Introduction to the human gut microbiota

Lipidic drug delivery systems are responsive to the human microbiome

In vitro and in vivo tests for therapeutic agents are typically conducted in sterile environments, but many target areas for drug delivery are home to thousands of microbial species. Here, we examine the behaviour of lipidic nanomaterials after exposure to representative strains of four bacterial species found in the gastrointestinal tract and skin. Small angle X-ray scattering measurements show that the nanostructure of monoolein cubic and inverse hexagonal phases are transformed, respectively, into inverse hexagonal and inverse micellar cubic phases upon exposure to a strain of live Staphylococcus aureus often present on skin and mucosa. Further investigation demonstrates that enzymatic hydrolysis and cell membrane lipid transfer are both likely responsible for this effect. The structural responses to S. aureus are rapid and significantly reduce the rate of drug release from monoolein-based nanomaterials. These findings are the first to demonstrate how a key species in the live human microbiome can trigger changes in the structure and drug release properties of lipidic nanomaterials. The effect appears to be strain specific, varies from patient to patient and body region to body region, and is anticipated to affect the bioapplication of monoglyceride-based formulations.

Evolution of multi-scale structure and microbiota metabolism of lentil resistant starch during the dynamic fermentation in vitro

This study investigated the structural changes of resistant starch (RS) derived from autoclaved lentil starch (ALRS) and untreated lentil starch (ULRS) during in vitro colonic fermentation, as well as their regulatory effects on the composition of the intestinal microbiota. Following in vitro fermentation, both RS samples exhibited a progressive decrease in molecular weight and a gradual increase in double helix/order. Bifidobacterium was more abundant in ULRS during the initial period of fermentation, while ALRS showed higher abundance in the later stage. ALRS demonstrated greater production of short-chain fatty acids (SCFAs) compared to ULRS, likely attributed to its higher structural order and faster fermentation pattern. The distinct surface morphologies of ULRS and ALRS played a crucial role in determining the accessibility of RS substrates for microbial fermentation. These different structural patterns also influenced the shifts in microbial composition in fecal cultures, leading to variations in SCFAs production through anaerobic fermentation.

Dysbiosis and Staphylococcus species over representation in the exit site skin microbiota of hemodialysis patients carrying tunneled cuffed central venous catheter

OBJECTIVES

Hemodialysis patients with end-stage renal disease (ESRD) are susceptible to infections and dysbiosis. Catheter-related infections are typically caused by opportunistic skin pathogens. This study aims to compare the skin microbiota changes around the exit site of tunneled cuffed catheters (peri-catheter group) and the contralateral site (control group).

METHODS

ESRD patients on hemodialysis were recruited. The skin microbiota were collected with moist skin swabs and analyzed using high-throughput sequencing of the 16S rDNA V3-V4 region. After denoising, de-replication, and removal of chimeras, the reads were assigned to zero-radius operational taxonomic units (ZOTU).

RESULTS

We found significantly reduced alpha diversity in the peri-catheter group compared to the control group, as indicated by the Shannon, Jost, and equitability indexes, but not by the Chao1 or richness indexes. Beta diversity analysis revealed significant deviation of the peri-catheter microbiota from its corresponding control group. There was an overrepresentation of Firmicutes and an underrepresentation of Actinobacteria, Proteobacteria, and Acidobacteria at the phylum level in the peri-catheter group. The most abundant ZOTU (Staphylococcus spp.) drastically increased, while Cutibacterium, a commensal bacterium, decreased in the peri-catheter group. Network analysis revealed that the skin microbiota demonstrated covariance with both local and biochemical factors.

CONCLUSIONS

In conclusion, there was significant skin microbiota dysbiosis at the exit sites compared to the control sites in ESRD dialysis patients. Managing skin dysbiosis represents a promising target in the prevention of catheter-related bacterial infections.

Influence of mode of delivery on infant gut microbiota composition: a pilot study

BACKGROUND

Microbial colonisation in infants is initially dependent on the mother and is affected by the mode of delivery. Understanding these impacts is crucial as the early-life gut microbiota plays a vital role in immune development, metabolism, and overall health. Early-life infant gut microbiota is diverse among populations and geographic origins. However, in this context, only a few studies have explored the impact of the mode of delivery on the intestinal microbiome in children in Guangzhou, China. Therefore, this study aimed to investigate the influence of birth mode on the intestinal microbiota of healthy infants in Guangzhou, China.

METHODS

Faecal samples were collected once from 20 healthy full-term infants aged 1-6 months, delivered via either caesarean section (CS) or vaginal delivery (VD), post-enrolment. The intestinal microbiota were characterised using full-length 16S rRNA gene sequencing. Bacterial quantity and community composition were compared between the two groups.

RESULTS

No significant differences in gut bacterial diversity and richness were observed between the CS and VD groups. The Pseudomonadota phylum (44.15 ± 33.05% vs 15.62 ± 15.60%, p = 0.028) and Enterobacteriaceae family (44.00 ± 33.11% vs 15.31 ± 15.47%, p = 0.028) were more abundant in the CS group than in the VD group. The VD group exhibited a higher abundance of the Bacillota phylum (40.51 ± 32.77% vs 75.57 ± 27.83%, p = 0.019).

CONCLUSIONS

The early stage of intestinal bacterial colonisation was altered in the CS group as compared with the VD group. Our findings provide evidence that CS has the potential to disrupt the maturation of intestinal microbial communities in infants by influencing the colonisation of specific microorganisms. Further comprehensive studies that consider geographical locations are necessary to elucidate the progression of microbiota in infants born via different delivery modes.

Impacts of polyhydroxybutyrate (PHB) microplastic exposure on physiology and metabolic profiles of Litopenaeus vannamei

In light of increasing concerns about microplastic pollution, it is crucial to understand the biological impacts of biodegradable PHB microplastics on marine organisms. This study included a 96-h exposure experiment to assess acute toxicity at PHB concentrations of 0 mg/L, 100 mg/L, 500 mg/L and 1000 mg/L. Additionally, a 60-day feeding trial was conducted with PHB concentrations of 0, 0.5, 1.0 and 2.0 g/kg to evaluate the long-term effects on growth, physiological health and metabolic responses of Litopenaeus vannamei. Results from the exposure experiment indicated that PHB microplastics up to 100 mg/L were non-toxic to shrimp. However, the 60-day feeding trial revealed that higher concentrations led to slight reductions in survival rates and growth performance, indicating a concentration-dependent response. Analysis of antioxidant and immune enzymes showed minimal changes across most parameters. However, increases in malondialdehyde content and lysozyme activity at higher PHB levels suggested a stress response. Microbial analysis indicated higher species richness and greater community diversity in the PHB group compared to controls, as evidenced by Chao1, ACE, Shannon and Simpson indices. Linear discriminant analysis revealed that Enterobacteriales and related taxa were more prevalent in the PHB group, while Rhodobacteraceae and associated taxa dominated the control group. Pathway analysis highlighted enhanced signal transduction, cell mobility and metabolic resource reallocation in response to PHB-induced stress. Integrated transcriptomic and metabolomic analyses revealed significant regulatory changes, especially in lipid metabolism pathways. These findings suggest that while PHB microplastics trigger adaptive metabolic responses in shrimp, they do not cause acute toxicity. Significant variations in intestinal microbiome composition reflect potential shifts in gut health dynamics due to PHB ingestion. This study enhances our understanding of the ecological impacts of microplastics and underscores the necessity for further research into the environmental safety of biodegradable alternatives.

The role of the fecal microbiota in inflammatory bowel disease

The understanding of the potential role of the microbiota in the pathogenesis of inflammatory bowel disease (IBD) is ever-evolving. Traditionally, the management of IBD has involved medical therapy and/or surgical intervention. IBD can be characterized by gut microbiome alterations through various pathological processes. Various studies delve into nontraditional methods such as probiotics and fecal microbiota transplant and their potential therapeutic effects. Fecal microbiota transplant involves the delivery of a balanced composition of gut microorganisms into an affected patient via multiple possible routes and methods, while probiotics consist of live microorganisms given via the oral route. At present, neither method is considered first-line treatment, however, fecal microbiota transplant has shown potential success in inducing and maintaining remission in ulcerative colitis. In a study by Kruis and colleagues, Escherichia coli Nissle 1917 was considered to be equivalent to mesalamine in mild ulcerative colitis. Alteration of the microbiome in the management of Crohn's disease is less well defined. Furthermore, variation in the clinical usefulness of 5-aminosalicylic acid medication has been attributed, in part, to its acetylation and inactivation by gut microbes. In summary, our understanding of the microbiome's role is continually advancing, with the possibility of paving the way for personalized medicine based on the microbiome.

Therapeutic strategies to modulate gut microbial health: Approaches for sarcopenia management

Sarcopenia is a progressive and generalized loss of skeletal muscle and functions associated with ageing with currently no definitive treatment. Alterations in gut microbial composition have emerged as a significant contributor to the pathophysiology of multiple diseases. Recently, its association with muscle health has pointed to its potential role in mediating sarcopenia. The current review focuses on the association of gut microbiota and mediators of muscle health, connecting the dots between the influence of gut microbiota and their metabolites on biomarkers of sarcopenia. It further delineates the mechanism by which the gut microbiota affects muscle health with progressing age, aiding the formulation of a multi-modal treatment plan involving nutritional supplements and pharmacological interventions along with lifestyle changes compiled in the review. Nutritional supplements containing proteins, vitamin D, omega-3 fatty acids, creatine, curcumin, kefir, and ursolic acid positively impact the gut microbiome. Dietary fibres foster a conducive environment for the growth of beneficial microbes such as Bifidobacterium, Faecalibacterium, Ruminococcus, and Lactobacillus. Probiotics and prebiotics act by protecting against reactive oxygen species (ROS) and inflammatory cytokines. They also increase the production of gut microbiota metabolites like short-chain fatty acids (SCFAs), which aid in improving muscle health. Foods rich in polyphenols are anti-inflammatory and have an antioxidant effect, contributing to a healthier gut. Pharmacological interventions like faecal microbiota transplantation (FMT), non-steroidal anti-inflammatory drugs (NSAIDs), ghrelin mimetics, angiotensin-converting enzyme inhibitors (ACEIs), and butyrate precursors lead to the production of anti-inflammatory fatty acids and regulate appetite, gut motility, and microbial impact on gut health. Further research is warranted to deepen our understanding of the interaction between gut microbiota and muscle health for developing therapeutic strategies for ameliorating sarcopenic muscle loss.

Agmatine modulation of gut-brain axis alleviates dysbiosis-induced depression-like behavior in rats

Depression is a global health concern affecting nearly 280 million individuals. It not only imposes a significant burden on economies and healthcare systems but also manifests complex physiological connections and consequences. Agmatine, a putative neuromodulator derived primarily from beneficial gut microbes specially Lactobacillus, has emerged as a potential therapeutic agent for mental health. The microbiota-gut-brain axis is involved in the development of depression through the peripheral nervous system, endocrine system, and immune system and may be a key factor in the effect of agmatine. Therefore, this study aimed to investigate the potential mechanism of agmatine in antibiotic-induced dysbiosis and depression-like behavior in rats, focusing on its modulation of the gut-brain axis. Depression-like behavior associated with dysbiosis was induced through a seven-day regimen of the broad-spectrum antibiotic, comprising ampicillin and metronidazole and validated through microbial, biochemical, and behavioral alterations. On day 8, antibiotic-treated rats exhibited loose fecal consistency, altered fecal microbiota, and depression-like behavior in forced swim test. Pro-inflammatory cytokines were elevated, while agmatine and monoamine levels decreased in the hippocampus and prefrontal cortex. Antibiotic administration disrupted tight junction proteins in the ileum, affecting gut architecture. Oral administration of agmatine alone or combined with probiotics significantly reversed antibiotic-induced dysbiosis, restoring gut microbiota and mitigating depression-like behaviors. This intervention also restored neuro-inflammatory markers, increased agmatine and monoamine levels, and preserved gut integrity. The study highlights the regulatory role of endogenous agmatine in the gut-brain axis in broad-spectrum antibiotic induced dysbiosis and associated depression-like behavior.

Time-Resolved Multiomics Illustrates Host and Gut Microbe Interactions during Salmonella Infection

Salmonella infection, also known as Salmonellosis, is one of the most common food-borne illnesses. Salmonella infection can trigger host defensive functions, including an inflammatory response. The provoked-host inflammatory response has a significant impact on the bacterial population in the gut. In addition, Salmonella competes with other gut microorganisms for survival and growth within the host. Compositional and functional alterations in gut bacteria occur because of the host immunological response and competition between Salmonella and the gut microbiome. Host variation and the inherent complexity of the gut microbial community make understanding commensal and pathogen interactions particularly difficult during a Salmonella infection. Here, we present metabolomics and lipidomics analyses along with the 16S rRNA sequence analysis, revealing a comprehensive view of the metabolic interactions between the host and gut microbiota during Salmonella infection in a CBA/J mouse model. We found that different metabolic pathways were altered over the four investigated time points of Salmonella infection (days -2, +2, +6, and +13). Furthermore, metatranscriptomics analysis integrated with metabolomics and lipidomics analysis facilitated an understanding of the heterogeneous response of mice, depending on the degree of dysbiosis.

Gut antibiotic resistome during pregnancy associates with the risk of gestational diabetes mellitus: New evidence from a prospective nested case-control study

Antibiotic resistome has emerged as a global threat to public health. However, gestational antibiotic resistome and potential link with adverse pregnancy outcomes remains poorly understood. Our study reports for the first time an association between gut antibiotic resistome during early pregnancy and the risk of gestational diabetes mellitus (GDM) based on a prospective nested case-control cohort including 120 cases and 120 matched controls. A total of 214 antibiotic resistance gene (ARG) subtypes belonging to 17 ARG types were identified in > 10 % fecal samples collected during each trimester. The data revealed dynamic profiles of gut antibiotic resistome through pregnancy, and significant positive associations between selected features (i.e., ARG abundances and a GDM-ARG score which is a new feature characterizing the association between ARGs and GDM) of gut antibiotic resistome during early pregnancy and GDM risk as well as selected endogenous metabolites. The findings demonstrate ubiquitous presence of ARGs in pregnant women and suggest it could constitute an important risk factor for the development of GDM.

Impact of gut microbiota on metabolic dysfunction-associated steatohepatitis and hepatocellular carcinoma: pathways, diagnostic opportunities and therapeutic advances

Metabolic dysfunction-associated steatohepatitis (MASH) and progression to hepatocellular carcinoma (HCC) exhibits distinct molecular and immune characteristics. These traits are influenced by multiple factors, including the gut microbiome, which interacts with the liver through the "gut-liver axis". This bidirectional relationship between the gut and its microbiota and the liver plays a key role in driving various liver diseases, with microbial metabolites and immune responses being central to these processes. Our review consolidates the latest research on how gut microbiota contributes to MASH development and its progression to HCC, emphasizing new diagnostic and therapeutic possibilities. We performed a comprehensive literature review across PubMed/MedLine, Scopus, and Web of Science from January 2000 to August 2024, focusing on both preclinical and clinical studies that investigate the gut microbiota's roles in MASH and HCC. This includes research on pathogenesis, as well as diagnostic and therapeutic advancements related to the gut microbiota. This evidence emphasizes the critical role of the gut microbiome in the pathogenesis of MASH and HCC, highlighting the need for further clinical studies and trials. This is to refine diagnostic techniques and develop targeted therapies that exploit the microbiome's capabilities, aiming to enhance patient care in liver diseases.

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.

The importance of gut microbiome in the perinatal period

This narrative review describes the settlement of the neonatal microbiome during the perinatal period and its importance on human health in the long term. Delivery methods, maternal diet, antibiotic exposure, feeding practices, and early infant contact significantly shape microbial colonization, influencing the infant's immune system, metabolism, and neurodevelopment. By summarizing two decades of research, this review highlights the microbiome's role in disease predisposition and explores interventions like maternal vaginal seeding and probiotic and prebiotic supplementation that may influence microbiome development.

CONCLUSION

The perinatal period is a pivotal phase for the formation and growth of the neonatal microbiome, profoundly impacting long-term health outcomes.

WHAT IS KNOWN

• The perinatal period is a critical phase for the development of the neonatal microbiome, with factors such as mode of delivery, maternal diet, antibiotic exposure, and feeding practices influencing its composition and diversity, which has significant implications for long-term health. • The neonatal microbiome plays a vital role in shaping the immune system, metabolism, and neurodevelopment of infants.

WHAT IS NEW

• Recent studies have highlighted the potential of targeted interventions, such as probiotic and prebiotic supplementation, and innovative practices like maternal vaginal seeding, to optimize microbiome development during the perinatal period. • Emerging evidence suggests that specific bacterial genera and species within the neonatal microbiome are associated with reduced risks of developing chronic conditions, indicating new avenues for promoting long-term health starting from early life.

Glycaemic sugar metabolism and the gut microbiota: past, present and future

Non-communicable diseases (NCDs), such as type 2 diabetes (T2D) and metabolic dysfunction-associated fatty liver disease, have reached epidemic proportions worldwide. The global increase in dietary sugar consumption, which is largely attributed to the production and widespread use of cheap alternatives such as high-fructose corn syrup, is a major driving factor of NCDs. Therefore, a comprehensive understanding of sugar metabolism and its impact on host health is imperative to rise to the challenge of reducing NCDs. Notably, fructose appears to exert more pronounced deleterious effects than glucose, as hepatic fructose metabolism induces de novo lipogenesis and insulin resistance through distinct mechanisms. Furthermore, recent studies have demonstrated an intricate relationship between sugar metabolism and the small intestinal microbiota (SIM). In contrast to the beneficial role of colonic microbiota in complex carbohydrate metabolism, sugar metabolism by the SIM appears to be less beneficial to the host as it can generate toxic metabolites. These fermentation products can serve as a substrate for fatty acid synthesis, imposing negative health effects on the host. Nevertheless, due to the challenging accessibility of the small intestine, our knowledge of the SIM and its involvement in sugar metabolism remains limited. This review presents an overview of the current knowledge in this field along with implications for future research, ultimately offering potential therapeutic avenues for addressing NCDs.

Mixed species biofilm: Structure, challenge and its intricate involvement in hospital associated infections

Hospital associated infections or healthcare associated infections (HAIs) are a major threat to healthcare and medical management, mostly because of their recalcitrant nature. The primary cause of these HAIs is bacterial associations, especially the interspecies interactions. In interspecies interactions, more than one species co-exists in a common platform of extracellular polymeric substances (EPS), establishing a strong interspecies crosstalk and thereby lead to the formation of mixed species biofilms. In this process, the internal microenvironment and the surrounding EPS matrix of the biofilms ensure the protection of the microorganisms and allow them to survive under antagonistic conditions. The communications between the biofilm members as well as the interactions between the bacterial cells and the matrix polymers, also aid in the rigidity of the biofilm structure and allow the microorganisms to evade both the host immune response and a wide range of anti-microbials. Therefore, to design a treatment protocol for HAIs is difficult and it has become a growing point of concern. This review therefore first aims to discuss the role of microenvironment, molecular structure, cell-cell communication, and metabolism of mixed species biofilms in manifestation of HAIs. In addition, we discuss the electrochemical properties of mixed-species biofilms and their mechanism in developing drug resistance. Then we focus on the most dreaded bacterial HAI including oral and gut multi-species infections, catheter-associated urinary tract infections, surgical site infections, and ventilator-associated pneumonia. Further, we highlight the challenges to eradication of the mixed species biofilms and the current and prospective future strategies for the treatment of mixed species-associated HAI. Together, the review presents a comprehensive understanding of mixed species biofilm-mediated infections in clinical scenario, and summarizes the current challenge and prospect of therapeutic strategies against HAI.

Production of new functional coconut milk kefir with blueberry extract and microalgae: the comparison of the prebiotic potentials on lactic acid bacteria of kefir grain and biochemical characteristics

Probiotic foods are recognized for their importance on human health. Kefir is a versatile probiotic food that can be made from non-dairy sources for vegan diet. This study evaluated the addition of microalga Haematococcus pluvialis (0.50% w/v) and blueberry Vaccinium myrtillus (0.50% w/v) extracts to compare their influence on the biochemical properties and the bacterial community of coconut milk kefir through Nanopore-based DNA sequencing. Results revealed that the V. myrtillus increased the microbial diversity in coconut milk kefir with more abundant Proteobacteria species such as Lacticaseibacillus paracasei (22%) and Lactococcus lactis (6.3%). Microalga demonstrated the opposite effect on C, making Firmicutes represent the whole of the microbiota. Biochemical analysis revealed increased fat content in the kefir samples, with the C1 registering 1.62% and the 1.07% in C2, in contrast to the control group's 0.87% fat content. The crude protein content exhibited a decrease in both samples compared to the control group (0.00% and 0.88% versus 1.07%). These findings suggest that fortifying vegan kefir with prebiotics has the potential to induce significant alterations in the kefir microbiota.

Graphical abstract

Gram-negative bacterial colonization in the gut: Isolation, characterization, and identification of resistance mechanisms

BACKGROUND

The gut microbiome is made up of a diverse range of bacteria, especially gram-negative bacteria, and is crucial for human health and illness. There is a great deal of interest in the dynamic interactions between gram-negative bacteria and their host environment, especially considering antibiotic resistance. This work aims to isolate gram-negative bacteria that exist in the gut, identify their species, and use resistance-associated gene analysis to define their resistance mechanisms.

METHODS

Samples were collected from all patients who had a stool culture at a tertiary care center in Lebanon. Each type of bacteria that was identified from the stool samples was subjected to critical evaluations, and all discovered strains underwent antimicrobial susceptibility testing. Polymerase chain reaction was used to profile the genes for Carbapenem-resistant Enterobacteriaceae (CRE), Extended-spectrum beta-lactamase (ESBL), and that of Pseudomonas aeruginosa strains.

RESULTS

Escherichia coli, Klebsiella species, and Pseudomonas aeruginosa turned out to be the predominant microbiota members. Escherichia coli strains had a high frequency of extended-spectrum beta-lactamase genes, with the most discovered gene being bla CTX-M. Additionally, a considerable percentage of isolates had carbapenemase-resistant Enterobacteriaceae genes, suggesting the rise of multidrug-resistant strains. Multidrug resistance genes, such as bla mexR, bla mexB, and bla mexA, were found in strains of Pseudomonas aeruginosa, highlighting the possible difficulties in treating infections brought on by these bacteria.

CONCLUSION

The findings highlight the critical importance of effective surveillance and response measures to maintain the effectiveness of antibiotics considering the introduction of multidrug resistance genes in Pseudomonas aeruginosa and ESBL and CRE genes in Escherichia coli.

The connection between aging, cellular senescence and gut microbiome alterations: A comprehensive review

The intricate interplay between cellular senescence and alterations in the gut microbiome emerges as a pivotal axis in the aging process, increasingly recognized for its contribution to systemic inflammation, physiological decline, and predisposition to age-associated diseases. Cellular senescence, characterized by a cessation of cell division in response to various stressors, induces morphological and functional changes within tissues. The complexity and heterogeneity of senescent cells, alongside the secretion of senescence-associated secretory phenotype, exacerbate the aging process through pro-inflammatory pathways and influence the microenvironment and immune system. Concurrently, aging-associated changes in gut microbiome diversity and composition contribute to dysbiosis, further exacerbating systemic inflammation and undermining the integrity of various bodily functions. This review encapsulates the burgeoning research on the reciprocal relationship between cellular senescence and gut dysbiosis, highlighting their collective impact on age-related musculoskeletal diseases, including osteoporosis, sarcopenia, and osteoarthritis. It also explores the potential of modulating the gut microbiome and targeting cellular senescence as innovative strategies for healthy aging and mitigating the progression of aging-related conditions. By exploring targeted interventions, including the development of senotherapeutic drugs and probiotic therapies, this review aims to shed light on novel therapeutic avenues. These strategies leverage the connection between cellular senescence and gut microbiome alterations to advance aging research and development of interventions aimed at extending health span and improving the quality of life in the older population.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Intestinal microbiome as a diagnostic marker of coronary artery disease: a systematic review and meta-analysis

Background

The intestinal microbiome has been recently linked to several metabolic and chronic disorders, one of which is coronary artery disease (CAD). Our study aimed to analyze the intestinal microbiome of CAD patients and assess the eligibility of dysbiosis as a diagnostic marker of CAD.

Methods

PubMed, Scopus, Embase, and Web of Science were searched using terms, such as 'CAD' and 'microbiome'. Only observational controlled studies were included. R version 4.2.2 was used for the analysis.

Results

A significant association was found between the CAD group and increased Simpson and Shannon Indices compared with the control group (MD=0.04, 95% CI=0.03-0.05, and MD=0.11, 95% CI=0.01-0.22, respectively). Our analysis yielded a statistically significant association between the CAD group and increased Prevotella genus (MD=13.27, 95% CI=4.12-22.42, P-value=0.004), Catenibacterium genus (MD=0.09, 95% CI=0.09-0.10), Pseudomonas genus (MD=0.54, 95% CI=0.29-0.78, P-value), and Subdoligranulum (MD=-0.06, 95% CI=-0.06 to -0.06) compared with the control group. Another significant association was detected between the CAD group and decreased Bacteroides vulgatus and Bacteroides dorei (MD=-10.31, 95% CI=-14.78 to -5.84, P-value <0.00001).

Conclusion

Dysbiosis is an acceptable diagnostic marker of CAD. Decreased B. dorei and B. vulgatus among CAD patients suggests a protective role of these bacteria. Future clinical trials are necessary to investigate the potential benefit of supplementation of these bacteria in treating or preventing CAD.

Balancing the mind: Toward a complete picture of the interplay between gut microbiota, inflammation and major depressive disorder

The intricate interplay existing between gut microbiota and homeostasis extends to the realm of the brain, where emerging research underscores the significant impact of the microbiota on mood regulation and overall neurological well-being and vice-versa, with inflammation playing a pivotal role in mediating these complex interactions. This comprehensive review explores the complex interplay between inflammation, alterations in gut microbiota, and their impact on major depressive disorder (MDD). It provides a cohesive framework for the puzzle pieces of this triad, emphasizing recent advancements in understanding the gut microbiota and inflammatory states' contribution to the depressive features. Two directions of communication between the gut and the brain in depression are discussed, with inflammation serving as a potential modulator. Therapeutic implications were discussed as well, drawing insights from interventional studies on the effects of probiotics on gut bacterial composition and depressive symptoms. Ultimately, this review will attempt to provide a complete and valuable framework for future research and therapeutic interventions in MDD.

A comprehensive review on the pharmacological role of gut microbiome in neurodegenerative disorders: potential therapeutic targets

Neurological disorders, including Alzheimer and Parkinson's, pose significant challenges to public health due to their complex etiologies and limited treatment options. Recent advances in research have highlighted the intricate bidirectional communication between the gut microbiome and the central nervous system (CNS), revealing a potential therapeutic avenue for neurological disorders. Thus, this review aims to summarize the current understanding of the pharmacological role of gut microbiome in neurological disorders. Mounting evidence suggests that the gut microbiome plays a crucial role in modulating CNS function through various mechanisms, including the production of neurotransmitters, neuroactive metabolites, and immune system modulation. Dysbiosis, characterized by alterations in gut microbial composition and function, has been observed in many neurological disorders, indicating a potential causative or contributory role. Pharmacological interventions targeting the gut microbiome have emerged as promising therapeutic strategies for neurological disorders. Probiotics, prebiotics, antibiotics, and microbial metabolite-based interventions have shown beneficial effects in animal models and some human studies. These interventions aim to restore microbial homeostasis, enhance microbial diversity, and promote the production of beneficial metabolites. However, several challenges remain, including the need for standardized protocols, identification of specific microbial signatures associated with different neurological disorders, and understanding the precise mechanisms underlying gut-brain communication. Further research is necessary to unravel the intricate interactions between the gut microbiome and the CNS and to develop targeted pharmacological interventions for neurological disorders.

Robust prediction of colorectal cancer via gut microbiome 16S rRNA sequencing data

Introduction. The study addresses the challenge of utilizing human gut microbiome data for the early detection of colorectal cancer (CRC). The research emphasizes the potential of using machine learning techniques to analyze complex microbiome datasets, providing a non-invasive approach to identifying CRC-related microbial markers.Hypothesis/Gap Statement. The primary hypothesis is that a robust machine learning-based analysis of 16S rRNA microbiome data can identify specific microbial features that serve as effective biomarkers for CRC detection, overcoming the limitations of classical statistical models in high-dimensional settings.Aim. The primary objective of this study is to explore and validate the potential of the human microbiome, specifically in the colon, as a valuable source of biomarkers for colorectal cancer (CRC) detection and progression. The focus is on developing a classifier that effectively predicts the presence of CRC and normal samples based on the analysis of three previously published faecal 16S rRNA sequencing datasets.Methodology. To achieve the aim, various machine learning techniques are employed, including random forest (RF), recursive feature elimination (RFE) and a robust correlation-based technique known as the fuzzy forest (FF). The study utilizes these methods to analyse the three datasets, comparing their performance in predicting CRC and normal samples. The emphasis is on identifying the most relevant microbial features (taxa) associated with CRC development via partial dependence plots, i.e. a machine learning tool focused on explainability, visualizing how a feature influences the predicted outcome.Results. The analysis of the three faecal 16S rRNA sequencing datasets reveals the consistent and superior predictive performance of the FF compared to the RF and RFE. Notably, FF proves effective in addressing the correlation problem when assessing the importance of microbial taxa in explaining the development of CRC. The results highlight the potential of the human microbiome as a non-invasive means to detect CRC and underscore the significance of employing FF for improved predictive accuracy.Conclusion. In conclusion, this study underscores the limitations of classical statistical techniques in handling high-dimensional information such as human microbiome data. The research demonstrates the potential of the human microbiome, specifically in the colon, as a valuable source of biomarkers for CRC detection. Applying machine learning techniques, particularly the FF, is a promising approach for building a classifier to predict CRC and normal samples. The findings advocate for integrating FF to overcome the challenges associated with correlation when identifying crucial microbial features linked to CRC development.

Effects of metformin on the glucose regulation, lipid levels and gut microbiota in high-fat diet with streptozotocin induced type 2 diabetes mellitus rats

OBJECTIVE

Metformin, an anti-diabetic drug, regulates blood glucose by affecting gut microbiotas. However, the potential mechanism underlying this effect remains unclear. This study aimed to evaluate the effect of metformin on glucose regulation, lipid levels, and the gut microbiota in rats with type 2 diabetes mellitus induced by a high-fat diet with streptozotocin.

RESEARCH DESIGN METHODS

Thirty Wistar rats was using in this experiment. T2DM rats were administered 300 mg/kg metformin for 8 weeks. The glucose regulation, lipid levels, organ coefficients, and gut microbiotawere measured by 16S rDNA.

RESULT

The metformin-gavaged rats exhibited significant improvements in blood glucose and serum lipid levels, accompanied by alterations in short-chain fatty acid levels and the intestinal microbiota (p < 0.05). In the diabetic rats, metformin potentially increased specific probiotics, thus improving the hypoglycaemic effects of the oral anti-diabetic drug. Further, damage to the liver and kidney was effectively alleviated in the metformin-gavaged rats.

CONCLUSION

This study's findings demonstrate that metformin exerts a positive anti-diabetic effect in HFD- and STZ-induced T2DM rats. These findings potentially provide a basis for the recommended use of metformin as a reliable oral drug for T2DM owing to its positive effect on the intestinal microbiota.

Gut Microbes in Polycystic Ovary Syndrome and Associated Comorbidities; Type 2 Diabetes, Non-Alcoholic Fatty Liver Disease (NAFLD), Cardiovascular Disease (CVD), and the Potential of Microbial Therapeutics

Polycystic ovary syndrome (PCOS) is one of the most common endocrine anomalies among females of reproductive age, highlighted by hyperandrogenism. PCOS is multifactorial as it can be associated with obesity, insulin resistance, low-grade chronic inflammation, and dyslipidemia. PCOS also leads to dysbiosis by lowering microbial diversity and beneficial microbes, such as Faecalibacterium, Roseburia, Akkermenisa, and Bifidobacterium, and by causing a higher load of opportunistic pathogens, such as Escherichia/Shigella, Fusobacterium, Bilophila, and Sutterella. Wherein, butyrate producers and Akkermansia participate in the glucose uptake by inducing glucagon-like peptide-1 (GLP-1) and glucose metabolism, respectively. The abovementioned gut microbes also maintain the gut barrier function and glucose homeostasis by releasing metabolites such as short-chain fatty acids (SCFAs) and Amuc_1100 protein. In addition, PCOS-associated gut is found to be higher in gut-microbial enzyme β-glucuronidase, causing the de-glucuronidation of conjugated androgen, making it susceptible to reabsorption by entero-hepatic circulation, leading to a higher level of androgen in the circulatory system. Overall, in PCOS, such dysbiosis increases the gut permeability and LPS in the systemic circulation, trimethylamine N-oxide (TMAO) in the circulatory system, chronic inflammation in the adipose tissue and liver, and oxidative stress and lipid accumulation in the liver. Thus, in women with PCOS, dysbiosis can promote the progression and severity of type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular diseases (CVD). To alleviate such PCOS-associated complications, microbial therapeutics (probiotics and fecal microbiome transplantation) can be used without any side effects, unlike in the case of hormonal therapy. Therefore, this study sought to understand the mechanistic significance of gut microbes in PCOS and associated comorbidities, along with the role of microbial therapeutics that can ease the life of PCOS-affected women.

Exploring Anticancer Potential of Lactobacillus Strains: Insights into Cytotoxicity and Apoptotic Mechanisms on HCT 115 Cancer Cells

Introduction

This study aims to systematically assess the anticancer potential of distinct Lactobacillus strains on Human Colorectal Tumor (HCT) 115 cancer cells, with a primary focus on the apoptotic mechanisms involved. Lactobacillus strains were isolated from sheep milk and underwent a meticulous microbial isolation process. Previous research indicates that certain probiotic bacteria, including Lactobacillus species, may exhibit anticancer properties through mechanisms such as apoptosis induction. However, there is limited understanding of how different Lactobacillus strains exert these effects on cancer cells and the underlying molecular pathways involved.

Methods

Cytotoxicity was evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and exposure durations of Lactobacillus cell-free lyophilized filtrates. Additional apoptotic features were characterized using 4.6-diamidino-2-phenylindole (DAPI) analysis for nuclear fragmentation and Annexin V/PI analysis for apoptosis quantification. Genetic analysis explored the modulation of apoptotic proteins (Bax and Bcl2) in response to Lactobacillus treatment. Whole-genome sequencing (WGS) was performed to understand the genetic makeup of the Lactobacillus strains used in the study.

Results

The study demonstrated a significant reduction in HCT 115 cell viability, particularly with L. plantarum, as evidenced by Sulforhodamine B (SRB) and MTT assays. DAPI analysis revealed nuclear fragmentation, emphasizing an apoptotic cell death mechanism. Annexin V/PI analysis supported this, showing a higher percentage of early and late apoptosis in L. plantarum-treated cells. Genetic analysis uncovered up-regulation of pro-apoptotic protein Bax and down-regulation of anti-apoptotic protein Bcl2 in response to Lactobacillus treatment. WGS study revealed a strain reported to NCBI PRJNA439183.

Discussion

L. plantarum emerged as a potent antiproliferative agent against HCT 115 cancer cells, inducing apoptosis through intricate molecular mechanisms. This study underscores the scientific basis for L. plantarum's potential role in cancer therapeutics, highlighting its impact on antiproliferation, adhesion, and gene-protein regulation. Further research is warranted to elucidate the specific molecular pathways involved and to evaluate the therapeutic potential of L. plantarum in preclinical and clinical settings.

From gut to bone: deciphering the impact of gut microbiota on osteoporosis pathogenesis and management

Osteoporosis (OP) is characterized by decreased bone mineral density (BMD) and increased fracture risk, poses a significant global health burden. Recent research has shed light on the bidirectional relationship between gut microbiota (GM) and bone health, presenting a novel avenue for understanding OP pathogenesis and developing targeted therapeutic interventions. This review provides a comprehensive overview of the GM-bone axis, exploring the impact of GM on OP development and management. We elucidate established risk factors and pathogenesis of OP, delve into the diversity and functional changes of GM in OP. Furthermore, we examine experimental evidence and clinical observations linking alterations in GM composition or function with variations in BMD and fracture risk. Mechanistic insights into microbial mediators of bone health, such as microbial metabolites and products, are discussed. Therapeutic implications, including GM-targeted interventions and dietary strategies, are also explored. Finally, we identify future research directions and challenges in translating these findings into clinical practice.

Neonatal gut microbiota profile and the association with retinopathy of prematurity in preterm infants

BACKGROUND

To explore the role of gut microbiota in preterm infants at high risk of developing retinopathy of prematurity (ROP).

METHODS

Preterm infants with gestational age (GA) < 32 weeks and/or birth weight (BW) < 1500 g born between 2020 and 2021 were prospectively enrolled. Their faecal samples were collected and analysed at different postnatal ages of life using 16S rRNA gene sequencing on the Miseq platform. The main outcome measures were the microbial diversity, taxonomy, relative abundance, bacterial predicted functional analysis, and their associations with different ROP groups. Subgroup analyses were performed by matching their GA and BW across different ROP groups.

RESULTS

A total of 268 stool samples were collected from 110 preterm infants, including 13 with type 1 ROP, 44 with type 2 or mild ROP, and 53 without ROP. Type 1 ROP showed no significant difference in microbial diversity up to 8 postnatal weeks (p = 0.057), while type 2 and no ROP groups displayed increased diversity (p = 0.0015 and p = 0.049, respectively). Bifidobacterium genera was notably less abundant in type 1 ROP group at first postnatal week (p = 0.022) and remained low in subsequent weeks. Predicted functional analysis revealed enriched pathways in membrane transport, carbohydrate metabolism, amino acid metabolism, and replication and repair.

CONCLUSIONS

Reduced gut microbial diversity may be associated with ROP development in high-risk preterm infants. Further research is needed to comprehend how early-life Bifidobacterium reduction affects metabolism and how targeting microbiome may help for ROP prevention and management.

Role of Gut Microbial Metabolites in Cardiovascular Diseases-Current Insights and the Road Ahead

Cardiovascular diseases (CVDs) are the leading cause of premature morbidity and mortality globally. The identification of novel risk factors contributing to CVD onset and progression has enabled an improved understanding of CVD pathophysiology. In addition to the conventional risk factors like high blood pressure, diabetes, obesity and smoking, the role of gut microbiome and intestinal microbe-derived metabolites in maintaining cardiovascular health has gained recent attention in the field of CVD pathophysiology. The human gastrointestinal tract caters to a highly diverse spectrum of microbes recognized as the gut microbiota, which are central to several physiologically significant cascades such as metabolism, nutrient absorption, and energy balance. The manipulation of the gut microbial subtleties potentially contributes to CVD, inflammation, neurodegeneration, obesity, and diabetic onset. The existing paradigm of studies suggests that the disruption of the gut microbial dynamics contributes towards CVD incidence. However, the exact mechanistic understanding of such a correlation from a signaling perspective remains elusive. This review has focused upon an in-depth characterization of gut microbial metabolites and their role in varied pathophysiological conditions, and highlights the potential molecular and signaling mechanisms governing the gut microbial metabolites in CVDs. In addition, it summarizes the existing courses of therapy in modulating the gut microbiome and its metabolites, limitations and scientific gaps in our current understanding, as well as future directions of studies involving the modulation of the gut microbiome and its metabolites, which can be undertaken to develop CVD-associated treatment options. Clarity in the understanding of the molecular interaction(s) and associations governing the gut microbiome and CVD shall potentially enable the development of novel druggable targets to ameliorate CVD in the years to come.

Microbiome as an endocrine organ and its relationship with eye diseases: Effective factors and new targeted approaches

Microbiome is an endocrine organ that refers to both the complicated biological system of microbial species that colonize our bodies and their genomes and surroundings. Recent studies confirm the connection between the microbiome and eye diseases, which are involved in the pathogenesis of eye diseases, including age-related macular disorders, diabetic retinopathy, glaucoma, retinitis pigmentosa, dry eye, and uveitis. The aim of this review is to investigate the microbiome in relation to eye health. First, a brief introduction of the characteristics of the gut microorganisms terms of composition and work, the role of dysbiosis, the gut microbiome and the eye microbiome in the progression of eye illnesses are highlighted, then the relationship among the microbiome and the function of the immune system and eye diseases, the role of inflammation and aging and the immune system, It has been reviewed and finally, the control and treatment goals of microbiome and eye diseases, the role of food factors and supplements, biotherapy and antibiotics in relation to microbiome and eye health have been reviewed.

Advances in the pharmacological mechanisms of berberine in the treatment of fibrosis

The rising incidence of fibrosis poses a major threat to global public health, and the continuous exploration of natural products for the effective treatment of fibrotic diseases is crucial. Berberine (BBR), an isoquinoline alkaloid, is widely used clinically for its anti-inflammatory, anti-tumor and anti-fibrotic pharmacological effects. Until now, researchers have worked to explore the mechanisms of BBR for the treatment of fibrosis, and multiple studies have found that BBR attenuates fibrosis through different pathways such as TGF-β/Smad, AMPK, Nrf2, PPAR-γ, NF-κB, and Notch/snail axis. This review describes the anti-fibrotic mechanism of BBR and its derivatives, and the safety evaluation and toxicity studies of BBR. This provides important therapeutic clues and strategies for exploring new drugs for the treatment of fibrosis. Nevertheless, more studies, especially clinical studies, are still needed. We believe that with the continuous implementation of high-quality studies, significant progress will be made in the treatment of fibrosis.

Appraisal of postbiotics in cancer therapy

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

Engineering bacterial theranostics: from logic gates to in vivo applications

Over the past 2 decades, rapid advances in synthetic biology have enabled the design of increasingly intricate and biologically relevant systems with broad applications in healthcare. A growing area of interest is in designing bacteria that sense and respond to endogenous disease-associated signals, creating engineered theranostics that function as disease surveyors for human health. In particular, engineered cells hold potential in facilitating greatly enhanced temporal and spatial control over the release of a range of therapeutics. Such systems are particularly useful for targeting challenging, under-drugged disease targets in a more nuanced manner than is currently possible. This review provides an overview of the recent advances in the design, delivery, and dynamics of bacterial theranostics to enable safe, robust, and genetically tractable therapies to treat disease. It outlines the primary challenges in theranostic clinical translation, proposes strategies to overcome these issues, and explores promising future avenues for the field.

Limited support for a direct connection between prebiotics and intestinal permeability - a systematic review

The intestinal barrier is a selective interface between the body´s external and the internal environment. Its layer of epithelial cells is joined together by tight junction proteins. In intestinal permeability (IP), the barrier is compromised, leading to increased translocation of luminal contents such as large molecules, toxins and even microorganisms. Numerous diseases including Inflammatory Bowel Disease (IBD), Coeliac disease (CD), autoimmune disorders, and diabetes are believed to be associated with IP. Dietary interventions, such as prebiotics, may improve the intestinal barrier. Prebiotics are non-digestible food compounds, that promote the growth and activity of beneficial bacteria in the gut. This systematic review assesses the connection between prebiotic usage and IP. PubMed and Trip were used to identify relevant studies conducted between 2010-2023. Only six studies were found, which all varied in the characteristics of the population, study design, and types of prebiotics interventions. Only one study showed a statistically significant effect of prebiotics on IP. Alteration of intestinal barrier function was measured by lactulose/mannitol, chromium-labelled Ethylenediaminetetraacetic acid (51Cr-EDTA), lactulose/rhamnose, and sucralose/erythritol excretion as well as zonulin and glucagon-like peptide 2 levels. Three studies also conducted gut microbiota assessment, and one of them showed statistically significant improvement of the gut microbiome. This study also reported a decrease in zonulin level. The main conclusion from this review is that there is a lack of human studies in this important field. Futhermore, large population studies and using standardized protocols, would be required to properly assess the impact of prebiotic intervention and improvement on IP.

The Effect of Dietary Types on Gut Microbiota Composition and Development of Non-Communicable Diseases: A Narrative Review

INTRODUCTION

The importance of diet in shaping the gut microbiota is well established and may help improve an individual's overall health. Many other factors, such as genetics, age, exercise, antibiotic therapy, or tobacco use, also play a role in influencing gut microbiota.

AIM

This narrative review summarizes how three distinct dietary types (plant-based, Mediterranean, and Western) affect the composition of gut microbiota and the development of non-communicable diseases (NCDs).

METHODS

A comprehensive literature search was conducted using the PubMed, Web of Science, and Scopus databases, focusing on the keywords "dietary pattern", "gut microbiota" and "dysbiosis".

RESULTS

Both plant-based and Mediterranean diets have been shown to promote the production of beneficial bacterial metabolites, such as short-chain fatty acids (SCFAs), while simultaneously lowering concentrations of trimethylamine-N-oxide (TMAO), a molecule associated with negative health outcomes. Additionally, they have a positive impact on microbial diversity and therefore are generally considered healthy dietary types. On the other hand, the Western diet is a typical example of an unhealthy nutritional approach leading to an overgrowth of pathogenic bacteria, where TMAO levels rise and SCFA production drops due to gut dysbiosis.

CONCLUSION

The current scientific literature consistently highlights the superiority of plant-based and Mediterranean dietary types over the Western diet in promoting gut health and preventing NCDs. Understanding the influence of diet on gut microbiota modulation may pave the way for novel therapeutic strategies.

Depletion of the paternal gut microbiome alters sperm small RNAs and impacts offspring physiology and behavior in mice

The paternal environment prior to conception has been demonstrated to influence offspring physiology and behavior, with the sperm epigenome (including noncoding RNAs) proposed as a potential facilitator of non-genetic inheritance. Whilst the maternal gut microbiome has been established as an important influence on offspring development, the impact of the paternal gut microbiome on offspring development, health and behavior is largely unknown. Gut microbiota have major influences on immunity, and thus we hypothesized that they may be relevant to paternal immune activation (PIA) modulating epigenetic inheritance in mice. Therefore, male C57BL/6J mice (F0) were orally administered non-absorbable antibiotics via drinking water in order to substantially deplete their gut microbiome. Four weeks after administration of the antibiotics (gut microbiome depletion), F0 male mice were then mated with naïve female mice. The F1 offspring of the microbiome-depleted males had reduced body weight as well as altered gut morphology (shortened colon length). F1 females showed significant alterations in affective behaviors, including measures of anxiety and depressive-like behaviors, indicating altered development. Analysis of small noncoding RNAs in the sperm of F0 mice revealed that gut microbiome depletion is associated with differential expression of 8 different PIWI-interacting RNAs (piRNAs), each of which has the potential to modulate the expression of multiple downstream gene targets, and thus influence epigenetic inheritance and offspring development. This study demonstrates that the gut-germline axis influences sperm small RNA profiles and offspring physiology, with specific impacts on offspring affective and/or coping behaviors. These findings may have broader implications for other animal species with comparable gut microbiota, intergenerational epigenetics and developmental biology, including humans.

Metabolic mediators: microbial-derived metabolites as key regulators of anti-tumor immunity, immunotherapy, and chemotherapy

The human microbiome has recently emerged as a focal point in cancer research, specifically in anti-tumor immunity, immunotherapy, and chemotherapy. This review explores microbial-derived metabolites, emphasizing their crucial roles in shaping fundamental aspects of cancer treatment. Metabolites such as short-chain fatty acids (SCFAs), Trimethylamine N-Oxide (TMAO), and Tryptophan Metabolites take the spotlight, underscoring their diverse origins and functions and their profound impact on the host immune system. The focus is on SCFAs' remarkable ability to modulate immune responses, reduce inflammation, and enhance anti-tumor immunity within the intricate tumor microenvironment (TME). The review critically evaluates TMAO, intricately tied to dietary choices and gut microbiota composition, assessing its implications for cancer susceptibility, progression, and immunosuppression. Additionally, the involvement of tryptophan and other amino acid metabolites in shaping immune responses is discussed, highlighting their influence on immune checkpoints, immunosuppression, and immunotherapy effectiveness. The examination extends to their dynamic interaction with chemotherapy, emphasizing the potential of microbial-derived metabolites to alter treatment protocols and optimize outcomes for cancer patients. A comprehensive understanding of their role in cancer therapy is attained by exploring their impacts on drug metabolism, therapeutic responses, and resistance development. In conclusion, this review underscores the pivotal contributions of microbial-derived metabolites in regulating anti-tumor immunity, immunotherapy responses, and chemotherapy outcomes. By illuminating the intricate interactions between these metabolites and cancer therapy, the article enhances our understanding of cancer biology, paving the way for the development of more effective treatment options in the ongoing battle against cancer.

The inhibitory effects of the novel Lactobacillus cocktail on colorectal cancer development through modulating BMP signaling pathway: In vitro and in vivo study

This study investigates the impact of a five-strain Lactobacillus cocktail (comprising two strains of L. plantarum, and one strain each of L. brevis, L. reuteri, and L. rhamnosus) on colorectal cancer (CRC) modulation by targeting the bone morphogenetic proteins (BMP) signaling pathway. Both in vitro and in vivo (models were employed. The antiproliferative effects of the Lactobacillus cocktail on HT-29 cells were assessed via the MTT assay. Mice were divided into three groups: a negative control (treated with PBS), a positive control (treated with azoxymethane (AOM)/dextran sulfate sodium (DSS) + PBS), and a test group (treated with AOM/DSS + Lactobacillus cocktail in PBS). The role of the Lactobacillus cocktail in inhibiting the BMP signaling pathway was evaluated using qRT-PCR for gene expression analysis and western blotting for β-catenin protein assessment in both models. The MTT assay results demonstrated a significant, time-dependent reduction in HT-29 cell proliferation. qRT-PCR indicated downregulation of the BMP signaling pathway in treated cells, which subsequently led to decreased expression of the hes1 gene, crucial for cell differentiation and proliferation control. This inhibitory effect was corroborated in the mice model, showing significant downregulation of BMP pathway genes and hes1 in the AOM/DSS/Lactobacillus cocktail-treated group. Additionally, western blotting revealed a marked decrease in β-catenin expression in both in vitro and in vivo experiments. Collectively, these findings suggest that the Lactobacillus cocktail may aid in CRC prevention by downregulating the BMP signaling pathway.

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

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

Contributions of multiple transport mechanisms to intestinal uptake of serotonin

This study aimed to analyze the contributions of multiple transport mechanisms to the intestinal uptake of serotonin (5-HT) by employing a variety of in vitro experimental techniques, focusing on organic cation transporters expressed in the gastrointestinal (GI) tract, such as SERT, PMAT, THTR2, OCT3, and OCTN2. Analysis of the concentration dependence of 5-HT uptake by Caco-2 cells revealed multi-affinity kinetics with high-affinity and low-affinity components, suggesting that multiple transporters are involved in the intestinal 5-HT uptake. Comparative analysis of transporters using Km values obtained in Xenopus oocyte expression systems suggested that SERT is responsible for the high-affinity transport, while PMAT, THTR2, and OCT3 contribute to the low-affinity transport. Further analysis indicated that the relative contributions of SERT and PMAT to the intestinal 5-HT uptake (0.01 µM) are approximately 94.9% and 1.1%, respectively. Interestingly, at the concentration of 10 µM, the reported steady-state concentration of 5-HT in the human colon, the contributions of SERT, PMAT, THTR2, and OCT3 were estimated to be approximately 37.0%, 1.0%, 18.2%, and 20.5%, respectively. In conclusion, the present study indicated that the contributions of multiple transporters to 5-HT uptake in the GI tract are dependent upon the colon luminal concentration of 5-HT.

The complex interplay between autism spectrum disorder and gut microbiota in children: A comprehensive review

Autism spectrum disorder (ASD) is characterized by defects in social communication and interaction along with restricted interests and/or repetitive behavior. Children with ASD often also experience gastrointestinal (GI) problems in fact incidence of GI problems in ASD is estimated up to 80 percent. Intestinal microbiota, which is a collection of trillions of microorganisms both beneficial and potentially harmful bacteria living inside the gut, has been considered one of the key elements of gut disorders. The goal of this review is to explore potential link between gut microbiota and ASD in children, based on the recently available data. This review discusses recent advances in this rapidly expanding area of neurodevelopmental disorders, which focuses on what is known about the changes in composition of gut bacteria in children with ASD, exploration of possible mechanisms via which gut microbiota might influence the brain and thus lead to appearance of ASD symptoms, as well as potential treatments that involve modulation of gut flora to improve symptoms in children with ASD, i.e., probiotics, postbiotics or changes in the diet. Of course, it's important to keep in mind inherent difficulties in proving of existence of causal relationships between gut bacteria and ASD. There are significant gaps in understanding of the mechanism of gut-brain axis and the mechanisms that underlie ASD. Standardized approaches for research in this area are needed. This review would provide an overview of this exciting emerging field of research.

The role of gut-derived short-chain fatty acids in Parkinson's disease

The emerging function of short-chain fatty acids (SCFAs) in Parkinson's disease (PD) has been investigated in this article. SCFAs, which are generated via the fermentation of dietary fiber by gut microbiota, have been associated with dysfunction of the gut-brain axis and, neuroinflammation. These processes are integral to the development of PD. This article examines the potential therapeutic implications of SCFAs in the management of PD, encompassing their capacity to modulate gastrointestinal permeability, neuroinflammation, and neuronal survival, by conducting an extensive literature review. As a whole, this article emphasizes the potential therapeutic utility of SCFAs as targets for the management and treatment of PD.

First Molecular Detection and Genetic Characterization of Tetratrichomonas buttreyi and Pentatrichomonas hominis in Donkeys in Shanxi Province, China

Two species of trichomonads, Tetratrichomonas buttreyi and Pentatrichomonas hominis, are common intestinal parasites that can impact animal health and productivity. Severe infection by these parasites can lead to diarrhea and wasting in affected animals. Notably, P. hominis is known to cause diarrhea and has the potential to be transmitted between animals and humans. Donkeys hold significant economic importance in China's agricultural sector. However, whether donkeys are infected with T. buttreyi and P. hominis remains unknown globally. To address this gap in knowledge, 815 fecal samples were collected from donkeys in three representative regions in Shanxi Province, North China. Then, the presence and genetic characteristics of T. buttreyi and P. hominis were examined using species-specific PCR primers amplifying the small subunit ribosomal RNA genes. The overall prevalence was detected to be 25.4% (207/815) for T. buttreyi and 0.7% (6/815) for P. hominis in donkeys in Shanxi Province. All obtained P. hominis sequences were identified as genotype CC1. Genetic analysis revealed that all P. hominis isolates from donkeys were clustered into the same branch with isolates detected in humans, suggesting possible zoonotic transmission. This study is the first to report the occurrence and prevalence of T. buttreyi and P. hominis in donkeys globally. These findings expand the host range of trichomonads and improve our understanding of their genetic diversity and zoonotic potential, providing essential baseline data for the prevention and control of these parasites in donkeys in the region.

Population-specific differences in the human microbiome: Factors defining the diversity

Differences in microbial communities at different body habitats define the microbiome composition of the human body. The gut, oral, skin vaginal fluid and tissue microbiome, are pivotal for human development and immune response and cross talk between these microbiomes is evident. Population studies reveal that various factors, such as host genetics, diet, lifestyle, aging, and geographical location are strongly associated with population-specific microbiome differences. The present review discusses the factors that shape microbiome diversity in humans, and microbiome differences in African, Asian and Caucasian populations. Gut microbiome studies show that microbial species Bacteroides is commonly found in individuals living in Western countries (Caucasian populations), while Prevotella is prevalent in non-Western countries (African and Asian populations). This association is mainly due to the high carbohydrate, high fat diet in western countries in contrast to high fibre, low fat diets in African/ Asian regions. Majority of the microbiome studies focus on the bacteriome component; however, interesting findings reveal that increased bacteriophage richness, which makes up the virome component, correlates with decreased bacterial diversity, and causes microbiome dysbiosis. An increase of Caudovirales (bacteriophages) is associated with a decrease in enteric bacteria in inflammatory bowel diseases. Future microbiome studies should evaluate the interrelation between bacteriome and virome to fully understand their significance in the pathogenesis and progression of human diseases. With ethnic health disparities becoming increasingly apparent, studies need to emphasize on the association of population-specific microbiome differences and human diseases, to develop microbiome-based therapeutics. Additionally, targeted phage therapy is emerging as an attractive alternative to antibiotics for bacterial infections. With rapid rise in microbiome research, focus should be on standardizing protocols, advanced bioinformatics tools, and reducing sequencing platform related biases. Ultimately, integration of multi-omics data (genomics, transcriptomics, proteomics and metabolomics) will lead to precision models for personalized microbiome therapeutics advancement.

Intestinal Dysbiosis: Exploring Definition, Associated Symptoms, and Perspectives for a Comprehensive Understanding - a Scoping Review

Dysbiosis is a clinical condition marked by altered gut microbiota resulting from external and internal host factors. It is strongly associated with gastrointestinal and extraintestinal alterations, so its symptomatology is broad and nonspecific. To date, gaps remain that limit professionals from making a timely diagnosis and prescribing the appropriate treatment. We aim to synthesize existing literature regarding clinical parameters for the early detection of patients with intestinal dysbiosis and the clinical events in which the use of probiotics as adjuvant therapy is most frequently reported. A scoping review of the literature was conducted in PubMed, Embase, Cochrane, and BVS (Biblioteca Virtual en Salud in Spanish) databases for articles published in the last 5 years. Primary studies and literature reviews related to clinical presentation, dysbiosis screening, and probiotics as adjuvant therapy for adult and pediatric patients were included. Twenty-three articles were retrieved in which the most frequently reported symptoms were abdominal distension, abdominal pain, and diarrhea. Chronic and metabolic diseases where the conditions most strongly associated with dysbiosis. Depending on symptomatology and etiology, dysbiosis is often treated with probiotics. Dysbiosis, often linked to diarrhea, should be considered with other symptoms like abdominal distension and pain, along with predisposing conditions and patient risk factors. Probiotics are commonly used as co-adjuvant treatments for antibiotic-associated diarrhea, irritable bowel syndrome, and childhood allergic diseases. The most commonly used probiotics were Weizmannia coagulans (formerly B. coagulans), Alkalihalobacillus clausii (formerly Bacillus clausii), Lacticaseibacillus rhamnosus, Limosilactobacillus reuteri, and Saccharomyces boulardii.

Mapping the relationship between atopic dermatitis and gut microbiota: a bibliometric analysis, 2014-2023

Background

Atopic dermatitis (AD) is a chronic inflammatory skin condition affecting a significant portion of the population, with prevalence rates of 25% in children and 7-10% in adults. AD not only poses physical challenges but also profoundly impacts patients' mental well-being and quality of life. The stability of gut microbiota is crucial for overall health and can influence AD progression by modulating immune function, skin barrier integrity, and neuroendocrine signaling, which may be an effective target for the prevention and treatment of AD. Thus, exploring the interactions between AD and gut microbiota, particularly in infants, can provide insights into potential preventive and therapeutic strategies. This study aimed to explore the correlation between AD and gut microbiota while providing an overview of current research trends and emerging areas of interest in this field.

Methods

A comprehensive search was conducted on the Web of Science Core Collection (WOSCC) for relevant publications from January 1, 2014, to December 31, 2023. English-language articles and reviews were included. Two investigators independently screened the publications, and visual analysis was performed using CiteSpace, VOSviewer, Scimago Graphica, and Microsoft Excel software.

Results

A total of 804 articles were included, showing a significant increase in publications over the past decade. The United States, Wageningen University, and University Ulsan (represented by Hong SJ) had the highest number of published papers. Nutrients was the journal with the most publications, while the Journal of Allergy and Clinical Immunology had the highest number of citations and centrality among co-cited journals. Keyword visualization analysis identified "atopic dermatitis" and "gut microbiota" as central themes. Notably, there has been a notable shift in research focus over the years, with early studies concentrating on "Fecal microbiota," "caesarean section," and "first 6 months," while recent studies have highlighted the roles of "cells," "dysbiosis," and "prebiotics." This shift indicates growing interest in the underlying mechanisms and potential therapeutic interventions related to the intestinal microecology in AD treatment.

Conclusion

The field of AD and gut microbiota research has evolved significantly, with an increasing focus on understanding the intricate interactions between gut microbiota and AD pathogenesis. Recent years have witnessed increased interest in understanding the relationship between AD and gut microbiota, with researchers conducting extensive studies exploring various aspects of this connection. This review analyzes research trends over the past decade, highlighting trends and hotspots in the study of AD, particularly in infants, and the role of microbiota. This review serves as a valuable reference for future investigations, aiming to provide deeper insights into this burgeoning field and suggests directions for future research.

Specific gut microbiome's role in skin pigmentation: insights from SCARB1 mutants in Oujiang colour common carp

AIMS

Beyond the pivotal roles of the gut microbiome in initiating physiological processes and modulating genetic factors, a query persists: Can a single gene mutation alter the abundance of the gut microbiome community? Not only this, but the intricate impact of gut microbiome composition on skin pigmentation has been largely unexplored.

METHODS AND RESULTS

Based on these premises, our study examines the abundance of lipase-producing gut microbes about differential gene expression associated with bile acid synthesis and lipid metabolism-related blood metabolites in red (whole wild) and white (whole white wild and SCARB1-/- mutant) Oujiang colour common carp. Following the disruption of the SCARB1 gene in the resulting mutant fish with white body colour (SCARB1-/-), there is a notable decrease in the abundance of gut microbiomes (Bacillus, Staphylococcus, Pseudomonas, and Serratia) associated with lipase production. This reduction parallels the downregulation seen in wild-type white body colour fish (WW), as contrasting to the wild-type red body colour fish (WR). Meanwhile, in SCARB1-/- fish, there was a downregulation noted not only at the genetic and metabolic levels but also a decrease in lipase-producing bacteria. This consistency with WW contrasts significantly with WR. Similarly, genes involved in the bile acid synthesis pathway, along with blood metabolites related to lipid metabolism, exhibited downregulation in SCARB1-/- fish.

CONCLUSIONS

The SCARB1 knockout gene blockage led to significant alterations in the gut microbiome, potentially influencing the observed reduction in carotenoid-associated skin pigmentation. Our study emphasizes that skin pigmentation is not only impacted by genetic factors but also by the gut microbiome. Meanwhile, the gut microbiome's adaptability can be rapidly shaped and may be driven by specific single-gene variations.

Fecal Microbiota, Live-jslm for the Prevention of Recurrent Clostridioides difficile Infection : Subgroup Analysis of PUNCH CD2 and PUNCH CD3

GOALS

To assess fecal microbiota, live-jslm (REBYOTA, abbreviated as RBL, formerly RBX2660) efficacy and safety in participants grouped by recurrent Clostridioides difficile infection (rCDI) risk factors and treatment-related variables.

BACKGROUND

RBL is the first microbiota-based live biotherapeutic approved by the US Food and Drug Administration for the prevention of rCDI in adults after antibiotic treatment for rCDI.

STUDY

Treatment success rates across subgroups for PUNCH CD3 (NCT03244644) were estimated using a Bayesian hierarchical model, borrowing data from PUNCH CD2 (NCT02299570). Treatment-emergent adverse events were summarized for the double-blind treatment period within 8 weeks.

RESULTS

Treatment differences between RBL and placebo at 8 weeks were similar to the total population for most subgroups. Treatment effect sizes were similar between CDI tests, higher for oral vancomycin courses >14 days versus ≤14 days and higher for antibiotic washout periods of 3 days versus ≤2 days. The largest reductions in the rate of rCDI with RBL versus placebo were observed for participants with a 3-day CDI antibiotic washout period and participants with ≥4 previous CDI episodes. Most RBL-treated participants experienced TEAEs that were mild or moderate in severity and related to preexisting conditions.

CONCLUSION

This analysis provides further evidence of RBL efficacy and safety across subgroups, including those at high risk for rCDI.

Discrete interplay of gut microbiota L-tryptophan metabolites in host biology and disease

The gut microbiota and the host maintain a conjoint relationship and together achieve optimal physiology via a multitude of interactive signalling cues. Dietary-derived L-tryptophan (L-trp) is enzymatically metabolized by the resident symbiotic gut microbiota to indole and various indole derivatives. Indole and indole metabolites secreted by the gut bacteria act locally in the intestinal cells as well as distally and modulate tissue-specific functions which are beneficial to the host. Functions attributed to these microbial indole metabolites in the host include regulation of intestinal permeability, immunity and mucosal roles, inflammation, and insulin sensitivity. On the other hand, dysregulation of gut microbiota L-trp metabolism compromises the optimal availability of indole and indole metabolites and can induce the onset of metabolic disorders, inflammation, liver steatosis, and decrease gut barrier integrity. Gut dysbiosis is regarded as one of the prime reasons for this deregulated microbial-derived indole metabolites. A number of indole metabolites from the gut bacteria have been identified recently displaying variable affinity towards xenobiotic nuclear receptors. Microbial metabolite mimicry concept can be used to design and develop novel indole-moiety-containing compounds with higher affinity towards the receptors and efficacy in preclinical studies. Such compounds may serve as therapeutic drugs in clinical trials in the future. In this article, I review L-trp metabolism in the host and gut microbiota and the various physiological functions, patho-physiologies associated with the microbial-released indole metabolites in the host, including the metabolite mimicry-based concept to develop tailored indole-containing novel experimental drugs.

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

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