在2025年欧洲胃肠病学周（UEG Week 2025）活动上发布的一项最新研究表明，微塑料（环境中常 见的小于5毫米的塑料颗粒）会改变人类肠道微生物群，其中一些变化类似于与抑郁症和结直肠癌相关 的模式。这项研究是首批直接检查不同类型微塑料如何与人体肠道微生物群相互作用的研究之一。 这些细菌组成的变化伴随着细菌产生的化学物质的变化，其中一些与观察到的酸度增加相对应。某 些微塑料类型改变了戊酸和5-氨基戊酸的水平，而另一些则影响赖氨酸或乳酸，突出了微塑料—微生物 群相互作用的复杂性。 重要的是，在这些微塑料诱导的微生物组成变化中，有些反映了先前与抑郁症和结直肠癌等疾病相 关的模式，凸显了微塑料暴露对疾病风险的潜在影响。 虽然总细菌细胞数和活细菌细胞数基本保持不变，但与对照组相比，经微塑料处理的培养物的酸度 持续显著增加，表明微生物代谢活动发生了改变。 进一步分析显示，细菌组成发生了微塑料特异性的变化，某些细菌群体的数量增加或减少，具体取 决于微塑料的类型。在几个细菌科中观察到的变化，大多发生在芽孢杆菌门内。芽孢杆菌门是肠道细菌 的一个关键群体，对消化和整体肠道健康至关重要。 该研究使用5名健康志愿者的粪便样本进 ...

Core Insights - The gut microbiome is a significant predictor of health, influencing metabolism, weight, brain health, and aging [3][4] - Dysbiosis, or an imbalance in gut microbes, is linked to various chronic diseases, including obesity, cardiovascular disease, and neurodegenerative disorders [22][30] Group 1: Microbiome and Health - The gut microbiome consists of over 30 trillion microbes, comparable in number to human cells, and plays a crucial role in digestion and nutrient absorption [5][10] - Changes in the microbiome can occur rapidly in response to diet, antibiotics, and environmental factors, affecting overall health and resilience [8][13] - Dysbiosis can lead to increased intestinal permeability, systemic inflammation, and is associated with conditions like metabolic syndrome and autoimmune diseases [22][23][24] Group 2: Chronic Diseases Linked to Dysbiosis - Cardiovascular disease is linked to dysbiosis through microbial metabolites such as trimethylamine N-oxide (TMAO), which is associated with higher risks of heart attack and stroke [25][31] - Neurodegenerative diseases like Alzheimer's and Parkinson's show microbial shifts that may precede clinical symptoms, suggesting potential for early intervention [28][51] - Mental health issues, including major depressive disorder, have been correlated with reduced levels of beneficial gut bacteria [27][32] Group 3: Dietary Influence on the Microbiome - A diverse, plant-based diet rich in fiber, resistant starches, and polyphenols is essential for maintaining a healthy microbiome [35][39][54] - Fermented foods can enhance microbial diversity and reduce inflammation, supporting overall gut health [38][54] - Long-term dietary changes are necessary to achieve lasting improvements in microbiome composition, as short-term diets often revert to baseline [42][44] Group 4: Future of Microbiome Research and Therapies - Precision probiotics and live biotherapeutic products (LBPs) are being explored as potential treatments for metabolic and neurological disorders [46][49] - Emerging diagnostics, such as stool sequencing and capsule-based sampling, may allow for personalized microbiome-targeted therapies [51][52] - The integration of diet, lifestyle, and microbial therapeutics is anticipated to be the future approach for optimizing gut health and overall well-being [52][53]

Core Viewpoint - The article discusses the relationship between nasal microbiota, specifically Staphylococcus aureus, and depressive behavior, highlighting the role of sex hormone degradation in this process [4][5][11]. Group 1: Research Findings - A study published in Nature Microbiology indicates that nasal Staphylococcus aureus can promote depressive behavior in mice by degrading sex hormones [4][5]. - The enzyme 17β-hydroxysteroid dehydrogenase expressed by Staphylococcus aureus degrades testosterone and estradiol in mice, leading to decreased levels of dopamine and serotonin in the brain, which induces depressive-like behavior [5][11]. - Analysis of nasal microbiota shows a positive correlation between the abundance of Staphylococcus aureus and depression scores in both depressed patients and healthy controls [9]. Group 2: Implications - The findings suggest a significant link between nasal microbiota and brain function, particularly in the context of neuropsychiatric disorders, which has been under-researched [8]. - The study provides new insights into the nose-brain axis, indicating that nasal colonization by certain bacteria may influence mental health through hormonal pathways [11].

Core Insights - The research from the Charles Perkins Centre at the University of Sydney suggests that gut microbiome health may be influenced by genetics, not just diet, highlighting the role of a natural protein peptide called α-defensin in managing gut bacteria and protecting against unhealthy diets [1][2][3] Group 1: Research Findings - The study indicates that certain genes in mice lead to the production of α-defensin, which helps promote beneficial bacteria while eliminating harmful ones, resulting in healthier gut microbiomes and reduced risk of insulin resistance [1][2] - Mice that produced more α-defensin were found to be healthier compared to those that produced less, and synthetic α-defensin peptides were shown to protect mice from the negative effects of unhealthy diets [2] - The research emphasizes that while gut microbiomes influence various diseases, the body actively shapes its microbiome through genetic factors, suggesting potential for peptide-based treatments for chronic diseases like diabetes and obesity [2][3] Group 2: Implications for Personalized Medicine - The study highlights the importance of personalized medicine, indicating that individuals with different genetic backgrounds may respond differently to treatments involving defensin peptides [2][3] - The research team is expanding their studies to explore the application of α-defensin in human health, particularly its relationship with metabolic health and gut microbiomes [3] - The potential for precision medicine is underscored, as understanding individual responses to treatments could lead to more effective interventions for managing gut microbiomes and associated chronic diseases [3]

Core Viewpoint - The research highlights the importance of gut microbiota in enhancing the efficacy and safety of immune checkpoint blockade (ICB) therapy for cancer treatment, proposing a novel food-medicine homologous formula to improve outcomes and reduce adverse effects [2][6][10]. Group 1: Research Development - A new oral formulation, CV/APS-MS, was developed using microcapsules to co-load Chlorella vulgaris and Astragalus polysaccharides, which are recognized for their therapeutic and nutritional benefits [3][6]. - This formulation aims to prolong retention time in the gut, nourish beneficial gut microbiota, and alleviate inflammation [6][8]. Group 2: Experimental Findings - In mouse models of melanoma lung metastasis treated with ICB therapy, CV/APS-MS improved T cell-mediated anti-tumor immunity and mitigated ICB-induced colitis and pneumonia by restoring gut microbiota balance and reducing pro-inflammatory cytokines [8][10]. - The study suggests that combining food-grade bioreagents with modern medicine could be a powerful method to enhance cancer treatment efficacy and tolerance [10].

Core Viewpoint - The emergence of immunotherapy has significantly changed the landscape of cancer treatment, but resistance to immunotherapy remains a major obstacle for its broader clinical application. Recent studies indicate that gut microbiota can enhance the efficacy of immunotherapy by modulating anti-tumor immunity [2]. Group 1: Research Findings - A study published by Professor Xu Ruihua's team from Sun Yat-sen University on July 24, 2025, in the journal Cancer Cell, demonstrates that the gut bacterium Alistipes finegoldii can enhance the efficacy of immunotherapy against solid tumors [3][4]. - The research found that a higher abundance of Alistipes finegoldii is associated with improved responses to immunotherapy, particularly enhancing the efficacy of anti-PD-1 monoclonal antibodies in solid tumor models [8]. - Alistipes finegoldii activates the CXCL16-CXCR6 signaling axis to boost anti-tumor immune responses, with lipoproteins derived from Alistipes finegoldii triggering the TLR2-NF-κB-CXCL16 signaling pathway [7][8]. Group 2: Mechanism of Action - The mechanism involves lipoproteins from Alistipes finegoldii binding to Toll-like receptor 2 (TLR2), activating the NF-κB signaling pathway, which enhances the expression of CXCL16 in CCR7+ conventional dendritic cells [7]. - The released CXCL16 aids in recruiting CXCR6+ CD8+ T cells to the tumor microenvironment (TME), effectively inhibiting tumor growth [7][8]. Group 3: Implications for Treatment - Overall, the findings suggest that combining Alistipes finegoldii with immunotherapy could represent a new strategy for treating solid tumors [10].

Core Viewpoint - The study highlights the impact of gut microbiota dysbiosis induced by brain tumors on the efficacy of immunotherapy, suggesting that dietary supplementation with tryptophan can restore gut microbiota and significantly enhance the immune response through T cell circulation [2][11][14]. Group 1: Research Background - The influence of gut microbiota on various tumors, particularly gastrointestinal tumors, is recognized, but its effects on brain tumors remain largely unexplored [2][6]. - Glioblastoma (GBM) is known for its poor prognosis and limited survival rate improvements despite various treatments, attributed to unique characteristics of the tumor microenvironment [4][5]. Group 2: Research Findings - The research utilized a GBM mouse model and employed 16S rRNA sequencing to analyze changes in gut microbiota during tumor progression, finding that tryptophan supplementation could reverse these changes [9]. - Tryptophan supplementation not only restored gut microbiota balance but also significantly improved survival rates in mouse models and enhanced the effectiveness of immunotherapy [9][13]. Group 3: Key Microbial Insights - Among the gut bacteria responding positively to tryptophan, Duncaniella dubosii emerged as a key contributor to the immune modulation effects of tryptophan [10][13]. - The study emphasizes the potential of targeting gut microbiota modulation to improve cancer immunotherapy outcomes, particularly through mechanisms involving T cell regulation [14].

Core Viewpoint - The study highlights the role of gut microbiota, specifically the metabolite urocanic acid (UCA), in enhancing the efficacy of cancer immunotherapy when combined with tyrosine kinase inhibitors (TKIs) [3][8][11]. Group 1: Research Findings - The research demonstrates that TKIs increase the abundance of the gut bacterium Muribaculum gordoncarteri and its metabolite UCA, which enhances the response to immune checkpoint blockade (ICB) therapy [8][9]. - UCA interacts with IκBα to inhibit NF-κB activation in endothelial cells, thereby reducing the recruitment of myeloid-derived suppressor cells (MDSCs) mediated by CXCL1 [9][11]. - Higher levels of UCA and Muribaculum gordoncarteri are found in the feces of patients who respond to ICB therapy compared to non-responders, suggesting their potential as predictive biomarkers for treatment response [8][9][11]. Group 2: Implications for Cancer Treatment - The findings indicate that the interaction between TKIs and gut microbiota could be a crucial factor in improving cancer treatment outcomes, particularly for patients who currently do not respond well to existing therapies [7][9]. - Understanding the mechanisms by which UCA enhances ICB therapy could lead to new strategies for increasing the effectiveness of cancer immunotherapy [3][11].

Core Viewpoint - The article discusses a study published in Nature Metabolism that highlights the potential of Nicotinamide to accelerate recovery in mild to moderate COVID-19 patients and its role in modulating gut microbiota changes associated with the virus [2][12]. Group 1: Nicotinamide and COVID-19 - Nicotinamide is essential for the production of NAD+, a key coenzyme in cellular energy metabolism, which decreases during viral infections, particularly COVID-19 [5]. - The study indicates that during acute inflammation caused by SARS-CoV-2, tryptophan metabolism is enhanced, leading to increased kynurenine levels, which is a critical intermediate in the NAD+ synthesis pathway [5]. - COVID-19 is closely linked to gut microbiota dysbiosis, characterized by reduced microbial diversity and beneficial species, which is associated with increased inflammation and immune dysregulation [5]. Group 2: Research Findings - Previous research showed that tryptophan helps maintain gut microbiota homeostasis, and supplementation with Nicotinamide has strong, microbiota-dependent anti-inflammatory effects [6]. - The study developed a pH-dependent matrix tablet formulation for Nicotinamide, designed to release in the lower small intestine and colon, ensuring systemic supply and targeting gut microbiota [6]. - The COVit-2 trial involved 900 symptomatic COVID-19 patients and demonstrated that 57.6% of those treated with Nicotinamide recovered from physical decline by week 2, compared to 42.6% in the placebo group [7]. Group 3: Clinical Implications - The changes in gut microbiome characteristics correlated with clinical efficacy, suggesting that Nicotinamide can regulate fecal microbiota changes associated with SARS-CoV-2 infection [8]. - Follow-up after 6 months indicated that those who responded to Nicotinamide treatment had a lower incidence of post-COVID syndrome compared to the placebo group [8]. - Throughout the study, no safety risks related to Nicotinamide treatment were reported [8].