The gut microbiota is an indispensable symbiotic entity within the human holobiont, serving as a critical regulator of host lipid metabolism homeostasis. Therefore, it has emerged as a central subject of research in the pathophysiology of metabolic disorders. This microbial consortium orchestrates key aspects of host lipid dynamics-including absorption, metabolism, and storage-through multifaceted mechanisms such as the enzymatic processing of dietary polysaccharides, the facilitation of long-chain fatty acid uptake by intestinal epithelial cells (IECs), and the bidirectional modulation of adipose tissue functionality. Mounting evidence underscores that gut microbiota-derived metabolites not only directly mediate canonical lipid metabolic pathways but also interface with host immune pathways, epigenetic machinery, and circadian regulatory systems, thereby establishing an intricate crosstalk that coordinates systemic metabolic outputs. Perturbations in microbial composition (dysbiosis) drive pathological disruptions to lipid homeostasis, serving as a pathogenic driver for conditions such as obesity, hyperlipidemia, and non-alcoholic fatty liver disease (NAFLD). This review systematically examines the emerging mechanistic insights into the gut microbiota-mediated regulation of intestinal lipid metabolism, while it elucidates its translational implications for understanding metabolic disease pathogenesis and developing targeted therapies.
Humans ; Gastrointestinal Microbiome/physiology* ; Lipid Metabolism ; Animals ; Intestinal Mucosa/metabolism* ; Homeostasis ; Dysbiosis ; Obesity/metabolism* ; Intestines/microbiology* ; Non-alcoholic Fatty Liver Disease/metabolism* ; Metabolic Diseases/metabolism*

A growing interest in the comprehensive pathogenic mechanisms of psychiatric disorders from the perspective of the microbiome has been witnessed in recent decades; the intrinsic link between microbiota and brain function through the microbiota-gut-brain axis or other pathways has gradually been realized. However, little research has focused on viruses-entities characterized by smaller dimensions, simpler structures, greater diversity, and more intricate interactions with their surrounding milieu compared to bacteria. To date, alterations in several populations of bacteriophages and viruses have been documented in both mouse models and patients with psychiatric disorders, including schizophrenia, major depressive disorder, autism spectrum disorder, and Alzheimer's disease, accompanied by metabolic disruptions that may directly or indirectly impact brain function. In addition, eukaryotic virus infection-mediated brain dysfunction provides insights into the psychiatric pathology involving viruses. Efforts towards virus-based diagnostic and therapeutic approaches have primarily been documented. However, limitations due to the lack of large-scale cohort studies, reliability, clinical applicability, and the unclear role of viruses in microbiota interactions pose a challenge for future studies. Nevertheless, it is conceivable that investigations into viruses herald a new era in the field of precise psychiatry.
Humans ; Mental Disorders/virology* ; Animals ; Brain/virology* ; Gastrointestinal Microbiome/physiology* ; Viruses ; Virus Diseases/complications*

Microbial communities such as those residing in the human gut are highly diverse and complex, and many with important implications for health and diseases. The effects and functions of these microbial communities are determined not only by their species compositions and diversities but also by the dynamic intra- and inter-cellular states at the transcriptional level. Powerful and scalable technologies capable of acquiring single-microbe-resolution RNA sequencing information in order to achieve a comprehensive understanding of complex microbial communities together with their hosts are therefore utterly needed. Here we report the development and utilization of a droplet-based smRNA-seq (single-microbe RNA sequencing) method capable of identifying large species varieties in human samples, which we name smRandom-seq2. Together with a triple-module computational pipeline designed for the bacteria and bacteriophage sequencing data by smRandom-seq2 in four human gut samples, we established a single-cell level bacterial transcriptional landscape of human gut microbiome, which included 29,742 single microbes and 329 unique species. Distinct adaptive response states among species in Prevotella and Roseburia genera and intrinsic adaptive strategy heterogeneity in Phascolarctobacterium succinatutens were uncovered. Additionally, we identified hundreds of novel host-phage transcriptional activity associations in the human gut microbiome. Our results indicated that smRandom-seq2 is a high-throughput and high-resolution smRNA-seq technique that is highly adaptable to complex microbial communities in real-world situations and promises new perspectives in the understanding of human microbiomes.
Humans ; Gastrointestinal Microbiome/genetics* ; Bacteriophages/physiology* ; High-Throughput Nucleotide Sequencing ; Sequence Analysis, RNA/methods* ; Bacteria/virology*

Traditional Chinese medicine (TCM) plays an important role in preventing and treating diseases and improving human health. However, the complex bioactive components and regulation of signaling pathway and network restrict the elucidation of the mechanisms of action of TCM. A human being is regarded as a super "symbiont" composed of body cells and commensal microorganisms. Gut microbiota is the core commensal microorganism system of a human body, being considered as "the second genome" and the new "organ". Alterations in gut microbiota reflect the state of body health and progression of diseases. Recent investigations have revealed that the TCM rich in polysaccharides and polyphenols can modulate gut microbiota metabolites to rehabilitate gut homeostasis, thus ameliorating diseases via regulating gut-liver axis or gut-brain axis. This review summarizes the causal relationship and mechanisms of action of TCM in the treatment of diseases from the perspective of gut microbiota metabolites. Our findings are expected to provide new insights into the mechanisms of TCM in preventing and treating diseases and guidance for TCM-based drug discovery in the future.
Humans ; Gastrointestinal Microbiome/physiology* ; Medicine, Chinese Traditional/methods* ; Drugs, Chinese Herbal/therapeutic use* ; Polyphenols/pharmacology* ; Polysaccharides/pharmacology*

The intestine is a complex symbiotic system, and the gut microbiota is closely related to host health. Studies have indicated that the gut microbiota influences physiological functions of the host by producing a variety of metabolites, which act as signaling molecules and substrates for metabolic reactions in the host. Dysbiosis of the gut microbiota affects the abundance of gut microbiota-derived metabolites, thereby influencing host health by disrupting signal transduction in multiple organs. Additionally, dietary compounds can shape the gut microbiota, affecting gut microbiota-derived metabolite levels and regulating host metabolism. This article introduces the methods for mining gut microbiota-derived metabolites, reviews the roles of these metabolites in metabolic diseases and related dietary interventions. Which provides a perspective on the prevention and treatment of metabolic diseases by targeting these metabolites, enriching the knowledge on the role of gut microbiota in the regulation of host metabolism.
Gastrointestinal Microbiome/physiology* ; Humans ; Dysbiosis/microbiology* ; Metabolic Diseases/metabolism* ; Diet

Uric acid (UA) is the final metabolite of purines in the human body. An imbalance in UA production and excretion that disrupts homeostasis leads to elevated blood UA levels and the development of hyperuricemia (HUA). Approximately one-third of UA is excreted through the intestinal tract. As a crucial component of the intestinal microenvironment, the gut microbiota plays a pivotal role in regulating blood UA levels. Alterations or imbalances in gut microbiota composition are linked to the onset of HUA, which implies the potential of gut microbiota as a novel target for the prevention and treatment of HUA. This review introduces the occurrence mechanism and damage of hyperuricemia, examines the association between HUA and the gut microbiota and their metabolites, and explores the molecular mechanisms underlying gut microbiota-targeted therapies for HUA. Furthermore, it discusses the potential applications of probiotics, prebiotics, and traditional Chinese medicine (including both single herbs and compound formulas) with UA-lowering effects, along with cutting-edge technologies such as fecal microbiota transplantation and machine learning in HUA treatment. This review provides valuable perspectives and strategies for improving the prevention and treatment of HUA.
Hyperuricemia/microbiology* ; Humans ; Gastrointestinal Microbiome/physiology* ; Probiotics/therapeutic use* ; Uric Acid/blood* ; Fecal Microbiota Transplantation ; Prebiotics ; Medicine, Chinese Traditional

The gut microbiota is closely related to human health, and various gut microbiota health indices have been developed to assist in evaluating the health of the gut microbiota and even the overall health of the human body. Diets are one of the main factors that regulate the gut microbiota, while there is still no good method for evaluating the regulatory effects of dietary factors. To assess the regulatory effects of dietary factors on the gut microbiota of overweight individuals, we conducted an in vitro fermentation experiment based on 17 dietary factors, and developed an evaluation method for the regulatory effects of dietary factors based on the health index with principal component analysis (hiPCA). The results showed that most dietary factors had positive regulatory effects on the gut microbiota of overweight individuals. Galactooligosaccharides (GOS) and puerarin were the most significant dietary factors in regulating the gut microbiota of overweight individuals. The analysis of the contribution of species to the hiPCA indicated that GOS and puerarin might inhibit the activities of bacteria associated with overweight by regulating Eubacterium dolichum, Lactobacillus salivarius, Clostridium clostridioforme, Clostridium citroniae, and Lachnospiraceae bacterium 9_1_43BFAA. In addition, GOS may further enhance the inhibition of these activities by regulating Lachnospiraceae bacterium 6_1_63FAA, thereby reducing the gut health risks in overweight individuals. In summary, this study evaluated the health effects of dietary factors based on the hiPCA and specifically analyzed the role of different dietary factors in regulating the gut microbiota of overweight individuals. This provides new ideas and methods for improving gut microbiota health and has potential applications in the field of precision nutrition.
Humans ; Gastrointestinal Microbiome/physiology* ; Isoflavones/pharmacology* ; Overweight/microbiology* ; Diet ; Fermentation ; Oligosaccharides/pharmacology* ; Principal Component Analysis

Emerging evidence suggests that dysbiosis of the gut microbiota is associated with the pathogenesis of Parkinson's disease (PD), a prevalent neurodegenerative disorder. The microbiota-gut-brain axis plays a crucial role in the development and progression of PD, and numerous studies have demonstrated the potential therapeutic benefits of modulations in the intestinal microbiota. This review provides insights into the characterization of the gut microbiota in patients with PD and highlights associations with clinical symptoms and underlying mechanisms. The discussion underscores the increased influence of the gut microbiota in the pathogenesis of PD. While the relationship is not fully elucidated, existing research demonstrates a strong correlation between changes in the composition of gut microbiota and disease development, and further investigation is warranted to explain the specific underlying mechanisms.
Humans ; Parkinson Disease/microbiology* ; Gastrointestinal Microbiome/physiology* ; Dysbiosis/microbiology*

Inflammatory bowel disease (IBD) is an idiopathic intestinal inflammatory condition with chronic and relapsing manifestations and is characterized by a disturbance in the interplay between the intestinal microbiota, the gut, and the brain. The microbiota-gut-brain axis involves interactions among the nervous system, the neuroendocrine system, the gut microbiota, and the host immune system. Increasing published data indicate that psychological stress exacerbates the severity of IBD due to its negative effects on the microbiota-gut-brain axis, including alterations in the stress response of the hypothalamic-pituitary-adrenal (HPA) axis, the balance between the sympathetic nervous system and vagus nerves, the homeostasis of the intestinal flora and metabolites, and normal intestinal immunity and permeability. Although the current evidence is insufficient, psychotropic agents, psychotherapies, and interventions targeting the microbiota-gut-brain axis show the potential to improve symptoms and quality of life in IBD patients. Therefore, further studies that translate recent findings into therapeutic approaches that improve both physical and psychological well-being are needed.
Humans ; Inflammatory Bowel Diseases/metabolism* ; Stress, Psychological/microbiology* ; Gastrointestinal Microbiome/physiology* ; Brain/metabolism* ; Hypothalamo-Hypophyseal System ; Pituitary-Adrenal System ; Animals

Microbial-derived metabolites are important mediators of host-microbial interactions. In recent years, the role of intestinal microbial metabolites in colorectal cancer has attracted considerable attention. These metabolites, which can be derived from bacterial metabolism of dietary substrates, modification of host molecules such as bile acids, or directly from bacteria, strongly influence the progression of colitis-associated cancer (CAC) by regulating inflammation and immune response. Here, we review how microbiome metabolites short-chain fatty acids (SCFAs), secondary bile acids, polyamines, microbial tryptophan metabolites, and polyphenols are involved in the tumorigenesis and development of CAC through inflammation and immunity. Given the heated debate on the metabolites of microbiota in maintaining gut homeostasis, serving as tumor molecular markers, and affecting the efficacy of immune checkpoint inhibitors in recent years, strategies for the prevention and treatment of CAC by targeting intestinal microbial metabolites are also discussed in this review.
Humans ; Gastrointestinal Microbiome/physiology* ; Animals ; Carcinogenesis/metabolism* ; Colitis-Associated Neoplasms/microbiology* ; Fatty Acids, Volatile/metabolism* ; Bile Acids and Salts/metabolism* ; Colitis/microbiology*