The microbial metabolites, short-chain fatty acids, regulate colonic Treg cell homeostasis

Astragalus polysaccharides alleviate DSS-induced ulcerative colitis in mice by restoring SCFA production and regulating Th17/Treg cell homeostasis in a microbiota-dependent manner

Natural polysaccharides from Astragalus membranaceus have been shown to relieve ulcerative colitis (UC). However, the mechanism and causal relationship between the gut microbiota and Astragalus polysaccharides (APS) treatment of UC are unclear. The results of the present study showed that APS ameliorated colonic injury and the disruption of the gut microbiota and restored intestinal immune homeostasis in mice with DSS-induced colitis. Meanwhile, we found that APS treatment was ineffective in antibiotic-treated colitis mice but was effective when FMT (Fecal microbiota transplantation) was performed on UC mice using APS-treated mice as donors. APS increased the proportion of relevant microbiota that produce SCFAs and both direct administration of APS and administration of APS-adjusted gut microbiota significantly promoted the production of SCFAs in colitis mice. We demonstrated that APS dually inhibited NF-κB activation via the TLR4 and HDAC3 pathways and improved the balance in Th17/Treg cells in UC mice. In conclusion, our study revealed that APS is a promising prebiotic agent for the maintenance of intestinal health and demonstrated that APS may ameliorate colitis in a gut microbiota-dependent manner.

Should we consider microbiota-based interventions as a novel therapeutic strategy for schizophrenia? A systematic review and meta-analysis

Schizophrenia is a chronic psychiatric disorder characterized by a variety of symptoms broadly categorized into positive, negative, and cognitive domains. Its etiology is multifactorial, involving a complex interplay of genetic, neurobiological, and environmental factors, and its neurobiology is associated with abnormalities in different neurotransmitter systems. Due to this multifactorial etiology and neurobiology, leading to a wide heterogeneity of symptoms and clinical presentations, current antipsychotic treatments face challenges, underscoring the need for novel therapeutic approaches. Recent studies have revealed differences in the gut microbiome of individuals with schizophrenia compared to healthy controls, establishing an intricate link between this disorder and gastrointestinal health, and suggesting that microbiota-targeted interventions could help alleviate clinical symptoms. Therefore, this meta-analysis investigates whether gut microbiota manipulation can ameliorate psychotic outcomes in patients with schizophrenia receiving pharmacological treatment. Nine studies (n = 417 participants) were selected from 81 records, comprising seven randomized controlled trials and two open-label studies, all with a low risk of bias, included in this systematic review and meta-analysis. The overall combined effect size indicated significant symptom improvement following microbiota treatment (Hedges' g = 0.48, 95% CI = 0.09 to 0.88, p = 0.004, I2 = 62.35%). However, according to Hedges' g criteria, the effect size was small (approaching moderate), and study heterogeneity was moderate based on I2 criteria. This review also discusses clinical and preclinical studies to elucidate the neural, immune, and metabolic pathways by which microbiota manipulation, particularly with Lactobacillus and Bifidobacterium genera, may exert beneficial effects on schizophrenia symptoms via the gut-brain axis. Finally, we address the main confounding factors identified in our systematic review, highlight key limitations, and offer recommendations to guide future high-quality trials with larger participant cohorts to explore microbiome-based therapies as a primary or adjunctive treatment for schizophrenia.

Shaping immunity: the influence of the maternal gut bacteria on fetal immune development

The development of the fetal immune response is a highly complex process. In the present review, we describe the development of the fetal immune response and the role of the maternal gut bacteria in this process. In contrast to the previous belief that the fetal immune response is inert, it is now thought that the fetal immune response is uniquely tolerant to maternal and allo-antigens, but able to respond to infectious agents, such as bacteria. This is accomplished by the development of T cells toward regulatory T cells rather than toward effector T cells, but also by the presence of functional innate immune cells, such as monocytes and NK cells. Moreover, in fetuses there is different programming of CD8 + T cells and memory T cells toward innate immune cells rather than to adaptive immune cells. The maternal gut bacteria are important in shaping the fetal immune response by producing bacterial products and metabolites that pass the placenta into the fetus and influence development of the fetal immune response. Insight into how and when these products affect the fetal immune response may open new treatment options with pre- or probiotics to affect the maternal gut bacteria and therewith the fetal immune response.

The complex relationship between gut microbiota and Alzheimer's disease: A systematic review

Alzheimer's disease (AD) is a progressive, degenerative disorder of the central nervous system. Despite extensive research conducted on this disorder, its precise pathogenesis remains unclear. In recent years, the microbiota-gut-brain axis has attracted considerable attention within the field of AD. The gut microbiota communicates bidirectionally with the central nervous system through the gut-brain axis, and alterations in its structure and function can influence the progression of AD. Consequently, regulating the gut microbiota to mitigate the progression of AD has emerged as a novel therapeutic approach. Currently, numerous studies concentrate on the intrinsic relationship between the microbiota-gut-brain axis and AD. In this paper, we summarize the multifaceted role of the gut microbiota in AD and present detailed therapeutic strategies targeting the gut microbiota, including the treatment of AD with Traditional Chinese Medicine (TCM), which has garnered increasing attention in recent years. Finally, we discuss potential therapeutic strategies for modulating the gut microbiota to alleviate the progression of AD, the current challenges in this area of research, and provide an outlook on future research directions in this field.

Targeting gut microbiota to regulate the adaptive immune response in atherosclerosis

Atherosclerosis, the leading cause of death worldwide, is a chronic inflammatory disease leading to the accumulation of lipid-rich plaques in the intima of large and medium-sized arteries. Accumulating evidence indicates the important regulatory role of the adaptive immune system in atherosclerosis during all stages of the disease. The gut microbiome has also become a key regulator of atherosclerosis and immunomodulation. Whilst existing research extensively explores the impact of the microbiome on the innate immune system, only a handful of studies have explored the regulatory capacity of the microbiome on the adaptive immune system to modulate atherogenesis. Building on these concepts and the pitfalls on the gut microbiota and adaptive immune response interaction, this review explores potential strategies to therapeutically target the microbiome, including the use of prebiotics and vaccinations, which could influence the adaptive immune response and consequently plaque composition and development.

Effect of Artemisia annua on anticoccidial action, intestinal microbiota and metabolites of Hu lambs

BACKGROUND

Coccidia are among the primary pathogens causing diarrhea and even fatalities in lambs. With the increasing use of chemical drugs to treat coccidiosis, the problem of drug resistance is becoming more and more threatening. Therefore, there is an urgent need to identify novel alternative drugs for the treatment of the lamb coccidia. In this study, the effect of different doses and extraction methods of Artemisia annua (A. annua) on anticoccidial activity and growth performance was assessed by oocysts output (OPG), fecal index, average daily gain (ADG) and the new production value of experimental lambs. High-throughput sequencing technology was employed to investigate the effect of A. annua on the intestinal microbiota and metabolites of lambs afflicted with coccidiosis.

RESULTS

The results revealed that all A. annua treatment groups exhibited good anticoccidial effects. According to the soft stool index and ADG analysis, the Low-dose A. annua (AL) and A. annua alcohol extract (AA) groups demonstrated a better overall effect. The microbiota and metabolites of lambs changed after A. annua was administered. Unclassified_Muribaculaceae exhibited a significant positive correlation with ADG (P < 0.05) and a negative correlation with OPG, although the latter was not statistically significant (P > 0.05). Alistipes displayed a significant negative correlation with ADG (P < 0.05), and a positive correlation with OPG (P > 0.05). Additionally, UCG 005 exhibited a highly significant negative correlation with OPG (P < 0.01).

CONCLUSION

The above results demonstrated that AL and AA groups had more effective anticoccidial action. Unclassified_Muribaculaceae could be employed as a suitable probiotic to enhance weight gain in lambs, while UCG-005 could inhibit intestinal Eimeria colonization in lambs. Alistipes may serve as a biomarker for predicting the risk of intestinal coccidia outbreaks in lambs. A. annua induced significant changes in gut microbiota, accompanied by corresponding changes in metabolites. These differences in gut microbiota and metabolites provide valuable insights for subsequent research on the mechanisms underlying anticoccidial action.

Oral amoxicillin treatment disrupts the gut microbiome and metabolome without interfering with luminal redox potential in the intestine of Wistar Han rats

Oral antibiotic treatment is well known to be one of the main factors affecting gut microbiota composition by altering bacterial diversity. It decreases the abundance of butyrate-producing bacteria such as Lachnospiraceae and Ruminococcaceae, while increasing abundance of Enterobacteriaceae. The recovery time of commensal bacteria post-antibiotic treatment varies among individuals, and often, complete recovery is not achieved. Recently, gut microbiota disruption has been associated with increased gut oxygen levels and higher redox potential in faecal samples. Given that redox balance is crucial for microbial metabolism and gut health, influencing fermentation processes and maintaining anaerobic conditions, we investigated the impact of oral amoxicillin treatment on the redox potential in the caecum. We used 24 Wistar Han male rats and measured caecal redox potential in situ with a probe, before and after 7 days of amoxicillin treatment, as well as after 7 days of recovery. Additionally, we analysed caecal weight, pH, antioxidant capacity, caecal microbiota, metabolome, and colonic tissue expression of relevant genes involved in the redox potential state. Our findings show that oral amoxicillin treatment significantly reduced archaeal load, and decreased the bacterial alpha diversity and affected bacterial composition of the caecal microbiome. The caecal metabolome was also significantly affected, exemplified by reduced amounts of short chain fatty acids during amoxicillin treatment. While the caecal metabolome fully recovered 7 days post amoxicillin treatment, the microbiome did not fully recover within this time frame. However, amoxicillin did not lead to an increase in luminal redox potential in the cecum during or post amoxicillin treatment. Limited differences were observed for colonic expression of genes involved in intestinal barrier function and generation of reactive oxygen species, except for the catalase gene, which was significantly upregulated post-amoxicillin treatment. Our results suggest that while oral amoxicillin disrupts the gut microbiome and metabolome, it does not directly interfere with gut luminal redox state.

Aging and sex differences in salt sensitivity of blood pressure

Salt sensitivity of blood pressure (SSBP) is a complex physiological trait characterized by changes in blood pressure in response to dietary salt intake. Aging introduces an additional layer of complexity to the pathophysiology of SSBP, with mitochondrial dysfunction, epigenetic modifications, and alterations in gut microbiota emerging as critical factors. Despite advancements in understanding these mechanisms, the processes driving increased salt sensitivity with age and their differential impacts across sexes remain unclear. This review explores the current understanding of salt sensitivity, delving into its underlying mechanisms, the role of inflammation, and the influence of aging and sex differences on these processes. We also aim to provide insights into the multifaceted nature of salt sensitivity and its implications for personalized treatment strategies in hypertension management.

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

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

Application of Raman Spectroscopy in Non-Invasive Analysis of the Gut Microbiota and Its Impact on Gastrointestinal Health

The gut microbiota, a complex community of microorganisms, plays a crucial role in gastrointestinal (GI) health, influencing digestion, metabolism, immune function, and the gut-brain axis. Dysbiosis, or an imbalance in microbiota composition, is associated with GI disorders, including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and colorectal cancer (CRC). Conventional microbiota analysis methods, such as next-generation sequencing (NGS) and nuclear magnetic resonance (NMR), provide valuable insights but are often expensive, time-consuming, and destructive. Raman spectroscopy (RS) is a non-invasive, cost-effective, and highly sensitive alternative. This analytical technique relies on inelastic light scattering to generate molecular "fingerprints", enabling real-time, marker-free analysis of microbiota composition and metabolic activity. This review explores the principles, sample preparation techniques, and advancements in RS, including surface-enhanced Raman spectroscopy (SERS), for microbiota research. RS facilitates identifying microbial species, analysing key metabolites like short-chain fatty acids (SCFA), and monitoring microbiota responses to dietary and therapeutic interventions. The comparative analysis highlights RS's advantages over conventional techniques, such as the minimal sample preparation, real-time capabilities, and non-destructive nature. The integration of RS with machine learning enhances its diagnostic potential, enabling biomarker discovery and personalised treatment strategies for GI disorders. Challenges, including weak Raman signals and spectral complexity, are discussed alongside emerging solutions. As RS technology advances, mainly through portable spectrometers and AI integration, its clinical application in microbiota diagnostics and personalised medicine is poised to transform GI healthcare, bridging microbiota research with practical therapeutic strategies.

Changes in Gut Microbiota According to Disease Severity in a Lupus Mouse Model

Systemic lupus erythematosus (SLE) is a multifaceted autoimmune disease driven by immune dysregulation. This study investigated the relationship between gut microbiota and lupus severity using the MRL/lpr lupus mouse model. Mice were grouped based on total immunoglobulin (Ig)G, IgG2a levels, and urine albumin-to-creatinine ratio (ACR), allowing for the comparison of gut microbiota profiles across different disease severities. Interestingly, severe lupus mice exhibited significant reductions in Ruminiclostridium cellulolyticum, Lactobacillus johnsonii, and Kineothrix alysoides, while Clostridium saudiense, Pseudoflavonifractor phocaeensis, and Intestinimonas butyriciproducens were enriched. These microbial shifts correlated with elevated IgG, IgG2a, and ACR levels, indicating that changes in the gut microbiome may directly influence key immunological markers associated with lupus severity. The depletion of beneficial species and the enrichment of potentially pathogenic bacteria appear to contribute to immune activation and disease progression. This study suggests that gut microbiota dysbiosis plays a critical role in exacerbating lupus by modulating immune responses, reinforcing the link between microbial composition and lupus pathogenesis. Our findings provide the first evidence identifying these distinct gut microbial species as potential contributors to lupus severity, highlighting their role as key factors in disease progression.

Dietary content and eating behavior in ulcerative colitis: a narrative review and future perspective

Ulcerative colitis (UC) has experienced a steady increase in global incidence and prevalence recently. Current research into UC pathogenesis focuses on the complex interplay of genetic and environmental factors with the immune system and gut microbiome, leading to disruption of the intestinal barrier. Normally, the microbiome, intestinal epithelium, and immune system interact to maintain intestinal homeostasis. However, when this equilibrium is disturbed, a harmful cycle of dysbiosis, immune dysregulation, and inflammation emerges, resulting in intestinal barrier dysfunction and UC progression. Among various risk factors, diet significantly influences epithelial barrier integrity and architectural stability through both direct and indirect mechanisms, shaping the entire UC continuum from pre-clinical prevention to active phase treatment and remission maintenance. This review provides insights into the impact of dietary content and eating behaviors on UC, focusing on specific food, food groups, nutrients, and intermittent fasting, while providing a detailed explanation of why the gut microbiota may mediate the sustained effects of diet across all stages of UC. Additionally, it addresses the limitations of current studies, explores underexamined areas in UC dietary research and proposes potential directions for future research and expansion.

Gut Microbiota-Bone Axis

BACKGROUND

Knowledge of the complex interplay between gut microbiota and human health is gradually increasing as it has just recently been a field of such great interest.

SUMMARY

Recent studies have reported that communities of microorganisms inhabiting the gut influence the immune system through cellular responses and shape many physiological and pathophysiological aspects of the body, including muscle and bone metabolism (formation and resorption). Specifically, the gut microbiota affects skeletal homeostasis through changes in host metabolism, the immune system, hormone secretion, and the gut-brain axis. The major role on gut-bone axis is due to short-chain fatty acids (SCFAs). They have the ability to influence regulatory T-cell (Tregs) development and activate bone metabolism through the action of Wnt10. SCFA production may be a mechanism by which the microbial community, by increasing the serum level of insulin-like growth factor 1 (IGF-1), leads to the growth and regulation of bone homeostasis. A specific SCFA, butyrate, diffuses into the bone marrow where it expands Tregs. The Tregs induce production of the Wnt ligand Wnt10b by CD8+ T cells, leading to activation of Wnt signaling and stimulation of bone formation. At the hormonal level, the effect of the gut microbiota on bone homeostasis is expressed through the biphasic action of serotonin. Some microbiota, such as spore-forming microbes, regulate the level of serotonin in the gut, serum, and feces. Another group of bacterial species (Lactococcus, Mucispirillum, Lactobacillus, and Bifidobacterium) can increase the level of peripheral/vascular leptin, which in turn manages bone homeostasis through the action of brain serotonin.

The gut microbiome, immune modulation, and cognitive decline: insights on the gut-brain axis

The gut microbiome has emerged as a pivotal area of research due to its significant influence on the immune system and cognitive functions. Cognitive disorders, including dementia and Parkinson's disease, represent substantial global health challenges. This review explores the relationship between gut microbiota, immune modulation, and cognitive decline, with a particular focus on the gut-brain axis. Research indicates that gut bacteria produce metabolites, including short-chain fatty acids (SCFAs), which affect mucosal immunity, antigen presentation, and immune responses, thereby influencing cognitive functions. A noteworthy correlation has been identified between imbalances in the gut microbiome and cognitive impairments, suggesting novel pathways for the treatment of cognitive disorders. Additionally, factors such as diet, environment, and pharmaceuticals play a role in shaping the composition of the gut microbiome, subsequently impacting both immune and cognitive health. This article aims to clarify the complex interactions among gut microbiota, immune regulation, and cognitive disorders, evaluating their potential as therapeutic targets. The goal is to promote microbiome-based treatments and lay the groundwork for future research in this field.

Akkermansia muciniphila and its metabolite propionic acid maintains neuronal mitochondrial division and autophagy homeostasis during Alzheimer's disease pathologic process via GPR41 and GPR43

BACKGROUND

Alzheimer's disease (AD) is a prevalent neurodegenerative disease (ND). In recent years, multiple clinical and animal studies have shown that mitochondrial dysfunction may be involved in the pathogenesis of AD. In addition, short-chain fatty acids (SCFA) produced by intestinal microbiota metabolism have been considered to be important factors affecting central nervous system (CNS) homeostasis. Among the main mediators of host-microbe interactions, volatile fatty acids play a crucial role. Nevertheless, the influence and pathways of microorganisms and their metabolites on Alzheimer's disease (AD) remain uncertain.

RESULTS

In this study, we present distinctions in blood and fecal SCFA levels and microbiota composition between healthy individuals and those diagnosed with AD. We found that AD patients showed a decrease in the abundance of Akkermansia muciniphila and a decrease in propionic acid both in fecal and in blood. In order to further reveal the effects and the mechanisms of propionic acid on AD prevention, we systematically explored the effects of propionic acid administration on AD model mice and cultured hippocampal neuronal cells. Results showed that oral propionate supplementation ameliorated cognitive impairment in AD mice. Propionate downregulated mitochondrial fission protein (DRP1) via G-protein coupled receptor 41 (GPR41) and enhanced PINK1/PARKIN-mediated mitophagy via G-protein coupled receptor 43 (GPR43) in AD pathophysiology which contribute to maintaining mitochondrial homeostasis both in vivo and in vitro. Administered A. muciniphila to AD mice before disease onset showed improved cognition, mitochondrial division and mitophagy in AD mice.

CONCLUSIONS

Taken together, our results demonstrate that A. muciniphila and its metabolite propionate protect against AD-like pathological events in AD mouse models by targeting mitochondrial homeostasis, making them promising therapeutic candidates for the prevention and treatment of AD. Video Abstract.

A bibliometric study on the impact of gut microbiota on the efficacy of immune checkpoint inhibitors in cancer patients: analysis of the top 100 cited articles

Background

Immune checkpoint inhibitors (ICIs) have transformed oncological treatment by modulating immune responses against tumors. However, their efficacy is subject to inter-patient variability and is associated with immune-related adverse events (irAEs). The human gut microbiota, a complex microbial ecosystem, is increasingly implicated in modulating responses to ICIs. This bibliometric analysis examines the 100 most-cited articles to elucidate trends and advancements in research concerning the gut microbiota's impact on ICI efficacy.

Methods

A systematic literature retrieval was conducted within the Web of Science Core Collection (WoSCC), focusing on the 100 most-cited articles. VOSviewer and CiteSpace were utilized for bibliometric analysis, examining collaborative patterns and keyword co-occurrences. The relationship between citing and cited entities was analyzed, and burst ranking identified research hotspots based on citation frequency.

Results

The 100 most-cited publications encompassed a range of disciplines, with a predominance of oncological research. The United States and China were leading in publication volume, with France and Canada also contributing significantly. French institutions, particularly INSERM and Université Paris Cite, were prolific. Routy, Bertrand and Zitvogel, Laurence were prominent among high-impact authors. Dominant keywords included "gut microbiota," "immunotherapy," "efficacy," and "cancer." The article by Routy et al. (2018) was the most frequently cited.

Conclusions

This study highlights the significant role of the gut microbiota in ICI development and efficacy, emphasizing the necessity for international and interdisciplinary collaboration. The research is progressively focusing on managing immunotherapy side effects and optimizing treatment strategies. Challenges, including individual variability in gut microbiota composition, persist. Further research is imperative to exploit the potential of the gut microbiota in cancer therapy, advocating for personalized approaches and a more profound comprehension of the underlying mechanisms.

Metabolic tug-of-war: Microbial metabolism shapes colonization resistance against enteric pathogens

A widely recognized benefit of gut microbiota is that it provides colonization resistance against enteric pathogens. The gut microbiota and their products can protect the host from invading microbes directly via microbe-pathogen interactions and indirectly by host-microbiota interactions, which regulate immune system function. In contrast, enteric pathogens have evolved mechanisms to utilize microbiota-derived metabolites to overcome colonization resistance and increase their pathogenic potential. This review will focus on recent studies of metabolism-mediated mechanisms of colonization resistance and virulence strategies enteric pathogens use to overcome them, along with how induction of inflammation by pathogenic bacteria changes the landscape of the gut and enables alternative metabolic pathways. We will focus on how intestinal pathogens counteract the protective effects of microbiota-derived metabolites to illustrate the growing appreciation of how metabolic factors may serve as crucial virulence determinants and overcome colonization resistance.

A yeast-based oral therapeutic delivers immune checkpoint inhibitors to reduce intestinal tumor burden

Engineered probiotics are an emerging platform for in situ delivery of therapeutics to the gut. Herein, we developed an orally administered, yeast-based therapeutic delivery system to deliver next-generation immune checkpoint inhibitor (ICI) proteins directly to gastrointestinal tumors. We engineered Saccharomyces cerevisiae var. boulardii (Sb), a probiotic yeast with high genetic tractability and innate anticancer activity, to secrete "miniature" antibody variants that target programmed death ligand 1 (Sb_haPD-1). When tested in an ICI-refractory colorectal cancer (CRC) mouse model, Sb_haPD-1 significantly reduced intestinal tumor burden and resulted in significant shifts to the immune cell profile and microbiome composition. This oral therapeutic platform is modular and highly customizable, opening new avenues of targeted drug delivery that can be applied to treat a myriad of gastrointestinal malignancies.

From Gut to Brain: The Impact of Short-Chain Fatty Acids on Brain Cancer

The primary source of short-chain fatty acids (SCFAs), now recognized as critical mediators of host health, particularly in the context of neurobiology and cancer development, is the gut microbiota's fermentation of dietary fibers. Recent research highlights the complex influence of SCFAs, such as acetate, propionate, and butyrate, on brain cancer progression. These SCFAs impact immune modulation and the tumor microenvironment, particularly in brain tumors like glioma. They play a critical role in regulating cellular processes, including apoptosis, cell differentiation, and inflammation. Moreover, studies have linked SCFAs to maintaining the integrity of the blood-brain barrier (BBB), suggesting a protective role in preventing tumor infiltration and enhancing anti-tumor immunity. As our understanding of the gut-brain axis deepens, it becomes increasingly important to investigate SCFAs' therapeutic potential in brain cancer management. Looking into how SCFAs affect brain tumor cells and the environment around them could lead to new ways to prevent and treat these diseases, which could lead to better outcomes for people who are dealing with these challenging cancers.

16S rRNA and metabolomics reveal the key microbes and key metabolites that regulate diarrhea in Holstein male calves

Introduction

Diarrhea is a prevalent disease among calves, which significantly hinders their growth and development, thereby impacting farm productivity and revenue. This study aimed to investigate the impact of diarrhea on calf growth.

Methods

Holstein male calves with similar birth weight (39.5 ± 4.2 kg) were included in this study, and key parameters such as fecal score, diarrhea incidence, and growth performance from birth to weaning were measured. Rectal fecal samples from both diarrheic (n = 24) and healthy calves (n = 24) aged 1-4 weeks were analyzed using 16S rRNA gene sequencing and untargeted metabolomics.

Results

Our findings indicated a high prevalence of diarrhea among calves between 1-4 weeks of age on pasture, which led to a marked decrease in growth performance, including average daily gain. At the genus level, the relative abundance of GCA-900066575 in one-week-old diarrheic calves was significantly higher; Escherichia-Shigella and Pseudoflavonifractor were more abundant in two-week-old calves; while Tyzzerella and Lachnospiraceae_UCG-004 increased significantly in four-week-old calves, and correlated negatively with average daily gain, suggesting that these bacteria may promote the occurrence of diarrhea. Correlation analysis revealed that fecal metabolites such as arachidonic acid, cis-vaccenic acid, oleic acid, choline, creatinine, and others were significantly negatively correlated with calf growth performance and were significantly increased in diarrheic calves. WGNCA identified that dark magenta module metabolites were significantly associated with diarrhea traits from 1-4 weeks. Thirteen metabolites, including glycerophospholipids (such as 1-stearoyl-2-hydroxy-sn-glycero-3-phosphoethanolamine), fatty acids (such as dodecanoic acid), and arachidonic acid, were positively correlated with GCA-900066575, Escherichia-shigella, Tyzzerella, and Clostridium_butyricum, but negatively correlated with UBA1819, Lachnoclostridium_sp_YL32, and Clostridium_scindens.

Discussion

Therefore, GCA-900066575, Escherichia-shigella, Lachnospiraceae_UCG-004, and Tyzzerella are likely key bacterial genera causing diarrhea in calves, while arachidonic acid, glycerol phospholipids, and fatty acids are critical metabolites associated with this condition. These alterations in the fecal microbiota and metabolite composition were found to be the principal contributors to growth retardation in diarrheic calves.

Gut microbiota modulation in cardiac cell therapy with immunosuppression in a nonhuman primate ischemia/reperfusion model

Gut microbiota affect transplantation outcomes; however, the influence of immunosuppression and cell therapy on the gut microbiota in cardiovascular care remains unexplored. We investigated gut microbiota dynamics in a nonhuman primate (NHP) cardiac ischemia/reperfusion model while under immunosuppression and receiving cell therapy with human induced pluripotent stem cell (hiPSC)-derived endothelial cells (EC) and cardiomyocytes (CM). Both immunosuppression and EC/CM co-treatment increased gut microbiota alpha diversity. Immunosuppression promoted anaerobes, such as Faecalibacterium, Streptococcus, Anaerovibrio and Dialister, and altered amino acid metabolism and nucleosides/nucleotides biosynthesis in host plasma. EC + CM cotreatment favors Phascolarctobacterium, Fusicatenibacter, Erysipelotrichaceae UCG-006, Veillonella and Mailhella. Remarkably, gut microbiota of the EC/CM co-treatment group resembled that of the pre-injury group, and the NHPs exhibited a metabolic shift towards amino acid and fatty acid/lipid biosynthesis in plasma following cell therapy. The interplay between shift in microbial community and host homeostasis during treatment suggests gut microbiome modulation could improve cell therapy outcomes.

Intratumor microbiome-derived butyrate promotes chemo-resistance in colorectal cancer

Introduction

Colorectal cancer (CRC) is a leading cause of cancer-related mortality globally. Although tumor immunotherapy is widely recognized for treating unresectable CRC, challenges such as ineffective immunotherapy and drug resistance remain prevalent. While intratumor microbiome-derived butyrate has been implicated in promoting lung cancer metastasis, its role in CRC chemoresistance is not well understood. This study aimed to explore the relationship between intratumor butyrate and chemoresistance in CRC.

Methods

We performed a comprehensive analysis of the microbiome composition in CRC patients with varying resistance-free survival (RFS) durations, utilizing 16S rRNA sequencing. Furthermore, we assessed the prognostic significance of circulating microbiome DNA (cmDNA) and examined the effects of exogenous butyrate supplementation on the chemosensitivity of CRC cell lines.

Results

Our 16S sequencing analysis revealed a reduction in microbial diversity within tumor samples of patients with resistance, as indicated by metrics such as observed taxonomic units, Shannon, and Simpson indices. Notably, Roseburia and Fusobacteria emerged as prominent biomarkers for the resistance group, whereas Bifidobacterium, Helicobacter, and Akkermansia were identified as biomarkers for the non-resistant group. Utilizing a Lasso regression model, we identified six genera-Roseburia, Helicobacter, Gardnerella, Flavonifractor, Coprococcus, and Anaerostipes-that significantly correlated with recurrence-free survival. Furthermore, both the intratumor microbiome signature and circulating microbiome DNA were effective in accurately predicting CRC resistance. Experimental assays, including CCK8 and wound-healing, demonstrated that intratumor microbiome-derived butyrate enhances the proliferation and migration of HCT15 cells in a time- and concentration-dependent manner. Cell survival analysis further indicated that butyrate treatment significantly increased the IC50 value, suggesting heightened drug resistance in HCT15 cells. Mechanistically, this resistance was attributed to butyrate's activation of the PI3K-AKT signaling pathway.

Conclusion

Our results suggest that intratumor microbiome-derived butyrate contributes to chemoresistance in colorectal cancer, highlighting the potential prognostic and therapeutic significance of the intratumor microbiome.

Interactions of human milk oligosaccharides with the immune system

Human milk oligosaccharides (HMOs) are abundant, diverse and complex sugars present in human breast milk. HMOs are well-characterized barriers to microbial infection and by modulating the human microbiome they are also thought to be nutritionally beneficial to the infant. The structural variety of over 200 HMOs, including neutral, fucosylated and sialylated forms, allows them to interact with the immune system in various ways. Clinically, HMOs impact allergic diseases, reducing autoimmune and inflammatory responses, and offer beneficial support to the preterm infant immune health. This review examines the HMO composition and associated immunomodulatory effects, including interactions with immune cell receptors and gut-associated immune responses. These immunomodulatory properties highlight the potential for HMO use in early stage immune development and for use as novel immunotherapeutics. HMO research is rapidly evolving and promises innovative treatments for immune-related conditions and improved health outcomes.

Novel Insight into the Modulatory Effect of Traditional Chinese Medicine on Cerebral Ischemia-Reperfusion Injury by Targeting Gut Microbiota: A Review

Cerebral ischemia-reperfusion injury (CIRI) is clinically characterized by high rates of morbidity, disability, mortality, and recurrence as well as high economic burden. The clinical manifestations of CIRI are often accompanied by gastrointestinal symptoms such as intestinal bacterial dysbiosis and gastrointestinal bleeding. Gut microbiota plays an important role in the pathogenesis of CIRI, and its potential biological effects have received extensive attention. The gut microbiota not only affects intestinal barrier function but also regulates gastrointestinal immunity and host homeostasis. Traditional Chinese medicine (TCM), a multi-component and multi-targeted drug, has shown remarkable effects and few adverse reactions in the prevention and treatment of CIRI. Notably, the effect of TCM on CIRI by regulating gut microbiota and maintaining gastrointestinal homeostasis has gradually become a hot topic. This review summarizes the functional role of the gut microbiota in the development and progression of CIRI and the therapeutic effects of TCM on CIRI by improving gut microbiota dysbiosis, affecting gut microbiota metabolism, and maintaining host immunity. The active ingredients of TCM used for the treatment of CIRI in relevant studies were saponins, triterpenoids, phenolics, and alkaloids. In addition, the clinical effects of TCM used to treat CIRI were briefly discussed. This review established the clinical significance and development prospects of TCM-based CIRI treatments and provided the necessary theoretical support for the further development of TCM resources for the treatment of CIRI.

The ultimate microbial composition for correcting Th17/Treg cell imbalance and lipid metabolism disorders in osteoporosis

Osteoporosis is a systemic bone disease characterised by decreased bone mass and a deteriorated bone microstructure, leading to increased bone fragility and fracture risk. Disorders of the intestinal microbiota may be key inducers of osteoporosis. Furthermore, such disorders may contribute to osteoporosis by influencing immune function and lipid metabolism. Therefore, in this review, we aimed to summarise the molecular mechanisms through which the intestinal microbiota affect the onset and development of osteoporosis by regulating Th17/Treg imbalance and lipid metabolism disorders. We also discussed the regulatory mechanisms underlying the effect of intestinal microbiota-related modulators on Th17/Treg imbalance and lipid metabolism disorders in osteoporosis, to explore new molecular targets for its treatment and provide a theoretical basis for clinical management.

Inhibition of skin fibrosis via regulation of Th17/Treg imbalance in systemic sclerosis

Systemic sclerosis (SSc) is an idiopathic systemic connective tissue disorder characterized by fibrosis of the skin and internal organs, with growing interest in the imbalance between Th17 cells and regulatory T cells (Tregs) in the disease's pathogenesis. Heligmosomoides polygyrus (Hp), a natural intestinal parasite of mice, is known to induce Tregs in the host. We aimed to investigate the effects of Hp-induced Tregs on bleomycin-induced dermal fibrosis and clarify the role of the Th17/Treg balance in SSc fibrosis. Infection with Hp suppressed the development of bleomycin-induced dermal fibrosis and the infiltration of CD3+ T cells and CD68+ macrophages. Flow cytometric analysis revealed that Hp infection increased Tregs and inhibited the induction of bleomycin-induced Th17 cells. Treg depletion nullified these effects, suggesting that Hp-induced Tregs may prevent bleomycin-induced dermal fibrosis and inflammation. Analysis of the intestinal microbiota showed that bacteria positively correlated with Tregs exhibited a negative correlation with Th17 cells and dermal fibrosis in mice. SSc patients with severe fibrosis displayed a distinct microbiota profile. These results suggest that alterations in the intestinal microbiota may contribute to the Th17/Treg imbalance in SSc and its progression. Enhancing Tregs to regulate the Th17/Treg imbalance may present a promising strategy for suppressing fibrosis in SSc.

Effects of antibiotic therapy on the early development of gut microbiota and butyrate-producers in early infants

Background

Antibiotics, as the most commonly prescribed class of drugs in neonatal intensive care units, have an important impact on the developing neonatal gut microbiota. Therefore, comprehending the effects of commonly used antibiotic therapy on the gut microbiota and butyrate-producers in early infants could provide information for therapeutic decision-making in the NICU.

Objectives

To explore the effects of antibiotic therapy on the early development of gut microbiota and butyrate-producers in early infants.

Methods

A total of 72 infants were included in the study. We performed 16S rRNA sequencing on stool swab samples collected from neonatal intensive care unit patients who received amoxicillin-clavulanic acid (AC, n = 10), moxalactam (ML, n = 28) and non-antibiotics (NA, n = 34). We then compared the taxonomic composition between treatment regimens, focusing on differences in butyrate-producers.

Results

Our study showed that there were significant differences in Shannon index (p = 0.033) and Beta diversity (p = 0.014) among the three groups. At the family level, compared with the other two groups, the relative abundance of Clostridiaceae (p < 0.001) and Veillonellaceae (p = 0.004) were significantly higher, while the relative abundance of Enterococcidae (p < 0.001) was significantly lower in the NA group. The relative abundance of Enterobacteriaceae (p = 0.022) in the AC group was greater than that in the other two groups. Additionally, butyrate-producers (p < 0.001), especially Clostridiaceae (p < 0.001), were noticeably more abundant in the NA group. The relative abundance of Clostridiaceae and butyrate-producers were the lowest in the ML group (p < 0.001).

Conclusion

We found that antibiotic therapy had an adverse impact on the initial development of gut microbiota and leaded to a reduction in the abundance of butyrate-producers, particularly Clostridiaceae. Furthermore, moxalactam had a more pronounced effect on the gut microbiota compared to amoxicillin-clavulanic acid.

Ferroptosis: A New Pathway in the Interaction between Gut Microbiota and Multiple Sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disorder marked by neuroinflammation, demyelination, and neuronal damage. Recent advancements highlight a novel interaction between iron-dependent cell death, known as ferroptosis, and gut microbiota, which may significantly influences the pathophysiology of MS. Ferroptosis, driven by lipid peroxidation and tightly linked to iron metabolism, is a pivotal contributor to the oxidative stress observed in MS. Concurrently, the gut microbiota, known to affect systemic immunity and neurological health, emerges as an important regulator of iron homeostasis and inflammatory responses, thereby influencing ferroptotic pathways. This review investigates how gut microbiota dysbiosis and ferroptosis impact MS, emphasizing their potential as therapeutic targets. Through an integrated examination of mechanistic pathways and clinical evidence, we discuss how targeting these interactions could lead to novel interventions that not only modulate disease progression but also offer personalized treatment strategies based on gut microbiota profiling. This synthesis aims at deepening insights into the microbial contributions to ferroptosis and their implications in MS, setting the stage for future research and therapeutic exploration.

Xylo-oligosaccharides enhance intestinal and thymic immunity by modulating pyroptosis, gut microbiota, and Th17/Treg immune response in lipopolysaccharide-challenged piglets

Xylo-oligosaccharides (XOS) have been shown to improve the immune system of weaned piglets, but the molecular mechanism of their action remains unclear. Therefore, this study aimed to investigate the impact of XOS on intestinal and thymic immune function in weaned piglets challenged with lipopolysaccharide (LPS) and elucidate the underlying mechanism. In a 2 × 2 factorial arrangement, consisting of diet treatment (basal diet vs 0.02% XOS diet) and immunological challenge [saline vs LPS], 24 piglets were randomly divided into 4 groups (n = 6): CON group, basal diet + saline; LPS group, basal diet + LPS; XOS group, 0.02% XOS diet + saline; XOS_LPS group, 0.02% XOS diet + LPS. Piglets were fed either the basal or XOS diet for 21 d, followed by intraperitoneal injections of normal saline or LPS on the 22nd day. Ileum, thymus, and colon samples were collected 4 h after the intraperitoneal saline or LPS injection. The piglets fed the XOS diet had higher average daily feed intake and average daily weight gain (P < 0.05). The XOS diet increased ileal villus height and decreased crypt depth. XOS also enhanced ileal and thymic antioxidant enzyme activities, anti-inflammatory cytokine expression, and decreased malondialdehyde levels and mRNA abundance of pro-inflammatory cytokines in piglets (P < 0.05). The XOS diet also downregulated the ileal and thymic NOD-like receptor family pyrin domain containing 3 and gasdermin-D gene and protein expression associated with pyroptosis (P < 0.05). Moreover, The XOS diet increased the mRNA abundance of forkhead box P3, signal transducer and activator of transcription 5, and transforming growth factor beta 1 while decreasing signal transducer and activator of transcription 3 and retinoid-related orphan receptor-gammat mRNA abundance (P < 0.05). The XOS diet enhanced forkhead box P3 protein expression and reduced retinoid-related orphan receptor-gammat protein expression following the LPS challenge (P < 0.05). At the same time, The XOS diet affected the gut microbiota and increased levels of short-chain fatty acids (P < 0.05). In conclusion, XOS may modulate ileal and thymic immune function in weaned piglets following a 4-h LPS challenge by affecting gut microbiota, pyroptosis, and Th17/Treg immune responses.

Advancing therapeutic strategies for graft-versus-host disease by targeting gut microbiome dynamics in allogeneic hematopoietic stem cell transplantation: current evidence and future directions

Hematopoietic stem cell transplantation (HSCT) is a highly effective therapy for malignant blood illnesses that pose a high risk, as well as diseases that are at risk due to other variables, such as genetics. However, the prevalence of graft-versus-host disease (GVHD) has impeded its widespread use. Ensuring the stability of microbial varieties and associated metabolites is crucial for supporting metabolic processes, preventing pathogen intrusion, and modulating the immune system. Consequently, it significantly affects the overall well-being and susceptibility of the host to disease. Patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) may experience a disruption in the balance between the immune system and gut bacteria when treated with medicines and foreign cells. This can lead to secondary intestinal inflammation and GVHD. Thus, GM is both a reliable indicator of post-transplant mortality and a means of enhancing GVHD prevention and treatment after allo-HSCT. This can be achieved through various strategies, including nutritional support, probiotics, selective use of antibiotics, and fecal microbiota transplantation (FMT) to target gut microbes. This review examines research advancements and the practical use of intestinal bacteria in GVHD following allo-HSCT. These findings may offer novel insights into the prevention and treatment of GVHD after allo-HSCT.

Optimising vaccine immunogenicity in ageing populations: key strategies

Vaccination has been shown to be the most effective means of preventing infectious diseases, although older people commonly have a suboptimal immune response to vaccines and thus impaired protection against subsequent adverse outcomes. This Review provides an overview of the existing mechanistic insights into compromised vaccine response for respiratory infectious diseases in older people, defined as aged 65 years and older, including immunosenescence, epigenetic regulation, trained immunity, and gut microbiota. We further summarise the latest proven or potential strategies to strengthen weakened immunogenicity. Insights from these analyses will be conducive to the development of the next generation of vaccines.

The impact of fibre and prebiotic interventions on outcomes in cancer and haematopoietic stem cell transplantation: A systematic review

BACKGROUND & AIMS

Cancer therapy is associated with a range of toxicities that severely impact patient well-being and a range of clinical outcomes. Dietary fibre/prebiotics characteristically improve the gastrointestinal microenvironment, which consequently elicits beneficial downstream effects that could be relevant to the prevention and management of treatment-related toxicities. Despite the compelling theoretical scientific rationale there has been limited effort to synthesise the available evidence to conclude such scientific underpinning to the clinical use of fibre/prebiotics in cancer patients. Therefore, this systematic review aimed to evaluate the clinical impact of fibre/prebiotic-based interventions on gastrointestinal-side effects; gastrointestinal-microbiome; clinical outcomes; nutrition status and body composition; and quality-of-life in children and adults being treated for cancer or undergoing a haematopoietic stem cell transplant (HSCT).

METHODS

This study was conducted in adherence to PRISMA guidelines, and the protocol was published prospectively with PROSPERO (CRD42022299428). Three databases (MEDLINE (Ovid), CINHAL, EMBASE) were searched from inception to December 2023. All articles were assessed for bias using the Cochrane risk-of-bias tool RoB 2.0 (for RCTs) and ROBINS-I (for non-RCTs).

RESULTS

A total of 9989 de-duplicated records were identified, of these, 14 (paediatrics [n = 1], adults [n = 13]) met the inclusion criteria (randomised controlled trials (RCT) [n = 11], observational or non-RCTs [n = 3]). The risk-of-bias was graded to be serious/high (n = 6); moderate/some concerns (n = 7); low (n = 1). Interventions included prebiotic supplement (n = 8), nutrition supplement/formula with added fibre/prebiotic (n = 3) and dietary modification (n = 3). The dose of fibre intervention ranged from 2.4g to 30g per day. Substantial heterogeneity of target parameters was identified across a range all outcome categories, precluding definitive conclusions.

CONCLUSION

The scientific rationale for fibre/prebiotics-based interventions for the prevention or management of cancer treatment-related toxicities is compelling. However, it is clear that the scientific and clinical field remains disconnected in how to effectively translate this approach to improve cancer outcomes. High-quality intervention studies translatable to clinical practice are now evidently crucial to determine if and how fibre/prebiotics should be used to support people undergoing cancer or HSCT therapy.

Butyrate attenuates SA-AKI by inhibiting pyroptosis via the STING-GSDMD axis

Sepsis-associated acute kidney injury (SA-AKI) is a common and serious complication with high morbidity and mortality. The pathophysiology of SA-AKI is complex. The underlying mechanisms of SA-AKI remain unclear, and effective therapeutic strategies are limited. Butyrate is a type of short-chain fatty acid (SCFA) derived from the gut microbiota that plays a key role in kidney disease. However, the effect of butyrate on SA-AKI and its underlying mechanisms remain unclear. In this study, LPS was used to establish an SA-AKI model in C57BL/6 mice. Our results indicated that butyrate levels were substantially reduced in SA-AKI model mice. Notably, butyrate intervention attenuated kidney injury and inflammation in SA-AKI model mice. Moreover, the levels of NLRP3, STING, and GSDMD (a marker of pyroptosis) were significantly decreased by butyrate intervention. An in vitro model induced by LPS was established using HK-2 cells. Butyrate mitigated pyroptosis and reduced NLRP3, STING, and GSDMD protein expression. Furthermore, STING overexpression abrogated the downregulation of several proteins (NLRP3 and caspase 1) invovled in NLRP3 inflammsome-mediated pyroptosis and weakened the protective effect of butyrate. Hence, butyrate may attenuate SA-AKI by inhibiting pyroptosis via the STING-GSDMD axis, which provides a potential therapeutic strategy for preventing SA-AKI progression.

Investigating the role of gut microbiota in hemorrhagic stroke: Evidence from causal analysis

BACKGROUND

Hemorrhagic stroke is potentially fatal and debilitating. Previous studies have indicated a potential correlation between gut microbiota and hemorrhagic stroke.

METHODS

We conducted a two-sample Mendelian randomization (MR) study to assess the potential causal effects of gut microbiota on hemorrhagic stroke, including nontraumatic intracranial hemorrhage (ntICH), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). The inverse variance weighted (IVW) method was employed as the primary MR evaluation approach. Complementary methods of MR‒Egger, simple mode, weighted mode, and weighted median were utilized for validation. Heterogeneity and pleiotropy were assessed using Cochran's Q and MR‒Egger intercept tests. MR-PRESSO and leave-one-out analyses were employed to identify instrumental outliers.

RESULTS

The IVW estimates demonstrated significant causal associations between ntICH and taxa from two classes (Clostridia, Methanobacteria), one order (Methanobacteriales), two families (Clostridiales vadin BB60 group, Methanobacteriaceae), and two genera (Catenibacterium, unknown genus id. 1000000073) (P<0.05). Subgroup analyses revealed causal links between ICH and taxa from two classes (Clostridia, Methanobacteria), two orders (Methanobacteriales, Rhodospirillales), two families (Acidaminococcaceae, Methanobacteriaceae), and four genera (Butyricimonas, Catenibacterium, Lachnospiraceae UCG010, unknown genus id.2755) (P<0.05). Furthermore, for the SAH subgroup, we identified causal associations with taxa from one family (Rikenellaceae) and six genera (Alloprevotella, Enterorhabdus, Hungatella, Lachnoclostridium, Parabacteroides, Ruminococcus gauvreauii group) (P<0.05). These findings remained robust across all sensitivity tests.

CONCLUSIONS

Our findings provide support for the causal effects of specific gut microbial taxa on hemorrhagic stroke and identify promising targets for its prevention and therapy. Further research is warranted to validate these associations.

Oral administration of Bifidobacterium longum and Bifidobacterium infantis ameliorates cefcapene pivoxil-induced attenuation of anti-programmed cell death protein-1 antibody action in mice

Gut bacteria play pivotal roles in the antitumor effects of immune checkpoint inhibitors (ICIs). However, antimicrobial therapy, often necessary for infections in cancer patients, can reduce the efficacy of ICIs. The potential of probiotics to restore ICI efficacy remains uncertain. This study evaluated the effects of Bifidobacterium longum and Bifidobacterium infantis (BLBI) in a CT-26 subcutaneous tumor mouse model treated with anti-programmed cell death protein 1 antibody (αPD-1) and cefcapene pivoxil (CFPN-PI). BALB/c mice received daily oral gavage of CFPN-PI for 5 days before tumor inoculation, followed by weekly αPD-1 administration and tumor growth monitoring. BLBI was administered via ad libitum feeding, mixed in powdered feed. Gut microbiota composition and fecal short-chain fatty acid concentrations were assessed, along with gene expression and immune cell populations in the tumor microenvironment, using quantitative RT-PCR and flow cytometry, respectively. CFPN-PI alone increased tumor growth and attenuated the antitumor effect of αPD-1. In contrast, BLBI inhibited CFPN-PI-induced tumor growth and improved the efficacy of αPD-1. Probiotic treatment increased the stool propionic acid concentration and the number of tumor-infiltrating conventional type 1 dendritic cells. Relative decreases in Bacteroides and Lachnospiraceae _NK4A136_group species and relative increases in Muribaculaceae and Unclassified_f_Oscillospiraceae species correlated with an improved αPD-1 response. These results suggest that probiotic administration may be a new therapeutic strategy to rescue the attenuated efficacy of ICIs in patients with cancer who require antimicrobial therapy.

Causal associations between gut Bifidobacteriaceae and transplant failure: a Mendelian randomization study

Aim: Transplant rejection and failure are the primary causes of shortened lifespan in transplant patients and are closely associated with the status of the human immune system. Gut microbiota have the capacity to modulate the human immune system. However, it remains unclear whether any gut microbiota can influence the risk of transplant failure.Materials & methods: A Mendelian randomization study was conducted to explore the causal relationship between gut microbiota and transplant failure. This study utilized three Genome-Wide Association Study results focusing on the gut microbiome, transplant failure and transplantation status. Single nucleotide polymorphisms that were strongly associated with gut microbiota abundance were selected as instrumental variables.Results: The abundance of Bifidobacteriaceae demonstrated a significant causal relationship with transplant failure (inverse variance weighted [IVW] p = 0.049, OR = 0.658, 95% CI: 0.433-0.998), but was not related to the risk of transplantation status (IVW p > 0.200). Notably, a higher intestinal abundance of Bifidobacteriaceae corresponded to a decreased risk of transplant failure. Bifidobacteriaceae instrumental variables were enriched in pathways related to synapses and membranes.Conclusion: The Bifidobacteriaceae may play a crucial role in the mechanism of transplant failure. These study results contribute to elucidating the mechanisms underlying transplant failure.

Rebalancing immune homeostasis in combating disease: The impact of medicine food homology plants and gut microbiome

BACKGROUND

Gut microbiota plays an important role in multiple human physiological processes and an imbalance in it, including the species, abundance, and metabolites can lead to diseases. These enteric microorganisms modulate immune homeostasis by presenting a myriad of antigenic determinants and microbial metabolites. Medicinal and food homologous (MFH) plants, edible herbal materials for both medicine and food, are important parts of Traditional Chinese Medicine (TCM). MFH plants have drawn much attention due to their strong biological activity and low toxicity. However, the interplay of MFH and gut microbiota in rebalancing the immune homeostasis in combating diseases needs systematic illumination.

PURPOSE

The review discusses the interaction between MFH and gut microbiota, including the effect of MFH on the major group of gut microbiota and the metabolic effect of gut microbiota on MFH. Moreover, how gut microbiota influences the immune system in terms of innate and adaptive immunity is addressed. Finally, the immunoregulatory mechanisms of MFH in regulation of host pathophysiology via gut microbiota are summarized.

METHODS

Literature was searched, analyzed, and collected using databases, including PubMed, Web of Science, and Google Scholar using relevant keywords. The obtained articles were screened and summarized by the research content of MFH and gut microbiota in immune regulation.

RESULTS

The review demonstrates the interaction between MFH and gut microbiota in disease prevention and treatment. Not only do the intestinal microorganisms and intestinal mucosa constitute an important immune barrier of the human body, but also lymphoid tissue and diffused immune cells within the mucosa participate in the response of innate immunity and adaptive immunity. MFH modulates immune regulation by affecting intestinal flora, helps maintain the balance of the immune system and interfere with the occurrence and development of a broad category of diseases.

CONCLUSION

Being absorbed from the gastrointestinal tract, MFH can have profound effects on gut microbiota. In turn, the gut microbiota also actively participate in the bioconversion of complex constituents from MFH, which could further influence their physiological and pharmacological properties. The review deepens the understanding of the relationship among MFH, gut microbiota, immune system, and human diseases and further promotes the progression of additional relevant research.

Butyrolactone-I from marine fungi alleviates intestinal barrier damage caused by DSS through regulating lactobacillus johnsonii and its metabolites in the intestine of mice

Butyrolactone-I (BTL-1), a secondary metabolite from the marine fungus Aspergillus terreus, exhibits numerous biological activities. Previous research has indicated that Butyrolactone-I alleviates intestinal epithelial inflammation via the TLR4/NF-κB and MAPK pathways. However, the mechanisms underlying its protection against intestinal barrier damage remain unclear. This study aims to further elucidate these mechanisms. We observed that BTL-1 administration increased the abundance of Lactobacillus johnsonii (LJ) in both in vivo and in vitro experiments, prompting an investigation into the effects of LJ and its metabolites on DSS-induced inflammatory bowel disease (IBD). The results demonstrated that BTL-1 significantly upregulated tight junction (TJ) and adherens junction (AJ) proteins, maintained intestinal barrier integrity, and alleviated DSS-induced IBD in mice. These effects were associated with the proliferation of LJ and its metabolites, such as butyric and propionic acids, and the inhibition of the MAPK signaling pathway in the colon. Interestingly, administering LJ alone produced a protective effect against DSS-induced IBD similar to that observed with BTL-1. Furthermore, butyric acid, a metabolite of LJ, also upregulated TJ/AJ proteins in intestinal epithelial cells through the MAPK signaling pathway. Our findings suggest that BTL-1 regulates intestinal flora, promotes LJ proliferation, protects intestinal barrier integrity, increases the concentrations of butyric and propionic acids, and ultimately inhibits the activation of the MAPK signaling pathway in mice to alleviate IBD. Therefore, BTL-1 could potentially be used as a natural drug to prevent IBD and maintain intestinal flora balance. We explored how butyrolactone-I exerts a preventive effect on IBD through intestinal bacteria (Lactobacillus johnsonii).

Microbial Metabolites-induced Epigenetic Modifications for Inhibition of Colorectal Cancer: Current Status and Future Perspectives

Globally, one of the most prevalent cancers is colorectal cancer (CRC). Chemotherapy and surgery are two common conventional CRC therapies that are frequently ineffective and have serious adverse effects. Thus, there is a need for complementary and different therapeutic approaches. The use of microbial metabolites to trigger epigenetic alterations as a way of preventing CRC is one newly emerging field of inquiry. Small chemicals called microbial metabolites, which are made by microbes and capable of altering host cell behaviour, are created. Recent research has demonstrated that these metabolites can lead to epigenetic modifications such as histone modifications, DNA methylation, and non-coding RNA regulation, which can control gene expression and affect cellular behaviour. This review highlights the current knowledge on the epigenetic modification for cancer treatment, immunomodulatory and anti-carcinogenic attributes of microbial metabolites, gut epigenetic targeting system, and the role of dietary fibre and gut microbiota in cancer treatment. It also focuses on short-chain fatty acids, especially butyrates (which are generated by microbes), and their cancer treatment perspective, challenges, and limitations, as well as state-of-the-art research on microbial metabolites-induced epigenetic changes for CRC inhibition. In conclusion, the present work highlights the potential of microbial metabolites-induced epigenetic modifications as a novel therapeutic strategy for CRC suppression and guides future research directions in this dynamic field.

Exploring the relationship between periodontal diseases and osteoporosis: Potential role of butyrate

Osteoporosis, a condition marked by the loss of bone density and mass, affects individuals of all ages. However, it becomes more prevalent and severe with aging, increasing the risk of fractures and other health complications. Recent research has highlighted a link between osteoporosis and periodontitis, a chronic gum disease, as both conditions involve excessive bone loss that can lead to significant oral health problems if untreated. The growing interest in strategies to prevent bone loss has brought attention to butyrate, a short-chain fatty acid produced by gut bacteria during fiber fermentation. Butyrate has demonstrated protective effects against systemic bone loss, particularly in the context of osteoporosis. Notably, oral bacteria also produce butyrate, suggesting its potential as a therapeutic tool for preventing periodontal bone loss. Given the connection between systemic and oral health, understanding the role of butyrate in bone metabolism could offer new avenues for treating osteoporosis and periodontitis. This review will explore the biological mechanisms through which butyrate influences bone health, aiming to highlight its potential therapeutic applications in preventing bone loss across these conditions.

Non-SCFA microbial metabolites associated with fiber fermentation and host health

Dietary fiber is degraded by commensal gut microbes to yield host-beneficial short-chain fatty acids (SCFAs), but personalized responses to fiber supplementation highlight a role for other microbial metabolites in shaping host health. In this review we summarize recent findings from dietary fiber intervention studies describing health impacts attributed to microbial metabolites other than SCFAs, particularly secondary bile acids (2°BAs), aromatic amino acid derivatives, neurotransmitters, and B vitamins. We also discuss shifts in microbial metabolism occurring through altered maternal dietary fiber intake and agricultural practices, which warrant further investigation. To optimize the health benefits of dietary fibers, it is essential to survey a range of metabolites and adapt recommendations on a personalized basis, according to the different functional aspects of the microbiome.

Unveiling gut microbiota's role: Bidirectional regulation of drug transport for improved safety

Drug safety is a paramount concern in the field of drug development, with researchers increasingly focusing on the bidirectional regulation of gut microbiota in this context. The gut microbiota plays a crucial role in maintaining drug safety. It can influence drug transport processes in the body through various mechanisms, thereby modulating their efficacy and toxicity. The main mechanisms include: (1) The gut microbiota directly interacts with drugs, altering their chemical structure to reduce toxicity and enhance efficacy, thereby impacting drug transport mechanisms, drugs can also change the structure and abundance of gut bacteria; (2) bidirectional regulation of intestinal barrier permeability by gut microbiota, promoting the absorption of nontoxic drugs and inhibiting the absorption of toxic components; (3) bidirectional regulation of the expression and activity of transport proteins by gut microbiota, selectively promoting the absorption of effective components or inhibiting the absorption of toxic components. This bidirectional regulatory role enables the gut microbiota to play a key role in maintaining drug balance in the body and reducing adverse reactions. Understanding these regulatory mechanisms sheds light on novel approaches to minimize toxic side effects, enhance drug efficacy, and ultimately improve drug safety. This review systematically examines the bidirectional regulation of gut microbiota in drug transportation from the aforementioned aspects, emphasizing their significance in ensuring drug safety. Furthermore, it offers a prospective outlook from the standpoint of enhancing therapeutic efficacy and reducing drug toxicity, underscoring the importance of further exploration in this research domain. It aims to provide more effective strategies for drug development and treatment.

Phlorizin ameliorates cognitive and behavioral impairments via the microbiota-gut-brain axis in high-fat and high-fructose diet-induced obese male mice

The long-term high-fat, high-sugar diet exacerbates type 2 diabetes mellitus (T2DM)-related cognitive impairments. Phlorizin, a well-studied natural compound found in apples and other plants, is recognized for its bioactive properties, including modulation of glucose and lipid metabolism. Despite its established role in mitigating metabolic disorders, the neuroprotective effects of phlorizin, particularly against diabetes-related cognitive dysfunction, have not been fully elucidated. Therefore, the present study aimed to investigate the effect of dietary supplementation of phlorizin on high-fat and high-fructose diet (HFFD)-induced cognitive dysfunction and evaluate the crucial role of the microbiota-gut-brain axis. We found that dietary supplementation of phlorizin for 14 weeks effectively prevented glucolipid metabolism disorder, spatial learning impairment, and memory impairment in HFFD mice. In addition, phlorizin improved the HFFD-induced decrease in synaptic plasticity, neuroinflammation, and excessive activation of microglia in the hippocampus. Transcriptomics analysis shows that the protective effect of phlorizin on cognitive impairment was associated with increased expression of neurotransmitters and synapse-related genes in the hippocampus. Phlorizin treatment alleviated colon microbiota disturbance, mainly manifested by an increase in gut microbiota diversity and the abundance of short-chain fatty acid (SCFA)-producing bacteria. The level of microbial metabolites, including SCFA, inosine 5'-monophosphate (IMP), and D (-)-beta-hydroxybutyric acid (BHB) were also significantly increased after phlorizin treatment. Integrating multiomics analysis observed tight connections between phlorizin-regulated genes, microbiota, and metabolites. Furthermore, removal of the gut microbiota via antibiotics treatment diminished the protective effect of phlorizin against HFFD-induced cognitive impairment, underscoring the critical role of the gut microbiota in mediating cognitive behavior. Importantly, supplementation with SCFA and BHB alone mimicked the regulatory effects of phlorizin on cognitive function. Therefore, phlorizin shows promise as a potential nutritional therapy for addressing cognitive impairment associated with metabolic disorders. Further research is needed to explore its effectiveness in preventing and alleviating neurodegenerative diseases.

Gut microbial alteration in chronic spontaneous urticaria unresponsive to second generation antihistamines and its correlation with disease characteristics- a cross-sectional case-control study

BACKGROUND

Gut microbial involvement has been speculated in chronic spontaneous urticaria (CSU). The aim of the study was to compare the gut microbiome composition and diversity in CSU patients uncontrolled with second-generation antihistamines (sgAHs) and healthy individuals, as well as to explore any association between gut microbiome and disease characteristics.

METHODS

A cross-sectional case-control study including 20 CSU patients unresponsive to standard doses of sgAHs, and 15 age-and-sex matched healthy controls was conducted. Clinico-demographic profile, laboratory investigations and stool analysis were conducted in all study participants. 16S RNA gene sequencing and DNA isolation was performed for all stool samples, followed by bioinformatic analysis.

RESULTS

The CSU patients (mean age 39.5 ± 9.3, M:F 1:4) and healthy controls (mean age 35 ± 13, M:F 1:2) were statistically comparable. The median (IQR) duration of CSU was 42 months (7-81). Concomitant angioedema and concomitant symptomatic dermographism were present in 30% and 20% CSU patients, respectively. At inclusion, 60% patients were receiving add-on omalizumab, while the remaining 40% were on up-dosed sgAHs. Stool microbial analysis revealed increased diversity and higher microbial richness in CSU patients compared with healthy individuals. CSU patients showed reduced load of short-chain fatty acid (SCFA) producing microbiota and increased load of opportunistic pathogens. The Firmicutes/Bacteroides (F/B) ratio was higher in CSU patients. Among CSU patients, higher Bacteroides and reduced Firmicutes count were associated with higher disease activity and poor control; however, there was no link with the type of therapy.

CONCLUSION

Gut microbial dysbiosis is seen in CSU and is linked with disease control.

Chemical Composition of Cynanchum auriculatum Royle Ex Wight and Its Potential Role in Ameliorating Colitis

Cynanchum auriculatum Royle ex Wight, commonly known as "Baishouwu," has been traditionally used in China for its medicinal and dietary benefits. Despite its long history of use, the potential therapeutic effects of C. auriculatum in the treatment of colitis have not been fully investigated. This study aims to evaluate the effects of the water extract of C. auriculatum root on colitis and elucidate its potential mechanisms of action. The water extract of C. auriculatum root (CW) was prepared and characterized using UPLC-Q-TOF-MS, identifying thirty-two distinct compounds, including saponins, organic acids, fatty acid derivatives, and alkaloids. The therapeutic efficacy of CW was assessed in a colitis mouse model. CW significantly alleviated colitis symptoms, evidenced by increased colon length, reduced disease activity indices, and decreased colon tissue damage. CW reduced colonic inflammatory cytokine production and enhanced the expression of tight junction proteins, including claudin-1, occludin, and ZO-1, thereby strengthening intestinal barrier integrity. Additionally, CW modulated the gut microbiota by increasing microbial diversity, promoting beneficial Lactobacillus growth, reducing pathogenic Pseudomonas levels, and enhancing short-chain fatty acid production. The results suggest that CW exhibits significant therapeutic potential in the management of colitis by attenuating inflammation, restoring gut barrier function, and modulating the gut microbiota. These findings provide a basis for further exploration of C. auriculatum as a functional food for prevention and treatment of colitis.

Immune Dysregulation in Obesity

The immune system plays fundamental roles in maintaining physiological homeostasis. With the increasing prevalence of obesity-a state characterized by chronic inflammation and systemic dyshomeostasis-there is growing scientific and clinical interest in understanding how obesity reshapes immune function. In this review, we propose that obesity is not merely an altered metabolic state but also a fundamentally altered immunological state. We summarize key seminal and recent findings that elucidate how obesity influences immune function, spanning its classical role in microbial defense, its contribution to maladaptive inflammatory diseases such as asthma, and its impact on antitumor immunity. We also explore how obesity modulates immune function within tissue parenchyma, with a particular focus on the role of T cells in adipose tissue. Finally, we consider areas for future research, including investigation of the durable aspects of obesity on immunological function even after weight loss, such as those observed with glucagon-like peptide-1 (GLP-1) receptor agonist treatment. Altogether, this review emphasizes the critical role of systemic metabolism in shaping immune cell functions, with profound implications for tissue homeostasis across various physiological contexts.

DAMP-ing IBD: Extinguish the Fire and Prevent Smoldering

In inflammatory bowel diseases (IBD), the most promising therapies targeting cytokines or immune cell trafficking demonstrate around 40% efficacy. As IBD is a multifactorial inflammation of the intestinal tract, a single-target approach is unlikely to solve this problem, necessitating an alternative strategy that addresses its variability. One approach often overlooked by the pharmaceutically driven therapeutic options is to address the impact of environmental factors. This is somewhat surprising considering that IBD is increasingly viewed as a condition heavily influenced by such factors, including diet, stress, and environmental pollution-often referred to as the "Western lifestyle". In IBD, intestinal responses result from a complex interplay among the genetic background of the patient, molecules, cells, and the local inflammatory microenvironment where danger- and microbe-associated molecular patterns (D/MAMPs) provide an adjuvant-rich environment. Through activating DAMP receptors, this array of pro-inflammatory factors can stimulate, for example, the NLRP3 inflammasome-a major amplifier of the inflammatory response in IBD, and various immune cells via non-specific bystander activation of myeloid cells (e.g., macrophages) and lymphocytes (e.g., tissue-resident memory T cells). Current single-target biological treatment approaches can dampen the immune response, but without reducing exposure to environmental factors of IBD, e.g., by changing diet (reducing ultra-processed foods), the adjuvant-rich landscape is never resolved and continues to drive intestinal mucosal dysregulation. Thus, such treatment approaches are not enough to put out the inflammatory fire. The resultant smoldering, low-grade inflammation diminishes physiological resilience of the intestinal (micro)environment, perpetuating the state of chronic disease. Therefore, our hypothesis posits that successful interventions for IBD must address the complexity of the disease by simultaneously targeting all modifiable aspects: innate immunity cytokines and microbiota, adaptive immunity cells and cytokines, and factors that relate to the (micro)environment. Thus the disease can be comprehensively treated across the nano-, meso-, and microscales, rather than with a focus on single targets. A broader perspective on IBD treatment that also includes options to adapt the DAMPing (micro)environment is warranted.

Gut Microbiota as Emerging Players in the Development of Alcohol-Related Liver Disease

The global incidence and mortality rates of alcohol-related liver disease are on the rise, reflecting a growing health concern worldwide. Alcohol-related liver disease develops due to a complex interplay of multiple reasons, including oxidative stress generated during the metabolism of ethanol, immune response activated by immunogenic substances, and subsequent inflammatory processes. Recent research highlights the gut microbiota's significant role in the progression of alcohol-related liver disease. In patients with alcohol-related liver disease, the relative abundance of pathogenic bacteria, including Enterococcus faecalis, increases and is positively correlated with the level of severity exhibited by alcohol-related liver disease. Supplement probiotics like Lactobacillus, as well as Bifidobacterium, have been found to alleviate alcohol-related liver disease. The gut microbiota is speculated to trigger specific signaling pathways, influence metabolite profiles, and modulate immune responses in the gut and liver. This research aimed to investigate the role of gut microorganisms in the onset and advancement of alcohol-related liver disease, as well as to uncover the underlying mechanisms by which the gut microbiota may contribute to its development. This review outlines current treatments for reversing gut dysbiosis, including probiotics, fecal microbiota transplantation, and targeted phage therapy. Particularly, targeted therapy will be a vital aspect of future alcohol-related liver disease treatment. It is to be hoped that this article will prove beneficial for the treatment of alcohol-related liver disease.