The long-term genetic stability and individual specificity of the human gut microbiome.

By following up the gut microbiome, 51 human phenotypes and plasma levels of 1,183 metabolites in 338 individuals after 4 years, we characterize microbial stability and variation in relation to host physiology. Using these individual-specific and temporally stable microbial profiles, including bacterial SNPs and structural variations, we develop a microbial fingerprinting method that shows up to 85% accuracy in classifying metagenomic samples taken 4 years apart. Application of our fingerprinting method to the independent HMP cohort results in 95% accuracy for samples taken 1 year apart. We further observe temporal changes in the abundance of multiple bacterial species, metabolic pathways, and structural variation, as well as strain replacement. We report 190 longitudinal microbial associations with host phenotypes and 519 associations with plasma metabolites. These associations are enriched for cardiometabolic traits, vitamin B, and uremic toxins. Finally, mediation analysis suggests that the gut microbiome may influence cardiometabolic health through its metabolites.

Host genetic regulation of human gut microbial structural variation.

Although the impact of host genetics on gut microbial diversity and the abundance of specific taxa is well established1-6, little is known about how host genetics regulates the genetic diversity of gut microorganisms. Here we conducted a meta-analysis of associations between human genetic variation and gut microbial structural variation in 9,015 individuals from four Dutch cohorts. Strikingly, the presence rate of a structural variation segment in Faecalibacterium prausnitzii that harbours an N-acetylgalactosamine (GalNAc) utilization gene cluster is higher in individuals who secrete the type A oligosaccharide antigen terminating in GalNAc, a feature that is jointly determined by human ABO and FUT2 genotypes, and we could replicate this association in a Tanzanian cohort. In vitro experiments demonstrated that GalNAc can be used as the sole carbohydrate source for F. prausnitzii strains that carry the GalNAc-metabolizing pathway. Further in silico and in vitro studies demonstrated that other ABO-associated species can also utilize GalNAc, particularly Collinsella aerofaciens. The GalNAc utilization genes are also associated with the host's cardiometabolic health, particularly in individuals with mucosal A-antigen. Together, the findings of our study demonstrate that genetic associations across the human genome and bacterial metagenome can provide functional insights into the reciprocal host-microbiome relationship.

Diphosphine Ligand-Enabled Nickel-Catalyzed Chelate-Assisted Inner-Selective Migratory Hydroarylation of Alkenes.

The precise control of the regioselectivity in the transition metal-catalyzed migratory hydrofunctionalization of alkenes remains a big challenge. With a transient ketimine directing group, the nickel-catalyzed migratory ß-selective hydroarylation and hydroalkenylation of alkenyl ketones has been realized with aryl boronic acids using alkyl halide as the mild hydride source for the first time. The key to this success is the use of a diphosphine ligand, which is capable of the generation of a Ni(II)-H species in the presence of alkyl bromide, and enabling the efficient migratory insertion of alkene into Ni(II)-H species and the sequent rapid chain walking process. The present approach diminishes organosilanes reductant, tolerates a wide array of complex functionalities with excellent regioselective control. Moreover, this catalytic system could also be applied to the migratory hydroarylation of alkenyl azahetereoarenes, thus providing a general approach for the preparation of 1,2-aryl heteroaryl motifs with wide potential applications in pharmaceutical discovery.

Ligand-Enabled NiII -Catalyzed Hydroxylarylation of Alkenes with Molecular Oxygen.

The use of molecular oxygen as the terminal oxidant in transition metal catalyzed oxidative process is an appealing and challenging task in organic synthetic chemistry. Here, we report a Ni-catalyzed hydroxylarylation of unactivated alkenes enabled by a ß-diketone ligand with high efficiency and excellent regioselectivity employing molecular oxygen as the oxidant and hydroxyl source. This reaction features mild conditions, broad substrate scope and incredible heterocycle compatibility, providing a variety of ß-hydroxylamides, γ-hydroxylamides, ß-aminoalcohols, γ-aminoalcohols, and 1,3-diols in high yields. The synthetic value of this methodology was demonstrated by the efficient synthesis of two bioactive compounds, (±)-3'-methoxyl citreochlorol and tea catechin metabolites M4.

Systematic analysis of relationships between plasma branched-chain amino acid concentrations and cardiometabolic parameters: an association and Mendelian randomization study.

BACKGROUND: Branched-chain amino acids (BCAAs; valine, leucine, and isoleucine) are essential amino acids that are associated with an increased risk of cardiometabolic diseases (CMD). However, there are still only limited insights into potential direct associations between BCAAs and a wide range of CMD parameters, especially those remaining after correcting for covariates and underlying causal relationships. METHODS: To shed light on these relationships, we systematically characterized the associations between plasma BCAA concentrations and a large panel of 537 CMD parameters (including atherosclerosis-related parameters, fat distribution, plasma cytokine concentrations and cell counts, circulating concentrations of cardiovascular-related proteins and plasma metabolites) in 1400 individuals from the Dutch population cohort LifeLines DEEP and 294 overweight individuals from the 300OB cohort. After correcting for age, sex, and BMI, we assessed associations between individual BCAAs and CMD parameters. We further assessed the underlying causality using Mendelian randomization. RESULTS: A total of 838 significant associations were detected for 409 CMD parameters. BCAAs showed both common and specific associations, with the most specific associations being detected for isoleucine. Further, we found that obesity status substantially affected the strength and direction of associations for valine, which cannot be corrected for using BMI as a covariate. Subsequent univariable Mendelian randomization (UVMR), after removing BMI-associated SNPs, identified seven significant causal relationships from four CMD traits to BCAA levels, mostly for diabetes-related parameters. However, no causal effects of BCAAs on CMD parameters were supported. CONCLUSIONS: Our cross-sectional association study reports a large number of associations between BCAAs and CMD parameters. Our results highlight some specific associations for isoleucine, as well as obesity-specific effects for valine. MR-based causality analysis suggests that altered BCAA levels can be a consequence of diabetes and alteration in lipid metabolism. We found no MR evidence to support a causal role for BCAAs in CMD. These findings provide evidence to (re)evaluate the clinical importance of individual BCAAs in CMD diagnosis, prevention, and treatment.

Redox-Neutral Nickel(II) Catalysis: Hydroarylation of Unactivated Alkenes with Arylboronic Acids.

Reported here is the discovery of a redox-neutral NiII /NiII catalytic cycle which is capable of the linear-selective hydroarylation of unactivated alkenes with arylboronic acids for the first time. This novel catalytic cycle, enabled by the use of an electron-rich diimine ligand, features broad substrate scope, and excellent functional-group and heterocycle compatibility under mild reaction conditions in the absence of additional oxidants and reductants. Mechanistic investigations using kinetic analysis and deuterium-labelling experiments revealed the protonation to be the rate-determining step in this redox-neutral catalysis, and the reversible chain-walking nature of the newly developed diimine-Ni catalyst.

A Clamping Force Estimation Method Based on a Joint Torque Disturbance Observer Using PSO-BPNN for Cable-Driven Surgical Robot End-Effectors.

The ability to sense external force is an important technique for force feedback, haptics and safe interaction control in minimally-invasive surgical robots (MISRs). Moreover, this ability plays a significant role in the restricting refined surgical operations. The wrist joints of surgical robot end-effectors are usually actuated by several long-distance wire cables. Its two forceps are each actuated by two cables. The scope of force sensing includes multidimensional external force and one-dimensional clamping force. This paper focuses on one-dimensional clamping force sensing method that do not require any internal force sensor integrated in the end-effector's forceps. A new clamping force estimation method is proposed based on a joint torque disturbance observer (JTDO) for a cable-driven surgical robot end-effector. The JTDO essentially considers the variations in cable tension between the actual cable tension and the estimated cable tension using a Particle Swarm Optimization Back Propagation Neural Network (PSO-BPNN) under free motion. Furthermore, a clamping force estimator is proposed based on the forceps' JTDO and their mechanical relations. According to comparative analyses in experimental studies, the detection resolutions of collision force and clamping force were 0.11 N. The experimental results verify the feasibility and effectiveness of the proposed clamping force sensing method.

The Design and Development of an Omni-Directional Mobile Robot Oriented to an Intelligent Manufacturing System.

In order to transport materials flexibly and smoothly in a tight plant environment, an omni-directional mobile robot based on four Mecanum wheels was designed. The mechanical system of the mobile robot is made up of three separable layers so as to simplify its combination and reorganization. Each modularized wheel was installed on a vertical suspension mechanism, which ensures the moving stability and keeps the distances of four wheels invariable. The control system consists of two-level controllers that implement motion control and multi-sensor data processing, respectively. In order to make the mobile robot navigate in an unknown semi-structured indoor environment, the data from a Kinect visual sensor and four wheel encoders were fused to localize the mobile robot using an extended Kalman filter with specific processing. Finally, the mobile robot was integrated in an intelligent manufacturing system for material conveying. Experimental results show that the omni-directional mobile robot can move stably and autonomously in an indoor environment and in industrial fields.

Construction of Lactones via Ligand-Enabled Ni-Catalyzed Alkene Hydroxylarylation/Lactonization.

Here, we report the preparation of lactones via Ni-catalyzed alkene hydroxylarylation and sequential intramolecular lactonization with O2 as a green oxidant and oxygen source. The bulky 1,3-diketone ligand is crucial by enabling Ni-catalyzed hydroxylarylation of alkenes, providing numerous phthalide and furanone derivatives with high efficiency under mild conditions. The synthetic value of this methodology was further demonstrated by the efficient synthesis of typhaphthalide and a monoamine oxidase B inhibitor.

Pd(II)-Catalyzed 1,2-Oxyarylation of Alkenes with O-Acylhydroxylamines as the Oxygen Source.

O-Acylhydroxylamine has been widely employed as an electrophilic amination reagent in transition-metal-catalyzed C-N coupling reactions, but its use as an electrophilic oxygen source has not been disclosed. Here, we report a Pd-catalyzed 1,2-oxyarylation of alkenes with O-acylhydroxylamines as an oxidant and an oxygen source for the first time. With simple amide as the monodentate directing group, this method features a broad substrate scope, good functional group tolerance, and mild conditions.

Bipartite nuclear localization sequence is indispensable for nuclear import and stability of self-dimerization of ADARa in Bombyx mori.

The conservative post-transcriptional modification in mammals and Drosophila is adenosine-to-inosine (A-to-I) deamination in double-stranded RNA, catalyzed by RNA-editing enzymes known as adenosine deaminases acting on RNA (ADARs). The traditional nuclear import pathway for ADARs involves the recognition of a putative classical nuclear localization sequence (NLS) by importin α4 and α5. In our previous research, ADAR in silkworm, Bombyx mori (BmADARa) was confirmed predominantly located in the nucleus. However, the location of the NLS in BmADARa and its impact on nuclear import and self-dimerization remained unclear. Utilizing NLS prediction software, we predicted the presence of a bipartite NLS within the amino-terminal, 85 amino acids of BmADARa (N85). This prediction was validated through point mutation, which demonstrated that the bipartite NLS could directly mediate nuclear import of BmADARa. Co-immunoprecipitation analysis revealed that BmADARa is mainly dependent on BmKaryopherin α3 (homologous to mammalian importin α4) for nuclear import, although both BmKaryopherin α3 and BmImportin α5 could recognize bipartite NLS. The N-terminal truncated mutants and the bipartite NLS mutants of BmADARa suggest that the bipartite NLS is the major nuclear import site and a crucial structure for self-dimerization of BmADARa. In conclusion, the N-terminal bipartite NLS of BmADARa is recognized by BmKaryopherin α3 and BmImportin α5, facilitating its nuclear import. This promotes BmADARa self-dimerization and maintains the stability of dimerization, thereby enhancing its editing efficiency on target substrates. The results of this research demonstrate the role of bipartite NLS in BmADARa editing and laying a foundation for further research on the regulation of BmADARa in the growth and development in B. mori.

CRISPR dynamics during the interaction between bacteria and phage in the first year of life.

Gut microbiomes in infancy have a profound impact on health in adulthood. CRISPRs play an essential role in the interaction between bacteria and phages. However, the dynamics of CRISPRs in gut microbiomes during early life are poorly understood. In this study, using shotgun metagenomic sequencing data from 82 Swedish infants' gut microbiomes, 1882 candidate CRISPRs were identified, and their dynamics were analysed. We found large-scale turnover of CRISPRs and their spacers during the first year of life. As well as changes in relative abundance of the bacteria containing CRISPR, acquisition, loss and mutation of spacers were observed within the same CRISPR array sampled over time. Accordingly, the inferred interaction network of bacteria and phage was distinct at different times. This research underpins CRISPR dynamics and their potential role in the interaction between bacteria and phage in early life.

Prevotella copri alleviates sarcopenia via attenuating muscle mass loss and function decline.

BACKGROUND: The gut microbiome and fecal metabolites have been found to influence sarcopenia, but whether there are potential bacteria that can alleviate sarcopenia has been under-investigated, and the molecular mechanism remains unclear. METHODS: To investigate the relationships between the gut microbiome, fecal metabolites and sarcopenia, subjects were selected from observational multi-ethnic study conducted in Western China. Sarcopenia was diagnosed according to the criteria of the Asian Working Group for Sarcopenia 2014. The gut microbiome was profiled by shotgun metagenomic sequencing. Untargeted metabolomic analysis was performed to analyse the differences in fecal metabolites. We investigated bacterium with the greatest relative abundance difference between healthy individuals and sarcopenia patients, and the differences in metabolites associated with the bacteria, to verify its effects on muscle mass and function in a mouse model. RESULTS: The study included 283 participants (68.90% females, mean age: 66.66 years old) with and without sarcopenia (141 and 142 participants, respectively) and from the Han (98 participants), Zang (88 participants) and Qiang (97 participants) ethnic groups. This showed an overall reduction (15.03% vs. 20.77%, P = 0.01) of Prevotella copri between the sarcopenia and non-sarcopenia subjects across the three ethnic groups. Functional characterization of the differential bacteria showed enrichment (odds ratio = 15.97, P = 0.0068) in branched chain amino acid (BCAA) metabolism in non-sarcopenia group. A total of 13 BCAA and their derivatives have relatively low levels in sarcopenia. In the in vivo experiment, we found that the blood BCAA level was higher in the mice gavaged with live P. copri (LPC) (P < 0.001). The LPC mice had significantly longer wire and grid hanging time (P < 0.02), longer time on rotor (P = 0.0001) and larger grip strength (P < 0.0001), indicating better muscle function. The weight of gastrocnemius mass and rectus femoris mass (P < 0.05) was higher in LPC mice. The micro-computed tomography showed a larger leg area (P = 0.0031), and a small animal analyser showed a higher lean mass ratio in LPC mice (P = 0.0157), indicating higher muscle mass. CONCLUSIONS: The results indicated that there were lower levels of both P. copri and BCAA in sarcopenia individuals. In vivo experiments, gavage with LPC could attenuate muscle mass and function decline, indicating alleviating sarcopenia. This suggested that P. copri may play a therapeutic potential role in the management of sarcopenia.

Gut microbial structural variation associates with immune checkpoint inhibitor response.

The gut microbiota may have an effect on the therapeutic resistance and toxicity of immune checkpoint inhibitors (ICIs). However, the associations between the highly variable genomes of gut bacteria and the effectiveness of ICIs remain unclear, despite the fact that merely a few gene mutations between similar bacterial strains may cause significant phenotypic variations. Here, using datasets from the gut microbiome of 996 patients from seven clinical trials, we systematically identify microbial genomic structural variants (SVs) using SGV-Finder. The associations between SVs and response, progression-free survival, overall survival, and immune-related adverse events are systematically explored by metagenome-wide association analysis and replicated in different cohorts. Associated SVs are located in multiple species, including Akkermansia muciniphila, Dorea formicigenerans, and Bacteroides caccae. We find genes that encode enzymes that participate in glucose metabolism be harbored in these associated regions. This work uncovers a nascent layer of gut microbiome heterogeneity that is correlated with hosts' prognosis following ICI treatment and represents an advance in our knowledge of the intricate relationships between microbiota and tumor immunotherapy.

Gut dysbiosis associates with cytokine production capacity in viral-suppressed people living with HIV.

Background: People living with human immunodeficiency virus (PLHIV) are exposed to chronic immune dysregulation, even when virus replication is suppressed by antiretroviral therapy (ART). Given the emerging role of the gut microbiome in immunity, we hypothesized that the gut microbiome may be related to the cytokine production capacity of PLHIV. Methods: To test this hypothesis, we collected metagenomic data from 143 ART-treated PLHIV and assessed the ex vivo production capacity of eight different cytokines [interleukin-1ß (IL-1ß), IL-6, IL-1Ra, IL-10, IL-17, IL-22, tumor necrosis factor, and interferon-γ] in response to different stimuli. We also characterized CD4+ T-cell counts, HIV reservoir, and other clinical parameters. Results: Compared with 190 age- and sex-matched controls and a second independent control cohort, PLHIV showed microbial dysbiosis that was correlated with viral reservoir levels (CD4+ T-cell-associated HIV-1 DNA), cytokine production capacity, and sexual behavior. Notably, we identified two genetically different P. copri strains that were enriched in either PLHIV or healthy controls. The control-related strain showed a stronger negative association with cytokine production capacity than the PLHIV-related strain, particularly for Pam3Cys-incuded IL-6 and IL-10 production. The control-related strain is also positively associated with CD4+ T-cell level. Conclusions: Our findings suggest that modulating the gut microbiome may be a strategy to modulate immune response in PLHIV.

Microbial vitamin production mediates dietary effects on diabetic risk.

Adequate levels of essential vitamins are important for the prevention of diabetes. While the main efforts to address this are currently focused on the intake of vitamin supplements, improving and maintaining intrinsic vitamin production capacity, which is determined by gut microbes, has received insufficient attention. In this study, we systematically investigated the relationship between gut microbial vitamin production and factors related to diabetes and cardiometabolic health in a deeply phenotyped cohort, Lifelines-DEEP (N = 1,135). We found that blood glucose-related factors, lipids, circulating inflammation, and fecal short-chain fatty acids are associated with gut microbial vitamin production. Use of laxatives and metformin are associated with increased levels of vitamin B1/B6 biosynthesis pathways. We further reveal a mediatory role for microbial vitamin B1/B2 production on the influence of fruit intake on diabetes risk. This study provides preliminary evidence for microbiome-targeted vitamin metabolism interventions to promote health.

Ligand-enabled Ni-catalyzed hydroarylation and hydroalkenylation of internal alkenes with organoborons.

The transition metal-catalyzed hydrofunctionalization of alkenes offers an efficient solution for the rapid construction of complex functional molecules, and significant progress has been made during last decades. However, the hydrofunctionalization of internal alkenes remains a significant challenge due to low reactivity and the difficulties of controlling the regioselectivity. Here, we report the hydroarylation and hydroalkenylation of internal alkenes lacking a directing group with aryl and alkenyl boronic acids in the presence of a nickel catalyst, featuring a broad substrate scope and wide functional group tolerance under redox-neutral conditions. The key to achieving this reaction is the identification of a bulky 1-adamantyl ß-diketone ligand, which is capable of overcoming the low reactivity of internal 1,2-disubstituted alkenes. Preliminary mechanistic studies unveiled that this reaction undergoes an Ar-Ni(II)-H initiated hydroarylation process, which is generated by the oxidative addition of alcoholic solvent with Ni(0) species and sequential transmetalation. In addition, the oxidative addition of the alcoholic solvent proves to be the turnover-limiting step.

Plasticity of the adult human small intestinal stoma microbiota.

The human distal small intestine (ileum) has a distinct microbiota, but human studies investigating its composition and function have been limited by the inaccessibility of the ileum without purging and/or deep intubation. We investigated inherent instability, temporal dynamics, and the contribution of fed and fasted states using stoma samples from cured colorectal cancer patients as a non-invasive access route to the otherwise inaccessible small and large intestines. Sequential sampling of the ileum before and after stoma formation indicated that ileostoma microbiotas represented that of the intact small intestine. Ileal and colonic stoma microbiotas were confirmed as distinct, and two types of instability in ileal host-microbial relationships were observed: inter-digestive purging followed by the rapid postprandial blooming of bacterial biomass and sub-strain appearance and disappearance within individual taxa after feeding. In contrast to the relative stability of colonic microbiota, the human small intestinal microbiota biomass and its sub-strain composition can be highly dynamic.

Helicobacter pylori infection affects the human gastric microbiome, as revealed by metagenomic sequencing.

Helicobacter pylori infection is a prevalent infectious disease, associated with many gastric diseases, including gastritis, gastric ulcer, and gastric cancer. To reveal the characteristics of the gastric microbiome in patients infected with H. pylori, we performed metagenomic shotgun sequencing of stomach swab samples from 96 patients and then conducted metagenomic association analyses between alterations in the gastric microbiome and H. pylori infection status. The overall composition of the gastric microbiota in H. pylori-infected individuals was distinctly different from the negative controls; H. pylori became the dominant species after colonizing the human stomach and significantly decreased the α-diversity of the gastric community (P < 0.05, Wilcoxon rank-sum test). We also identified 6 HPI-associated microbial species (FDR < 0.05, Wilcoxon rank-sum test): Stenotrophomonas maltophilia, Stenotrophomonas unclassified, Chryseobacterium unclassified, Pedobacter unclassified, Variovorax unclassified, and Pseudomonas stutzeri. Furthermore, 55 gastric microbial pathways were enriched in the H. pylori-positive group, whereas only 2 pathways were more abundant in the H. pylori-negative group: dTDP-L-rhamnose biosynthesis and tetrapyrrole biosynthesis (FDR < 0.05, Wilcoxon rank-sum test). Gastritis was not associated with non-H. pylori species in the stomach (P > 0.05, Wilcoxon rank-sum test). This study revealed alterations in gastric microbial taxa and function associated with HPI in the Chinese population, which provides an insight into gastric microbial interactions and their potential role in the pathological process of gastric diseases.

Discovery, diversity, and functional associations of crAss-like phages in human gut metagenomes from four Dutch cohorts.

The crAss-like phages are a diverse group of related viruses that includes some of the most abundant viruses of the human gut. To explore their diversity and functional role in human population and clinical cohorts, we analyze gut metagenomic data collected from 1,950 individuals from the Netherlands. We identify 1,556 crAss-like phage genomes, including 125 species-level and 32 genus-level clusters absent from the reference databases used. Analysis of their genomic features shows that closely related crAss-like phages can possess strikingly divergent regions responsible for transcription, presumably acquired through recombination. Prediction of crAss-like phage hosts points primarily to bacteria of the phylum Bacteroidetes, consistent with previous reports. Finally, we explore the temporal stability of crAss-like phages over a 4-year period and identify associations between the abundance of crAss-like phages and several human phenotypes, including depletion of crAss-like phages in inflammatory bowel disease patients.