Microbiome research reports最新文献

Aim: Accumulating evidence highlights the crucial role of the "gut-brain axis" and emphasizes the potential of dietary interventions to improve brain health through this pathway. This study assesses the effects of the probiotic Pediococcus acidilactici CCFM6432 on mood, sleep, and gastrointestinal function in patients with depressive disorder. Methods: This clinical trial is a randomized, placebo-controlled study (Registration: ChiCTR2300071025). It enrolled 39 adult patients diagnosed with depressive disorder, who were randomly assigned to either the placebo control group (n = 19) or the CCFM6432 intervention group (n = 20). The intervention period spanned four weeks. Assessments were conducted at both the beginning and end of the trial, including comprehensive questionnaire evaluations and the collection of serum and fecal samples. Results: In comparison to the placebo, treatment with CCFM6432 significantly decreased depression and anxiety scores, as well as ameliorated gastrointestinal dysfunction and poor sleep quality commonly associated with mood disorders. Microbiota analysis revealed an increase in species richness without notable changes in overall diversity, yet Pediococcus species was found to be more abundant post-treatment. Functional analysis indicated reduced activity in the NOD-like receptor signaling pathway, suggesting anti-inflammatory effects induced by the probiotic. Metabolomic profiling identified elevated levels of fecal lactic acid, which correlated with lower Hospital Anxiety and Depression Scale (HADS) scores, thereby linking probiotic metabolism to mood enhancement. Conclusion: These findings imply that CCFM6432 may improve brain function by modulating gut microbiota and their mediated immune homeostasis, underscoring its potential as an adjunctive treatment for mental disorders.

Akkermansia muciniphila (A. muciniphila) is a promising candidate bacterium for stress management due to its beneficial effects on the microbiota-gut-brain axis (MGBA). As a well-known mucin-degrading bacterium in the digestive tract, A. muciniphila has demonstrated significant benefits for host physiology. Recent research highlights its potential in treating several neuropsychiatric disorders. Proposed mechanisms of action include the bacterium's outer membrane protein Amuc_1100 and potentially its extracellular vesicles (EVs), which interact with host immune receptors and influence serotonin pathways, which are crucial for emotional regulation. Despite its potential, the administration of probiotics containing A. muciniphila faces technological challenges, prompting the development of pasteurized forms recognized as safe by the European Food Safety Authority (EFSA). This review systematically examines the existing literature on the role of A. muciniphila in stress management, emphasizing the need for further research to validate its efficacy. The review follows a structured methodology, including comprehensive database searches and thematic data analysis, to provide a detailed understanding of the relationship between stress, microbiota, and A. muciniphila therapeutic potential.

Intestinal homeostasis is essential for maintaining human health, and its dysfunction is related to the onset and progression of various diseases, including immune and metabolic disorders, and even tumorigenesis. Intestinal microbiota plays a critical role in intestinal homeostasis, with Akkermansia muciniphila (A. muciniphila) emerging as a key commensal bacterium utilizing mucin as its sole carbon and nitrogen source. A. muciniphila has been recognized in both experimental and clinical studies for its beneficial role in managing intestinal inflammation, tumors, functional gastrointestinal disorders, and secondary conditions such as liver and metabolic diseases. This review provides a comprehensive overview of the research history and current understanding of A. muciniphila, its association with various intestinal-related diseases, and the potential mechanisms behind its effects. This paper also explores the possibilities of leveraging the probiotic enzyme such as the active ingredients of A. muciniphila for the innovative clinical treatment of intestinal-related diseases.

Synbiotics are defined as "a mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confers a health benefit on the host". The definition discriminates between synergistic and complementary synbiotics. Synergistic synbiotics involve a direct interaction between the substrate and co-administered microbe(s), while complementary synbiotics act through independent mechanisms. Here, we evaluate the complexity of discrimination between these two synbiotic concepts using an exemplary study performed with a panel of Lactiplantibacillus plantarum (L. plantarum) strains to identify strain-specific synergistic synbiotics that eventually turned out to work via a complementary synbiotic mechanism. This study highlights that assessing the in situ selectivity of synergistic synbiotics in the intestinal tract is challenging due to the confounding effects of the substrate ingredient on the endogenous microbiome, thereby raising doubts about the added value of distinguishing between synergistic and complementary concepts in synbiotics.

Background: Members of the Bifidobacterium genus and lactobacilli are the most commonly used probiotics to promote human health. In this context, genome-based in silico analyses have been demonstrated as a fast and reliable tool for identifying and characterizing health-promoting activities imputed to probiotics. Methods: This study is an extension of the Integrated Probiotic Database (IPDB) previously created on probiotics of the genus Bifidobacterium, facilitating a comprehensive understanding of the genetic characteristics that contribute to the diverse spectrum of beneficial effects of probiotics. The strains integrated into this new version of the IPDB, such as various lactobacilli and strains belonging to the species Streptococcus thermophilus (S. thermophilus) and Heyndrickxia coagulans (H. coagulans) (formerly Bacillus coagulans), were selected based on the labels of probiotic formulations currently on the market and using the bacterial strains whose genome had already been sequenced. On these bacterial strains, comparative genome analyses were performed, mainly focusing on genetic factors that confer structural, functional, and chemical characteristics predicted to be involved in microbe-host and microbe-microbe interactions. Results: Our investigations revealed marked inter- and intra-species variations in the genetic makeup associated with the biosynthesis of external structures and bioactive metabolites putatively associated with microbe- and host-microbe interactions. Conclusion: Although genetic differences need to be confirmed as functional or phenotypic differences before any probiotic intervention, we believe that considering these divergences will aid in improving effective and personalized probiotic-based interventions.

Background: The human skin microbiome plays an essential role in protecting against pathogens and other external substances. This open ecosystem is also influenced by personal and environmental factors, but the precise impact of these factors, such as lifestyle and season, is understudied. We focused here on the inner elbow, a skin site prone to inflammatory conditions like atopic dermatitis and psoriasis. Methods: We collected skin swabs from the inner elbow of 52 children and adults, with no signs of skin disorders, in the winter and summer seasons. Samples were analyzed using metagenomic shallow shotgun sequencing. In addition, metadata were collected using questionnaires on health, lifestyle, and environmental factors. Results: The core inner elbow community, taxa with a prevalence of 95% or higher, consisted of several well-known skin taxa, such as Staphylococcus hominis, Staphylococcus capitis, Staphylococcus epidermidis, and Cutibacterium acnes. In addition, Streptococcus and Lactobacillus species were also found to be highly prevalent members of the skin microbiota, especially in the age group up to 3 years old. Of all investigated factors, age appeared to be the major driver defining the skin microbiome composition and longitudinal stability over the seasons. Differential abundance analysis using three statistical tests also pointed out that specific skin species were significantly associated with sampling season, age, hygiene practices, vitamin D supplements, probiotics, and the number of household members. Conclusion: This study identifies novel factors influencing the inner elbow skin microbiome composition and paves the way for future comparative and intervention studies in skin disorders such as atopic dermatitis.

Aim: The gut microbiota is implicated in the development of intestinal tumors. Furthermore, Western diet is a risk factor for colorectal cancer and induces alterations in both the microbiota and bile acid metabolism. Therefore, we aimed to investigate the causal role of Western diet-induced changes in the microbiota and secondary bile acid production, which were linked to disease exacerbation in APC ^1311/+ pigs. Methods: We performed fecal microbiota transfer experiments by inoculating germfree Apc ^1368N/+ mice with stool from genetically engineered APC ^1311/+ pigs. A control group of Apc ^1368N/+ mice stayed germfree. All mice were fed either a control diet, or the same diet supplemented with the primary bile acid cholic acid (CA) to stimulate secondary bile acid production. Results: Unexpectedly, the germfree mice fed CA had a high number of lesions in the upper small intestine, which was reduced by the colonization with microbes. The same mice (germfree, CA diet) were characterized by a remarkable lengthening of the small intestine (approximately +10 cm on average). Colonic lesions were rare and only observed in the mice that received stool from control pigs and fed the CA diet. Diversity and composition analyses showed that the microbiota transfer was incomplete. Nevertheless, mice receiving the Western diet-associated microbiota clustered separately from control animals. The effects of the CA diet on the microbiota were less pronounced and were observed primarily in mice that received stool from control pigs. Bile acid analysis in the recipient mice revealed associations between the phenotype and specific bile acid species in bile and cecum. Conclusion: This descriptive study highlights the importance of diet-microbiota-bile acid interactions in intestinal morphogenesis and tumorigenesis.

Background: Parkinson's disease (PD) is a neurodegenerative disorder, and the main clinical characteristics are bradykinesia and muscle stiffness. Cognitive impairment (CI) is a prevalent non-motor manifestation observed in individuals with PD. According to disease severity, it can be divided into PD with mild cognitive impairment (MCI) and PD dementia. CI in PD patients may precede motor symptoms, and the gut microbiota plays an important role in PD pathogenesis. Therefore, gut microbiota may be one of the diagnostic targets for PD-CI. Methods: This study compared the gut microbiota of 43 PD-CI patients [Montreal Cognitive Assessment (MoCA) score < 26] and 38 PD patients without CI (MoCA ≥ 26). Patients' neuropsychological conditions, depression scale, and brain structure scanned by magnetic resonance imaging (MRI) were also recorded. The fecal metagenomic datasets of patients with PD, PD-CI, and CI only were retrieved from public databases for reanalysis to explore the relationship between PD, CI, and gut microbiota. Results: We found that the cortical thickness and the volume of the hippocampus, gray matter, and thalamus were significantly reduced among patients with PD-CI compared to PD without CI (P < 0.05). Moreover, the gut microbiome in patients with PD-CI had fewer short-chain fatty acid (SCFA) producing bacteria and more pathogenic bacteria. There were also alterations in patterns of metabolic pathway-encoding genes. Additionally, PD affected gut microbiota more than CI. Conclusion: CI may aggravate the severity of PD, but it did not drastically alter subjects' gut microbiota. This study reveals the relationship between gut microbiota, PD, and CI.

Background: The gut microbiota has been implicated as a major factor contributing to metabolic diseases and the response to drugs used for the treatment of such diseases. In this study, we tested the effect of cholestyramine, a bile acid sequestrant that reduces blood cholesterol, on the murine gut microbiota and metabolism. We also explored the hypothesis that some effects of this drug on systemic metabolism can be attributed to alterations in the gut microbiota. Methods: We used a Western diet (WD) for 8 weeks to induce metabolic disease in mice, then treated some mice with cholestyramine added to WD. Metabolic phenotyping, gene expression in liver and ileum, and microbiota 16S rRNA genes were analyzed. Then, transkingdom network analysis was used to find candidate microbes for the cholestyramine effect. Results: We observed that cholestyramine decreased glucose and epididymal fat levels and detected dysregulation of genes known to be regulated by cholestyramine in the liver and ileum. Analysis of gut microbiota showed increased alpha diversity in cholestyramine-treated mice, with fourteen taxa showing restoration of relative abundance to levels resembling those in mice fed a control diet. Using transkingdom network analysis, we inferred two amplicon sequence variants (ASVs), one from the Lachnospiraceae family (ASV49) and the other from the Muribaculaceae family (ASV1), as potential regulators of cholestyramine effects. ASV49 was also negatively linked with glucose levels, further indicating its beneficial role. Conclusion: Our results indicate that the gut microbiota has a role in the beneficial effects of cholestyramine and suggest specific microbes as targets of future investigations.