lactobacillus) following probiotic intervention.

CONCLUSION

Our study suggests that the strain GKM3 modulates gut flora, leading to reduced fat absorption and improved gastrointestinal functions in overweight and obese individuals.

Abnormal gill color of Manila clam Ruditapes philippinarum due to the unhealthy gut mcirobiota and the role of gut-gill axis

The Manila clam (Ruditapes philippinarum) is an ecologically and economically important species. Recently, a novel disease of Manila clam with abnormal gill colour has emerged, leading to growth inhibition and death in severe cases. In this study, a multi-omics approach was used to investigate the underlying mechanisms of abnormal gill colour in Manila clam and its association with gut microbiota. High-throughput sequencing revealed a reduction in the uniformity of gut microbiota in diseased clams, with increased abundance of Pseudomonas and Pseudoaltermonas. Network and null model analyses revealed a decline in microbiota stability and a shift toward deterministic assembly in diseased clams. Transcriptomic analysis revealed different gene expression profiles in the gills of healthy and diseased Manila clams, including down-regulation of several immune-related genes such as genes encoding heat shock proteins and involved in Toll and Imd signalling pathways. A total of 38 specialists were identified in the gut microbiota of diseased Manila clams based on their specificity and occupancy. Four of them (two Psychrobacter, one Pseudoaltermonas and one Halomonas) were closely correlated with the expression of gill genes associated with abnormal gill colour. In addition, a gene encoding a major vault protein was identified as the keystone of abnormal gill colour through the network of host genes and their gut microbiota. This study revealed the substantial variation in gut microbiota and gill gene expression in Manila clam with abnormal gill colour and provided insights into the complex host-microbiota interactions involved in disease development.

Specific Bacterial Taxa and Their Metabolite, DHPS, May Be Linked to Gut Dyshomeostasis in Patients with Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis

Background: Neurodegenerative diseases (NDDs) are multifactorial disorders frequently associated with gut dysbiosis, oxidative stress, and inflammation; however, the pathophysiological mechanisms remain poorly understood. Methods: Using untargeted mass spectrometry-based metabolomics and 16S sequencing of human stool, we investigated bacterial and metabolic dyshomeostasis in the gut microbiome associated with early disease stages across three NDDs-amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD)-and healthy controls (HC). Results: We discovered a previously unrecognized link between a microbial-derived metabolite with an unknown role in human physiology, 2,3-dihydroxypropane-1-sulfonate (DHPS), and gut dysbiosis in NDDs. DHPS was downregulated in AD, ALS, and PD, while bacteria involved in DHPS metabolism, Eubacterium and Desulfovibrio, were increased in all disease cohorts. Additionally, select taxa within the Clostridia class had strong negative correlations to DHPS, suggesting a potential role in DHPS metabolism. A catabolic product of DHPS is hydrogen sulfide, and when in excess, it is known to promote inflammation, oxidative stress, mitochondrial damage, and gut dysbiosis, known hallmarks of NDDs. Conclusions: These findings suggest that cryptic sulfur metabolism via DHPS is a potential missing link in our current understanding of gut dysbiosis associated with NDD onset and progression. As this was a hypothesis generating study, more work is needed to elucidate the role of DHPS in gut dysbiosis and neurodegenerative diseases.

Probiotics modulation of the endotoxemic effect on the gut and liver of the lipopolysaccharide challenged mice

The multistrain probiotics' efficacy in ameliorating the endotoxemic effect in Lipopolysaccharide (LPS) challenged mice was evaluated with the agonist of anti-inflammatory peptide, neurotensin (NTS), especially targeting the inflammation of the gut and liver. Swiss Albino Mice (Female, 8 weeks old) were maintained in eight groups: Group I as Control, Group II-Group V were exposed to intraperitoneal (i.p.) LPS (1 mg/kg bw) for 5 days. After that, Group III and Group VI were administered probiotics orally (0.6 gm/kg bw/day), Group IV and Group VII with NTS receptor 1 (NTSR1) agonist PD149163 (50 µg/kg bw/day i.p.), and Group V and Group VIII co-administered with probiotics and PD149163 for 28 days. Group II (LPS-exposed) was maintained without any further treatment; mice of all the groups were sacrificed at day 34. In the LPS-exposed mice, endotoxemia was distinct from a significant (P < 0.001) increase of plasma pro-inflammatory cytokines (TNF-α; IL-6), a decrease of anti-inflammatory cytokine (IL-10), oxidative stress, and inflammation of the gut and liver. Increased serum transaminases indicated hepatic inflammation. A decreased population of the bifidobacteria and increased clostridia indicated microbiota dysbiosis. Probiotics when used as an adjunct along with PD149163 have shown better efficacy in inflammation modulation as reflected in the significantly decreased (P < 0.001) inflammatory mediators, oxidative stress, restoration of the beneficial bacterial population, along with a significant reduction in histopathological scores of the gut and the liver than when used alone. This study suggests probiotics could be used as an adjunct in clinical practice along with anti-inflammatory drugs for better therapeutic efficacy.

Non-starch polysaccharides and health: gut-target organ axis influencing obesity

Obesity is recognized as a global epidemic that can result in changes in the human body and metabolism. Accumulating evidence indicates that gut microbiota (GM) can affect the development of obesity. The GM not only plays a crucial role in digesting and absorbing nutrients, but also in maintaining the overall health of the host. Dietary supplements such as non-starch polysaccharides are mainly fermented by the GM in the colon. Recent findings suggest that shaping the GM through the prebiotic function of non-starch polysaccharides may be a viable strategy against obesity. In this paper, the effects of non-starch polysaccharides on host health, together with their prebiotic function influencing the GM to control obesity via the gut-target organ axis, are reviewed. Potential perspectives of non-starch polysaccharides exhibiting anti-obesity effects via the gut-target organ axis are proposed for future research.

Graphical abstract

Xenobiotics mediated modulation of gut microbiota and its role in lifestyle diseases: a critical appraisal on exposomics

Gastrointestinal tract of humans provides a niche to thousands of microbes, referred as gut microbiota (GM). GM establishes an intricate relationship with other organs via gut-organ axis, and modulates host health. The structure and functioning of these gut microbes can be influenced by the type of external exposome an individual experiences. Depending upon GM perturbations and host genotype, this can result in variable health implications. On the other hand, the huge arsenal of enzymes possessed by GM can chemically alter the xenobiotic structure. Its consequences can be numerous, including formation of harmful metabolites that cause organ damage, reversal of host detoxification pathways, or favourable health effects. Additionally, GM-mediated bio-transformation of pharmaceuticals can alter their pharmacokinetics and pharmacodynamics, potentially yielding variable drug responses, resulting into prolonged or ineffective treatments. To address this bi-facial relationship and the pivotal role of GM, this review incorporates recent in vitro, in vivo, and multiomics studies. It also suggests the need of machine learning approaches to decode the complex host-microbiota-xenobiotics interactions. These knowledge will aid in comprehending recent rise in chronic lifestyle-diseases which poses a huge burden on the health sector, and can also be a learning curve in making formulations and therapies for personalized treatment.

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.

Modulation of the gut-bone axis: Lacticaseibacillus paracasei LC86 improves bone health via anti-inflammatory metabolic pathways in zebrafish models of osteoporosis and cartilage damage

Aim

Osteoporosis and cartilage injury are major health concerns with limited treatment options. This study investigates the therapeutic effects of Lacticaseibacillus paracasei LC86 (LC86) on osteoporosis and cartilage damage in a zebrafish (Danio rerio) model, focusing on its modulation of the gut-bone axis and its potential mechanisms for enhancing bone health.

Methods

A Dexamethasone-induced zebrafish model was used to mimic osteoporosis and cartilage injury. Zebrafish were divided into control, model, and LC86 treatment groups (3×107 CFU/mL). Bone and cartilage health were assessed using Alizarin red staining and fluorescence microscopy. Bone marker expression (sp7, runx2a, bmp2a, bmp4, and col2a1a) was quantified via qPCR. Metabolic alterations were analyzed using untargeted metabolomics, and changes in gut microbiota were examined through 16S rRNA gene sequencing.

Results

LC86 treatment significantly improved bone and cartilage health, as evidenced by increased fluorescence intensity in the skull, hard bone, and cartilage (p < 0.01, p < 0.05). qPCR results showed upregulation of key bone-related genes (sp7, runx2a, bmp2a, bmp4, and col2a1a), indicating enhanced bone and cartilage structure. Metabolomics analysis revealed alterations in over 300 metabolites, with changes in anti-inflammatory and energy pathways. Gut microbiota analysis demonstrated an increase in beneficial bacteria and a decrease in pathogenic genera.

Conclusions

LC86 significantly improved bone health, cartilage structure, and gut microbiota composition in a Dexamethasone-induced zebrafish model, supporting its potential as a therapeutic strategy for osteoporosis and cartilage injury via modulation of the gut-bone axis.

Effects of Dairy Matrix on the Intestinal, Liver, and Bone Transcriptome of Healthy Rats

Fermentation is one of the oldest food processing techniques and is widely utilized in dairy product processing, during which nutrient availability and bioactive compounds are altered. However, the complete mode of action by which fermented dairy exerts beneficial effects on the host remains unknown. The present study investigated the effect of milk and yogurt ingestion alone or combined with prebiotic inulin on the transcriptome of colonic mucosa, liver, and femur in healthy rats. Young growing male rats were fed one of four experimental diets containing (1) skimmed milk, (2) skimmed milk supplemented with inulin (5% w/w), (3) yogurt, or (4) yogurt supplemented with inulin (5% w/w) for 6 weeks. Microarray results revealed that yogurt consumption resulted in 2195 upregulated differential expressed genes (DEGs) and 1474 downregulated DEGs in colonic mucosa as compared with milk consumption. According to Gene Ontology (GO) categories and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, tight junction-, immune system-related pathways in the colonic mucosa and metabolic pathways in the liver were enriched with yogurt consumption. No evident differences were identified in the bone transcriptome between the diet groups. In conclusion, the study found that the intake of fermented dairy exerts more pronounced effects on gene expression in the intestinal tissue than prebiotics supplementation.

Dextran from human feces-derived Weissella cibaria facilitates intestinal mucosal barrier function by modulating gut bacteria and propionate levels

The disruption of the intestinal mucosal barrier is strongly associated with the onset of various diseases, including inflammatory bowel disease. Exopolysaccharides (EPS) support the functionality of the intestinal barrier. Weissella Cibaria (W. cibaria), belonging to the lactic acid bacteria, exhibits a significant capacity for EPS production. However, the specific mechanisms by which the EPS produced by W. cibaria confers intestinal barrier protection remain unexplored. Here, we characterized the polysaccharide, EPS-2, produced by W. cibaria isolated from the feces of healthy infants. EPS-2 was a novel dextran composed of α-(1 → 6) and α-(1 → 3,6) glycosidic linkages with a molecular weight of 845 kDa. EPS-2 alleviates intestinal mucosal barrier dysfunction in a mouse model of colitis, via a mechanism specifically reliant on the gut microbiota and their metabolic products, which is different from the well-known direct protective effects of other EPS on the intestinal barrier. EPS-2 reversed colitis-induced reductions in Muribaculaceae and propionate levels, thereby enhancing colonic goblet cell function and mucin content. Additionally, EPS-2 decreased the number of LPS-producing bacteria, such as Escherichia_Shigella. EPS-2 alleviated dextran sulfate sodium-induced intestinal inflammation and barrier damage. Therefore, EPS-2 shows promise as a postbiotic treatment for diseases associated with intestinal barrier dysfunction.

TENS improves CFL injury rat and regulates the intestinal microbiota

AIM

This study revealed the mechanism of transcutaneous electrical nerve stimulation (TENS) for improving the calcaneofibular ligament (CFL) injury rats by regulating the intestinal microbiota.

METHODS

After 1, 2, and 3 weeks of TENS treatment, the improvement of CFL injury rats model and the expressions of IL-1β/NF-κB/IL-17 signaling pathway were measured. Then the intestinal microbiota was analyzed by 16S rDNA sequencing and its functions related to improve CFL injury rat were analyzed.

RESULTS

TENS could improved the athletic ability of CFL injury rats and reduced the expressions of IL-1β/NF-κB by regulating the IL-17 signaling pathway. By 16S rDNA sequencing analysis, the TENS treatment improved the intestinal dysbacteriosisof CFL injury rats and decrease pathogenic bacteria Ruminococcus and Dubosiella. The changed intestinal microbiota maybe relative with the ankle injury, whereas the increase in probiotics (Bacteroides and Lactobacillus) was relative with anti-inflammation.

CONCLUSION

TENS could down-regulate the expressions of IL-1β/NF-κB to improve CFL injury rat. TENS could change the intestinal microbiota of CFL rats and the changed bacteria whose function related to anti-inflammation could improve CFL rat. The intestinal microbiota could become a potential treatment for CFL injury.

Roles of probiotics against HPV through the gut-vaginal axis

Human papillomavirus (HPV) is a sexually transmitted virus, whose persistent infection is the main reason for invasive cervical cancer (ICC), which is the fourth most common type of cancer in women, with more than 500 000 new cases every year. After infection, various alterations occur in the host, facilitating the virus's evasion of immune system clearance and promoting its proliferation. Oral probiotic consumption can influence the whole body's immunity, inflammatory reflection, neural, endocrine humoral, metabolic pathways and other organs by adjusting the components of gut microbiota (GM). Some evidence shows there is a tight connection between GM and vaginal microbiota (VM), which is referred to as the gut-vaginal axis. This review investigates the potential role of probiotics in clearing HPV via the gut-vagina axis, emphasizing the effectiveness of Lactobacillus in preventing vaginal diseases and suggesting its potential for HPV clearance. Understanding the role of probiotics in the gut-vagina axis could pave the way for new strategies to reduce and eliminate HPV and related diseases.

Fecal microbiome composition in neonates with or without urinary tract infection

BACKGROUND

Most infants with febrile urinary tract infection (UTI) do not have an underlying anatomical risk factor. Thus, other non-anatomical risk factors should be considered. Since the most common pathogens arise from the fecal microbiota, our aim was to investigate whether the gut microbiota composition differs between febrile infants younger than 2 months with or without UTI.

METHODS

In this prospective, case-control, pilot study, we performed 16S ribosomal ribonucleic acid amplicon sequencing to characterize gut microbiota of febrile neonates with and without UTI admitted to the pediatric ward at Shamir Medical Center between February 2019 and May 2021.

RESULTS

The study cohort included 42 febrile neonates: 17 with and 25 without febrile UTI. We found a significant difference in beta diversity (i.e. between-sample/study group similarity indices) between the UTI and non-UTI group (p = 0.016). There were also distinct differences in the relative abundance of the 20 most prevalent genera. Furthermore, several genera were significantly enriched in the UTI group, with others dominating the non-UTI group. Streptococci were underrepresented in the UTI group. There was no difference in alpha diversity (i.e. within-sample diversity/richness) between groups.

CONCLUSION

Febrile neonates with UTI have a different fecal microbiota composition (beta-diversity), but not alpha diversity, in comparison to febrile neonates without UTI. A larger study is warranted to confirm these findings and their potential applications.

High-fat diet induces sarcopenic obesity in natural aging rats through the gut-trimethylamine N-oxide-muscle axis

INTRODUCTION

The lack of suitable animal models for sarcopenic obesity (SO) limits in-depth research into the disease. Emerging studies have demonstrated that gut dysbiosis is involved in the development of SO. As the importance of microbial metabolites is starting to unveil, it is necessary to comprehend the specific metabolites associated with gut microbiota and SO.

OBJECTIVES

We aimed to investigate whether high-fat diet (HFD) causes SO in natural aging animal models and specific microbial metabolites that are involved in linking HFD and SO.

METHODS

Young rats received HFD or control diet for 80 weeks, and obesity-related metabolic disorders and sarcopenia were measured. 16S rRNA sequencing and non-targeted and targeted metabolomics methods were used to detect fecal gut microbiota and serum metabolites. Gut barrier function was evaluated by intestinal barrier integrity and intestinal permeability. Trimethylamine N-oxide (TMAO) treatment was further conducted for verification.

RESULTS

HFD resulted in body weight gain, dyslipidemia, impaired glucose tolerance, insulin resistance, and systemic inflammation in natural aging rats. HFD also caused decreases in muscle mass, strength, function, and fiber cross-sectional area and increase in muscle fatty infiltration in natural aging rats. 16S rRNA sequencing and nontargeted and targeted metabolomics analysis indicated that HFD contributed to gut dysbiosis, mainly characterized by increases in deleterious bacteria and TMAO. HFD destroyed intestinal barrier integrity and increased intestinal permeability, as evaluated by reducing levels of colonic mucin-2, tight junction proteins, goblet cells and elevating serum level of fluorescein isothiocyanate-dextran 4. Correlation analysis showed a positive association between TMAO and SO. In addition, TMAO treatment aggravated the development of SO in HFD-fed aged rats through regulating the ROS-AKT/mTOR signaling pathway.

CONCLUSION

HFD leads to SO in natural aging rats, partially through the gut-microbiota-TMAO-muscle axis.

Immune cells mediated the causal relationship between the gut microbiota and anxiety disorders: A Mendelian randomization study

BACKGROUND

Studies have demonstrated that the gut microbiome-immune system-brain axis plays an important role in neurological disorders. Furthermore, recent studies have shown that the gut microbiota influences the occurrence and progression of anxiety disorders, with potential involvement of immune cells. We aimed to investigate the causal impact of gut microbiota on anxiety disorders and identify potential immune cell mediators.

METHODS

We made use of the summary statistics of 196 gut microbiota (MiBioGen consortium), 731 immune cells, and anxiety disorders (Medical Research Council Integrative Epidemiology Unit consortium), from the extensive genome-wide association studies to date. To determine the causal links between gut microbiota and anxiety disorders, we employed bidirectional Mendelian randomization (MR) analyses, and further employed 2-step MR to confirm potential mediating roles of immune cells. Moreover, we conducted rigorous sensitivity analyses to assess the heterogeneity, robustness, and horizontal pleiotropy of our findings.

RESULTS

Bi-directional MR analysis revealed that 11 gut microbiota species can affect anxiety disorders, while the reversed causal relationship was not existed. Mediation analysis revealed that three immune cells mediated the causal relationships between two gut microbiota species and anxiety disorders. Specifically, "CD39+ resting Treg %resting Treg", "CD39+ resting Treg % CD4 Treg", and "BAFF-R on IgD+ CD38- naive B cell" mediated the effects of class Melainabacteria on anxiety disorders, with mediating impacts of 0.000075, 0.000096, and 0.000263, representing 5.98 %, 7.67 %, and 21.01 % of the total effects, respectively. Additionally, "BAFF-R on IgD+ CD38- naive B cell" also mediated the effects of order Gastranaerophilales on anxiety disorders, with a mediating impact of 0.000266, accounting for 19.06 % of the total effects.

LIMITATIONS

The bacterial analysis was limited to genus level, overlooking species or strains. We used a lenient p-value threshold of p < 1.0 × 10-5 for instrumental variables, instead of the typical p < 5 × 10-8. Lastly, the GWAS focused on European participants, potentially limiting the generalizability of our findings to other ethnicities.

CONCLUSION

The risk of anxiety disorders has been linked causally to gut microbiota, with three distinct immunophenotypes acting as potential mediators in this relationship. The role of gut microbiota in modulating immune cells, thereby influencing anxiety disorders, may offer new therapeutic strategies and management approaches.

Nobiletin-mediated autophagy mitigates nanoplastic-induced toxicity in human intestinal Caco-2 cells

The presence of nanoplastics (NPs), which cause oxidative stress and damage to the cell structure due to the breakdown of microplastics (MPs), poses considerable ecological and health challenges. This study investigated the protective role of nobiletin (NOB), a flavonoid derived from citrus peel, in modulating autophagy and mitigating NP-induced toxicity in human intestinal Caco-2 cells. The Caco-2 cells were treated with NPs and varying concentrations of NOB to evaluate cell viability, apoptosis, and autophagic activity. We observed that exposure to NPs resulted in a concentration-dependent decrease in cell viability and an increase in the expression of apoptosis markers. Exposure to NPs reduced Caco-2 cell viability and disrupted autophagic processes by decreasing LC3B and increasing p62 levels, indicating impaired autophagy. NOB treatment reversed these effects by enhancing autophagic activity by upregulating LC3B and downregulating p62. Furthermore, NOB improved lysosomal integrity and decreased apoptotic markers such as Bax and cleaved caspase-3 while increasing Bcl-2 expression. NOB also facilitated the nuclear translocation of transcription factor EB through activating AMP-activated protein kinase (AMPK) and inhibiting mechanistic target of rapamycin (mTOR), promoting cellular detoxification and homeostasis. NOB has the potential as a therapeutic agent that leverages the autophagic pathway to mitigate the adverse effects of NPs, suggesting a novel approach for managing NPs toxicity in human intestinal Caco-2 cells.

The Impact of Tetracycline on the Soil Microbiome and the Rhizosphere of Lettuce (Lactuca sativa L.)

The impact of tetracycline on the soil and rhizosphere microbiome of lettuce was analyzed. Soil was collected from an agricultural field regularly fertilized with manure, and tetracycline was added at two concentrations (5 mg/kg and 25 mg/kg). In untreated soil, dominant bacteria included Proteobacteria (43.17%), Bacteroidota (17.91%), and Firmicutes (3.06%). Tetracycline addition caused significant shifts in the microbiome composition, notably increasing Actinobacteriota (22%) and favoring Mycobacterium tuberculosis (low concentration) and Mycobacterium holsaticum (high concentration). Proteobacteria decreased by 21%, possibly indicating antibiotic resistance development. An increase in Firmicutes, particularly Bacillales, suggested a selection for resistant strains. In the lettuce rhizosphere, tetracycline-induced changes were less pronounced than in soil. Proteobacteria remained dominant, but taxa like Burkholderiales and Chitinophagales increased in response to tetracycline. The rise in chitin-degrading bacteria might result from fungal overgrowth linked to the bacteriostatic effects of tetracycline. Pathogens such as M. tuberculosis, observed in the soil, were not detected in the lettuce rhizosphere.

Integrated Multi-Omics Analyses Reveal Lipid Metabolic Signature in Osteoarthritis

Osteoarthritis (OA) is the most common degenerative joint disease and the second leading cause of disability worldwide. Single-omics analyses are far from elucidating the complex mechanisms of lipid metabolic dysfunction in OA. This study identified a shared lipid metabolic signature of OA by integrating metabolomics, single-cell and bulk RNA-seq, as well as metagenomics. Compared to the normal counterparts, cartilagesin OA patients exhibited significant depletion of homeostatic chondrocytes (HomCs) (P = 0.03) and showed lipid metabolic disorders in linoleic acid metabolism and glycerophospholipid metabolism which was consistent with our findings obtained from plasma metabolomics. Through high-dimensional weighted gene co-expression network analysis (hdWGCNA), weidentified PLA2G2A as a hub gene associated with lipid metabolic disorders in HomCs. And an OA-associated subtype of HomCs, namely HomC1 (marked by PLA2G2A, MT-CO1, MT-CO2, and MT-CO3) was identified, which also exhibited abnormal activation of lipid metabolic pathways. This suggests the involvement of HomC1 in OA progression through the shared lipid metabolism aberrancies, which were further validated via bulk RNA-Seq analysis. Metagenomic profiling identified specific gut microbial species significantly associated with the key lipid metabolism disorders, including Bacteroides uniformis (P < 0.001, R = -0.52), Klebsiella pneumonia (P = 0.003, R = 0.42), Intestinibacter_bartlettii (P = 0.009, R = 0.38), and Streptococcus anginosus (P = 0.009, R = 0.38). By integrating the multi-omics features, a random forest diagnostic model with outstanding performance was developed (AUC = 0.97). In summary, this study deciphered the crucial role of a integrated lipid metabolic signature in OA pathogenesis, and established a regulatory axis of gut microbiota-metabolites-cell-gene, providing new insights into the gut-joint axis and precision therapy for OA.

Effect of Toxocara canis infection on liver and lung microbial flora diversity and composition in dogs

Toxocariasis is a zoonotic parasitic disease that is widely prevalent in the world. Toxocara canis adults are parasitic in the small intestinal tract of canids, and the larvae migrate to the liver and lungs before reaching the final destination. Our previous experiments have confirmed that T. canis infection could affect the composition of host intestinal microbial flora. In this experiment, we further analyze the potential effects of T. canis infection on host liver and lung microbial flora. Utilizing 16s rRNA high-throughput sequencing, coupled with various bioinformatics analysis techniques, our study revealed that T. canis infection significantly elevated the abundance of certain opportunistic pathogens in the host's liver and lungs. This marked elevation contributes to the establishment of infection. Through cluster analysis, we found that the changes in the microbiota of the liver and lungs were independent of the microbial flora carried by T. canis adults. However, whether the changes are due to the migration of larvae remains to be explored. In short, T. canis infections have a significant impact on the abundance and diversity of flora in the host tissues, and the changes in microbiota abundance and diversity could further influence tissue homeostasis and immune responses, thus regulating the establishment of infection.

Microbiome analysis of gut microbiota in patients with colorectal polyps and healthy individuals

Colorectal polyps serve as the primary precursors for colorectal cancer. A close relationship has been observed between colorectal polyps and gut microbiota. However, the composition and role of the microbiome associated with tubular adenoma are not well understood. In this study, we prospectively evaluated alterations in gut microbiota among patients with colorectal polyps. A total of 60 subjects were enrolled in this study, including 30 patients with colorectal polyps (CP group) and 30 healthy controls (control group). The 16S rRNA sequencing was employed to characterize the gut microbiome in fecal samples. The results revealed that the beta diversity of the gut microbiota in the CP group significantly differs from that of the control group (p = 0.001). At the phylum level, the relative abundance of Bacteroides, Fusobacteria, and Proteobacteria was higher in the CP group compared to the control group (p < 0.05), whereas the relative abundance of Actinobacteria was higher in the control group in comparison to the CP group (p < 0.05). At the genus level, the abundance of Bacteroides increased in the CP group (p < 0.05), while Bifidobacterium declined in the CP group (p < 0.05). At the species level, the abundance of Clostridium perfringens, unidentified_Bacteroides, unidentified_Dorea, Escherichia coli, Clostridium ramosum, and Ruminococcus gnavus was higher (p < 0.05), whereas the abundance of Bifidobacterium adolescentis, unclassified_Bifidobacterium, Bifidobacterium longum, Faecalibacterium prausnitzii, and unidentified_Bifidobacterium is lower in CP group compared to the control group (p < 0.05). There was a structural imbalance in the composition of intestinal colonization flora for CP patients, characterized by a decrease in beneficial bacteria and an increase in harmful bacteria. Escherichia, Shigella, and Bacteroides may serve as promising biomarkers for early detection of colorectal polyps.

Gut microbiota regulates optic nerve fiber myelination

Introduction

Recent evidence supports the hypothesis of an association between gut microbiota and the pathogenesis of retinal and eye diseases, suggesting the existence of a gut-eye axis. However, no data are available on the possible effect of the gut microbiota on the optic nerve fiber maturation and myelin development.

Methods

We investigated the impact of gut microbiota on the optic nerves collected from neonatal and young adult germ-free (GF), gnotobiotic (stably colonized with 12 bacteria strains, OMM12) and control (colonized with a complex gut microbiota, CGM) mice, by performing stereological and morphoquantitative analyses with transmission electron microscopy and gene expression analysis by quantitative real-time PCR.

Results

Young adult GF and OMM12 optic nerve axons are smaller and hypermyelinated compared to CGM ones, while no such differences were detected in neonatal optic nerves. The transcription factors Olig1, Olig2, and Sox10 (oligodendrocyte myelination positive regulators) are downregulated in CGM and OMM12 young adult mice compared to the respective neonates. Such developmental downregulation was not observed in GF optic nerves, suggesting that the absence of the gut microbiota prolongs the stimulation of optic nerve fiber myelination, possibly through mechanisms that are yet to be identified.

Discussion

Altogether, these data underscore the gut microbiota pivotal role in driving optic nerve myelination, contributing to our knowledge about both the gut-eye axis and the gut-brain axis, and opening new horizons for further investigations that will explore the role of the microbiota also in pathologies, injuries and regeneration associated with the optic nerve.

Gut microbiota and atrial cardiomyopathy

Atrial cardiomyopathy is a multifaceted heart disease characterized by structural and functional abnormalities of the atria and is closely associated with atrial fibrillation and its complications. Its etiology involves a number of factors, including genetic, infectious, immunologic, and metabolic factors. Recent research has highlighted the critical role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, and this is consistent with the gut-heart axis having major implications for cardiac health. The aim of this work is to bridge the knowledge gap regarding the interactions between the gut microbiota and atrial cardiomyopathy, with a particular focus on elucidating the mechanisms by which gut dysbiosis may induce atrial remodeling and dysfunction. This article provides an overview of the role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, including changes in the composition of the gut microbiota and the effects of its metabolites. We also discuss how diet and exercise affect atrial cardiomyopathy by influencing the gut microbiota, as well as possible future therapeutic approaches targeting the gut-heart axis. A healthy gut microbiota can prevent disease, but ecological dysbiosis can lead to a variety of symptoms, including the induction of heart disease. We focus on the pathophysiological aspects of atrial cardiomyopathy, the impact of gut microbiota dysbiosis on atrial structure and function, and therapeutic strategies exploring modulation of the microbiota for the treatment of atrial cardiomyopathy. Finally, we discuss the role of gut microbiota in the treatment of atrial cardiomyopathy, including fecal microbiota transplantation and oral probiotics or prebiotics. Our study highlights the importance of gut microbiota homeostasis for cardiovascular health and suggests that targeted interventions on the gut microbiota may pave the way for innovative preventive and therapeutic strategies targeting atrial cardiomyopathy.

Vagus nerve stimulation and gut microbiota interactions: A novel therapeutic avenue for neuropsychiatric disorders

The rising prevalence of treatment-resistant neuropsychiatric disorders underscores the need for innovative and effective treatment strategies. The gut microbiota (GM) plays a pivotal role in the progression of these diseases, influencing the brain and mental health through the gut-brain axis (GBA). The vagus nerve plays a significant role in the GBA, making it a key area of focus for potential novel therapeutic interventions. Vagus nerve stimulation (VNS) was introduced and approved as a treatment for refractory forms of some neuropsychological disorders, such as depression and epilepsy. Considering its impact on several brain regions that play a vital part in mood, motivation, affection, and cognitive function, the VNS has shown significant therapeutic potential for treating a variety of neuropsychiatric disorders. Using VNS to target the bidirectional communication pathways linking the GM and the VN could present an exciting and novel approach to treating neuropsychological disorders. Imbalances in the GM, such as dysbiosis, can impair the communication pathways between the gut and the brain, contributing to the development of neuropsychological disorders. VNS shows potential for modulating these interconnected systems, helping to restore balance. Interestingly, the composition of the GM may also influence the effectiveness of VNS, as it has the potential to modify the brain's response to this therapeutic approach. This study provides a comprehensive analysis of a relatively unexplored but noteworthy interaction between VNS and GM in the treatment of neuropsychiatric disorders. In addition, we discussed the mechanisms, therapeutic potential, and clinical implications of VNS on the GBA across neuropsychiatric disorders.

Enhancing Gut Microbiome and Metabolic Health in Mice Through Administration of Presumptive Probiotic Strain Lactiplantibacillus pentosus PE11

Background: Over the past decade, probiotics have gained increasing recognition for their health benefits to the host. While most research has focused on the therapeutic effects of probiotics in the treatment of various diseases, recent years have seen a shift towards exploring their role in enhancing and supporting overall health. Methods: In this work, we have studied the effects of a novel potential probiotic strain, Lactiplantibacillus pentosus PE11, in healthy mice following a six-week dietary intervention. The assessment included monitoring the general health of the animals, biochemical analyses, profiling of the gut and fecal microbial communities, and gene expression analysis. Results: Our results showed that the administration of Lactiplantibacillus pentosus PE11 led to changes in the composition of the fecal microbiome, specifically an increase in the Firmicutes/Bacteroidetes ratio and in the relative abundance of the Lachnospiraceae, Ruminococcaceae, and Rikenellaceae families. Reduced Tnf expression and elevated Zo1 expression were also observed in the cecum, pointing to anti-inflammatory properties and improved intestinal barrier integrity. Additionally, a significant reduction in triglycerides and alanine aminotransferase levels-within physiological ranges-was observed, along with a trend toward decreased total cholesterol levels. Conclusions: These findings suggest that in healthy mice, Lactiplantibacillus pentosus PE11 has the potential to positively influence gut microbiome structure and metabolism, thereby supporting improved overall health.

Evaluation of variations in predominant gut microbiota members in inflammatory bowel disease using real-time PCR

Inflammatory Bowel Disease (IBD) is a persistent ailment that impacts many individuals worldwide. The interaction between the immune system and gut microbiome is thought to influence IBD development. This study aimed to assess some microbiota in IBD patients compared to healthy individuals. The investigation involved a selected group of twenty patients suffering from IBD and an equal number of healthy participants. Stool specimens were obtained and analyzed for Lactobacillus, Bifidobacterium, Bacteroides, Clostridium leptum, Akkermansia muciniphila, Fusobacterium and Enterobacteriaceae using real-time PCR. The findings indicated significantly higher levels of Bifidobacterium in IBD patients (Pv = 0.009) and lower levels of A. muciniphila (Pv = 0.003) healthy individuals. Other bacteria tested did not show significant differences. The study suggests that the progression of IBD patients could be influenced by the rising of Bifidobacterium and the declining of A. muciniphila. Targeting these bacteria could lead to improved treatments and quality of life for those with IBD.

New horizons in the treatment of psoriasis: Modulation of gut microbiome

The last decennia have witnessed spectacular advances in our knowledge about the influence of the gut microbiome on the development of a wide swathe of diseases that extend beyond the digestive tract, including skin diseases like psoriasis, atopic dermatitis, acne vulgaris, rosacea, alopecia areata, and hidradenitis suppurativa. The novel concept of the gut-skin axis delves into how skin diseases and the microbiome interact through inflammatory mediators, metabolites, and the intestinal barrier. Elucidating the effects of the gut microbiome on skin health could provide new opportunities for developing innovative treatments for dermatological diseases. Psoriasis is a complex disease with multiple factors contributing to its development, such as diet, lifestyle, genetic predisposition, and the microbiome. This paper has a dual purpose. First, we outline the current knowledge on the unique gut microbiota patterns implicated in the pathogenesis of psoriasis. Second, and of equal importance, we briefly discuss the reciprocal impact of psoriasis treatment and gut microbiome. In addition, this review explores potential therapeutic targets based on microbial interventions, which hold promise for providing new treatment options for psoriasis.

Exploring the mediating role of blood metabolites in the relationship between gut microbiota and gastric cancer risk: a Mendelian randomization study

Background

Prior studies have established correlations between gut microbiota (GM) dysbiosis, circulating metabolite alterations, and gastric cancer (GC) risk. However, the causal nature of these associations remains uncertain.

Methods

We utilized summary data from genome-wide association studies (GWAS) on GM (European, n=8,956), blood metabolites (European, n=120,241; East Asian, n=4,435), and GC (European, n=476,116; East Asian, n=167,122) to perform a bidirectional Mendelian randomization (MR) analysis, investigating the causal effects of GM and metabolites on GC risk. Additionally, we conducted mediation analysis (two-step MR) to identify potential metabolite mediators in the GM-GC relationship.

Results

We identified twelve negative and seven positive associations between specific GM taxa and GC risk. For blood metabolites, seven traits were found to be significantly associated with reduced GC risk in the European population, with these findings subsequently validated in the East Asian cohort. Three GM taxa showed potential causal associations with five metabolic traits: the Bacteroidia class and Bacteroidales order were positively correlated with five metabolites (all P < 0.013), while Bacteroides OTU97_27 exhibited a negative correlation with one metabolite (P = 0.007). Two-step MR analysis indicated that total lipids in intermediate-density lipoprotein (IDL), IDL particle concentration, phospholipids in medium low-density lipoprotein (LDL), phospholipids in small LDL, and free cholesterol in small LDL indirectly influenced the association between Bacteroidia class/Bacteroidales order and GC, with mediation proportions of 1.71% (P = 0.048), 1.69% (P = 0.048), 2.05% (P = 0.045), 1.85% (P = 0.048), and 1.99% (P = 0.045), respectively.

Conclusion

The present study provides suggestive evidence of a causal relationship between specific GM, blood metabolites, and GC risk, potentially offering new insights into GC etiology.

Involvement of intestinal mucosal microbiota in adenine-induced liver function injury

Adenine is frequently utilized as a model medication for chronic renal disease. Adenine can affect organs other than the kidneys, including the heart and the intestine. The liver is a vital organ involved in the in vivo metabolism of adenine. Adenine may negatively impact liver function. Research indicated that adenine caused dysbiosis of the gut microbiota in mice. Investigations into the gut-liver axis have demonstrated a substantial association between drug-induced hepatic dysfunction and gut microbiota. Consequently, we delivered distinct dosages of adenine via gavage to mice to examine the correlation between adenine-induced liver impairment and gut microbiota dysbiosis. Mice were treated with low-dose adenine suspension (NLA), medium-dose adenine suspension (NMA), high-dose adenine suspension (NHA), and sterile water (NC) as a control. The results indicated that mice in the NLA, NMA, and NHA groups had decreased body weight and a reduction in liver index. Subsequent to adenine administration, the concentrations of AST, ALT, and LDH increased, whereas SDH levels decreased. As doses increased, liver function impairment and hepatic energy metabolism abnormalities aggravated. Adenine also damaged the colonic architecture in mice. Moreover, adenine modified the makeup and structure of the gut mucosal microbiota, enhancing specific bacterial genera and influencing the microbiota's energy metabolism-related functions. The results of our research established a correlation among certain bacteria, liver function injury, and hepatic energy metabolism. The gut mucosal microbiota was involved in adenine-induced liver injury and hepatic energy metabolism. These results can offer novel insights into the role of gut microbiota in drug-induced liver injury and provide specific guidelines for the modeling and therapeutic application of adenine.

IUPHAR review: Targeted therapies of signaling pathways based on the gut microbiome in autism spectrum disorders: Mechanistic and therapeutic applications

Autism spectrum disorders (ASD) are complex neurodevelopmental disorders characterized by impairments in social interaction, communication and repetitive activities. Gut microbiota significantly influences behavior and neurodevelopment by regulating the gut-brain axis. This review explores gut microbiota-influenced treatments for ASD, focusing on their therapeutic applications and mechanistic insights. In addition, this review discusses the interactions between gut microbiota and the immune, metabolic and neuroendocrine systems, focusing on crucial microbial metabolites including short-chain fatty acids (SCFAs) and several neurotransmitters. Furthermore, the review explores various therapy methods including fecal microbiota transplantation, dietary modifications, probiotics and prebiotics and evaluates their safety and efficacy in reducing ASD symptoms. The discussion shows the potential of customized microbiome-based therapeutics and the integration of multi-omics methods to understand the underlying mechanisms. Moreover, the review explores the intricate relationship between gut microbiota and ASD, aiming to develop innovative therapies that utilize the gut microbiome to improve the clinical outcomes of ASD patients. Microbial metabolites such as neurotransmitter precursors, tryptophan metabolites and SCFAs affect brain development and behavior. Symptoms of ASD are linked to changes in these metabolites. Dysbiosis in the gut microbiome may impact neuroinflammatory processes linked to autism, negatively affecting immune signaling pathways. Research indicates that probiotics and prebiotics can improve gut microbiota and alleviate symptoms in ASD patients. Fecal microbiota transplantation may also improve behavioral symptoms and restore gut microbiota balance. The review emphasizes the need for further research on gut microbiota modification as a potential therapeutic approach for ASD, highlighting its potential in clinical settings.

Gut microbiota contributes to the intestinal and extraintestinal immune homeostasis by balancing Th17/Treg cells

Gut microbiota is generally considered to play an important role in host health due to its extensive immunomodulatory activities. Th17 and Treg cells are two important CD4+ T cell subsets involved in immune regulation, and their imbalance is closely tied to many immune diseases. Recently, abundant researches have highlighted the importance of gut microbiota in supporting intestinal and extraintestinal immunity through the balance of Th17 and Treg cells. Here, we presented a comprehensive review of these findings. This review first provided an overview of gut microbiota, along with Th17/Treg cell differentiation and cytokine production. Subsequently, the review summarized the regulatory effects of gut microbiota (in terms of species, components, and metabolites) on the Th17/Treg cell balance in the local intestines and extraintestinal organs, such as lung, liver, brain, kidney, and bone. Specifically, the Th17 and Treg cells that can be modulated by gut microbiota originate not only from the gut and extraintestinal organs, but also from peripheral blood and spleen. Then, the microbial therapeutics, including probiotics, prebiotics, postbiotics, and fecal microbiota transplantation (FMT), were also reviewed because of their therapeutic potentials in addressing intestinal and extraintestinal diseases via the Th17/Treg axis. Finally, the review discussed the clinical applications and future study prospects of microbial therapeutics by targeting the Th17/Treg cell balance. In conclusion, this review focused on elucidating the regulatory effects of gut microbiota in balancing Th17/Treg cells to maintain intestinal and extraintestinal immune homeostasis, contributing to the further development and promotion of microbial therapeutics.

Impact of Edible Insect Polysaccharides on Mouse Gut Microbiota: A Study on White-Spotted Flower Chafer Larva (Protaetia brevitarsis seulensis) and Silkworm Pupa (Bombyx mori)

The increasing global population and the environmental consequences of meat consumption have led to the exploration of alternative sources of protein. Edible insects have gained attention as a sustainable and nutritionally rich meat alternative. We investigated the effects of two commonly consumed insects, Protaetia brevitarsis seulensis larva and Bombyx mori pupa, on beneficial gut microbiota growth, using whole 16s metagenome sequencing to assess diet-associated changes. Seven-week-old female C57BL/6J mice were administered the edible insects, along with fracto-oligosaccharide (FOS) as a positive control and sham (phosphate buffer saline (PBS)) as a negative control, to assess the relative abundance of insect-diet-associated gut microbes. In total, 567 genera and 470 species were observed, and among these, 15 bacterial genera were differentially abundant in all three groups. These results show that among the two insects, Bombyx mori pupa polysaccharides have a greater ability to regulate beneficial probiotics and next-generation probiotics. In particular, Lactococcus garvieae, which has promising effects on the gastrointestinal tracts of humans and animals, was significantly enriched in both Protaetia brevitarsis seulensis larva and Bombyx mori pupa polysaccharides, similar to fracto-oligosaccharide. The results suggest that the consumption of these insects, particularly polysaccharides, can enhance the growth of beneficial gut microbes, potentially leading to improved overall health in healthy populations.

Gut microbiota as a modulator of type 1 diabetes: A molecular perspective

Type 1 diabetes (T1D) is defined as an autoimmune metabolic disorder, characterized by destruction of pancreatic β-cells and high blood sugar levels. If left untreated, T1D results in severe health complications, including cardiovascular and kidney disease, as well as nerve damage, with ultimately grave consequences. Besides the role of genetic and certain environmental factors in T1D development, in the last decade, one new player emerged to affect T1D pathology as well, and that is a gut microbiota. Dysbiosis of gut bacteria can contribute to T1D by gut barrier disruption and the activation of autoimmune response, leading to the destruction of insulin producing cells, causing the development and aggravation of T1D symptoms. The relationship between gut microbiota and diabetes is complex and varies between individuals and additional research is needed to fully understand the effects of gut microbiome alternations in T1D pathogenesis. Therefore, the goal of this review is to understand the current knowledge in underlying molecular mechanism of gut microbiota effects, which leads to the new approaches for further studies in the prevention and treatment of T1D.

Akkermansia muciniphila- and Pathogenic Bacteria-Derived Endotoxins Differently Regulate Human Dendritic Cell Generation and γδ T Lymphocyte Activation

Lipopolysaccharide (LPS) is a potent endotoxin released at high concentrations in acute infections, causing massive host inflammatory response. Accumulating evidence indicates that dysbiosis-associated chronic low levels of circulating LPS can sustain a prolonged sterile low-grade inflammation that increases the risk of several non-communicable diseases. Interventions aimed at increasing the abundance of beneficial/probiotic bacteria, including Akkermansia muciniphila, result in reduced inflammation, favoring metabolic and immune health. Immunosuppression is a common feature in conditions of chronic inflammation, and dendritic cells (DCs) represent key targets given their ability to shift the balance toward immunity or tolerance. In this study, the effects of low concentrations of LPS from pathogenic (Escherichia coli and Salmonella enterica) and probiotic (Akkermansia muciniphila) bacterial species on human DC generation and functions were compared. We report that monocyte precursor priming with Escherichia coli and Salmonella enterica LPS forces the differentiation of PD-L1-expressing DCs, releasing high levels of IL-6 and IL-10, and impairs their capacity to drive full TCR-Vδ2 T cell activation. Conversely, comparable concentrations of Akkermansia muciniphila promoted the generation of DCs with preserved activating potential and immunostimulatory properties. These results shed light on potential mechanisms underlying the impact of low endotoxemia on disease risk and pathogenesis, and increase our understanding of the immunomodulatory effects of Akkermansia muciniphila.

Sex-bias of core intestinal microbiota in different stocks of Chinese mitten crabs (Eriocheir sinensis)

The differences in intestinal microbiota composition are synergistically shaped by internal and external factors of the host. The core microbiota plays a vital role in maintaining intestinal homeostasis. In this study, we conducted 16S rRNA sequencing analysis to investigate the stability of intestinal microbiota and sex-bias of six stocks of Chinese mitten crabs (105 females; and 110 males). The dominant phyla in all six stocks were Proteobacteria, Tenericutes, Bacteroidetes and Firmicutes; however, their relative abundance differed significantly. Twenty-seven core operational taxonomic units (OTUs), corresponding to 18 genera, were screened. Correlation analysis revealed that OTUs of four stocks in the Yangtze River system play important roles in maintaining the stability of intestinal microbiota. Additionally, the core intestinal microbiota was significantly sex-biased, and the top three genera in terms of relative abundance (Acinetobacter, Vibrio, and Candidatus_Hepatoplasma) were significantly dominant in female crabs. Network structure analysis also confirmed gender differences in the association pattern of intestinal microbiota. The intestinal microbiota of male crabs has a higher degree of functional enrichment. This study provided a theoretical basis for further investigating exploring the shaping effect of gender and geographical factors on the intestinal microbiota of Chinese mitten crabs.

Fecal Microbiota Transplantation: Indications, Methods, and Challenges

Over the past two decades, as the importance of gut microbiota to human health has become widely known, attempts have been made to treat diseases by correcting dysbiosis of gut microbiota through fecal microbiota transplantation (FMT). Apart from current knowledge of gut microbiota, FMT to treat disease has a long history, from the treatment of food poisoning in the fourth century to the treatment of Clostridioides difficile infections in the twentieth century. In 2013, FMT was recognized as a standard treatment for recurrent C. difficile because it consistently showed high efficacy. Though recurrent C. difficile is the only disease internationally recognized for FMT efficacy, FMT has been tested for other diseases and shown some promising preliminary results. Different FMT methods have been developed using various formulations and administration routes. Despite advances in FMT, some issues remain to be resolved, such as donor screening, manufacturing protocols, and unknown components in the fecal microbiota. In this review, we discuss the mechanisms, clinical indications, methods, and challenges of current FMT. We also discuss the development of alternative therapies to overcome the challenges of FMT.

Gut microbiota in health and disease: advances and future prospects

The gut microbiota plays a critical role in maintaining human health, influencing a wide range of physiological processes, including immune regulation, metabolism, and neurological function. Recent studies have shown that imbalances in gut microbiota composition can contribute to the onset and progression of various diseases, such as metabolic disorders (e.g., obesity and diabetes) and neurodegenerative conditions (e.g., Alzheimer's and Parkinson's). These conditions are often accompanied by chronic inflammation and dysregulated immune responses, which are closely linked to specific forms of cell death, including pyroptosis and ferroptosis. Pathogenic bacteria in the gut can trigger these cell death pathways through toxin release, while probiotics have been found to mitigate these effects by modulating immune responses. Despite these insights, the precise mechanisms through which the gut microbiota influences these diseases remain insufficiently understood. This review consolidates recent findings on the impact of gut microbiota in these immune-mediated and inflammation-associated conditions. It also identifies gaps in current research and explores the potential of advanced technologies, such as organ-on-chip models and the microbiome-gut-organ axis, for deepening our understanding. Emerging tools, including single-bacterium omics and spatial metabolomics, are discussed for their promise in elucidating the microbiota's role in disease development.

Lactiplantibacillus plantarum KABP051: Stability in Fruit Juices and Production of Bioactive Compounds During Their Fermentation

The lactic fermentation of fruit and vegetable juices by well-characterised probiotics remains relatively underexplored. We have investigated the stability and impact of Lactiplantibacillus plantarum KABP051 fermentation on orange, apple, and peach juices by microbiological, physicochemical, and sensory evaluation means. For each fruit juice, three different samples were analysed: original fruit juice without probiotic as blank (B), fruit juice inoculated with 107 CFU/mL of probiotic without fermentation (P), and fruit juice inoculated with 107 CFU/mL of probiotic and fermented at 37 °C for 24 h (PF). P samples displayed good stability throughout the study, and PF samples showed an initial increase in CFUs accompanied by a change in pH, confirming the ability of the probiotic to ferment these juices. After 60 days of refrigeration, PF samples contained >107 CFU/mL. Total phenolic content and antioxidant capacity were equivalent in F, P, and PF. Remarkably, deep metabolomic analyses confirmed malolactic fermentation and revealed the production of several bioactive compounds including the antimicrobial substance phenyllactic acid, the immunomodulatory and anti-fatigue amino acid N-acetyl glutamine, the vitamin B3 form nicotinic acid, the monoterpene (-)-β-pinene, and the neurotransmitter acetylcholine, among others, during probiotic fermentation. Finally, a hedonic analysis involving 51 participants showed that probiotic fermented orange juice is well accepted by panellists, with scores comparable to those of the control juice. Overall, we here show that fruit juices are excellent carriers for the delivery of the probiotic L. plantarum KABP051 and its non-alcoholic fermentation can result in tasty functional fruit juices enriched with health-promoting compounds.

The Gut-Heart Axis: Molecular Perspectives and Implications for Myocardial Infarction

Myocardial infarction (MI) remains the leading cause of death globally, imposing a significant burden on healthcare systems and patients. The gut-heart axis, a bidirectional network connecting gut health to cardiovascular outcomes, has recently emerged as a critical factor in MI pathophysiology. Disruptions in this axis, including gut dysbiosis and compromised intestinal barrier integrity, lead to systemic inflammation driven by gut-derived metabolites like lipopolysaccharides (LPSs) and trimethylamine N-oxide (TMAO), both of which exacerbate MI progression. In contrast, metabolites such as short-chain fatty acids (SCFAs) from a balanced microbiota exhibit protective effects against cardiac damage. This review examines the molecular mediators of the gut-heart axis, considering the role of factors like sex-specific hormones, aging, diet, physical activity, and alcohol consumption on gut health and MI outcomes. Additionally, we highlight therapeutic approaches, including dietary interventions, personalized probiotics, and exercise regimens. Addressing the gut-heart axis holds promise for reducing MI risk and improving recovery, positioning it as a novel target in cardiovascular therapy.

Intestinal Insights: The Gut Microbiome's Role in Atherosclerotic Disease: A Narrative Review

Recent advances have highlighted the gut microbiota as a significant contributor to the development and progression of atherosclerosis, which is an inflammatory cardiovascular disease (CVD) characterized by plaque buildup within arterial walls. The gut microbiota, consisting of a diverse collection of microorganisms, impacts the host's metabolism, immune responses, and lipid processing, all of which contribute to atherosclerosis. This review explores the complex mechanisms through which gut dysbiosis promotes atherogenesis. We emphasize the potential of integrating microbiota modulation with traditional cardiovascular care, offering a holistic approach to managing atherosclerosis. Important pathways involve the translocation of inflammatory microbial components, modulation of lipid metabolism through metabolites such as trimethylamine-N-oxide (TMAO), and the production of short-chain fatty acids (SCFAs) that influence vascular health. Studies reveal distinct microbial profiles in atherosclerosis patients, with increased pathogenic bacteria (Megamonas, Veillonella, Streptococcus) and reduced anti-inflammatory genera (Bifidobacterium, Roseburia), highlighting the potential of these profiles as biomarkers and therapeutic targets. Probiotics are live microorganisms that have health benefits on the host. Prebiotics are non-digestible dietary fibers that stimulate the growth and activity of beneficial gut bacteria. Interventions targeting microbiota, such as probiotics, prebiotics, dietary modifications, and faecal microbiota transplantation (FMT), present effective approaches for restoring microbial equilibrium and justifying cardiovascular risk. Future research should focus on longitudinal, multi-omics studies to clarify causal links and refine therapeutic applications.

Unraveling the Role of the Human Gut Microbiome in Health and Diseases

The human gut is a complex ecosystem that supports billions of living species, including bacteria, viruses, archaea, phages, fungi, and unicellular eukaryotes. Bacteria give genes and enzymes for microbial and host-produced compounds, establishing a symbiotic link between the external environment and the host at both the gut and systemic levels. The gut microbiome, which is primarily made up of commensal bacteria, is critical for maintaining the healthy host's immune system, aiding digestion, synthesizing essential nutrients, and protecting against pathogenic bacteria, as well as influencing endocrine, neural, humoral, and immunological functions and metabolic pathways. Qualitative, quantitative, and/or topographic shifts can alter the gut microbiome, resulting in dysbiosis and microbial dysfunction, which can contribute to a variety of noncommunicable illnesses, including hypertension, cardiovascular disease, obesity, diabetes, inflammatory bowel disease, cancer, and irritable bowel syndrome. While most evidence to date is observational and does not establish direct causation, ongoing clinical trials and advanced genomic techniques are steadily enhancing our understanding of these intricate interactions. This review will explore key aspects of the relationship between gut microbiota, eubiosis, and dysbiosis in human health and disease, highlighting emerging strategies for microbiome engineering as potential therapeutic approaches for various conditions.

Large-scale metagenomic assembly provide new insights into the genetic evolution of gut microbiomes in plateau ungulates

Trillions of microbes colonize the ungulate gastrointestinal tract, playing a pivotal role in enhancing host nutrient utilization by breaking down cellulose and hemicellulose present in plants. Here, through large-scale metagenomic assembly, we established a catalog of 131,416 metagenome-assembled genomes (MAGs) and 11,175 high-quality species-level genome bins (SGBs) from 17 species of ungulates in China. Our study revealed the convergent evolution of high relative abundances of carbohydrate-active enzymes (CAZymes) in the gut microbiomes of plateau-dwelling ungulates. Notably, two significant factors contribute to this phenotype: structural variations in their gut microbiome genomes, which contain more CAZymes, and the presence of novel gut microbiota species, particularly those in the genus Cryptobacteroides, which are undergoing independent rapid evolution and speciation and have higher gene densities of CAZymes. Furthermore, these enrichment CAZymes in the gut microbiomes are highly enrichment in known metabolic pathways for short-chain fatty acid (SCFA) production. Our findings not only provide a valuable genomic resource for understanding the gut microbiomes of ungulates but also offer fresh insights into the interaction between gut microbiomes and their hosts, as well as the co-adaptation of hosts and their gut microbiomes to their environments.

Gut Microbiota and Liver Regeneration: A Synthesis of Evidence on Structural Changes and Physiological Mechanisms

Liver regeneration (LR) is a unique biological process with the ability to restore up to 70% of the organ. This allows for the preservation of liver resections for various liver tumors and for living donor liver transplantation (LDLT). However, in some cases, LR is insufficient and interventions that can improve LR are urgently needed. Gut microbiota (GM) is one of the factors influencing LR, as the liver and intestine are intimately connected through the gut-liver axis. Thus, healthy GM facilitates normal LR, whereas dysbiosis leads to impaired LR due to imbalance of bile acids, inflammatory cytokines, microbial metabolites, signaling pathways, etc. Therefore, GM can be considered as a new possible therapeutic target to improve LR. In this review, we critically observe the current knowledge about the influence of gut microbiota (GM) on liver regeneration (LR) and the possibility to improve this process, which may reduce complication and mortality rates after liver surgery. Although much research has been done on this topic, more clinical trials and systemic reviews are urgently needed to move this type of intervention from the experimental phase to the clinical field.

Evaluation of inter- and intra-variability in gut health markers in healthy adults using an optimised faecal sampling and processing method

Despite advances in gut health research, the variability of important gut markers within individuals over time remains underexplored. We investigated the intra-individual variation of various faecal gut health markers using an optimised processing protocol aimed at reducing variability. Faecal samples from ten healthy adults over three consecutive days demonstrated marker-specific intra-individual coefficients of variation (CV%), namely: stool consistency (16.5%), water content (5.7%), pH (3.9%), total SCFAs (17.2%), total BCFAs (27.4%), total bacteria and fungi copies (40.6% and 66.7%), calprotectin and myeloperoxidase (63.8% and 106.5%), and untargeted metabolites (on average 40%). For thirteen microbiota genera, including Bifidobacterium and Akkermansia, variability exceeded 30%, whereas microbiota diversity was less variable (Phylogenetic Diversity 3.3%, Inverse Simpson 17.2%). Mill-homogenisation of frozen faeces significantly reduced the replicates CV% for total SCFAs (20.4-7.5%) and total BCFAs (15.9-7.8%), and untargeted metabolites compared to faecal hammering only, without altering mean concentrations. Our results show the potential need for repeated sampling to accurately represent specific gut health markers. We also demonstrated the effectiveness of optimised preprocessing of human stool samples in reducing overall analytical variability.

Oral administration of Lactobacillus delbrueckii UFV-H2b20 protects mice against Aspergillus fumigatus lung infection

INTRODUCTION

Probiotics provide therapeutic benefits not only in the gut but also other mucosal organs, including the lungs.

OBJECTIVE AND DESIGN

To evaluate the effects of the probiotic strain L. delbrueckii UFV-H2b20 oral administration in an experimental murine model of A. fumigatus pulmonary infection. BALB/c mice were associated with L. delbrueckii and infected with Aspergillus fumigatus and compared with non-associated group.

METHODS

We investigated survival, respiratory mechanics, histopathology, colony forming units, cytokines in bronchoalveolar lavage, IgA in feces, efferocytosis, production of reactive oxygen species and the cell population in the mesenteric lymph nodes.

RESULTS

L. delbrueckii induces tolerogenic dendritic cells, IL-10+macrophages and FoxP3+regulatory T cells in mesenteric lymph nodes and increased IgA levels in feces; after infection with A. fumigatus, increased survival and decreased fungal burden. There was decreased lung vascular permeability without changes in the leukocyte profile. There was enhanced neutrophilic response and increased macrophage efferocytosis. L. delbrueckii-treated mice displayed more of FoxP3+Treg cells, TGF-β and IL-10 levels in lungs, and concomitant decreased IL-1β, IL-17 A, and CXCL1 production.

CONCLUSION

Uur results indicate that L. delbrueckii UFV H2b20 ingestion improves immune responses, controlling pulmonary A. fumigatus infection. L. delbrueckii seems to play a role in pathogenesis control by promoting immune regulation.

The effects of stress on gut virome: Implications on infectious disease and systemic disorders

The role of gut microbiota in health and disease is being thoroughly examined in various contexts, with a specific focus on the bacterial fraction due to its significant abundance. However, despite their lower abundance, viruses within the gut microbiota are gaining recognition for their crucial role in shaping the structure and function of the intestinal microbiota, with significant effects on the host as a whole, particularly the immune system. Similarly, environmental factors such as stress are key in modulating the host immune system, which in turn influences the composition of the gut virome and neurological functions through the bidirectional communication of the gut-brain axis. In this context, alterations in the host immune system due to stress and/or dysbiosis of the gut virome are critical factors in the development of both infectious and noninfectious diseases. The molecular mechanisms and correlation patterns between microbial species are not yet fully understood. This literature review seeks to explore the interconnected relationship between stress and the gut virome, with a focus on how this interaction is influenced by the host's immune system. We also discuss how disturbances in this finely balanced system can lead to the onset and/or progression of diseases.