Gut Microbial Dysbiosis in the Pathogenesis of Gastrointestinal Dysmotility and Metabolic Disorders

Comparative analysis of gut microbiota in healthy and diarrheic foals

Diarrhea presents a substantial risk of high morbidity and mortality among foals. Although studies have shown connections between gut microbiota and several gastrointestinal diseases, there is still inadequate information on gut microbial alterations in foals during diarrhea. In this study, we conducted 16S rRNA and ITS gene amplicon sequencing to investigate gut bacterial and fungal differences between healthy and diarrheic foals. The results unveiled significant reductions in gut bacterial and fungal diversities among foals experiencing diarrhea, accompanied by notable shifts in the composition of gut microbial communities. A considerable decrease was observed in the relative abundance of 30 bacterial and 34 fungal genera. Moreover, two bacterial and eight fungal genera were utterly undetectable in the gut microbiota of diarrheic foals. Some decreased genera, such as Bifidobacterium and Saccharomyces, were deemed beneficial and recognized as probiotics. The study revealed significant alterations in foals' gut bacterial and fungal communities during diarrhea, which enriched our comprehension of gut microbial dynamics in foals across varying health statuses. These findings offer valuable insights for managing diarrhea through gut microbiota modulation, suggesting that probiotics may be superior to antibiotics in preventing and controlling foal diarrhea.IMPORTANCEThis research advances the understanding of gut bacterial and fungal dynamics in foals, highlighting gut microbiota dysbiosis as a potential contributor to foal diarrhea. Additionally, we observed that many altered bacteria and fungi were downregulated during diarrhea, including some probiotic strains. Consequently, our findings provide evidence that probiotics may offer superior efficacy compared with antibiotics as potential candidates for preventing and treating foal diarrhea.

Cross-talks between osteoporosis and gut microbiome

The gut microbiome comprises a vast community of microbes inhabiting the human alimentary canal, playing a crucial role in various physiological functions. These microbes generally live in harmony with the host; however, when dysbiosis occurs, it can contribute to the pathogenesis of diseases, including osteoporosis. Osteoporosis, a systemic skeletal disease characterized by reduced bone mass and increased fracture risk, has attracted significant research attention concerning the role of gut microbes in its development. Advances in molecular biology have highlighted the influence of gut microbiota on osteoporosis through mechanisms involving immunoregulation, modulation of the gut-brain axis, and regulation of the intestinal barrier and nutrient absorption. These microbes can enhance bone mass by inhibiting osteoclast differentiation, inducing apoptosis, reducing bone resorption, and promoting osteoblast proliferation and maturation. Despite these promising findings, the therapeutic effectiveness of targeting gut microbes in osteoporosis requires further investigation. Notably, gut microbiota has been increasingly studied for their potential in early diagnosis, intervention, and as an adjunct therapy for osteoporosis, suggesting a growing utility in improving bone health. Further research is essential to fully elucidate the therapeutic potential and clinical application of gut microbiome modulation in the management of osteoporosis.

Evaluating the Effect of Dietary Protein-Energy Ratios on Yak Intestinal Microbiota Using High-Throughput 16S rRNA Gene Sequencing

This study investigated the impact of varying dietary protein-energy ratios on the intestinal microbiota composition in postpartum weaned female yak. For this study, forty yaks were divided into four groups and provided with different dietary treatments (group FA: high-energy high-protein, FB: high-energy low-protein, FC: low-energy high-protein, and FD: control group, provided with 48% alfalfa hay, 48% oat grass, and 4% premix) to investigate the variations in microflora profiles and metabolic responses. Rectal fecal samples (n = 24 × 2) were collected at day 15 and 30, from all four groups, and total DNA was extracted to estimate microbial heterogeneity and community structures by 16S rRNA sequencing focusing V3-V4 regions, using the Illumina Nova Seq 6000 platform. The results revealed a total of 5,669,645 raw data sequences (3,189,115 and 2,480,530 from day 15 and day 30, respectively). Results showed that groups FA and FB had enhanced protein metabolism and microbial diversity, which was marked by a significant increase (p < 0.05) in abundance of Ruminococcus. Conversely, the FD group showed a low level of microbial diversity with a significant (p < 0.05) predominance of Clostridium and Proteobacteria, indicating microbial dysbiosis and metabolic stress. It was concluded that imbalanced diets (groups FC and FD) upregulated the stress-related pathways with no favorable microbial shifts, whereas, dietary treatments in group FA and FB significantly (p < 0.05) supported the pathways involved in amino acids and carbohydrate metabolism and beneficially shifted the gut microbiota. These findings emphasize the importance of postpartum supplementation with appropriate proportions of protein and energy feed to promote optimal microbial health and metabolic functioning, particularly for yaks inhabiting high-altitude regions, which is a challenging environment.

The link between obesity and the gut microbiota and immune system in early-life

In early-life, the gut microbiota is highly modifiable, being modulated by external factors such as maternal microbiota, mode of delivery, and feeding strategies. The composition of the child's gut microbiota will deeply impact the development and maturation of its immune system, with consequences for future health. As one of the main sources of microorganisms to the child, the mother represents a crucial factor in the establishment of early-life microbiota, impacting the infant's wellbeing. Recent studies have proposed that dysbiotic maternal gut microbiota could be transmitted to the offspring, influencing the development of its immunity, and leading to the development of diseases such as obesity. This paper aims to review recent findings in gut microbiota and immune system interaction in early-life, highlighting the benefits of a balanced gut microbiota in the regulation of the immune system.

Health effects of astaxanthin in the intestinal tract of yellow-feathered broilers

Astaxanthin (AST), a keto carotenoid, is widely recognized for its antioxidant, anti-inflammatory, and apoptosis-regulating properties, but its effects on intestinal health have not been elucidated. Therefore, this experiment aimed to investigate the effects of astaxanthin on intestinal morphology, barrier function, mucosal immunity, and cecal flora in yellow-feathered broilers, and to explore the potential mechanisms. A total of 288 male yellow-feathered broilers (1-day-old) were randomly allocated to four groups with six replicates of 12 birds each. The control group (CON) was fed a basal diet, the test groups were fed a basal diet added with 20 mg/kg, 40 mg/kg, and 80mg/kg of astaxanthin (AST20, AST40, and AST80), respectively. The results showed that compared with the CON group, the villus height and the villus-to-crypt ratio of broiler jejunum in the astaxanthin-added group increased, while the crypt depth decreased (P < 0.05). In addition, IL-1β content and gene expression in broiler jejunal mucosa decreased, IL-6 gene expression decreased, and IL-4 content and gene expression increased (P < 0.05). The tight junction protein ZO-1 expression level in the jejunum mucosa of broilers was up-regulated, and the content of serum D-lactic acid was decreased (P < 0.05). Besides, the α-diversity and β-diversity analyses showed that astaxanthin regulated both the diversity and the structure of the intestinal flora of broilers. After multiple comparative analyses, the relative abundance of norank_f__Eubacterium_coprostanoligenes_group, Lachnospiraceae NC2004_group, and unclassified_p_Firmicutes increased in the AST20 group compared to the CON group, while that of Ruminococcus_torques_group in the AST80 group decreased (P < 0.05). Therefore, AST can regulate the immune function of broiler intestinal mucosa, improve intestinal morphology and structure, and then influence intestinal permeability. It also has a considerable regulatory effect on the diversity and structure of broiler intestinal flora and plays a multifaceted role in maintaining broiler intestinal health.

Streptococcus salivarius and Ligilactobacillus salivarius: Paragons of Probiotic Potential and Reservoirs of Novel Antimicrobials

This review highlights several basic problems associated with bacterial drug resistance, including the decreasing efficacy of commercially available antimicrobials as well as the related problem of microbiome irregularity and dysbiosis. The article explains that this present situation is addressable through LAB species, such as Streptococcus salivarius and Ligilactobacillus salivarius, which are well established synthesizers of both broad- and narrow-spectrum antimicrobials. The sheer number of antimicrobials produced by LAB species and the breadth of their biological effects, both in terms of their bacteriostatic/bactericidal abilities and their immunomodulation, make them prime candidates for new probiotics and antibiotics. Given the ease with which several of the molecules can be biochemically engineered and the fact that many of these compounds target evolutionarily constrained target sites, it seems apparent that these compounds and their producing organisms ought to be looked at as the next generation of robust dual action symbiotic drugs.

Verification of the Utility of the Standardized Melissa officinalis Extract to Control Gut Contractility in Sheep-Ex Vivo Study

BACKGROUND

Modern societies and policymakers increasingly emphasize the advancement of organic farming practices and the preservation of rural culture. Sheep farming faces several challenges, including environmental impacts, antibiotic usage, and public concerns regarding animal welfare. The purpose of this study was to investigate the effects of Melissa officinalis extract and its principal phenolic acids on the motility of the sheep jejunum and colon, with the goal of assessing their potential as health-promoting feed additives, particularly in animals with dysmotilities.

METHODS

The trials were performed on isolated jejunum and colon preparations collected from sheep undergoing routine slaughter. The effect of extracts from Melissa Officinalis and three major phenolic acids (rosmarinic, chlorogenic, and lithospermic) was evaluated to identify their ability to modify the spontaneous and pharmacologically-induced contractility of circular and longitudinal smooth muscle.

RESULTS

Regarding spontaneous contractions: Melissa officinalis extract, rosmarinic acid, and lithospermic acid caused a significant decrease in spontaneous contractility in the jejunum and colon, while chlorogenic acid exhibited myocontractile effects except for colon circular preparations where the effect was myorelaxant as in the other acids. In the case of ACh-induced contractions, all acids and the Melissa officinalis extract caused mostly a significant decrease in the magnitude of acetylcholine-induced contractions in both longitudinal and circular smooth muscle strips of the colon and jejunum.

CONCLUSIONS

The findings suggest a predominantly myorelaxant effect of the Melissa officinalis extract and its major phenolic acids on the smooth muscle of the sheep jejunum and colon. These results underscore the potential application of the Melissa officinalis extract as a feed additive to modulate intestinal motility and address challenges in livestock production.

Prolonged storage reduces viability of Peptacetobacter (Clostridium) hiranonis and core intestinal bacteria in fecal microbiota transplantation preparations for dogs

Introduction

Fecal microbiota transplantation (FMT) has been described useful as an adjunct treatment for chronic enteropathy in dogs. Different protocols can be used to prepare and store FMT preparations, however, the effect of these methods on microbial viability is unknown. We aimed (1) to assess the viability of several core intestinal bacterial species by qPCR and (2) to assess Peptacetobacter (Clostridium) hiranonis viability through culture to further characterize bacterial viability in different protocols for FMT preparations.

Methods

Bacterial abundances were assessed in feces from six healthy dogs by qPCR after propidium monoazide (PMA-qPCR) treatment for selective quantitation of viable bacteria. Conservation methods tested included lyophilization (stored at 4°C and at -20°C) and freezing with glycerol-saline solution (12.5%) and without any cryoprotectant (stored at -20°C). Additionally, the abundance of P. hiranonis was quantified using bacterial culture.

Results

Using PMA-qPCR, the viability of Faecalibacterium, Escherichia coli, Streptococcus, Blautia, Fusobacterium, and P. hiranonis was reduced in lyophilized fecal samples kept at 4°C and -20°C up to 6 months (p < 0.05). In frozen feces without cryoprotectant, only Streptococcus and E. coli were not significantly reduced for up to 3 months (p > 0.05). Lastly, no differences were observed in the viability of those species in glycerol-preserved samples up to 6 months (p > 0.05). When using culture to evaluate the viability of P. hiranonis, we observed that P. hiranonis abundance was lower in lyophilized samples kept at 4°C than -20°C; and P. hiranonis abundance was higher in glycerol-preserved samples for up to 6 months than in samples preserved without glycerol for up to 3 months. Moreover, the highest abundance of P. hiranonis was observed in glycerol-preserved feces. After 3 months, P. hiranonis was undetectable by culture in 83% (5/6) of the frozen samples without glycerol.

Discussion

While the lyophilization procedure initially reduced P. hiranonis abundance, P. hiranonis viability was stable thereafter for up to 6 months at -20°C. The higher bacterial viability detected in fecal samples preserved with glycerol confirms the use of this cryoprotectant as a reliable method to keep bacteria alive in the presence of fecal matrix for FMT purposes.

Metagenomic analyses of gut microbiome composition and function with age in a wild bird; little change, except increased transposase gene abundance

Studies on wild animals, mostly undertaken using 16S metabarcoding, have yielded ambiguous evidence regarding changes in the gut microbiome (GM) with age and senescence. Furthermore, variation in GM function has rarely been studied in such wild populations, despite GM metabolic characteristics potentially being associated with host senescent declines. Here, we used 7 years of repeated sampling of individuals and shotgun metagenomic sequencing to investigate taxonomic and functional changes in the GM of Seychelles warblers (Acrocephalus sechellensis) with age. Our results suggest that taxonomic GM species richness declines with age and in the terminal year, with this terminal decline occurring consistently across all ages. Taxonomic and functional GM composition also shifted with host age. However, the changes we identified occurred linearly with age (or even mainly during early years prior to the onset of senescence in this species) with little evidence of accelerated change in later life or during their terminal year. Therefore, the results suggest that changes in the GM with age are not linked to senescence. Interestingly, we found a significant increase in the abundance of a group of transposase genes with age, which may accumulate passively or due to increased transposition induced as a result of stressors that arise with age. These findings reveal taxonomic and functional GM changes with age, but not senescence, in a wild vertebrate and provide a blueprint for future wild functional GM studies linked to age and senescence.

Beyond metabolic messengers: Bile acids and TGR5 as pharmacotherapeutic intervention for psychiatric disorders

Psychiatric disorders pose a significant global health challenge, exacerbated by the COVID-19 pandemic and insufficiently addressed by the current treatments. This review explores the emerging role of bile acids and the TGR5 receptor in the pathophysiology of psychiatric conditions, emphasizing their signaling within the gut-brain axis. We detail the synthesis and systemic functions of bile acids, their transformation by gut microbiota, and their impact across various neuropsychiatric disorders, including major depressive disorder, general anxiety disorder, schizophrenia, autism spectrum disorder, and bipolar disorder. The review highlights how dysbiosis and altered bile acid metabolism contribute to the development and exacerbation of these neuropsychiatric disorders through mechanisms involving inflammation, oxidative stress, and neurotransmitter dysregulation. Importantly, we detail both pharmacological and non-pharmacological interventions that modulate TGR5 signaling, offering potential breakthroughs in treatment strategies. These include dietary adjustments to enhance beneficial bile acids production and the use of specific TGR5 agonists that have shown promise in preclinical and clinical settings for their regulatory effects on critical pathways such as cAMP-PKA, NRF2-mediated antioxidant responses, and neuroinflammation. By integrating findings from the dynamics of gut microbiota, bile acids metabolism, and TGR5 receptor related signaling events, this review underscores cutting-edge therapeutic approaches poised to revolutionize the management and treatment of psychiatric disorders.

Fecal microbiome alterations of mice following immunization with gold nanoparticle vaccines against enterohemorrhagic Escherichia coli

BACKGROUND

Enterohemorrhagic Escherichia coli (EHEC), a group of enteric pathogenic bacteria that is a major cause of human diarrheal disease, must interact with the diverse intestinal microbiome during colonization and subsequently overcome the environmental challenges to survive and cause disease. While this relationship, and how the microbiome modulates infection of EHEC, has been studied, it is less understood how the microbiome is impacted during treatment for an EHEC infection. One area that is notably lacking in knowledge is how vaccination can impact the intestinal microbiome composition, and therefore, influence vaccine efficacy. We previously developed vaccine formulations consisting of gold nanoparticles (AuNPs) conjugated to various EHEC antigens and tested them in mice models using both EHEC and its murine counterpart Citrobacter rodentium. The goal of this study was to evaluate the relationship between these EHEC vaccines and their effects on the gut microbiome.

RESULTS

We found that immunization with the vaccines or adjuvant-only control did not lead to major alterations in the composition of the fecal microbiome; however, there were measurable variations in individual mice within the same vaccine group housed in separate cages. Also, immunization with one vaccine (AuNP-EscC) prevented both a decrease in the diversity of the fecal microbiome and an increase in detectable C. rodentium following infection compared to control animals.

CONCLUSIONS

Overall, our small study argues in favor of evaluating the intestinal microbiome during vaccine development not just for EHEC, but for other enteric pathogens.

From Gut to Brain: Unraveling the Intricate Link Between Microbiome and Stroke

Stroke, a neurological disorder, is intricately linked to the gut microbiota, influencing microbial composition and elevating the risk of ischemic stroke. The neuroprotective impact of short-chain fatty acids (SCFAs) derived from dietary fiber fermentation contrasts with the neuroinflammatory effects of lipopolysaccharide (LPS) from gut bacteria. The pivotal role of the gut-brain axis, facilitating bidirectional communication between the gut and the brain, is crucial in maintaining gastrointestinal equilibrium and influencing cognitive functions. An in-depth understanding of the interplay among the gut microbiota, immune system, and neurological outcomes in stroke is imperative for devising innovative preventive and therapeutic approaches. Strategies such as dietary adjustments, probiotics, prebiotics, antibiotics, or fecal transplantation offer promise in modulating stroke outcomes. Nevertheless, comprehensive research is essential to unravel the precise mechanisms governing the gut microbiota's involvement in stroke and to establish effective therapeutic interventions. The initiation of large-scale clinical trials is warranted to assess the safety and efficacy of interventions targeting the gut microbiota in stroke management. Tailored strategies that reinstate eubiosis and foster a healthy gut microbiota hold potential for both stroke prevention and treatment. This review underscores the gut microbiota as a promising therapeutic target in stroke and underscores the need for continued research to delineate its precise role and develop microbiome-based interventions effectively.

Differences in clinical manifestations and the fecal microbiome between irritable bowel syndrome and small intestinal bacterial overgrowth

BACKGROUND

Irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO) share similar abdominal symptoms; however, their differentiation remains controversial.

AIMS

To illustrate the differences between the two conditions.

METHODS

Patients and healthy controls completed questionnaires and provided stool samples for analysis.

RESULTS

IBS presented with the most severe symptoms and was specifically characterized by intense abdominal pain and frequent episodes of diarrhea. Patients with IBS displayed more dysregulated taxonomy within the fecal microbiota than SIBO. Opportunistic pathogens, including Lachnoclostridium, Escherichia-Shigella, and Enterobacter were enriched in the IBS group which contributed to increased bacterial pathogenicity and positively correlated with abdominal pain and bloating, meanwhile, Lachnoclostridium and Escherichia-Shigella were found to be associated with metabolites affiliated to bile acids, alcohols and derivatives. Bacteria enriched in SIBO group correlated with constipation. The bacterial co-occurrence network within the SIBO group was the most intricate. Ruminococcaceae Group were defined as core bacteria in SIBO. Differential metabolites affiliated to androstane steroids and phenylacetic acids were associated with core bacteria.

CONCLUSIONS

Our study elucidates the differences between IBS and SIBO in terms of symptoms, microbiota and functions, which provides insights into a better understanding of both diseases and evidence for different treatment strategies.

Fecal Microbiome Alterations of Mice Following Immunization with Gold Nanoparticle Vaccines Against Enterohemorrhagic Escherichia coli

Background

Enterohemorrhagic Escherichia coli (EHEC), a group of enteric pathogenic bacteria that is a major cause of human diarrheal disease, must interact with the diverse intestinal microbiome during colonization and subsequently overcome the environmental challenges to survive and cause disease. While this relationship, and how the microbiome modulates infection of EHEC, has been studied, it is less understood how the microbiome is impacted during treatment for an EHEC infection. One area that is notably lacking in knowledge is how vaccination can impact the intestinal microbiome composition, and therefore, influence vaccine efficacy. We previously developed vaccine formulations consisting of gold nanoparticles (AuNPs) conjugated to various EHEC antigens and tested them in small animal infection models using both EHEC and its murine counterpart Citrobacter rodentium. The goal of this study was to evaluate the relationship between these EHEC vaccines and their effects on the gut microbiome.

Results

We found that immunization with the vaccines or adjuvant-only control did not lead to major alterations in the composition of the fecal microbiome; however, there were measurable variations in individual mice within the same vaccine group housed in separate cages. Finally, immunization with one vaccine (AuNP-EscC) did prevent a decrease in the diversity of the fecal microbiome and an increase in detectable C. rodentium following infection compared to the control animals.

Conclusions

Overall, our small study argues in favor of evaluating the intestinal microbiome during vaccine development not just for EHEC, but for other enteric pathogens as well.

Enteroendocrine cells regulate intestinal homeostasis and epithelial function

Enteroendocrine cells (EECs) are well-known for their systemic hormonal effects, especially in the regulation of appetite and glycemia. Much less is known about how the products made by EECs regulate their local environment within the intestine. Here, we focus on paracrine interactions between EECs and other intestinal cells as they regulate three essential aspects of intestinal homeostasis and physiology: 1) intestinal stem cell function and proliferation; 2) nutrient absorption; and 3) mucosal barrier function. We also discuss the ability of EECs to express multiple hormones, describe in vitro and in vivo models to study EECs, and consider how EECs are altered in GI disease.

Characterizing the gut microbiome of diarrheal mink under farmed conditions: A metagenomic analysis

This study aimed to comprehensively characterize the gut microbiota in diarrheal mink. We conducted Shotgun metagenomic sequencing on samples from five groups of diarrheal mink and five groups of healthy mink. The microbiota α-diversity and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology did not show significant differences between the groups. However, significant differences were observed in microbiota β-diversity and the function of carbohydrate-active enzymes (CAZymes) between diarrheal and healthy mink. Specifically, The relative abundance of Firmicutes was lower, whereas that of Bacteroidetes was higher in diarrheal mink. Fusobacteria were enriched as invasive bacteria in the gut of diarrheal mink compared with healthy mink. In addition, Escherichia albertii was identified as a new bacterium in diarrheal mink. Regarding functions, nicotinate and nicotinamide metabolism and glycoside hydrolases 2 (GH2) family were the enhanced KEGG orthology and CAZymes in diarrheal mink. Furthermore, the diversity and number of antibiotic-resistant genes were significantly higher in the diarrheal mink group than in the healthy group. These findings enhance our understanding of the gut microbiota of adult mink and may lead to new approaches to the diagnosis and treatment of mink diarrhea.

The causality between gut microbiota and functional dyspepsia: A two-sample Mendelian randomization analysis

To investigate the potential link between gut microbiota and functional dyspepsia (FD). Genome-wide association studies (GWAS) of gut microbiota and FD were used in Mendelian randomization (MR) research. Using the GWAS of 18,340 people, instrumental variables related to gut microbiota as an exposure factor were identified. In a GWAS investigation, 189,695 control individuals and 4376 FD patients were included as outcome variables. The primary analysis technique was inverse variance weighted analysis. The reliability of MR analysis results is tested using sensitivity analysis. Two-sample Mendelian randomization analysis revealed the presence of 7 gut microbiota associated to FD. In the inverse variance weighted analysis method, Order Erysipelotrichales (odds ratio (OR): 1.301; 95% confidence interval (CI): 1.016, 1.665; P = .037), Family Erysipelotrichales (OR: 1.301; 95% CI: 1.016, 1.665; P = .037), Genus Haemophilus (OR: 1.236; 95% CI 1.059, 1.442; P = .007), Genus Ruminiclostridium 9 (OR: 1.422; 95% CI: 1.078, 1.877; P = .013), Genus Lachnospiraceae NK4A 136 group (OR: 1.297; 95% CI: 1.059, 1.589; P = .012) was positively associated with FD. Class Gammaproteobacteria (OR: 0.705; 95% CI: 0.522, 0.952; P = .022) and Genus Erysipelatoclostridium (OR: 0.747; 95% CI: 0.628, 0.888; P = .001) were found to be inversely related to FD. There was no evidence of pleiotropy or heterogeneity in the sensitivity analysis. Our research provides evidence for a possible link between FD and a number of gut microbiota. The role that gut microbiota plays in the development of FD requires more investigation.

Manipulating the molecular specificity of transcriptional biosensors for tryptophan metabolites and analogs

Tryptophan and its metabolites, produced by the gut microbiota, are pivotal for human physiological and mental health. Yet, quantifying these structurally similar compounds with high specificity remains a challenge, hindering point-of-care diagnostics and targeted therapeutic interventions. Leveraging the innate specificity and adaptability of biological systems, we present a biosensing approach capable of identifying specific metabolites in complex contexts with minimal cross-activity. This study introduces a generalizable strategy that combines evolutionary analysis, key ligand-binding residue identification, and mutagenesis scanning to pinpoint ligand-specific transcription factor variants. Furthermore, we uncover regulatory mechanisms within uncharacterized ligand-binding domains, whether in homodimer interfaces or monomers, through structural prediction and ligand docking. Notably, our "plug-and-play" strategy broadens the detection spectrum, enabling the exclusive biosensing of indole-3-acetic acid (an auxin), tryptamine, indole-3-pyruvic acid, and other tryptophan derivatives in engineered probiotics. This groundwork paves the way to create highly specific transcriptional biosensors for potential clinical, agricultural, and industrial use.

Understanding the impact of the gut microbiome on opioid use disorder: Pathways, mechanisms, and treatment insights

The widespread use of opioids for chronic pain management not only poses a significant public health issue but also contributes to the risk of tolerance, dependence, and addiction, leading to opioid use disorder (OUD), which affects millions globally each year. Recent research has highlighted a potential bidirectional relationship between the gut microbiome and OUD. This emerging perspective is critical, especially as the opioid epidemic intensifies, emphasizing the need to investigate how OUD may alter gut microbiome dynamics and vice versa. Understanding these interactions could reveal new insights into the mechanisms of addiction and tolerance, as well as provide novel approaches for managing and potentially mitigating OUD impacts. This comprehensive review explores the intricate bidirectional link through the gut-brain axis, focusing on how opiates influence microbial composition, functional changes, and gut mucosal integrity. By synthesizing current findings, the review aims to inspire new strategies to combat the opioid crisis and leverage microbiome-centred interventions for preventing and treating OUD.

What is the link between the dietary inflammatory index and the gut microbiome? A systematic review

PURPOSE

One highlighted pathogenesis mechanism of diseases is the negative impact of pro-inflammatory diets (PD) on the gut microbiome. This systematic review aimed to study the link between dietary inflammatory index (DII), as an indicator of PD, and gut microbiome.

METHODS

A systematic search was done in PubMed and Scopus, adhering to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis. The assessment of the included studies' quality was performed using the critical appraisal checklist from the Joanna Briggs Institute.

RESULTS

Ten articles were included eight cross-sectional, one case-control, and, one cohort study. Seven and three included articles reported a weak and moderate relationship between gut microbiome and DII scores, respectively. DII scores were linked to variety in microbiome composition and diversity/richness. More importantly, anti-inflammatory diets as measured by lower DII scores were linked to a more desirable gut microbiome profile. Prevotella stercorea, Veillonella rogosae, Morganella morganii, Ruminococcus torques, Eubacterium nodatum, Alistipes intestine, Clostridium leptum, Morganellaceae family, Enterobacteriaceae family, and, Bacteroides thetaiotaomicron were related to higher DII scores. While, Butyrate-producing bacteria such as Ruminococcaceae and Lachnospiraceae families, Faecalibacterium prausnitzii, and Akkermansia muciniphila were related to lower DII scores.

CONCLUSION

An anti-inflammatory diet, as measured by a lower DII score, might be linked to variations in the composition and variety of the microbiome. Therefore, the DII score could be useful in microbiota research, however, this possibility needs to be investigated more precisely in future studies.

Acupuncture and moxibustion intervention in functional dyspepsia: Gastric and duodenal regulation

Functional dyspepsia (FD) is a brain-gut interaction disorder located in the stomach and duodenum, which has complex pathophysiological mechanisms, and there is no effective treatment for FD. Acupuncture and moxibustion have been proven to have definite and significant efficacy on FD. Focusing on the affected area and combined with the potential pathophysiology of FD, here we discuss the possible mechanisms of acupuncture and moxibustion in treating FD to guide future clinical and experimental research. We argue that the pathological causes of FD can be roughly divided into gastrointestinal dysfunction, duodenal low-grade inflammation, visceral hypersensitivity, and duodenal intestinal barrier and microbial imbalance. Correspondingly, the possible mechanisms of acupuncture and moxibustion in treating FD are elucidated from the perspective of how they improve gastric accommodation, regulate gastrointestinal motility, reduce gastric visceral sensitivity, regulate eosinophil-mast cell axis, inhibit low-grade inflammatory responses, and possibly regulate intestinal microbial homeostasis and duodenal barrier function through the microbiota-gut-brain axis. Although some evidence is still lacking, acupuncture remains a promising treatment for FD. In the future, it is necessary to conduct additional clinical and experimental research on acupuncture and moxibustion in treating FD to further explore their effects and mechanisms.

Causal associations between intermediate very-low-density lipoprotein cholesterol-to-total lipids ratio and peptic ulcer: A bidirectional Mendelian randomization study

BACKGROUND

Previous epidemiologic investigations have consistently demonstrated a strong association between the ratio of cholesterol to total lipids in medium very-low-density lipoprotein (VLDL) and the occurrence of peptic ulcers (PU). However, the precise causal relationship between these factors remains ambiguous. Consequently, this study aims to elucidate the potential correlation between the ratio of cholesterol to total lipids in medium VLDL and the incidence of peptic ulcer.

AIM

To investigate the ratio of cholesterol to total lipids in medium very-low-density lipoprotein (VLDL) association with PU via genetic methods, guiding future clinical research.

METHODS

Genome-wide association study (GWAS) datasets for the ratio of cholesterol to total lipids in intermediate VLDL and peptic ulcer were retrieved from the IEU OpenGWAS project (https://gwas.mrcieu.ac.uk). For the forward Mendelian randomization (MR) analysis, 72 single nucleotide polymorphisms (SNPs) were identified as instrumental variables. These SNPs were selected based on their association with the ratio of cholesterol to total lipids in intermediate VLDL, with peptic ulcer as the outcome variable. Conversely, for the inverse MR analysis, no SNPs were identified with peptic ulcer as the exposure variable and the ratio of cholesterol to total lipids in intermediate VLDL as the outcome. All MR analyses utilized inverse variance weighted (IVW) as the primary analytical method. Additionally, weighted median and MR-Egger methods were employed as supplementary analytical approaches to assess causal effects. Egger regression was used as a supplementary method to evaluate potential directional pleiotropy. Heterogeneity and multiplicity tests were conducted using the leave-one-out method to evaluate result stability and mitigate biases associated with multiple testing.

RESULTS

The genetically predicted ratio of cholesterol to total lipids in medium VLDL was significantly associated with an elevated risk of peptic ulcer (IVW: OR = 2.557, 95%CI = 1.274-5.132, P = 0.008). However, no causal association of peptic ulcer with the ratio of cholesterol to total lipids in medium VLDL was observed in the inverse Mendelian randomization analysis.

CONCLUSION

In conclusion, our study reveals a significant association between the ratio of cholesterol to total lipids in medium VLDL and an elevated risk of peptic ulcers. However, further validation through laboratory investigations and larger-scale studies is warranted to strengthen the evidence and confirm the causal relationship between these factors.

[Small intestinal bacterial overgrowth (SIBO) - Therapy, nutrition, microbiome]

SIBO (small intestinal bacterial overgrowth) is defined by bacterial overgrowth or colonization of the small intestine in combination with gastrointestinal symptoms such as bloating, nausea, pain, diarrhoea, malabsorption and food intolerance. SIBO can be caused by various mechanisms such as reduced intestinal motility, altered gastrointestinal anatomy, reduced gastric acid or pancreatic enzyme production, altered bile acid metabolism, or immune defects. Accordingly, SIBO often develops secondary to different underlying diseases.Diet has a fundamental influence on the composition of the intestinal microbiome and is therefore also a potential pathomechanism in SIBO. Furthermore, food intolerances are common in SIBO patients. However, both aspects have so far been insufficiently investigated. Nevertheless, elemental diets, carbohydrate-reduced diets, as well as pre- and probiotics are potential therapy options.This article provides a summary of current knowledge on the pathophysiology, diagnosis and treatment of SIBO, with particular emphasis on the role of nutrition and the microbiome.

Ccr2-dependent monocytes exacerbate intestinal inflammation and modulate gut serotonergic signaling following traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) leads to acute gastrointestinal dysfunction and mucosal damage, resulting in feeding intolerance. C-C motif chemokine receptor 2 (Ccr2 + ) monocytes are crucial immune cells that regulate the gut's inflammatory response via the brain-gut axis. Using Ccr2 ko mice, we investigated the intricate interplay between these cells to better elucidate the role of systemic inflammation after TBI.

METHODS

A murine-controlled cortical impact model was used, and results were analyzed on postinjury days 1 and 3. The experimental groups included (1) sham C57Bl/6 wild type (WT), (2) TBI WT, (3) sham Ccr2 ko , and (4) TBI Ccr2 ko . Mice were euthanized on postinjury days 1 and 3 to harvest the ileum and study intestinal dysfunction and serotonergic signaling using a combination of quantitative real-time polymerase chain reaction, immunohistochemistry, fluorescein isothiocyanate-dextran motility assays, and flow cytometry. Student's t test and one-way analysis of variance were used for statistical analysis, with significance achieved when p < 0.05.

RESULTS

Traumatic brain injury resulted in severe dysfunction and dysmotility of the small intestine in WT mice as established by significant upregulation of inflammatory cytokines iNOS , Lcn2 , TNFα , and IL1β and the innate immunity receptor toll-like receptor 4 ( Tlr4 ). This was accompanied by disruption of genes related to serotonin synthesis and degradation. Notably, Ccr2 ko mice subjected to TBI showed substantial improvements in intestinal pathology. Traumatic brain injury Ccr2 ko groups demonstrated reduced expression of inflammatory mediators ( iNOS , Lcn2 , IL1β , and Tlr4 ) and improvement in serotonin synthesis genes, including tryptophan hydroxylase 1 ( Tph1 ) and dopa decarboxylase ( Ddc ).

CONCLUSION

Our study reveals a critical role for Ccr2 + monocytes in modulating intestinal homeostasis after TBI. Ccr2 + monocytes aggravate intestinal inflammation and alter gut-derived serotonergic signaling. Therefore, targeting Ccr2 + monocyte-dependent responses could provide a better understanding of TBI-induced gut inflammation. Further studies are required to elucidate the impact of these changes on brain neuroinflammation and cognitive outcomes.

Therapeutic modulation of the kynurenine pathway in severe mental illness and comorbidities: A potential role for serotonergic psychedelics

Mounting evidence points towards a crucial role of the kynurenine pathway (KP) in the altered gut-brain axis (GBA) balance in severe mental illness (SMI, namely depression, bipolar disorder, and schizophrenia) and cardiometabolic comorbidities. Preliminary evidence shows that serotonergic psychedelics and their analogues may hold therapeutic potential in addressing the altered KP in the dysregulated GBA in SMI and comorbidities. In fact, aside from their effects on mood, psychedelics elicit therapeutic improvement in preclinical models of obesity, metabolic syndrome, and vascular inflammation, which are highly comorbid with SMI. Here, we review the literature on the therapeutic modulation of the KP in the dysregulated GBA in SMI and comorbidities, and the potential application of psychedelics to address the altered KP in the brain and systemic dysfunction underlying SMI and comorbidities. Psychedelics might therapeutically modulate the KP in the altered GBA in SMI and comorbidities either directly, via altering the metabolic pathway by influencing the rate-limiting enzymes of the KP and affecting the levels of available tryptophan, or indirectly, by affecting the gut microbiome, gut metabolome, metabolism, and the immune system. Despite promising preliminary evidence, the mechanisms and outcomes of the KP modulation with psychedelics in SMI and systemic comorbidities remain largely unknown and require further investigation. Several concerns are discussed surrounding the potential side effects of this approach in specific cohorts of individuals with SMI and systemic comorbidities.

Identification of key immune-related genes and potential therapeutic drugs in diabetic nephropathy based on machine learning algorithms

BACKGROUND

Diabetic nephropathy (DN) is a major contributor to chronic kidney disease. This study aims to identify immune biomarkers and potential therapeutic drugs in DN.

METHODS

We analyzed two DN microarray datasets (GSE96804 and GSE30528) for differentially expressed genes (DEGs) using the Limma package, overlapping them with immune-related genes from ImmPort and InnateDB. LASSO regression, SVM-RFE, and random forest analysis identified four hub genes (EGF, PLTP, RGS2, PTGDS) as proficient predictors of DN. The model achieved an AUC of 0.995 and was validated on GSE142025. Single-cell RNA data (GSE183276) revealed increased hub gene expression in epithelial cells. CIBERSORT analysis showed differences in immune cell proportions between DN patients and controls, with the hub genes correlating positively with neutrophil infiltration. Molecular docking identified potential drugs: cysteamine, eltrombopag, and DMSO. And qPCR and western blot assays were used to confirm the expressions of the four hub genes.

RESULTS

Analysis found 95 and 88 distinctively expressed immune genes in the two DN datasets, with 14 consistently differentially expressed immune-related genes. After machine learning algorithms, EGF, PLTP, RGS2, PTGDS were identified as the immune-related hub genes associated with DN. In addition, the mRNA and protein levels of them were obviously elevated in HK-2 cells treated with glucose for 24 h, as well as their mRNA expressions in kidney tissues of mice with DN.

CONCLUSION

This study identified 4 hub immune-related genes (EGF, PLTP, RGS2, PTGDS), as well as their expression profiles and the correlation with immune cell infiltration in DN.

Gut Microbiota Dysbiosis, Oxidative Stress, Inflammation, and Epigenetic Alterations in Metabolic Diseases

Gut dysbiosis, resulting from an imbalance in the gut microbiome, can induce excessive production of reactive oxygen species (ROS), leading to inflammation, DNA damage, activation of the immune system, and epigenetic alterations of critical genes involved in the metabolic pathways. Gut dysbiosis-induced inflammation can also disrupt the gut barrier integrity and increase intestinal permeability, which allows gut-derived toxic products to enter the liver and systemic circulation, further triggering oxidative stress, inflammation, and epigenetic alterations associated with metabolic diseases. However, specific gut-derived metabolites, such as short-chain fatty acids (SCFAs), lactate, and vitamins, can modulate oxidative stress and the immune system through epigenetic mechanisms, thereby improving metabolic function. Gut microbiota and diet-induced metabolic diseases, such as obesity, insulin resistance, dyslipidemia, and hypertension, can transfer to the next generation, involving epigenetic mechanisms. In this review, we will introduce the key epigenetic alterations that, along with gut dysbiosis and ROS, are engaged in developing metabolic diseases. Finally, we will discuss potential therapeutic interventions such as dietary modifications, prebiotics, probiotics, postbiotics, and fecal microbiota transplantation, which may reduce oxidative stress and inflammation associated with metabolic syndrome by altering gut microbiota and epigenetic alterations. In summary, this review highlights the crucial role of gut microbiota dysbiosis, oxidative stress, and inflammation in the pathogenesis of metabolic diseases, with a particular focus on epigenetic alterations (including histone modifications, DNA methylomics, and RNA interference) and potential interventions that may prevent or improve metabolic diseases.

Role of Bacillus coagulans (Heyndrickxia coagulans)BCP92 in managing irritable bowel syndrome: A randomized, double-blind, multicenter, placebo-controlled clinical trial

BACKGROUND

Irritable bowel syndrome (IBS) is a major global healthcare burden that requires effective and well-tolerated intervention. This study aimed to investigate the effectiveness and safety of Bacillus coagulans BCP92, a probiotic, in managing IBS symptoms.

METHODS

This randomized controlled trial included 100 participants who strictly adhered to the protocol. Various parameters such as IBS severity, digestive symptom frequency, gastrointestinal symptom frequency, stool consistency, interleukin-6 levels, stress relief, and anxiety levels were evaluated over 12 weeks.

RESULTS

B. coagulans BCP92 significantly improved IBS severity (P < .001), and gastrointestinal symptom frequency (P < .001) compared with that in the control group. The stool consistency significantly improved (P < .001). Mental stress relief was remarkable (P = .001), differentiating the test and control groups. No significant change in interleukin-6 levels was observed; however, the safety assessment revealed an excellent profile with no reported severe adverse events.

CONCLUSION

B. coagulans BCP92 is one of the most promising therapeutic options for the management of IBS because it has shown significant efficacy in alleviating symptoms among patients suffering from this condition, resulting in improved stool consistency changes in addition to improving overall mental well-being for its users, thereby foreseeing the elimination of any potential side effects experienced during the implementation of this approach strategy within our health care system, thereby improving patient outcomes and leading to individualization of treatment plans among all individuals diagnosed with this disease entity who may have symptoms, including abdominal pain or discomfort associated with changes in bowel habits.

Intratumoral Microbiota: Metabolic Influences and Biomarker Potential in Gastrointestinal Cancer

Gastrointestinal (GI) cancers impose a substantial global health burden, highlighting the necessity for deeper understanding of their intricate pathogenesis and treatment strategies. This review explores the interplay between intratumoral microbiota, tumor metabolism, and major types of GI cancers (including esophageal, gastric, liver, pancreatic, and colorectal cancers), summarizing recent studies and elucidating their clinical implications and future directions. Recent research revealed altered microbial signatures within GI tumors, impacting tumor progression, immune responses, and treatment outcomes. Dysbiosis-induced alterations in tumor metabolism, including glycolysis, fatty acid metabolism, and amino acid metabolism, play critical roles in cancer progression and therapeutic resistance. The integration of molecular mechanisms and potential biomarkers into this understanding further enhances the prognostic significance of intratumoral microbiota composition and therapeutic opportunities targeting microbiota-mediated tumor metabolism. Despite advancements, challenges remain in understanding the dynamic interactions within the tumor microenvironment (TME). Future research directions, including advanced omics technologies and prospective clinical studies, offer promising avenues for precision oncology and personalized treatment interventions in GI cancer. Overall, integrating microbiota-based approaches and molecular biomarkers into GI cancer management holds promise for improving patient outcomes and survival.

Streptococcus thermophilus iHA318 Improves Dry Eye Symptoms by Mitigating Ocular Surface Damage in a Mouse Model

Dry eye is a complicated ocular surface disease that causes discomfort, visual disturbance, and frequently observed ocular surface damage. Emerging hypotheses suggest probiotics may help relieve dry eye symptoms by modulating inflammation and oxidative stress. This study aimed to investigate the therapeutic effects of Streptococcus thermophilus iHA318 probiotics on dry eye using in vitro assays and an in vivo murine model of ultraviolet B (UVB) radiation-induced dry eye. In vitro analyses revealed that S. thermophilus iHA318® exhibited antioxidant activity and anti-inflammatory effects by inhibiting reactive oxygen species production and suppressing inflammatory cytokines. For the in vivo study, female ICR mice were assigned to normal control, UVB-induced dry eye, and UVB+iHA318 treatment groups. UVB exposure significantly decreased tear volume and tear film breakup time (TBUT) compared to normal controls. Supplementation with S. thermophilus iHA318® via oral gavage markedly improved tear production and TBUT on day 7 post-UVB exposure. Ocular surface photography demonstrated improved gradings of corneal opacity, smoothness, and lissamine green staining in the iHA318 group versus the UVB group. Topographical analysis further revealed improvement in the UVB-induced corneal irregularities by iHA318 treatment. Collectively, these results indicate that S. thermophilus iHA318 exerts a protective effect against dry eye symptoms by mitigating oxidative stress and inflammation, thereby preserving tear film stability and ocular surface integrity. This probiotic strain represents a promising therapeutic approach for managing dry eye syndrome.

Enteric neuropathy in diabetes: Implications for gastrointestinal function

Diabetes, commonly known for its metabolic effects, also critically affects the enteric nervous system (ENS), which is essential in regulating gastrointestinal (GI) motility, secretion, and absorption. The development of diabetes-induced enteric neuropathy can lead to various GI dysfunctions, such as gastroparesis and irregular bowel habits, primarily due to disruptions in the function of neuronal and glial cells within the ENS, as well as oxidative stress and inflammation. This editorial explores the pathophysiological mechanisms underlying the development of enteric neuropathy in diabetic patients. Additionally, it discusses the latest advances in diagnostic approaches, emphasizing the need for early detection and intervention to mitigate GI complications in diabetic individuals. The editorial also reviews current and emerging therapeutic strategies, focusing on pharmacological treatments, dietary management, and potential neuromodulatory interventions. Ultimately, this editorial highlights the necessity of a multidisciplinary approach in managing enteric neuropathy in diabetes, aiming to enhance patient quality of life and address a frequently overlooked complication of this widespread disease.

The Involvement of Immune Cells Between Ischemic Stroke and Gut Microbiota

Ischemic stroke, a disease with high mortality and disability rate worldwide, currently has no effective treatment. The systemic inflammation response to the ischemic stroke, followed by immunosuppression in focal neurologic deficits and other inflammatory damage, reduces the circulating immune cell counts and multiorgan infectious complications such as intestinal and gut dysfunction dysbiosis. Evidence showed that microbiota dysbiosis plays a role in neuroinflammation and peripheral immune response after stroke, changing the lymphocyte populations. Multiple immune cells, including lymphocytes, engage in complex and dynamic immune responses in all stages of stroke and may be a pivotal moderator in the bidirectional immunomodulation between ischemic stroke and gut microbiota. This review discusses the role of lymphocytes and other immune cells, the immunological processes in the bidirectional immunomodulation between gut microbiota and ischemic stroke, and its potential as a therapeutic strategy for ischemic stroke.

Sleep apnoea, gut dysbiosis and cognitive dysfunction

Sleep disorders are becoming increasingly common, and their distinct effects on physical and mental health require elaborate investigation. Gut dysbiosis (GD) has been reported in sleep-related disorders, but sleep apnoea is of particular significance because of its higher prevalence and chronicity. Cumulative evidence has suggested a link between sleep apnoea and GD. This review highlights the gut-brain communication axis that is mediated via commensal microbes and various microbiota-derived metabolites (e.g. short-chain fatty acids, lipopolysaccharide and trimethyl amine N-oxide), neurotransmitters (e.g. γ-aminobutyric acid, serotonin, glutamate and dopamine), immune cells and inflammatory mediators, as well as the vagus nerve and hypothalamic-pituitary-adrenal axis. This review also discusses the pathological role underpinning GD and altered gut bacterial populations in sleep apnoea and its related comorbid conditions, particularly cognitive dysfunction. In addition, the review examines the preclinical and clinical evidence, which suggests that prebiotics and probiotics may potentially be beneficial in sleep apnoea and its comorbidities through restoration of eubiosis or gut microbial homeostasis that regulates neural, metabolic and immune responses, as well as physiological barrier integrity via the gut-brain axis.

Applied physiology: gut microbiota and antimicrobial therapy

The gut microbiota plays an important role in maintaining human health and in the pathogenesis of several diseases. Antibiotics are among the most commonly prescribed drugs and have a significant impact on the structure and function of the gut microbiota. The understanding that a healthy gut microbiota prevents the development of many diseases has also led to its consideration as a potential therapeutic target. At the same time, any factor that alters the gut microbiota becomes important in this approach. Exercise and antibacterial therapy have a direct effect on the microbiota. The review reflects the current state of publications on the mechanisms of intestinal bacterial involvement in the pathogenesis of cardiovascular, metabolic, and neurodegenerative diseases. The physiological mechanisms of the influence of physical activity on the composition of the gut microbiota are considered. The mechanisms of the common interface between exercise and antibacterial therapy will be considered using the example of several socially important diseases. The aim of the study is to show the physiological relationship between the effects of exercise and antibiotics on the gut microbiota.

Dysregulated brain-gut axis in the setting of traumatic brain injury: review of mechanisms and anti-inflammatory pharmacotherapies

Traumatic brain injury (TBI) is a chronic and debilitating disease, associated with a high risk of psychiatric and neurodegenerative diseases. Despite significant advancements in improving outcomes, the lack of effective treatments underscore the urgent need for innovative therapeutic strategies. The brain-gut axis has emerged as a crucial bidirectional pathway connecting the brain and the gastrointestinal (GI) system through an intricate network of neuronal, hormonal, and immunological pathways. Four main pathways are primarily implicated in this crosstalk, including the systemic immune system, autonomic and enteric nervous systems, neuroendocrine system, and microbiome. TBI induces profound changes in the gut, initiating an unrestrained vicious cycle that exacerbates brain injury through the brain-gut axis. Alterations in the gut include mucosal damage associated with the malabsorption of nutrients/electrolytes, disintegration of the intestinal barrier, increased infiltration of systemic immune cells, dysmotility, dysbiosis, enteroendocrine cell (EEC) dysfunction and disruption in the enteric nervous system (ENS) and autonomic nervous system (ANS). Collectively, these changes further contribute to brain neuroinflammation and neurodegeneration via the gut-brain axis. In this review article, we elucidate the roles of various anti-inflammatory pharmacotherapies capable of attenuating the dysregulated inflammatory response along the brain-gut axis in TBI. These agents include hormones such as serotonin, ghrelin, and progesterone, ANS regulators such as beta-blockers, lipid-lowering drugs like statins, and intestinal flora modulators such as probiotics and antibiotics. They attenuate neuroinflammation by targeting distinct inflammatory pathways in both the brain and the gut post-TBI. These therapeutic agents exhibit promising potential in mitigating inflammation along the brain-gut axis and enhancing neurocognitive outcomes for TBI patients.

Changes in fecal lipidome after treatment with ivacaftor without changes in microbiome or bile acids

BACKGROUND

Alterations in gastrointestinal health are prominent manifestations of cystic fibrosis (CF) and can independently impact pulmonary function. Ivacaftor has been associated with robust improvements in pulmonary function and weight gain, but less is known about the impact of ivacaftor on the fecal microbiome, lipidome, and bile acids.

METHODS

Stool samples from 18 patients with CF and gating mutations (ages 6-61 years, 13 pancreatic insufficient) were analyzed for fecal microbiome and lipidome composition as well as bile acid concentrations at baseline and after 3 months of treatment with ivacaftor. Microbiome composition was also assessed in a healthy reference cohort.

RESULTS

Alpha and beta diversity of the microbiome were different between CF and reference cohort at baseline, but no treatment effect was seen in the CF cohort between baseline and 3 months. Seven lipids increased with treatment. No differences were seen in bile acid concentrations after treatment in CF. At baseline, 403 lipids and unconjugated bile acids were different between pancreatic insufficient (PI-CF) and sufficient (PS-CF) groups and 107 lipids were different between PI-CF and PS-CF after 3 months of treatment.

CONCLUSIONS

The composition and diversity of the fecal microbiome were different in CF as compared to a healthy reference, and did not change after 3 months of ivacaftor. We detected modest differences in the fecal lipidome with treatment. Differences in lipid and bile acid profiles between PS-CF and PI-CF were attenuated after 3 months of treatment.

Huanglian-banxia promotes gastric motility of diabetic rats by modulating brain-gut neurotransmitters through MAPK signaling pathway

BACKGROUND

Gastric motility disorder is an increasingly common problem among people with diabetes. Neurotransmitters have been recognized as critical regulators in the process of gastric motility. Previous study has shown that herb pair huanglian-banxia (HL-BX) can improve gastric motility, but the underlying mechanism is still unclear. The aim of this study was to further investigate the role of HL-BX in modulating brain-gut neurotransmission to promote gastric motility in diabetic rats, and to explore its possible mechanism.

METHODS

The diabetic rats were divided into five groups. Gastric emptying rate, intestinal propulsion rate, body weight, and average food intake were determined. Substance P (SP), 5- hydroxytryptamine (5-HT), and glucagon-like peptide -1 (GLP-1) in the serum were measured by enzyme-linked immunosorbent assay. Dopamine (DA) and norepinephrine (NE) in the brain were analyzed by high-pressure liquid chromatography with a fluorescence detector. Protein expression of the tissues in the stomach and brain was determined by Western blot.

KEY RESULTS

HL-BX reduced average food intake significantly, increased body weight, and improved gastric emptying rate and intestinal propulsion rate. HL-BX administration caused a significant increase in SP, GLP-1, and 5-HT, but a significant decrease in DA and NE. Interestingly, HL-BX regulated simultaneously the different expressions of MAPK and its downstream p70S6K/S6 signaling pathway in the stomach and brain. Moreover, berberine exhibited a similar effect to HL-BX.

CONCLUSIONS

These results indicated that HL-BX promoted gastric motility by regulating brain-gut neurotransmitters through the MAPK signaling pathway. HL-BX and MAPK provide a potential therapeutic option for the treatment of gastroparesis.

The Effect of Clostridium butyricum on Gut Microbial Changes and Functional Profiles of Metabolism in High-fat Diet-fed Rats Depending on Age and Sex

Background/Aims

A high-fat diet (HFD) causes dysbiosis and promotes inflammatory responses in the colon. This study aims to evaluate the effects of Clostridium butyricum on HFD-induced gut microbial changes in rats.

Methods

Six-week-old Fischer-344 rats with both sexes were given a control or HFD during 8 weeks, and 1-to-100-fold diluted Clostridium butyricum were administered by gavage. Fecal microbiota analyses were conducted using 16S ribosomal RNA metagenomic sequencing and predictive functional profiling of microbial communities in metabolism.

Results

A significant increase in Ruminococcaceae and Lachnospiraceae, which are butyric acid-producing bacterial families, was observed in the probiotics groups depending on sex. In contrast, Akkermansia muciniphila, which increased through a HFD regardless of sex, and decreased in the probiotics groups. A. muciniphila positively correlated with Claudin-1 expression in males (P < 0.001) and negatively correlated with the expression of Claudin-2 (P = 0.042), IL-1β (P = 0.037), and IL-6 (P = 0.044) in females. In terms of functional analyses, a HFD decreased the relative abundances of M00131 (carbohydrate metabolism module), M00579, and M00608 (energy metabolism), and increased those of M00307 (carbohydrate metabolism), regardless of sex. However, these changes recovered especially in male C. butyricum groups. Furthermore, M00131, M00579, and M00608 showed a positive correlation and M00307 showed a negative correlation with the relative abundance of A. muciniphila (P < 0.001).

Conclusion

The beneficial effects of C. butyricum on HFD-induced gut dysbiosis in young male rats originate from the functional profiles of carbohydrate and energy metabolism.

Fusobacterium nucleatum: An Overview of Evidence, Demi-Decadal Trends, and Its Role in Adverse Pregnancy Outcomes and Various Gynecological Diseases, including Cancers

Gynecological and obstetric infectious diseases are crucial to women's health. There is growing evidence that links the presence of Fusobacterium nucleatum (F. nucleatum), an anaerobic oral commensal and potential periodontal pathogen, to the development and progression of various human diseases, including cancers. While the role of this opportunistic oral pathogen has been extensively studied in colorectal cancer in recent years, research on its epidemiological evidence and mechanistic link to gynecological diseases (GDs) is still ongoing. Thus, the present review, which is the first of its kind, aims to undertake a comprehensive and critical reappraisal of F. nucleatum, including the genetics and mechanistic role in promoting adverse pregnancy outcomes (APOs) and various GDs, including cancers. Additionally, this review discusses new conceptual advances that link the immunomodulatory role of F. nucleatum to the development and progression of breast, ovarian, endometrial, and cervical carcinomas through the activation of various direct and indirect signaling pathways. However, further studies are needed to explore and elucidate the highly dynamic process of host-F. nucleatum interactions and discover new pathways, which will pave the way for the development of better preventive and therapeutic strategies against this pathobiont.

Gut Microbial Dysbiosis Differs in Two Distinct Cachectic Tumor-Bearing Models Consuming the Same Diet

The impact of cancer cachexia on the colonic microbiota is poorly characterized. This study assessed the effect of two cachectic-producing tumor types on the gut microbiota to determine if a similar dysbiosis could be found. In addition, it was determined if a diet containing an immunonutrient-rich food (walnuts) known to promote the growth of probiotic bacteria in the colon could alter the dysbiosis and slow cachexia. Male Fisher 344 rats were randomly assigned to a semi-purified diet with or without walnuts. Then, within each diet group, rats were further assigned randomly to a treatment group: tumor-bearing ad libitum fed (TB), non-tumor-bearing ad libitum fed (NTB-AL), and non-tumor-bearing group pair-fed to the TB (NTB-PF). The TB group was implanted either with the Ward colon carcinoma or MCA-induced sarcoma, both transplantable tumor lines. Fecal samples were collected after the development of cachexia, and bacteria species were identified using 16S rRNA gene analysis. Both TB groups developed cachexia but had a differently altered gut microbiome. Beta diversity was unaffected by treatment (NTB-AL, TB, and NTB-PF) regardless of tumor type but was affected by diet. Also, diet consistently changed the relative abundance of several bacteria taxa, while treatment and tumor type did not. The control diet increased the abundance of A. Anaeroplasma, while the walnut diet increased the genus Ruminococcus. There were no common fecal bacterial changes characteristic of cachexia found. Diet consistently changed the gut microbiota, but these changes were insufficient to slow the progression of cachexia, suggesting cancer cachexia is more complex than a few gut microbiota shifts.

Supplementation of Crataegi fructus alleviates functional dyspepsia and restores gut microbiota in mice

Introduction

Functional dyspepsia (FD), also known as non-ulcerative dyspepsia, is a common digestive system disorder.

Methods

In this study, an FD model was established using hunger and satiety disorders combined with an intraperitoneal injection of L-arginine. Indices used to evaluate the efficacy of hawthorn in FD mice include small intestinal propulsion rate, gastric residual rate, general condition, food intake, amount of drinking water, gastric histopathological examination, and serum nitric oxide (NO) and gastrin levels. Based on the intestinal flora and their metabolites, short-chain fatty acids (SCFAs), the mechanism of action of Crataegi Fructus (hawthorn) on FD was studied. The fecal microbiota transplantation test was used to verify whether hawthorn altered the structure of the intestinal flora.

Results

The results showed that hawthorn improved FD by significantly reducing the gastric residual rate, increasing the intestinal propulsion rate, the intake of food and drinking water, and the levels of gastrointestinal hormones. Simultaneously, hawthorn elevated substance P and 5-hydroxytryptamine expression in the duodenum, reduced serum NO levels, and increased vasoactive intestinal peptide expression in the duodenum. Notably, hawthorn increased the abundance of beneficial bacteria and SCFA-producing bacteria in the intestines of FD mice, decreased the abundance of conditional pathogenic bacteria, and significantly increased the SCFA content in feces.

Discussion

The mechanism by which hawthorn improves FD may be related to the regulation of intestinal flora structure and the production of SCFAs.

Putting Functional Gastrointestinal Disorders within the Spectrum of Inflammatory Disorders Can Improve Classification and Diagnostics of These Disorders

The spectrum, intensity, and overlap of symptoms between functional gastrointestinal disorders (FGIDs) and other gastrointestinal disorders characterize patients with FGIDs, who are incredibly different in their backgrounds. An additional challenge with regard to the diagnosis of FGID and the applicability of a given treatment is the ongoing expansion of the risk factors believed to be connected to these disorders. Many cytokines and inflammatory cells have been found to cause the continuous existence of a low level of inflammation, which is thought to be a basic pathophysiological process. The idea of the gut-brain axis has been created to offer a basic framework for the complex interactions that occur between the nervous system and the intestinal functions, including the involvement of gut bacteria. In this review paper, we intend to promote the hypothesis that FGIDs should be seen through the perspective of the network of the neuroendocrine, immunological, metabolic, and microbiome pathways. This hypothesis arises from an increased understanding of chronic inflammation as a systemic disorder, that is omnipresent in chronic health conditions. A better understanding of inflammation's role in the pathogenesis of FGIDs can be achieved by clustering markers of inflammation with data indicating symptoms, comorbidities, and psycho-social factors. Finding subclasses among related entities of FGIDs may reduce patient heterogeneity and help clarify the pathophysiology of this disease to allow for better treatment.

Supplementing probiotics during intermittent fasting proves more effective in restoring ileum and colon tissues in aged rats

This study aimed to explore the impact of SCD Probiotics supplementation on biomolecule profiles and histopathology of ileum and colon tissues during a 30-day intermittent fasting (IF) program. Male Sprague-Dawley rats, aged 24 months, underwent 18-h daily fasting and received 3 mL (1 × 108 CFU) of SCD Probiotics. The differences in biomolecule profiles were determined using FTIR Spectroscopy and two machine learning techniques, Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM), which showed significant differences with high accuracy rates. Spectrochemical bands indicating alterations in lipid, protein and nucleic acid profiles in both tissues. The most notable changes were observed in the group subjected to both IF and SCD Probiotics, particularly in the colon. Both interventions, individually and in combination, decreased protein carbonylation levels. SCD Probiotics exerted a more substantial impact on membrane dynamics than IF alone. Additionally, both IF and SCD Probiotics were found to have protective effects on intestinal structure and stability by reducing mast cell density and levels of TNF-α and NF-κB expression in ileum and colon tissues, thus potentially mitigating age-related intestinal damage and inflammation. Furthermore, our results illustrated that while IF and SCD Probiotics individually instigate unique changes in ileum and colon tissues, their combined application yielded more substantial benefits. This study provides evidence for the synergistic potential of IF and SCD Probiotics in combating age-related intestinal alterations.

Knowledge of Dietitians on Gut Microbiota in Health-An Online Survey of the European Federation of the Associations of Dietitians (EFAD)

Explorations of current knowledge of dietitians about gut-health interconnection and the role of diet in gut microbiota manipulation are rather scarce in the literature. In this online survey we assessed the perceived and current knowledge of dietitians across Europe about gut microbiota and systemic health, nutrition as a modulator of the gut ecosystem, and the role of probiotics and prebiotics. Pre-graduate dietetic students and other professionals were also invited to participate. A total of 179 full responses were recorded (dietitians, n = 155), mainly from Southern and Western regions. Most participants (>78.0%) reported an average to good level of perceived knowledge, with significant positive correlations between perceived and current knowledge in all sections and overall (p for all <0.05). Nevertheless, a rather low current knowledge scoring of participants about probiotics and prebiotics was observed. Features such as being a dietitian, having a higher educational level as dietitian and working in an academic/research setting were usually associated with higher current knowledge. Further analysis revealed that dietitians had a trend for higher scoring about probiotics and prebiotics compared to pre-graduate students or other professionals. Moreover, for dietitians, working in an academic or research setting was an independent factor for scoring in the highest quartile in all tested sections and overall (p for all <0.05). In conclusion, this online survey shed some light on the current knowledge of dietitians across Europe about gut microbiota parameters, including dietary modulation, highlighting in parallel possible knowledge determinants. Potential areas for future educational efforts in this rather unexplored field were indicated.

Untargeted metabolomics analysis reveals spatial metabolic heterogeneity in different intestinal segments of type 1 diabetic mice

Type 1 diabetes (T1D) has been reported to cause systematic metabolic disorders, but metabolic changes in different intestinal segments of T1D remain unclear. In this study, we analyzed metabolic profiles in the jejunum, ileum, cecum and colon of streptozocin-induced T1D and age-matched control (CON) mice by an LC-MS-based metabolomics method. The results show that segment-specific metabolic disorders occurred in the gut of T1D mice. In the jejunum, we found that T1D mainly led to disordered amino acid metabolism and most amino acids were significantly lower relative to CON mice. Moreover, fatty acid metabolism was disrupted mainly in the ileum, cecum and colon of T1D mice, such as arachidonic acid, alpha-linolenic acid and linoleic acid metabolism. Thus, our study reveals spatial metabolic heterogeneity in the gut of T1D mice and provides a metabolic view on diabetes-associated intestinal diseases.

The Association between Functional Dyspepsia and Metabolic Syndrome-The State of the Art

Functional dyspepsia is a common functional disorder of the gastrointestinal tract that is responsible for many primary care visits. No organic changes have been found to explain its symptoms. We hypothesize that modern lifestyles and environmental factors, especially psychological stress, play a crucial role in the high prevalence of functional dyspepsia and metabolic syndrome. While gastrointestinal tract diseases are rarely linked to metabolic disorders, chronic stress, obesity-related metabolic syndrome, chronic inflammation, intestinal dysbiosis, and functional dyspepsia have significant pathophysiological associations. Functional dyspepsia, often associated with anxiety and chronic psychological stress, can activate the neuroendocrine stress axis and immune system, leading to unhealthy habits that contribute to obesity. Additionally, intestinal dysbiosis, which is commonly present in functional dyspepsia, can exacerbate systemic inflammation and obesity, further promoting metabolic syndrome-related disorders. It is worth noting that the reverse is also true: obesity-related metabolic syndrome can worsen functional dyspepsia and its associated symptoms by triggering systemic inflammation and intestinal dysbiosis, as well as negative emotions (depression) through the brain-gut axis. To understand the pathophysiology and deliver an effective treatment strategy for these two difficult-to-cure disorders, which are challenging for both caregivers and patients, a psychosocial paradigm is essential.

Sustained Effectiveness and Safety of Therapeutic miR-10a/b in Alleviating Diabetes and Gastrointestinal Dysmotility without Inducing Cancer or Inflammation in Murine Liver and Colon

microRNAs (miRNAs) are key regulators of both physiological and pathophysiological mechanisms in diabetes and gastrointestinal (GI) dysmotility. Our previous studies have demonstrated the therapeutic potential of miR-10a-5p mimic and miR-10b-5p mimic (miR-10a/b mimics) in rescuing diabetes and GI dysmotility in murine models of diabetes. In this study, we elucidated the safety profile of a long-term treatment with miR-10a/b mimics in diabetic mice. Male C57BL/6 mice were fed a high-fat, high-sucrose diet (HFHSD) to induce diabetes and treated by five subcutaneous injections of miR-10a/b mimics for a 5 month period. We examined the long-term effects of the miRNA mimics on diabetes and GI dysmotility, including an assessment of potential risks for cancer and inflammation in the liver and colon using biomarkers. HFHSD-induced diabetic mice subcutaneously injected with miR-10a/b mimics on a monthly basis for 5 consecutive months exhibited a marked reduction in fasting blood glucose levels with restoration of insulin and significant weight loss, improved glucose and insulin intolerance, and restored GI transit time. In addition, the miR-10a/b mimic-treated diabetic mice showed no indication of risk for cancer development or inflammation induction in the liver, colon, and blood for 5 months post-injections. This longitudinal study demonstrates that miR-10a/b mimics, when subcutaneously administered in diabetic mice, effectively alleviate diabetes and GI dysmotility for 5 months with no discernible risk for cancer or inflammation in the liver and colon. The sustained efficacy and favorable safety profiles position miR-10a/b mimics as promising candidates in miRNA-based therapeutics for diabetes and GI dysmotility.

Role of gut-microbiota in disease severity and clinical outcomes

A delicate balance of nutrients, antigens, metabolites and xenobiotics in body fluids, primarily managed by diet and host metabolism, governs human health. Human gut microbiota is a gatekeeper to nutrient bioavailability, pathogens exposure and xenobiotic metabolism. Human gut microbiota starts establishing during birth and evolves into a resilient structure by adolescence. It supplements the host's metabolic machinery and assists in many physiological processes to ensure health. Biotic and abiotic stressors could induce dysbiosis in gut microbiota composition leading to disease manifestations. Despite tremendous scientific advancements, a clear understanding of the involvement of gut microbiota dysbiosis during disease onset and clinical outcomes is still awaited. This would be important for developing an effective and sustainable therapeutic intervention. This review synthesizes the present scientific knowledge to present a comprehensive picture of the role of gut microbiota in the onset and severity of a disease.