Short Chain Fatty Acids (SCFAs)-Mediated Gut Epithelial and Immune Regulation and Its Relevance for Inflammatory Bowel Diseases

Overcoming immunotherapy resistance in gastric cancer: insights into mechanisms and emerging strategies

Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, with limited treatment options in advanced stages. Immunotherapy, particularly immune checkpoint inhibitors (ICIs) targeting PD1/PD-L1, has emerged as a promising therapeutic approach. However, a significant proportion of patients exhibit primary or acquired resistance, limiting the overall efficacy of immunotherapy. This review provides a comprehensive analysis of the mechanisms underlying immunotherapy resistance in GC, including the role of the tumor immune microenvironment, dynamic PD-L1 expression, compensatory activation of other immune checkpoints, and tumor genomic instability. Furthermore, the review explores GC-specific factors such as molecular subtypes, unique immune evasion mechanisms, and the impact of Helicobacter pylori infection. We also discuss emerging strategies to overcome resistance, including combination therapies, novel immunotherapeutic approaches, and personalized treatment strategies based on tumor genomics and the immune microenvironment. By highlighting these key areas, this review aims to inform future research directions and clinical practice, ultimately improving outcomes for GC patients undergoing immunotherapy.

The Effects of Tea Polyphenols in Feed on the Immunity, Antioxidant Capacity, and Gut Microbiota of Weaned Goat Kids

In this present study, we aimed to investigate the effects of adding tea polyphenols to feed on the immunity, antioxidant capacity, and gut microbiota of weaned goat kids. Thirty weaned kids (Leizhou goats, average initial weight of 9.32 ± 1.72 kg, 2 months old) were randomly divided into five groups with six kids in each group, with half being male and half being female. The control (CON) group was fed the basal diet, and the four other groups were supplemented with 2, 4, or 6 g/kg tea polyphenols or 50 mg/kg chlortetracycline in the basal diet (denoted as the T1, T2, T3, and CTC groups, respectively). The results showed that compared to the CON and CTC groups, adding 4 or 6 g/kg tea polyphenols could increase the expression levels of serum antioxidant enzymes and intestinal antioxidant genes in the kids. It also increased the expression of Nrf2 and IL-10 in the intestine, while reducing the content and gene expression of cytokines (IL-1β, IL-6, IFN-γ, and TNF-α). Dietary supplementation with 4 or 6 g/kg tea polyphenols reduced the expression levels of TLR4, MyD88, and NFκB in intestinal tissue, activated intestinal protective mechanisms, and enhanced the immune defense of the intestinal epithelium. Compared to the CTC group, feeding tea polyphenols significantly increased the Simpson indices. However, adding 4 g/kg tea polyphenols significantly increased the relative abundance of Verrucomicrobiota, Candidatus Soleaferrea, the Christensenellaceae R-7 group, and Prevotella, as well as the acetic acid content in the cecum of the kids (p < 0.05). Overall, the results indicate that dietary supplementation with 4 g/kg of tea polyphenols can effectively maintain the homeostasis of the gut microbiota and enhance the anti-inflammatory and antioxidant capabilities of weaned kids.

Fecal Short-Chain Fatty Acids Are Associated with Obesity in Gestational Diabetes

Background: Short-chain fatty acids (SCFAs), which are produced by the microbial fermentation of undigested carbohydrates, play an important role in the metabolism and physiology of the host. SCFAs are involved in the regulation of maternal metabolism during pregnancy and influence weight gain, glucose metabolism, and metabolic hormones. Methods: In 2017, women who were treated for gestational diabetes mellitus (GDM) at the University Medical Centre Ljubljana were invited to participate in a longitudinal study. A total of 45 women were included in this study and comprehensively phenotyped. During the second and third trimester of pregnancy, the women with GDM provided fecal samples for SCFA analysis. The samples were analyzed by high-performance liquid chromatography for the simultaneous determination of acetate, propionate, and butyrate. Results: SCFA concentrations in feces differed between overweight/obese and normal-weight women with GDM. Acetate and propionate concentrations were significantly higher in pregnant women who were overweight or obese before pregnancy compared to normal-weight women but butyrate concentrations were not. Butyrate was elevated in the third trimester in the group with excessive gestational weight gain. Conclusions: The relationship between SCFAs and obesity is complex, and the association between SCFAs and GDM remains to be clarified. Regardless of the conflicting publications on the role of SCFAs, our study showed that higher acetate and propionate levels were associated with the weight categories of overweight or obesity before pregnancy and higher butyrate levels were associated with excessive gestational weight gain.

A pro-inflammatory diet is associated with growth and virulence of Escherichia coli in pediatric Crohn's disease

BACKGROUND AND AIMS

Epidemiological studies have suggested an association between the inflammatory potential of dietary patterns and Crohn's disease (CD). However, the relationships of these inflammatory dietary determinants with the microbiome remain largely unknown. In this cross-sectional study, we evaluate the association between the inflammatory potential of habitual diet, as assessed by the modified Children-Dietary Inflammatory Index (mC-DII), and the fecal microbiome and metabolome of children with CD in comparison to healthy children.

METHODS

A cross-sectional study including 51 children with CD between 6 and 18 years of age and 50 healthy controls was conducted. Dietary inflammatory potential was measured using the mC-DII, and diet quality was assessed by the Healthy Eating Index (HEI)-2015 and alternate Mediterranean Eating Index (aMed). The microbiome was analyzed using shotgun metagenomic sequencing and untargeted metabolomic analysis.

RESULTS

A poor-quality, pro-inflammatory diet, with similar mC-DII, HEI-2015, and aMed scores, was found across healthy children and children with CD. In children with active disease, a pro-inflammatory diet was associated with decreased diversity, increased virulence potential, and expansion of the Proteobacteria phylum dominated by Escherichia coli (E. coli) spp. A positive correlation between E. coli relative abundance and mC-DII was associated with a low intake of a cluster composed of fibers, vitamins, and minerals with anti-inflammatory potential. A negative association between metabolites of fatty acid metabolism and HEI was found.

CONCLUSIONS

In total, our results suggest that a pro-inflammatory diet may potentiate hallmarks of the inflammation-associated dysbiosis in CD and highlight the need for microbiome-targeted dietary interventions optimizing the anti-inflammatory potential of habitual diet in the management of pediatric CD.

Multimedia: multimodal mediation analysis of microbiome data

Mediation analysis has emerged as a versatile tool for answering mechanistic questions in microbiome research because it provides a statistical framework for attributing treatment effects to alternative causal pathways. Using a series of linked regressions, this analysis quantifies how complementary data relate to one another and respond to treatments. Despite these advances, existing software's rigid assumptions often result in users viewing mediation analysis as a black box. We designed the multimedia R package to make advanced mediation analysis techniques accessible, ensuring that statistical components are interpretable and adaptable. The package provides a uniform interface to direct and indirect effect estimation, synthetic null hypothesis testing, bootstrap confidence interval construction, and sensitivity analysis, enabling experimentation with various mediator and outcome models while maintaining a simple overall workflow. The software includes modules for regularized linear, compositional, random forest, hierarchical, and hurdle modeling, making it well-suited to microbiome data. We illustrate the package through two case studies. The first re-analyzes a study of the microbiome and metabolome of Inflammatory Bowel Disease patients, uncovering potential mechanistic interactions between the microbiome and disease-associated metabolites, not found in the original study. The second analyzes new data about the influence of mindfulness practice on the microbiome. The mediation analysis highlights shifts in taxa previously associated with depression that cannot be explained indirectly by diet or sleep behaviors alone. A gallery of examples and further documentation can be found at https://go.wisc.edu/830110.

IMPORTANCE

Microbiome studies routinely gather complementary data to capture different aspects of a microbiome's response to a change, such as the introduction of a therapeutic. Mediation analysis clarifies the extent to which responses occur sequentially via mediators, thereby supporting causal, rather than purely descriptive, interpretation. Multimedia is a modular R package with close ties to the wider microbiome software ecosystem that makes statistically rigorous, flexible mediation analysis easily accessible, setting the stage for precise and causally informed microbiome engineering.

Protective Role of Nano-encapsulated Bifidobacterium breve, Bacilllus coagulans, and Lactobacillus plantarum in Colitis Model: Insights Toward Propagation of Short-Chain Fatty Acids and Reduction of Exaggerated Inflammatory and Oxidative Response

Irritable bowel disease (IBD), also known as ulcerative colitis and Crohn's disease, is a chronic inflammatory disorder affecting millions of people worldwide. Herein, nano-encapsulated multi-strain probiotics formulation, comprising Bifidobacterium breve DSM24732 and B. coagulans SANK 70258 and L. plantarum DSM24730 (BBLNPs) is used as an effective intervention technique for attenuating IBD through gut microenvironment regulation. The efficacy of the prophylactic role of BBLNPs in alleviating injury induced by dextran sulfate sodium (DSS) was evaluated by assessing oxidative and inflammatory responses, levels of short-chain fatty acids (SCFAs) and their regulation on GPR41/43 pathway, expression of genes related to tight-junctions and autophagy, immunohistochemistry of IL1β and GPR43, and histological examination of inflamed colonic tissue. The severity of clinical signs and paracellular permeability to FITC (fluorescein isothiocyanate)-labeled dextran was significantly decreased after BBLNP treatment. Reduction of oxidative stress-associated biomarkers (MDA, ROS, and H2O2) and acceleration of antioxidant enzyme activities (SOD, CAT, and GSH-Px) were noted in the BBLNP-treated group. Subsiding of inflammatory markers (TNF-α, IL-18, IL-6, TRL-4, CD-8, NLRP3, and caspase 1) and upregulation of tight-junction-related genes (occludin and JAM) was detected in BBLNPs. Administration of BBLNPs remarkably resulted in a higher level of SCFAs which parrel with colonic upregulation of GPR41 and GPR43 expression compared to DSS-treated rats. Notable modulation of autophagy-related genes (p62, mTOR, LC3, and Beclin-1) was identified post BBLNP treatment. The mRNA expressions of p62 and mTOR were significantly downregulated, while LC3 and Beclin-1 were upregulated after prophylactic treatment with BBLNPs. Immune-stained labeled cells showed lower expression of IL-1β and higher expression levels of GPR43 in BBLNPs compared to the DSS-induced group. The intestinal damage caused by DSSwas effectively mitigated by oral BBLNP treatment, as supported by the restoration of healthy colonic tissue architecture. The findings suggest that BBLNPs have a promising avenue in the remission of IBD by modulating inflammation, oxidative stress, microbial metabolites such as SCFAs, and autophagy.

Sanguinarine chloride hydrate mitigates colitis symptoms in mice through the regulation of the intestinal microbiome and metabolism of short-chain fatty acids

Sanguinarine constitutes the main components of Macleaya cordata, and exhibits diverse biological and pharmacological activities. This study investigated the effects of sanguinarine chloride hydrate (SGCH) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice. Five groups were designed to investigate the effects of SGCH on the pathological symptoms, the mRNA expression levels of inflammatory cytokines, colonic mucosal barrier damage, microbiota composition, and SCFAs metabolism in UC mice. The administration of SGCH in DSS-induced UC mice resulted in the amelioration of pathological symptoms, as evidenced by an increase in body weight, a decrease in disease activity index score, elongation of colon length, reduction in spleen index, and improvement in colon injury. SGCH can regulate the expression of inflammatory cytokines (IL-6, TNF-α, IL-1β and IL-10) and tight junction proteins (ZO-1 and Occludin) associated with UC. SGCH exhibited a significant decrease in NF-κB P65 mRNA expression levels, accompanied by a significantly reduced protein level of NF-κB P-P65/P65. Further studies revealed SGCH effectively reversed the decrease in intestinal microbiota diversity induced by UC, thereby promoting the growth of beneficial bacteria such as Akkermansia, Alistipes, and norank_o_Clostridia_UCG-014. Correlation analysis demonstrated a positive association between butanoic acid, propanoic acid, isobutyric acid, isovaleric acid, valeric acid, hexanoic acid with Colidextribacter, while Coriobacteriaceae_UCG-002 exhibited a negative correlation with butanoic acid, acetic acid and propanoic acid. In conclusion, the administration of SGCH can ameliorate clinical symptoms in UC mice, regulate the expression of inflammatory cytokines and tight junction proteins, modulate intestinal microbiota metabolism and SCFAs production.

Associations Between Gut Microbiota and Diabetic Nephropathy: A Mendelian Randomization Study

Objectives

Diabetic nephropathy (DN) is a severe complication of diabetes mellitus, and its pathogenesis remains incompletely understood. Emerging evidence suggests a potential link between gut microbiota and DN. This study aimed to explore the causal relationship between gut microbiota and DN using a two-sample Mendelian randomization (MR) approach.

Methods

Gut microbiota data were obtained from the MiBioGen consortium, which provides the most comprehensive genome-wide association studies (GWAS) on gut microbiota. Summary-level genetic data for DN were sourced from publicly available GWAS data provided by the FinnGen consortium. The primary analysis was conducted using the inverse variance-weighted (IVW) method, complemented by sensitivity analyses to evaluate pleiotropy and heterogeneity.

Results

Fourteen gut microbiota species demonstrated significant genetic associations with DN in the MR analysis, including five negatively and nine positively associated species, as determined by the IVW method. No evidence of pleiotropy or heterogeneity was observed, ensuring the robustness of the findings.

Conclusions

This study provides novel insight into the causal role of gut microbiota in DN pathogenesis, uncovering specific microbial species that may contribute to disease progression. These findings offer a promising avenue for future research and therapeutic development targeting gut microbiota.

How do probiotics alleviate constipation? A narrative review of mechanisms

Constipation is a common gastrointestinal condition, which may occur at any age and affects countless people. The search for new treatments for constipation is ongoing as current drug treatments fail to provide fully satisfactory results. In recent years, probiotics have attracted much attention because of their demonstrated therapeutic efficacy and fewer side effects than pharmaceutical products. Many studies attempted to answer the question of how probiotics can alleviate constipation. It has been shown that different probiotic strains can alleviate constipation by different mechanisms. The mechanisms on probiotics in relieving constipation were associated with various aspects, including regulation of the gut microbiota composition, the level of short-chain fatty acids, aquaporin expression levels, neurotransmitters and hormone levels, inflammation, the intestinal environmental metabolic status, neurotrophic factor levels and the body's antioxidant levels. This paper summarizes the perception of the mechanisms on probiotics in relieving constipation and provides some suggestions on new research directions.

Short-chain fatty acids and cancer

Short-chain fatty acids (SCFAs), derived from the diet and the microbiota, serve as crucial links between the diet, gut microbiota, metabolism, immunity, and cancer. They function as energy sources through β-oxidation and regulate macromolecular synthesis, G protein-coupled receptor (GPCR) and histone deacetylase (HDAC) activities, protein modifications, signaling pathways, and gene expression in cells within the tumor microenvironment, particularly in tumor and immune cells. The critical role of SCFAs in maintaining normal homeostasis and influencing tumor progression highlights the potential of targeting SCFA-mediated cellular processes for cancer prevention and treatment.

Microbes: Drivers of Chenpi manufacturing, biotransformation, and physiological effects

Chenpi holds a rich history of both edible and medicinal applications worldwide, garnering increased attention from researchers in recent years due to its diverse physiological effects. While current research predominantly exploresed its chemical composition and physiological effects, there remains a notable gap in knowledge concerning its manufacturing, characteristic chemical substances, and the underlying mechanisms driving its physiological effects. In this review, the impacts of microbes on the manufacturing, biotransformation, and physiological effects of Chenpi were summarized, as well as the present status of product development. Furthermore, this review engaged in an in-depth discussion highlighting the challenges and shortcomings in recent research, while proposing potential directions and prospects. Additionally, the claim that "The longer the aging, the better the quality" of Chenpi was scientifically evaluated for the first time, providing a solid theoretical foundation for advancing the Chenpi industry.

Retrograded starch as colonic delivery carrier of taxifolin for treatment of DSS-induced ulcerative colitis in mice

Taxifolin, a natural dihydroflavonol compound, possesses notable anti-inflammatory properties and regulatory effects on intestinal microbiota. In this study, gelatinized-retrograded corn starch (GCS) was utilized as a carrier for colonic delivery of taxifolin, and its therapeutic efficacy against dextran sulfate sodium (DSS)-induced colitis in mice were systematically investigated. Taxifolin can integrate into the helical structure of starch, and the formation of GCS-Taxifolin complexes (GCS-Tax) significantly delayed the release of taxifolin in vitro. After oral administration of GCS-Tax, fecal excretion of taxifolin increased from 0.42 % to 10.89 % within 24 h compared to free taxifolin. Moreover, GCS-Tax facilitated the production of short-chain fatty acid in mice and effectively alleviated DSS-induced colitis symptoms, including weight loss, bloody stools, and colonic tissue damage. Additionally, GCS-Tax significantly suppressed proinflammatory factors such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and lipopolysaccharide (LPS), while elevating anti-inflammatory interleukin-10 (IL-10) level in mice serum. Furthermore, it restored intestinal mucosal barrier function by upregulating the expression of Mucin 2, Occludin, and zonula occludens-1 (ZO-1), reducing Beclin 1 expression, and exhibited hepatoprotective effects by enhancing total antioxidant capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities. High-throughput sequencing analysis revealed that GCS-Tax improved intestinal flora diversity, reducing inflammation-related Bacterium 1 and Staphylococcus, while promoting the abundance of beneficial bacteria like Lachnospiraceae.

Berberine Alleviates Kainic Acid-Induced Acute Epileptic Seizures in Mice via Reshaping Gut Microbiota-Associated Lipid Metabolism

BACKGROUND

Berberine (BBR) has been reported to mitigate epileptic seizures. However, the potential mechanism of its anti-seizure effect remains uncharacterized.

AIMS

This study aimed to investigate the protective effect of BBR on acute epileptic seizures induced by kainic acid (KA) in mice and further explore its mechanism of action in the aspect of analysis of gut microbiota.

MATERIALS AND METHODS

The protective effect of BBR against acute epileptic seizures was assessed via Racine score and Nissl training. Alterations of gut microbiota and metabolites in seizure mice after BBR treatment were analyzed through 16S sequencing and lipidomics, respectively.

RESULTS

Our results showed that the BBR remarkably alleviated acute epileptic seizures and hippocampal neuron damage in KA-induced mice. The analysis of gut microbiota indicated that BBR reduced the acute epileptic seizures in KA-induced mice by increasing the abundance of Bacteroidetes and Alloprevotella, regulating short-chain fatty acids (SCFAs). Results of lipidomics also identified 21 candidate metabolites in the colon and hippocampus possibly involved in the protective effect of BBR against acute seizures.

CONCLUSION

These findings suggest that BBR exerts neuroprotection against KA-induced epileptic seizures through remodeling gut microbiota-associated lipid metabolism in the colon and hippocampus. BBR may serve as a valuable candidate drug for curing patients with epilepsy.

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.

Modulation of inflammatory markers in type 2 diabetes mellitus through gut microbiome-targeted interventions: An umbrella review on meta-analyses

BACKGROUND & AIMS

Type 2 diabetes mellitus (T2DM) poses a significant global health challenge due to various lifestyle factors contributing to its prevalence and associated complications. Chronic low-grade inflammation, characterized by elevated levels of inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), plays a pivotal role in the pathogenesis of T2DM. Modulation of the gut microbiota through microbiome-targeted therapy (MTT), including probiotics, prebiotics, and synbiotics, has emerged as a potential strategy to mitigate inflammation and improve metabolic outcomes in T2DM.

METHODS

A systematic review and meta-analysis were conducted following PRISMA guidelines to evaluate the impact of MTT on inflammatory markers in patients with T2DM. Searches were performed in PubMed, Scopus, and Web of Science databases up to June 2024, with inclusion criteria limited to English-language meta-analyses of randomized controlled trials (RCTs) assessing the effects of probiotics, prebiotics, or synbiotics on inflammatory markers in T2DM patients.

RESULTS

Ten meta-analyses met the inclusion criteria, comprising studies investigating the effects of various MTT interventions on CRP, IL-6, and TNF-α levels in T2DM patients. Meta-analysis results indicated significant reductions in CRP (SMD: -0.070; 95 % CI: -0.119 to -0.020) and TNF-α (SMD: -0.370; 95 % CI: -0.554 to -0.186) levels following MTT, while IL-6 reductions (SMD: -0.070; 95 % CI: -0.269 to 0.129) did not reach statistical significance. However, heterogeneity in study quality, intervention protocols, and participant demographics posed challenges in interpretation.

CONCLUSIONS

While improvements in inflammatory markers with MTT have been observed, significant limitations-such as heterogeneity in study quality and variation in intervention protocols-highlight the need for further research to confirm its efficacy and clarify underlying mechanisms. Future studies should aim to address these limitations by exploring variations in dosage, supplement formulations, and bacterial strains, which are crucial for improving the reliability and broader applicability of MTT in the management of T2DM.

Effects of Fish Oil with Heat Treatment on Obesity, Inflammation, and Gut Microbiota in Ovariectomized Mice

Background/Objectives: Menopause induces substantial metabolic changes, including a reduction in metabolic rate and an elevated risk of developing metabolic diseases. Fish oil (FO) supplementation has been shown to ameliorate menopause-associated metabolic risks. Hyperthermia treatment (HT) has recently gained attention for its potential to improve metabolic and immune health. However, it remains to be determined whether HT can confer metabolic benefits comparable to those of FO supplementation or enhance the metabolic benefits of FO supplementation. This study aims to delineate the distinctive and collaborative effects of HT and FO supplementation in mitigating menopause-associated metabolic dysfunction. Methods: Female C57BL/6 ovariectomized (OVX) mice were randomly assigned to four groups (n = 12/group) to evaluate the individual and combined effects of FO supplementation (5% w/w) and HT treatment. For HT, whole-body heat exposure was conducted at 40-41 °C for 30 min, 5 days per week. After 12 weeks, animals were used to evaluate the changes in glucose and lipid metabolism, obesity outcome, and inflammatory markers. The gut microbiome analysis was conducted from cecal content by 16S rRNA sequencing. Acute inflammation was induced by lipopolysaccharide (LPS) injection to evaluate inflammatory responses. Results: HT alone distinctively reduced weight gain, lowered core body temperature, and attenuated insulin resistance comparable to FO supplement in OVX mice. The collaborative effect of FO and HT was not evident in metabolic parameters but more prominent in attenuating proinflammatory responses and microbiota modulation. Conclusions: Our findings suggest that the combined treatment of FO supplementation and HT may serve as an effective strategy to mitigate menopause-associated immune susceptibility and metabolic dysfunction. These benefits are likely mediated, at least in part, through the reduction in inflammation and modulation of the gut microbiota.

Modulation of Intestinal Flora: a Novel Immunotherapeutic Approach for Enhancing Thyroid Cancer Treatment

Over the past 3 years, there has been a growing interest in clinical research regarding the potential involvement of intestinal flora in thyroid cancer (TC). This review delves into the intricate connection between intestinal flora and TC, focusing on the particular intestinal flora that is directly linked to the disease and identifying which may be able to predict potential microbial markers of TC. In order to shed light on the inflammatory pathways connected to the onset of TC, we investigated the impact of intestinal flora on immune modulation and the connection between chronic inflammation when investigating the role of intestinal flora in the pathogenesis of TC. Furthermore, the potential role of intestinal flora metabolites in the regulation of thyroid function was clarified by exploring the effects of short-chain fatty acids and lipopolysaccharide on thyroid hormone synthesis and metabolism. Based on these findings, we further explore the effects of probiotics, prebiotics, postbiotics, vitamins, and trace elements.

The Interplay of Nutrition, the Gut Microbiota and Immunity and Its Contribution to Human Disease

Nutrition, the gut microbiota and immunity are all important factors in the maintenance of health. However, there is a growing realization of the complex interplay between these elements coalescing in a nutrition-gut microbiota-immunity axis. This regulatory axis is critical for health with disruption being implicated in a broad range of diseases, including autoimmune disorders, allergies and mental health disorders. This new perspective continues to underpin a growing number of innovative therapeutic strategies targeting different elements of this axis to treat relevant diseases. This review describes the inter-relationships between nutrition, the gut microbiota and immunity. It then details several human diseases where disruption of the nutrition-gut microbiota-immunity axis has been identified and presents examples of how the various elements may be targeted therapeutically as alternate treatment strategies for these diseases.

Fecal fatty acid-linked bile acid profiles in pediatric patients with ulcerative colitis

OBJECTIVE

Effect of gut dysbiosis on fatty acid (FA) linked 3β-hydroxy-bile acid esters (FA-isoBAs) formation is currently unknown. This study aimed to investigate the profile of FA-isoBAs in fecal samples from pediatric patients with ulcerative colitis (UC).

METHODS

Fecal samples were collected from seven pediatric patients diagnosed with UC and seven age-matched healthy controls. Liquid chromatography-tandem mass spectrometry (LC/MS) method was set up for quantifications of thirteen different FA-isoBAs, including three new FA-isoBAs which had never been characterized. Method validation tests were performed with optimization of sample preparation. Statistical analyses were conducted to compare FA-isoBA concentrations between UC patients and healthy controls.

RESULTS

The LC/MS method had sufficient linearity (r > 0.998), with the low detection limit (0.03-2.82 nmol/g stool), and limits of quantification (0.10-9.40 nmol/g stool) for all FA-isoBAs. The total FA-isoBAs concentration in UC patients was significantly lower than healthy controls, regardless of the degree of the disease severity. The UC subjects had markedly increased primary bile acid (BA) levels with decreased secondary BAs. Propionic acid-linked isoBA and stearic acid-linked 12-oxo-isolithocholic acid were newly identified from healthy subjects but they were not present in UC subjects. In agreement with the previous report, composition of long-chain (C16-C18) FA-linked BAs dominated over short-chain FA-linked BAs both in healthy and disease subjects.

CONCLUSION

The present study reported the fecal FA-isoBA profiles in pediatric UC patients for the first time. The results open the door to the new field that investigates the role of these microbial-driven BAs in gastrointestinal health.

Postbiotics in inflammatory bowel disease: efficacy, mechanism, and therapeutic implications

Inflammatory bowel disease (IBD) is one of the most challenging diseases in the 21st century, and more than 10 million people around the world suffer from IBD. Because of the limitations and adverse effects associated with conventional IBD therapies, there has been increased scientific interest in microbial-derived biomolecules, known as postbiotics. Postbiotics are defined as the preparation of inanimate microorganisms and/or their components that confer a health benefit on the host, comprising inactivated microbial cells, cell fractions, metabolites, etc. Postbiotics have shown potential in enhancing IBD treatment by reducing inflammation, modulating the immune system, stabilizing intestinal flora and maintaining the integrity of intestinal barriers. Consequently, they are considered promising adjunctive therapies for IBD. Recent studies indicate that postbiotics offer distinctive advantages, including spanning clinical (safe origin), technological (easy for storage and transportation) and economic (reduced production costs) dimensions, rendering them suitable for widespread applications in functional food/pharmaceutical. This review offers a comprehensive overview of the definition, classification and applications of postbiotics, with an emphasis on their biological activity in both the prevention and treatment of IBD. © 2024 Society of Chemical Industry.

Mechanism of action of exercise regulating intestinal microflora to improve spontaneous hypertension in rats

Hypertension is a prevalent cardiovascular disease. Exercise is widely recognized as an effective treatment for hypertension, and it may also influence the composition of the intestinal microflora. However, it remains unclear whether exercise can specifically regulate the intestinal microflora in the context of hypertension treatment. In this study, tail blood pressure in spontaneously hypertensive rats (SHR) was measured using a blood pressure meter after exercise intervention and fecal bacteria transplantation following exercise. Blood lipid levels were assessed using an automatic biochemical analyzer, and 16S rRNA sequencing was employed to analyze the intestinal microflora. Histological examinations of ileal tissue were conducted using HE and Masson staining. Intestinal permeability, inflammatory status, and sympathetic activity were evaluated by measuring the levels of diamine oxidase, D-lactic acid, C-reactive protein, interleukin-6, tumor necrosis factor-α, lipopolysaccharide, norepinephrine, angiotensin II, cyclic adenosine monophosphate, and cyclic guanosine monophosphate. Exercise was found to reduce blood pressure and blood lipid levels in SHR. It also improved the composition of the intestinal microflora, as evidenced by a reduced Firmicutes/Bacteroidetes ratio, an increase in bacteria that produce acetic and butyric acid, and higher Chao 1 and Shannon diversity indices. Furthermore, exercise reduced the thickness of the fibrotic and muscular layers in the ileum, increased the goblet cell/villus ratio and villus length, and decreased intestinal permeability, inflammatory markers, and sympathetic nerve activity. The intestinal microbial flora regulated by exercise demonstrated similar effects on hypertension. In conclusion, exercise appears to regulate the intestinal microflora, and this exercise-induced change in flora may contribute to improvements in hypertension in rats.

The use of metagenomic and untargeted metabolomics in the analysis of the effects of the Lycium barbarum glycopeptide on allergic airway inflammation induced by Artemesia annua pollen

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of allergic airway inflammation (AAI) worldwide is high. Artemisia annua L. pollen is spread worldwide, and allergic diseases caused by its plant polysaccharides, which are closely related to the intestinal microbiota, have anti-inflammatory effects. Further isolation and purification of Lycium barbarum L. yielded its most effective component Lycium barbarum L. glycopeptide (LbGP), which can inhibit inflammation in animal models. However, its therapeutic effect on AAI and its mechanism of regulating the intestinal flora have not been fully investigated.

AIM OF THE STUDY

To explore LbGP in APE-induced immunological mechanisms of AAI and the interaction mechanism of the intestinal flora and metabolites.

METHODS

A mouse model of AAI generated from Artemisia annua pollen was constructed, and immunological indices related to the disease were examined. A combination of macrogenomic and metabolomic analyses was used to investigate the effects of LbGP on the gut microbial and metabolite profiles of mice with airway inflammation.

RESULTS

LbGP effectively alleviated Artemisia. annua pollen extract (APE)-induced AAI, corrected Th1/Th2 immune dysregulation, decreased Th17 cells, increased Treg cells, and altered the composition and function of the intestinal microbiota. LbGP treatment increased the number of OdoribacterandDuncaniella in the intestines of the mice, but the numble of Alistipes and Ruminococcus decreased. Metabolite pathway enrichment analysis were used to determine the effects of taurine and hypotaurine metabolism, bile acid secretion, and pyrimidine metabolism pathways on disease.

CONCLUSION

Our results revealed significant changes in the macrogenome and metabolome following APE and LbGP intervention, revealed potential correlations between gut microbial species and metabolites, and highlighted the beneficial effects of LbGP on AAI through the modulation of the gut microbiome and host metabolism.

Prebiotics Beyond the Gut: Omics Insights, Artificial Intelligence, and Clinical Trials in Organ-Specific Applications

Prebiotics, traditionally linked to gut health, are increasingly recognized for their systemic benefits, influencing multiple organ systems through interactions with the gut microbiota. Compounds like inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS) enhance short-chain fatty acid (SCFA) production, benefiting neurocognitive health, cardiovascular function, immune modulation, and skin integrity. Advances in biotechnology, including deep eutectic solvents (DES) for extraction and machine learning (ML) for personalized formulations, have expanded prebiotic applications. Integrating these innovations with "omics" technologies enables precise microbial modulation, fostering personalized nutrition and precision therapies. This review examines organ-specific effects of prebiotics, highlights findings from clinical trials, and explores biotechnological innovations that enhance prebiotic efficacy, laying the groundwork for future personalized therapeutic strategies.

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.

Effects of the Curcuminoid and Non-Curcuminoid Compounds of Turmeric on the Gut Microbiome and Inflammation: Potential Use in the Treatment and Prevention of Disease

The gut microbiome is a complex system that directly interacts with and influences many systems in the body. This delicate balance of microbiota plays an important role in health and disease and is highly influenced by lifestyle factors and the surrounding environment. As further research emerges, understanding the full potential of the gut microbiome and the impact of using nutraceuticals to positively influence its function may open the door to greater therapeutic outcomes in the treatment and prevention of disease. Curcumin, a bioactive compound derived from the turmeric rhizome, has been studied in depth for its influence on human health as a potent anti-inflammatory and antioxidant properties. However, the therapeutic activity of curcumin is limited by its low oral bioavailability. While most available research has primarily focused on the curcuminoid compounds of turmeric, the non-curcuminoid compounds hold promise to offer therapeutic benefits while synergistically enhancing the bioavailability of curcumin and supporting the gut microbiome. This review summarizes current knowledge of the relationship between the gut and the various systems within the body, and how dysbiosis, or disruption in the gut microbial balance, leads to inflammation and increased risk of chronic disease. The review also summarizes recent research that focuses on the bioactivity of both the curcuminoid and non-curcuminoid compounds that comprise the whole turmeric root and their synergistic role in enhancing bioavailability to support a healthy gut microbiome and promising use in the treatment and prevention of disease.

Short-Chain Fatty Acids: Promising Therapeutic Targets for Respiratory Syncytial Virus Infection

The intestinal microbiota is a complex community of organisms present in the human gastrointestinal tract, some of which can produce short-chain fatty acids (SCFAs) through the fermentation of dietary fiber. SCFAs play a major role in mediating the intestinal microbiota's regulation of host immunity and intestinal homeostasis. Respiratory syncytial virus (RSV) can cause an imbalance between anti-inflammatory and proinflammatory responses in the host. In addition, changes in SCFA levels and the structure of the intestinal microbiota have been observed after RSV infection. Therefore, there may be a link between SCFAs and RSV infection, and SCFAs are expected to be therapeutic targets for RSV infection.

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.

Gut Barrier Dysfunction and Microbiota Variations in Cryptosporidiosis: A Comprehensive Review

Cryptosporidiosis is a zoonotic protozoan parasite-born disease, equally significant in both animals and humans, especially affecting immunocompromised individuals (e.g., AIDS patients) and neonates. The prime concerns of this review article are to demonstrate the disruption of the intestinal barrier and variations in the gut microbiome during cryptosporidiosis, and to explore host gut-parasite interactions that can lead to the development of novel therapeutics. The review concluded that the enteric barrier is particularly maintained by tight junction proteins (e.g., occludin, claudin, and ZO-1, etc.) and mucosal immunity, both of which are severely compromised during Cryptosporidium spp. infections, resulting in increased intestinal barrier permeability, inflammatory responses, diarrhea, and ultimately death in severe cases. Cryptosporidium-induced dysbiosis is characterized by reduced microbial diversity and richness, a shift from commensal to pathogenic bacteria, as evidenced by increased pro-inflammatory taxa like Proteobacteria, and reduced proportions of beneficial SCFAs producing bacteria, e.g., Firmicutes. Recent investigations have highlighted the interrelations between gut microbiota and epithelial barrier integrity, especially during cryptosporidiosis, demonstrating the modulations regarding tight junctions (TJs), immune reactions, and SCFA production, all of which are main players in alleviating this protozoal parasitic infection. This review comprehensively describes the fine details underlying these impairments, including autophagy-mediated TJs' degradation, inflammasome activation, and gut microbiome-driven alterations in metabolic pathways, providing the latest relevant, and well-organized piece of knowledge regarding intestinal barrier alterations and microbial shifts during cryptosporidiosis. This work emphasizes the future need for longitudinal studies and advanced sequencing techniques to understand host gut microbiota-parasite interactions, aiming to formulate innovative strategies to mitigate cryptosporidiosis.

Response of the gut microbiome and metabolome to dietary fiber in healthy dogs

Dietary fiber confers multiple health benefits originating from the expansion of beneficial gut microbial activity. However, very few studies have established the metabolic consequences of interactions among specific fibers, microbiome composition, and function in either human or representative animal models. In a study design reflective of realistic population dietary variation, fecal metagenomic and metabolomic profiles were analyzed from healthy dogs fed 12 test foods containing different fiber sources and quantities (5-13% as-fed basis). Taxa and functions were identified whose abundances were associated either with overall fiber intake or with specific fiber compositions. Fourteen microbial species were significantly enriched in response to ≥1 specific fiber source; enrichment of fiber-derived metabolites was more pronounced in response to these fiber sources. Positively associated fecal metabolites, including short-chain fatty acids, acylglycerols, fiber bound sugars, and polyphenols, co-occurred with microbes enriched in specific food groups. Critically, the specific metabolite pools responsive to differential fiber intake were dependent on differences both in individual microbial community membership and in overall ecological configuration. This helps to explain, for the first time, differences in microbiome-diet associations observed in companion animal epidemiology. Thus, our study corroborates findings in human cohorts and reinforces the role of personalized microbiomes even in seemingly phenotypically homogeneous subjects.

IMPORTANCE

Consumption of dietary fiber changes the composition of the gut microbiome and, to a larger extent, the associated metabolites. Production of health-relevant metabolites such as short-chain fatty acids from fiber depends both on the consumption of a specific fiber and on the enrichment of beneficial metabolite-producing species in response to it. Even in a seemingly homogeneous population, the benefit received from fiber consumption is personalized and emphasizes specific fiber-microbe-host interactions. These observations are relevant for both population-wide and personalized nutrition applications.

Predicting metabolite response to dietary intervention using deep learning

Due to highly personalized biological and lifestyle characteristics, different individuals may have different metabolite responses to specific foods and nutrients. In particular, the gut microbiota, a collection of trillions of microorganisms living in the gastrointestinal tract, is highly personalized and plays a key role in the metabolite responses to foods and nutrients. Accurately predicting metabolite responses to dietary interventions based on individuals' gut microbial compositions holds great promise for precision nutrition. Existing prediction methods are typically limited to traditional machine learning models. Deep learning methods dedicated to such tasks are still lacking. Here we develop a method McMLP (Metabolite response predictor using coupled Multilayer Perceptrons) to fill in this gap. We provide clear evidence that McMLP outperforms existing methods on both synthetic data generated by the microbial consumer-resource model and real data obtained from six dietary intervention studies. Furthermore, we perform sensitivity analysis of McMLP to infer the tripartite food-microbe-metabolite interactions, which are then validated using the ground-truth (or literature evidence) for synthetic (or real) data, respectively. The presented tool has the potential to inform the design of microbiota-based personalized dietary strategies to achieve precision nutrition.

Lactobacillus acidophilus alleviate Salmonella enterica Serovar Typhimurium-induced murine inflammatory/oxidative responses via the p62-Keap1-Nrf2 signaling pathway and cecal microbiota

Background

Salmonella enterica Serovar Typhimurium (S. Typhimurium) infection can cause inflammation and oxidative stress in the body, leading to gastroenteritis, fever and other diseases in humans and animals. More and more studies have emphasized the broad prospects of probiotics in improving inflammation and oxidative stress, but the ability and mechanism of Lactobacillus acidophilus (LA) to alleviate the inflammatory/oxidative reaction caused by pathogens are still unclear.

Methods and results

In this study, we treated the mice with LA for 14 days, infected them with S. Typhimurium for 24 h, and sacrificed the mice to collect samples. We found that the early intervention of LA alleviated the pathological injury and reversed the down-regulation of the duodenal and hepatic tight junction protein mRNA levels caused by S. Typhimurium infection. Compared with S. Typhimurium group, LA early intervention increased the expression of antioxidant enzymes, but decreased the levels of serum malondialdehyde (MDA), interleukin-8 and tumor necrosis factor-α (TNF-α). Additionally, LA early intervention significantly increased Nrf2 mRNA expression in the liver and decreased Keap1 mRNA expression in the duodenum compared to the S. Typhimurium group. Furthermore, early LA treatment reduced the abundance of Bacteroides acidificiens, increased the abundance of Akkermansia, and alleviated the decrease in SCFAs levels in the cecum of S. Typhimurium-infected mice. Spearman correlation analysis showed that there was a certain correlation between cecal flora and serum indicators and short chain fatty acids.

Conclusion

Taken together, the results indicate that LA early intervention may alleviates S. Typhimurium-induced inflammation and oxidative responses in mice by activating the p62-Keap1-Nrf2 signaling pathway and regulating the gut microbial community.

Significance and impact of the study

Exploring the ability of LA to resist animal oxidative stress and microflora regulation caused by pathogenic microbes, so as to provide more options for developing healthy disease-resistant feed additives.

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.

Citrobacter rodentium promotes brain cognitive dysfunction of type 2 diabetes mice by activating FXR mediated gut barrier damage

Type 2 diabetes (T2D) is an important risk factor for brain cognitive impairment, but the specific mechanism is still unclear. The imbalance of gut microbiota under pathological conditions (such as an increase in pathogenic bacteria) may be involved in the occurrence of various diseases. The purpose of this study is to investigate the effect of increased abundance of gut Citrobacter rodentium on cognitive function in T2D mice. Our results indicate that an increase in the abundance of Citrobacter rodentium leads to impaired intestinal barrier, elevated expression of inflammatory factors in blood and brain tissue, and promotes cognitive impairment in T2D mice. The specific pathway involves activation of farnesol X receptor (FXR) expression-mediated intestinal barrier dysfunction. The use of intestinal mucosal protectants and FXR inhibitors improved intestinal barrier function and brain cognitive function. Therefore, the research results provide a mechanistic link between the increased abundance of Citrobacter in the gut of T2D mice and brain cognitive function, and provide a reference for the occurrence of brain cognitive dysfunction in T2D.

Jingfang Granules alleviates the lipid peroxidation induced ferroptosis in rheumatoid arthritis rats by regulating gut microbiota and metabolism of short chain fatty acids

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation, bone and cartilage damage, musculoskeletal pain, swelling, and stiffness. Inflammation is one of the key factors that induce RA. Jingfang Granule (JFG) is a traditional Chinese medicine (TCM) with significant anti-inflammatory effects. Clinical studies have confirmed that JFG can be used to treat RA, but the mechanism is still vague.

PURPOSE

This study was designed to evaluate the protective function and the mechanism of JFG on rats with RA.

STUDY DESIGN AND METHODS

Complete Freud's Adjuvant (CFA) was used to establish a rat RA model, and JFG or Diclofenac Sodium (Dic) was orally administered. Foot swelling and hematoxylin eosin (H&E) staining were used to test the therapeutic effect of JFG on RA treatment, while ELISA kits were used to detect serum cytokines. Malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), and reactive oxygen species (ROS) were used to evaluate oxidative stress levels. The integration of label-free proteomics, fecal short chain fatty acid (SCFA) targeted metabolomics, peripheral blood SCFA, medium and long chain fatty acid targeted metabolomics, and 16S rDNA sequencing of gut microbiota were used to screen the mechanism. Western blot technology was used to validate the results of multiple omics studies. Serum D-Lactic acid, lipopolysaccharide specific IgA antibody (LPS IgA), diamine oxidase (DAO), and colon Claudin 5 and ZO-1 were used to evaluate the intestinal barrier.

RESULTS

The results confirmed that JFG effectively protected rats from RA injury, which was confirmed by improved foot swelling and synovial pathology. At the same time, JFG reduced the levels of TNF-α, IL-1β, and IL-6 in serum by inhibiting the NLRP3 inflammasome signaling pathway and TLR4/NF-κB signaling pathway in synovial tissue. Multiple omics studies indicated that JFG increased the abundance of gut microbiota and regulated the number of gut bacteria, thereby increased the levels of Acetic acid, Propionic acid, and Butyric acid in the gut and serum of RA rats, which activated AMPK to regulate fatty acid metabolism and fatty acid biosynthesis, thereby inhibited lipid oxidative stress induced ferroptosis to improve tissue damage caused by RA. Meanwhile, JFG improved the intestinal barrier by upregulating the expresses of Claudin 5 and ZO-1, which was confirmed by low concentrations of D-Lactic acid, LPS-SIgA and DAO in serum.

CONCLUSIONS

This study confirmed that JFG improved the disturbance of fatty acid metabolism by modulating gut microbiota and the production of fecal SCFAs to activate AMPK, and then inhibited ferroptosis caused by lipid oxidative stress in synovium tissue and prevented AR injury. This study proposes for the first time to investigate the mechanism of JFG treatment for RA from the perspective of the "Gut-joint" axis, and provides a promising approach for the treatment of RA.

Investigating the biological significance of the TCM principle "promoting urination to regulate bowel movements" through the influence of the intestinal microbiota and their metabolites on the renal-intestinal axis

Treatment methods in traditional Chinese medicine (TCM) are foundational to their theoretical, methodological, formulaic, and pharmacological systems, significantly contributing to syndrome differentiation and therapy. The principle of "promoting urination to regulate bowel movements" is a common therapeutic approach in TCM. The core concept is "promoting the dispersion and drainage of water dampness, regulating urination to relieve diarrhea," yet its scientific underpinning remains unclear. Modern medical treatment for watery diarrhea primarily focuses on electrolyte replenishment, as diuretics may lead to dehydration and other side effects. Some reports suggest that this TCM approach lacks scientific validity. Microecology, an area associated with the origins of TCM, is closely related to the development, diagnosis, and treatment of diarrhea. The renal-intestinal axis offers a molecular biological basis for examining associated pathological mechanisms, advancing therapeutic targets such as "treating the intestine to address kidney issues" and highlighting the interactions within the "renal-intestinal microbiota-liquid metabolism" framework, thus providing an endogenous mechanism to support "treating the intestine through the kidney." An increasing number of studies have shown that the intestinal microbiota and its metabolites, as unique mediators, are involved in the physiological and pathological changes of the body. Therefore, this study explores the relationship between fluid metabolism and diarrhea from the perspective of the intestinal microbiota and its metabolites, aiming to elucidate the biological mechanisms underlying the "promoting urination to regulate bowel movements" therapeutic approach and to clarify the scientific basis for treating diarrhea via the renal-intestinal axis. This research provides new insights for the study of TCM microbiology.

A data-driven machine learning algorithm to predict the effectiveness of inulin intervention against type II diabetes

Introduction

The incidence of type 2 diabetes mellitus (T2DM) has increased in recent years. Alongside traditional pharmacological treatments, nutritional therapy has emerged as a crucial aspect of T2DM management. Inulin, a fructan-type soluble fiber that promotes the growth of probiotic species like Bifidobacterium and Lactobacillus, is commonly used in nutritional interventions for T2DM. However, it remains unclear which type of T2DM patients are suitable for inulin intervention. The aim of this study was to predict the effectiveness of inulin treatment for T2DM using a machine learning model.

Methods

Original data were obtained from a previous study. After screening T2DM patients, feature election was conducted using LASSO regression, and a machine learning model was developed using XGBoost. The model's performance was evaluated based on accuracy, specificity, positive predictive value, negative predictive value and further analyzed using receiver operating curves, calibration curves, and decision curves.

Results

Out of the 758 T2DM patients included, 477 had their glycated hemoglobin (HbA1c) levels reduced to less than 6.5% after inulin intervention, resulting in an incidence rate of 62.93%. LASSO regression identified six key factors in patients prior to inulin treatment. The SHAP values for interpretation ranked the characteristic variables in descending order of importance: HbA1c, difference between fasting and 2 h-postprandial glucose levels, fasting blood glucose, high-density lipoprotein, age, and body mass index. The XGBoost prediction model demonstrated a training set accuracy of 0.819, specificity of 0.913, positive predictive value of 0.818, and negative predictive value of 0.820. The testing set showed an accuracy of 0.709, specificity of 0.909, positive predictive value of 0.705, and negative predictive value of 0.710.

Conclusion

The XGBoost-SHAP framework for predicting the impact of inulin intervention in T2DM treatment proves to be effective. It allows for the comparison of prediction effect based on different features of an individual, assessment of prediction abilities for different individuals given their features, and establishes a connection between machine learning and nutritional intervention in T2DM treatment. This offers valuable insights for researchers in this field.

Fecal Microbiota Transplantation Alleviates Airway Inflammation in Asthmatic Rats by Increasing the Level of Short-Chain Fatty Acids in the Intestine

Asthma is a prevalent chronic inflammatory disorder of the respiratory tract that not only manifests with respiratory symptoms but also often involves intestinal flora disorders and gastrointestinal dysfunction. Recent studies have confirmed the close relationship between the gut and lungs, known as the "gut-lung axis" theory. Fecal microbiota transplantation (FMT), a method for restoring normal intestinal flora, has shown promise in treating common gastrointestinal diseases. The "gut-lung axis" theory suggests that FMT may have significant therapeutic potential for asthma. In this study, we established an Ovalbumin (OVA)-induced rat model of asthma to investigate the protective effect of FMT on airway inflammation and the restoration of intestinal short-chain fatty acids (SCFAs), aiming to explore its underlying mechanism. Rats in the Control group underwent fecal treatment via gavage (Control-FMT, C-FMT group), while rats in the Asthma group underwent fecal treatment via gavage after asthma induction (Asthma-FMT, A-FMT group). Following a two-week period of continuous intragastric administration, various measurements were conducted to assess pulmonary function, peripheral blood neutrophil, lymphocyte, and eosinophil content, lung tissue pathology, and collagen fiber deposition in the lungs. Additionally, neutrophil and eosinophil content in bronchoalveolar lavage fluid (BALF), expression levels of Interleukin-4 (IL-4), IL-5, IL-13, IL-17, IL-33, leukotrienes (LT), thymic stromal lymphopoietin (TSLP), prostaglandin D2 (PGD2) protein and mRNA in lung tissue, and SCFAs content in stool were evaluated. In the C-FMT group, lung function significantly improved, inflammatory cell content in peripheral blood and BALF decreased, lung tissue pathology and collagen fiber deposition significantly improved, the protein and mRNA levels of lung inflammatory factors IL-4, IL-5, IL-13, IL-17, IL-33, LT, TSLP, PGD2 were significantly decreased, and SCFAs such as acetate (C2), propionate (C3), butyrate (C4), isobutyric acid (I-C4), valeric acid (C5), and isovaleric acid (I-C5) content in stool significantly increased. However, the indexes in the A-FMT group did not show significant recovery, and the treatment effect on asthma symptoms in rats was inferior to that in the C-FMT group. Asthma induced intestinal flora disorders in rats, and FMT treatment improved the inflammatory response in asthmatic rat models and corrected their intestinal SCFAs disorders. Encouraging the recovery of intestinal SCFAs may play a significant role, and beneficial bacteria present in feces may improve asthma symptoms by promoting the remodeling of intestinal flora. This experiment provides further scientific evidence supporting the "gut-lung axis" theory.

Gut microbiota and inflammasome-mediated pyroptosis: a bibliometric analysis from 2014 to 2023

Background

The role of gut microbiota in inflammatory disease development and progression has been recognized more recently. Inflammasome-mediated pyroptosis in involved in these diseases. This complex relationship between gut microbiota and inflammasome-mediated pyroptosis provides an important field of research. Bibliometric analysis provides a comprehensive understanding of this relationship, offering valuable insights into emerging research trends.

Materials and methods

Leveraging data spanning from 2014 to 2023 sourced from the Web of Science Core Collection, our analysis was conducted using advanced tools such as SCImago Graphica, VOSviewer, and CiteSpace software. Visualizations were created using GraphPad Prism software. We explored the nuanced aspects of research hotspots, collaborative networks, and developing trends in this field.

Results

A global bibliometric analysis identified 520 relevant studies spanning 41 countries and 887 institutions. Over the past decade, publication trends have shown consistent growth, with China and the United States leading the research output. Southern Medical University and Nanjing Medical University in China emerged as leading institutions in this filed. Prominent contributors include Jia Sun, Yuan Zhang, Wei Chen, Jing Wang, and Hongtao Liu from China, alongside Eicke Latz from Germany. High-impact journals such as Frontiers in Immunology and Nature Communications have been pivotal in disseminating research in this domain. Keyword analysis highlighted a primary focus on gut microbiota, NLRP3 inflammasome, pyroptosis pathways, and inflammatory diseases, themes that persist in recent studies. Furthermore, burst keyword analysis identified "butyrate" as the sole term currently experiencing a marked increase in research interest.

Conclusion

Research has been deeply focused on the gut microbiota and inflammasome triggered pyroptosis in years. Over the past decade, the exploration of how gut microbiota and NLRP3 or NLRP6 inflammasome-mediated pyroptosis has been an area of interest. Future investigations in this filed may primarily revolve around understanding the correlation between butyrate and NLRP3 inflammasome induced pyroptosis in relation to conditions. However, an in-depth analysis, through studies is crucial to uncover and elucidate the complex mechanisms linking these elements.

Human milk oligosaccharides: bridging the gap in intestinal microbiota between mothers and infants

Breast milk is an essential source of infant nutrition. It is also a vital determinant of the structure and function of the infant intestinal microbial community, and it connects the mother and infant intestinal microbiota. Human milk oligosaccharides (HMOs) are a critical component in breast milk. HMOs can reach the baby's colon entirely from milk and become a fermentable substrate for some intestinal microorganisms. HMOs can enhance intestinal mucosal barrier function and affect the intestinal function of the host through immune function, which has a therapeutic effect on specific infant intestinal diseases, such as necrotizing enterocolitis. In addition, changes in infant intestinal microbiota can reflect the maternal intestinal microbiota. HMOs are a link between the maternal intestinal microbiota and infant intestinal microbiota. HMOs affect the intestinal microbiota of infants and are related to the maternal milk microbiota. Through breastfeeding, maternal microbiota and HMOs jointly affect infant intestinal bacteria. Therefore, HMOs positively influence the establishment and balance of the infant microbial community, which is vital to ensure infant intestinal function. Therefore, HMOs can be used as a supplement and alternative therapy for infant intestinal diseases.

Cell free supernatants of Bifidobacterium adolescentis and Bifidobacterium longum suppress the tumor growth in colorectal cancer organoid model

The probiotic gut microbiome and its metabolites are pivotal in regulating host metabolism, inflammation, and immunity. Host genetics, colonization at birth, the host lifestyle, and exposure to diseases and drugs determine microbial composition. Dysbiosis and disruption of homeostasis in the beneficial microbiome have been reported to be involved in the tumorigenesis and progression of colorectal cancer (CRC). However, the influence of bacteria-secreted metabolites on CRC growth is yet to be fully elucidated. In this study, we compared the microbial composition of CRC patients to healthy controls to identify distinct patterns of microbiota-derived metabolites in CRC patients. Metagenomic analysis demonstrated that beneficial bacteria strains; Blautia producta, Bifidobacterium adolescentis, and Bifidobacterium longum decreased, while Parabacteroides distasonis and Bacteroides ovatus were more prevalent in the CRC patient group. Treatment of cancer organoid lines with microbial culture supernatants from Blautia producta, Bifidobacterium adolescentis, and Bifidobacterium longum showed remarkable inhibition of cancer growth. This study demonstrates that the bacterial metabolites depleted in CRC patients may inhibit cancer growth and highlights the effects of microbiome-derived metabolites on CRC growth.

Uncovering the Beneficial Role of Limosilactobacillus fermentum E7 Exhibiting Antioxidant Activity in Ameliorating DSS-Induced Ulcerative Colitis in a Murine Model

BACKGROUND

Ulcerative colitis (UC) is a chronic intestinal disease of growing global concern. Bacteria associated with fermented food or probiotics regulate immune and inflammatory responses, playing a key role in intestinal immune homeostasis.

RESULTS

Five probiotics with relatively good antioxidant effects, namely Lactiplantibacillus plantarum H6, Latilactobacillus sakei QC9, Limosilactobacillus fermentum E7, Bacillus subtills D1, and Bacillus licheniformis Q13, were screened out from 30 strains of probiotics through in vitro antioxidant assays. The five probiotics had varying degrees of alleviating effects on UC mice and improved various physiological indicators, such as oxidative stress parameters and histopathological sections. The effects of E7, D1, and Q13 were more pronounced. Furthermore, E7 effectively regulated UC mouse intestinal microbiota composition, increased short-chain fatty acid concentration, and promoted the expression of anti-inflammatory factors, such as interleukin 10 (IL-10), while suppressing that of pro-inflammatory factors, such as interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α). Meanwhile, D1 and Q13 only exhibited partial alleviating effects. Finally, E7 increased the expression of tight junction proteins in colon tissues.

CONCLUSIONS

E7 showed superior efficacy to other probiotics in alleviating UC, offering novel therapeutic prospects for safer and effective management of UC.

Microbiota-neuroepithelial signalling across the gut-brain axis

Research over the past two decades has established a remarkable ability of the gut microbiota to modulate brain activity and behaviour. Conversely, signals from the brain can influence the composition and function of the gut microbiota. This bidirectional communication across the gut microbiota-brain axis, involving multiple biochemical and cellular mediators, is recognized as a major brain-body network that integrates cues from the environment and the body's internal state. Central to this network is the gut sensory system, formed by intimate connections between chemosensory epithelial cells and sensory nerve fibres, that conveys interoceptive signals to the central nervous system. In this Review, we provide a broad overview of the pathways that connect the gut and the brain, and explore the complex dialogue between microorganisms and neurons at this emerging intestinal neuroepithelial interface. We highlight relevant microbial factors, endocrine cells and neural mechanisms that govern gut microbiota-brain interactions and their implications for gastrointestinal and neuropsychiatric health.

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.

Bidirectional association between pneumonia and intestinal infection: an analysis of the MIMIC-IV database

The purpose is to analyze the prevalence of intestinal infection in patients with pneumonia in intensive care units (ICU) and the impact of intestinal infection on the prognosis of patients with pneumonia, so as to explore the bidirectional association between pneumonia and intestinal infection. The study aims to investigate the correlation between the occurrence of pneumonia and intestinal infection among patients in the ICU, utilizing the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, as well as the impact of intestinal infection on the prognosis of pneumonia patients. The enrolled patients were first divided into pneumonia group and non-pneumonia group, and the primary outcome was that patients developed intestinal infection. Multivariate logistic regression was used to elucidate the association between pneumonia and the prevalence of intestinal infection, and propensity score matching (PSM) and inverse probability of treatment weighing (IPTW) were used to validate our findings. We then divided patients with pneumonia into two groups according to whether they were complicated by intestinal infection, and analyzed the effect of intestinal infection on 28-day mortality, length of ICU stay, and length of hospital stay in patients with pneumonia. This study included 50,920 patients, of which 7493 were diagnosed with pneumonia. Compared with non-pneumonia patients, the incidence of intestinal infection in pneumonia patients was significantly increased [OR 1.58 (95% CI 1.34-1.85; P < 0.001)]. Cox proportional hazards regression model showed no significant effect of co-infection on 28-day mortality in patients with pneumonia (P = 0.223). Patients in the intestinal infection group exhibited a longer length stay in ICU and hospital than those without intestinal infection (P < 0.001). In the ICU, patients with pneumonia were more likely linked to intestinal infection. In addition, the presence of concurrent intestinal infections can prolong both ICU and hospital stays for pneumonia patients.

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.

Food colorant brilliant blue causes persistent functional and structural changes in an in vitro simplified microbiota model system

The human gut microbiota plays a vital role in maintaining host health by acting as a barrier against pathogens, supporting the immune system, and metabolizing complex carbon sources into beneficial compounds such as short-chain fatty acids. Brilliant blue E-133 (BB), is a common food dye that is not absorbed or metabolized by the body, leading to substantial exposure of the gut microbiota. Despite this, its effects on the microbiota are not well-documented. In this study, we cultivated the Simplified Human Microbiota Model (SIHUMIx) in a three-stage in vitro approach (stabilization, exposure, and recovery). Using metaproteomic and metabolomic approaches, we observed significant shifts in microbial composition, including an increase in the relative abundance of Bacteroides thetaiotaomicron and a decrease in beneficial species such as Bifidobacterium longum and Clostridium butyricum. We observed lower protein abundance in energy metabolism, metabolic end products, and particularly lactate and butyrate. Disturbance in key metabolic pathways related to energy production, stress response, and amino acid metabolism were also observed, with some pathways affected independently of bacterial abundance. These functional changes persisted during the recovery phase, indicating that the microbiota did not fully return to its pre-exposure state. Our findings suggest that BB has a lasting impact on gut microbiota structure and function, raising concerns about its widespread use in the food industry. This study underscores the need for further research into the long-term effects of food colorants on the gut microbiota and their potential health implications.

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.

Effects of Probiotics on Liver Diseases: Current In Vitro and In Vivo Studies

Various types of liver or hepatic diseases cause the death of about 2 million people worldwide every year, of which 1 million die from the complications of cirrhosis and another million from hepatocellular carcinoma and viral hepatitis. Currently, the second most common solid organ transplant is the liver, and the current rate represents less than 10% of global transplant requests. Hence, finding new approaches to treat and prevent liver diseases is essential. In liver diseases, the interaction between the liver, gut, and immune system is crucial, and probiotics positively affect the human microbiota. Probiotics are a non-toxic and biosafe alternative to synthetic chemical compounds. Health promotion by lowering cholesterol levels, stimulating host immunity, the natural gut microbiota, and other functions are some of the activities of probiotics, and their metabolites, including bacteriocins, can exert antimicrobial effects against a broad range of pathogenic bacteria. The present review discusses the available data on the results of preclinical and clinical studies on the effects of probiotic administration on different types of liver diseases.

Immune aging and infectious diseases

ABSTRACT

The rise in global life expectancy has led to an increase in the older population, presenting significant challenges in managing infectious diseases. Aging affects the innate and adaptive immune systems, resulting in chronic low-grade inflammation (inflammaging) and immune function decline (immunosenescence). These changes would impair defense mechanisms, increase susceptibility to infections and reduce vaccine efficacy in older adults. Cellular senescence exacerbates these issues by releasing pro-inflammatory factors, further perpetuating chronic inflammation. Moreover, comorbidities, such as cardiovascular disease and diabetes, which are common in older adults, amplify immune dysfunction, while immunosuppressive medications further complicate responses to infections. This review explores the molecular and cellular mechanisms driving inflammaging and immunosenescence, focusing on genomic instability, telomere attrition, and mitochondrial dysfunction. Additionally, we discussed how aging-associated immune alterations influence responses to bacterial, viral, and parasitic infections and evaluated emerging antiaging strategies, aimed at mitigating these effects to improve health outcomes in the aging population.

Gut Microbiota and Metabolites Mediate Health Benefits of Oat and Oat Bran Consumption in IBD Mice

BACKGROUND/OBJECTIVES

Inflammatory bowel disease (IBD) is a chronic condition influenced by a variety of factors, including genetics, the environment, and gut microbiota. The incidence of IBD is increasing globally. Previous studies have shown that interactions between diet and gut microbiota influence the pathogenesis and treatment of IBD. Proper dietary nutrition including oat and oat bran regulates chronic inflammation, which is essential for individual health, and is one of the essential factors in reducing inflammation in the body and keeping the immune system functioning properly, which plays a role in the prevention and treatment of diseases. However, the mechanism of action of whether oat and oat bran will alleviate chronic inflammation by modulating intestinal flora and metabolites remains unknown.

METHODS

Therefore, in this study, we have used a mouse model of dextran sulfate sodium (DSS) chronic colitis to analyze the composition of intestinal microbiota, short-chain fatty acid content, and the expression of the relevant genes.

RESULTS

The results showed that diets supplemented with oat and oat bran improved intestinal barrier parameters, decreased the levels of inflammatory factors, modulated the composition of intestinal microbiota, and increased the content of short-chain fatty acids.

CONCLUSIONS

This study provides strong evidence that dietary interventions with oats or oat bran may have potential applications in clinical nutrition and dietary interventions for chronic IBD.