Shotgun Metagenomic Sequencing Research Articles

Friends and foes: symbiotic and Algicidal bacterial influence on Karenia brevis blooms

Abstract Harmful Algal Blooms (HABs) of the toxigenic dinoflagellate Karenia brevis are pivotal in structuring the ecosystem of the Gulf of Mexico (GoM), decimating coastal ecology, local economies and human health. Bacterial communities associated with toxigenic phytoplankton species play an important role in influencing toxin production in the laboratory, supplying essential factors to phytoplankton and even killing blooming species. However, our knowledge of the prevalence of these mechanisms during HAB events is limited, especially for Kophosoma brevis blooms. Here, we introduced native microbial communities from the GoM, collected during two phases of a Karenia bloom, into K. brevis laboratory cultures. Using bacterial isolation, physiological experiments, and shotgun metagenomic sequencing, we identified both putative enhancers and mitigators of K. brevis blooms. Metagenome-assembled genomes (MAGs) from the Roseobacter clade showed strong correlations with K. brevis populations during HABs, akin to symbionts. A bacterial isolate from this group of MAGs, Mameliella alba, alleviated vitamin limitations of K. brevis by providing it with vitamins B1, B7 and B12. Conversely, bacterial isolates belonging to Bacteroidetes and Gammaproteobacteria, Croceibacter atlanticus and Pseudoalteromonas spongiae, respectively, exhibited strong algicidal properties against K. brevis. We identified a serine protease homolog in P. spongiae that putatively drives the algicidal activity in this isolate. While the algicidal mechanism in C. atlanticus is unknown, we demonstrated the efficiency of C. atlanticus to mitigate K. brevis growth in blooms from the GoM. Our results highlight the importance of specific bacteria in influencing the dynamics of HABs and suggest strategies for future HAB management.

Microbial profiling of the East Siberian Sea sediments using 16S rRNA gene and metagenome sequencing

The Arctic Ocean is experiencing significant global warming, leading to reduced sea-ice cover, submarine permafrost thawing, and increased river discharge. The East Siberian Sea (ESS) undergoes more significant terrestrial inflow from coastal erosion and river runoff than other Arctic seas. Despite extensive research on environmental changes, microbial communities and their functions in the ESS, which are closely related to environmental conditions, remain largely unexplored. Here, we investigated microbial communities in ESS surface sediments spanning latitudes from 73°N to 77°N using 16S rRNA amplicon sequencing, and reconstructed 211 metagenome-assembled genomes (MAGs) using shotgun metagenome sequencing. Taxonomic analysis identified 209 bacterial MAGs, with the predominant phyla Pseudomonadota (n = 82), Actinobacteriota (n = 38), Desulfobacterota (n = 23), along with 2 archaeal MAGs of Thermoproteota. Notably, 86% of the MAGs (n = 183) could not be classified into known species, indicating the potential presence of novel and unidentified microorganisms in the ESS. This dataset provides invaluable information on the microbial diversity and ecological functions in the rapidly changing ESS.

Integrative analysis of gut microbiota and fecal metabolites in cynomolgus monkeys with spontaneous type 2 diabetes mellitus.

Accumulating evidence suggests that gut microbiota (GM) is clearly associated with the pathogenesis of type 2 diabetes mellitus (T2DM). However, the underlying mechanism of GM dysbiosis participates the onset of T2DM is not fully understood. The spontaneous T2DM cynomolgus monkeys are a powerful model for understanding the pathological mechanism of T2DM. Fecal samples were collected from 7 spontaneous T2DM cynomolgus monkeys and 7 healthy controls matched with similar age for multi-omics analysis, including shotgun metagenomic sequencing, untargeted metabolomics profiling, and targeted metabolomics focusing on short chain fatty acids (SCFAs). Lastly, the correlation network between differential gut microbial species and fecal metabolites was performed to explore the potential biomarkers of T2DM. We found that 17 low-abundance species showed significant differences between the two groups. Analysis of gut microbial functions revealed that 16 KEGG pathways and 51 KEGG modules were significantly different in the two groups. Meanwhile, 276 fecal DEMs were identified, and these DEMs were enriched in the KEGG pathways, including Nucleotide metabolism, ABC transporters, Purine metabolism and so on. Lastly, Spearman correlation network analysis showed that the species of Anaerostipes_hadrus and Lachnoanaerobaculum_umeaense, and the metabolites including Glycerophospho-N-palmitoyl ethanolamine and 2-Hydroxycinnamic acid might serve as potential biomarkers of T2DM. Our study provides novel insights into specific alterations in the GM composition, gene functions, and fecal metabolic profiles in spontaneous T2DM cynomolgus monkeys.

Plant-specific microbial diversity facilitates functional redundancy at the soil-root interface

Abstract Aims Plant-specific microbial diversity reflecting host-microbe coevolution was frequently shown at the structural level but less on the functional scale. We studied the microbiome of three compartments at the soil root interface (root endosphere, rhizosphere, bulk soil) of medicinal plants cultivated under organic management in Egypt. The study aimed to examine the impact of the rhizosphere on microbial community composition and diversity in desert agricultural soil, as well as to identify specific functions associated with the rhizosphere. Methods The microbiome community structure, diversity, and microbial functioning were evaluated through the utilization of 16S rRNA gene amplicon and shotgun metagenome sequencing. Results We found the typical rhizosphere effect and plant-species-specific enrichment of bacterial diversity. The annual plants Calendula officinalis and Matricaria chamomilla (Asteraceae) were more similar than the perennial Solanum distichum (Solanaceae). Altogether, plant species explained 50.5% of the variation in bacterial community structures in the rhizosphere. Our results indicate a stronger effect of the plant species in terms of modulating bacterial community structures in the rhizosphere than in root endosphere samples. The plant-driven rhizosphere effect could be linked to redundant plant beneficial functions in the microbiome, while enrichment of specific genes related to amino acid ion transport and metabolism, carbohydrate transport and metabolism, defense mechanisms, and secondary metabolites biosynthesis were more specific. Conclusions The study explores the microbiome continuum at the soil-root interface of medicinal plant species, revealing significant bacterial community structure shifts and plant specificity. The study provides insights into the essential microbiome components contributing to rhizosphere functionality.

Butyrate-producing Faecalibacterium prausnitzii suppresses natural killer/T-cell lymphoma by dampening the JAK-STAT pathway

BackgroundNatural killer/T-cell lymphoma (NKTCL) is a highly aggressive malignancy with a dismal prognosis, and gaps remain in understanding the determinants influencing disease outcomes.ObjectiveTo characterise the gut microbiota feature and identify...

Resistome in the indoor dust samples from workplaces and households: a pilot study.

The antibiotic resistance genes (ARGs) limit the susceptibility of bacteria to antimicrobials, representing a problem of high importance. Current research on the presence of ARGs in microorganisms focuses mainly on humans, livestock, hospitals, or wastewater. However, the spectrum of ARGs in the dust resistome in workplaces and households has gone relatively unexplored. This pilot study aimed to analyze resistome in indoor dust samples from participants' workplaces (a pediatric hospital, a maternity hospital, and a research center) and households and compare two different approaches to the ARGs analysis; high-throughput quantitative PCR (HT-qPCR) and whole metagenome shotgun sequencing (WMGS). In total, 143 ARGs were detected using HT-qPCR, with ARGs associated with the macrolides, lincosamides, and streptogramin B (MLSB) phenotype being the most abundant, followed by MDR (multi-drug resistance) genes, and genes conferring resistance to aminoglycosides. A higher overall relative quantity of ARGs was observed in indoor dust samples from workplaces than from households, with the pediatric hospital being associated with the highest relative quantity of ARGs. WMGS analysis revealed 36 ARGs, of which five were detected by both HT-qPCR and WMGS techniques. Accordingly, the efficacy of the WMGS approach to detect ARGs was lower than that of HT-qPCR. In summary, our pilot data revealed that indoor dust in buildings where people spend most of their time (workplaces, households) can be a significant source of antimicrobial-resistant microorganisms, which may potentially pose a health risk to both humans and animals.

Defective Atg16l1 in intestinal epithelial cells links to altered fecal microbiota and metabolic shifts during pregnancy in mice

ABSTRACT Throughout gestation, the female body undergoes a series of transformations, including profound alterations in intestinal microbial communities. Changes gradually increase toward the end of pregnancy and comprise reduced α-diversity of microbial communities and an increased propensity for energy harvest. Despite the importance of the intestinal microbiota for the pathophysiology of inflammatory bowel diseases, very little is known about the relationship between these microbiota shifts and pregnancy-associated complications of the disease. Here, we explored the longitudinal dynamics of gut microbiota composition and functional potential during pregnancy and after lactation in Atg16l1 ∆IEC mice carrying an intestinal epithelial deletion of the Crohn’s disease risk gene Atg16l1. Using 16S rRNA amplicon and shotgun metagenomic sequencing, we demonstrated divergent temporal shifts in microbial composition between Atg16l1 wildtype and Atg16l1 ∆IEC pregnant mice in trimester 3, which was validated in an independent experiment. Observed differences included microbial genera implicated in IBD such as Lachnospiraceae, Roseburia, Ruminococcus, and Turicibacter. Changes partially recovered after lactation. Additionally, metagenomic and metabolomic analyses suggest an increased capacity for chitin degradation, resulting in higher levels of free N-acetyl-glucosamine products in feces, alongside reduced glucose and myo-inositol levels in serum around the time of delivery. On the host side, we found that the immunological response of Atg16l1 ∆IEC mice is characterized by higher colonic mRNA levels of TNFα and CXCL1 in trimester 3 and a lower weight of offspring at birth. Understanding pregnancy-dependent microbiome changes in the context of IBD may constitute the first step in the identification of fecal microbial biomarkers and microbiota-directed therapies that could help improve precision care for managing pregnancies in IBD patients.

Sputum metagenomics reveals a multidrug resistant Pseudomonas‐dominant severe asthma phenotype in an Asian population

AbstractBackground and ObjectiveWhile the lung microbiome in severe asthma has been studied, work has employed targeted amplicon‐based sequencing approaches without functional assessment with none focused on multi‐ethnic Asian populations. Here we investigate the clinical relevance of microbial phenotypes of severe asthma in Asians using metagenomics.MethodsProspective assessment of clinical, radiological, and immunological measures were performed in a multi‐ethnic Asian severe asthma cohort (N = 70) recruited across two centres in Singapore. Sputum was subjected to shotgun metagenomic sequencing and patients followed up for a 2‐year period. Metagenomic assessment of sputum microbiomes, resistomes and virulomes were related to clinical outcomes.ResultsThe lung microbiome in a multi‐ethnic Asian cohort with severe asthma demonstrates an increased abundance of Pseudomonas species. Unsupervised clustering of sputum metagenomes identified two patient clusters: C1 (n = 52) characterized by upper airway commensals and C2 (n = 18) dominated by established respiratory pathogens including M. catarrhalis, S. aureus and most significantly P. aeruginosa. C2 patients demonstrated a significantly increased exacerbation frequency on 2‐year follow up and an antimicrobial resistome characterized by multidrug resistance. Virulomes appear indistinguishable between severe asthmatics with or without co‐existing bronchiectasis, and C2 patients exhibit increased gene expression related to biofilm formation, effector delivery systems and microbial motility. Independent comparison of the C2 cluster to a non‐asthmatic bronchiectasis cohort demonstrates analogous airway microbial virulence patterns.ConclusionSputum metagenomics demonstrates a multidrug‐resistant Pseudomonas‐dominant severe asthma phenotype in Asians, characterized by poor clinical outcome including increased exacerbations which is independent of co‐existing bronchiectasis.

The neonatal gut microbiota: A role in the encephalopathy of prematurity.

Preterm birth correlates with brain dysmaturation and neurocognitive impairment. The gut microbiome associates with behavioral outcomes in typical development, but its relationship with neurodevelopment in preterm infants is unknown. We characterize fecal microbiome in a cohort of 147 neonates enriched for very preterm birth using 16S-based and shotgun metagenomic sequencing. Delivery mode strongly correlates with the preterm microbiome shortly after birth. Low birth gestational age, infant sex assigned at birth, and antibiotics associate with microbiome composition at neonatal intensive care unit discharge. We integrate these data with term-equivalent structural and diffusion brain MRI. Bacterial community composition associates with MRI features of encephalopathy of prematurity. Particularly, abundances of Escherichia coli and Klebsiella spp. correlate with microstructural parameters in deep and cortical gray matter. Metagenome functional capacity analyses suggest that these bacteria may interact with brain microstructure via tryptophan and propionate metabolism. This study indicates that the gut microbiome associates with brain development following preterm birth.

Constructing phylogenetic trees for microbiome data analysis: A mini-review

As next-generation sequencing technologies advance rapidly and the cost of metagenomic sequencing continues to decrease, researchers now face an unprecedented volume of microbiome data. This surge has stimulated the development of scalable microbiome data analysis methods and necessitated the incorporation of phylogenetic information into microbiome analysis for improved accuracy. Tools for constructing phylogenetic trees from 16S rRNA sequencing data are well-established, as the highly conserved regions of the 16S gene are limited, simplifying the identification of marker genes. In contrast, metagenomic and whole genome shotgun (WGS) sequencing involve sequencing from random fragments of the entire gene, making identification of consistent marker genes challenging owing to the vast diversity of genomic regions, resulting in a scarcity of robust tools for constructing phylogenetic trees. Although bacterial sequence tree construction tools exist for upstream bioinformatics, many downstream researchers—those integrating these trees into statistical models or machine learning—are either unaware of these tools or find them difficult to use due to the steep learning curve of processing raw sequences. This is compounded by the fact that public datasets often lack phylogenetic trees, providing only abundance tables and taxonomic classifications. To address this, we present a comprehensive review of phylogenetic tree construction techniques for microbiome data (16S rRNA or whole-genome shotgun sequencing). We outline the strengths and limitations of current methods, offering expert insights and step-by-step guidance to make these tools more accessible and widely applicable in quantitative microbiome data analysis.

Combined analysis of cross-population healthy adult human microbiome reveals consistent differences in gut microbial characteristics between Western and non-Western countries

Despite extensive research on the gut microbiome of healthy individuals from a single country, there are still a limited number of population-level comparative studies. Moreover, the sequencing approach used in most related studies involves 16S ribosomal RNA (rRNA) sequencing with a limited resolution, which cannot provide detailed functional profiles. In the present study, we applied a combined analysis approach to analyze whole metagenomic shotgun sequencing data from 2035 healthy adult samples from six countries across four continents. Analysis of core species revealed that 13 species were present in more than 90% of all investigated individuals, the majority of which produced short-chain fatty acids (SCFA)-producing bacteria. Our analysis revealed consistently significant differences in gut microbial species and pathways between Western and non-Western countries, such as Escherichia coli and the relation of MetaCyc pathways to the TCA cycle. Specific changes in microbial species and pathways are potentially related to lifestyle and diet. Furthermore, we identified several noteworthy microbial species and pathways that exhibit distinct characteristics specific to China. Interestingly, we observed that China (CHN) was more similar to the United States (USA) and United Kingdom (GBR) in terms of the taxonomic and functional composition of the gut microbiome than India (IND) and Madagascar (MDG), which were more similar to the China (CHN) diet. The current study identified consistent microbial features associated with population and geography, which will inspire further clinical translations that consider paying attention to differences in microbiota backgrounds and confounding factors.

Comparison of Anaerobic Culture Methods for Detecting Clostridioides difficile in Bovine Faeces.

The study of the epidemiology of Clostridioides difficile in populations is greatly facilitated by the ability to isolate and further characterize individual organisms, which requires effective culture protocols. In cattle, where little is known about the epidemiology of C. difficile, no studies have assessed or compared the performance of different assays for detecting C. difficile. This study compared two culture protocols for detecting C. difficile in bovine faeces from 121 gestating cows and 70 of their neonatal calves, while situating results obtained with each protocol relative to those obtained with shotgun metagenomic sequencing. Protocol 1 involved direct plating enrichment onto taurocholine-cycloserine-cefoxitin-fructose agar (TCCFA), while Protocol 2 included an ethanol shock step before plating on CCFA/ChromID agar. For both protocols, one aliquot underwent broth enrichment prior to plating, while the other aliquot did not. Clostridioides difficile was detected following broth enrichment in two of the same calf samples using both protocols, and an additional cow sample was found to be positive with Protocol 2, though the difference in detection rates was not statistically significant (p = 1.0). The detection of C. difficile in a much high number of these samples by shotgun metagenomics, albeit at low levels of relative abundance, suggests that neither of these culture protocols is sensitive when levels of abundance are low.

Multi-biome analysis identifies distinct gut microbial signatures and their crosstalk in ulcerative colitis and Crohn’s disease

The integrative multi-kingdom interaction of the gut microbiome in ulcerative colitis (UC) and Crohn’s disease (CD) remains underinvestigated. Here, we perform shotgun metagenomic sequencing of feces from patients with UC and CD, and healthy controls in the Japanese 4D cohort, profiling bacterial taxa, gene functions, and antibacterial genes, bacteriophages, and fungi. External metagenomic datasets from the US, Spain, the Netherlands, and China were analyzed to validate our multi-biome findings. We found that Enterococcus faecium and Bifidobacterium spp. were enriched in both diseases. Enriched Escherichia coli was characteristic of CD and was linked to numerous antibiotic resistance genes involved in efflux pumps and adherent-invasive Escherichia coli virulence factors. Virome changes correlated with shifts in the bacteriome, including increased abundances of phages encoding pathogenic genes. Saccharomyces paradoxus and Saccharomyces cerevisiae were enriched in UC and CD, respectively. Saccharomyces cerevisiae and Escherichia coli had negative associations with short-chain fatty acid (SCFA)-producing bacteria in CD. Multi-biome signatures and their interactions in UC and CD showed high similarities between Japan and other countries. Since bacteria, phages, and fungi formed multiple hubs of intra- or trans-kingdom networks with SCFA producers and pathobionts in UC and CD, an approach targeting the interaction network may hold therapeutic promise.

Metagenomic Analysis Identifies Sex-Related Gut Microbial Functions and Bacterial Taxa Associated With Skeletal Muscle Mass.

This study aimed to explore the association between gut microbiota functional profiles and skeletal muscle mass, focusing on sex-specific differences in a population under 65 years of age. Stool samples from participants were analysed using metagenomic shotgun sequencing. Skeletal muscle mass and skeletal muscle mass index (SMI) were quantified (SMI [%] = total appendage muscle mass [kg]/body weight [kg] × 100) using bioelectrical impedance analysis. Participants were categorized into SMI quartiles, and associations between gut microbiota, functional profiling and SMI were assessed by sex, adjusting for age, BMI and physical activity. The cohort included 1027 participants (651 men, 376 women). In men, Escherichia coli (log2 fold change 3.08, q = 0.001), Ruminococcus_B gnavus (log2 fold change 2.89, q = 0.014) and Enterocloster sp001517625 (log2 fold change 2.47, q = 0.026) were more abundant in the lowest SMI compared to the highest SMI group. In contrast, Bifidobacterium bifidum (log2 fold change 3.13, q = 0.025) showed higher levels in the second lowest SMI group in women. Microbial pathways associated with amino acid synthesis (MET-SAM-PWY: log2 fold change 0.42; METSYN-PWY: log2 fold change 0.44; SER-GLYSYN-PWY: log2 fold change 0.20; PWY-5347: log2 fold change 0.41; P4-PWY: log2 fold change 0.53), N-acetylneuraminate degradation (log2 fold change 0.43), isoprene biosynthesis (log2 fold change 0.20) and purine nucleotide degradation and salvage (PWY-6353: log2 fold change 0.42; PWY-6608: log2 fold change 0.38; PWY66-409: log2 fold change 0.52; SALVADEHYPOX-PWY: log2 fold change 0.43) were enriched in the lowest SMI in men (q < 0.10). In women, the second lowest SMI group showed enrichment in energy-related pathways, including lactic acid fermentation (ANAEROFRUCAT-PWY: log2 fold change 0.19), pentose phosphate pathway (PENTOSE-P-PWY: log2 fold change 0.30) and carbohydrate degradation (PWY-5484: log2 fold change 0.31; GLYCOLYSIS: log2 fold change 0.29; PWY-6901: log2 fold change 0.27) (q < 0.05). This study highlights sex-specific differences in gut microbiota and functional pathways associated with SMI. These findings suggest that gut microbiota may play a role in muscle health and point toward microbiota-targeted strategies for maintaining muscle mass.

Concordance in molecular methods for detection of antimicrobial resistance: A cross sectional study of the influent to a wastewater plant

Methods that are used to characterise microbiomes and antimicrobial resistance genes (ARGs) in wastewater are not standardised. We used shotgun metagenomic sequencing (SM-Seq), RNA sequencing (RNA-seq) and targeted qPCR to compare microbial and ARG diversity in the influent to a municipal wastewater treatment plant in Australia. ARGs were annotated with CARD-RGI and MEGARes databases, and bacterial diversity was characterised by 16S rRNA gene sequencing and SM-Seq, with species annotation in SILVA/GreenGenes databases or Kraken2 and the NCBI nucleotide database respectively. CARD and MEGARes identified evenly distributed ARG profiles but MEGARes detected a richer array of ARGs (richness = 475 vs 320). Qualitatively, ARGs encoding for aminoglycoside, macrolide-lincosamide-streptogramin and multidrug resistance were the most abundant in all examined databases. RNA-seq detected only 32 % of ARGs identified by SM-Seq, but there was concordance in the qualitative identification of aminoglycoside, macrolide-lincosamide, phenicol, sulfonamide and multidrug resistance by SM-Seq and RNA-seq. qPCR confirmed the detection of some ARGs, including OXA, VEB and EREB, that were identified by SM-Seq and RNA-seq in the influent. For bacteria, SM-Seq or 16S rRNA gene sequencing were equally effective in population profiling at phyla or class level. However, SM-Seq identified a significantly higher species richness (richness = 15,000 vs 3750). These results demonstrate that SM-Seq with gene annotation in CARD and MEGARes are equally sufficient for surveillance of antimicrobial resistance in wastewater. For more precise ARG identification and quantification however, MEGARes presented a better resolution. The functionality of detected ARGs was not confirmed, but general agreement on the putative phenotypic resistance profile by antimicrobial class was observed between RNA-Seq and SM-Seq.

A nested case-control study on the association of gut virome in early pregnancy and gestational diabetes mellitus.

Recent studies have increasingly shown the connection between gut microbiome and gestational diabetes mellitus (GDM). However, no studies have explored the relationship between the gut virome and GDM, and the underlying mechanism remains unknown. We performed a nested case-control study within a follow-up cohort, enrolling 51 patients with GDM and 51 healthy controls. Shotgun metagenomics sequencing was used to explore gut virome profiles during early pregnancy. Diversity analysis revealed no difference in the overall gut virome composition between two groups, however, we found greater abundance of Escherichia phage SH2026Stx1 (Q = 0.23), Enterobacteria phage mEp043 c-1 (Q = 0.21), crAssphage cr50_1 (Q = 0.21), Enterobacteria phage phi80 (Q = 0.21), and Escherichia phage HK106 (Q = 0.23) in GDM patients. Cross-kingdom correlation analysis showed the negative correlation between the gut bacterium Eubacterium eligens and three bacteriophages (Escherichia phage SH2026Stx1, Enterobacteria phage mEp043 c-1, and Escherichia phage HK106) in GDM group (r < 0, P < 0.05). Based on gut microbial features and clinical indicators, we constructed a new prediction model using random forest method for GDM with good predictive performance (AUC of 0.893, 95% CI: 0.736 ∼ 0.990). This study is the first to investigate the relationship between the gut virome and GDM as well as the cross-kingdom correlation between gut viruses and bacteria in GDM. Our findings could enhance strategies for preventing and treating GDM from the perspective of gut microbiome, offering valuable insights into its pathogenesis.

Cultivar-dependent differences in plant bud microbiome and functional gene pathways in woody plants commonly used in urban green space.

Plant richness and microbiota have been associated with plant health; hardly any studies have investigated how plant taxa differs in microbiota in the context of human health. We investigated the microbial differences in buds of 83 woody plant taxa used in urban green spaces in hemiboreal climate, using 16S rRNA and whole metagenome shotgun sequencing. Bud microbial community was the richest in Cotoneaster Nanshan and C. integerrimus, and Malus domestica cultivars 'Sandra' and 'Lobo' and poorest in Ribes glandulosum. Metagenomic shotgun sequencing of two M. domestica and four Ribes varieties confirmed differences in taxa in bud microbiota and indicated higher siderophore synthesis in Malus. Microbial richness, including bacteria, archaea and viruses, and functional richness of gene pathways was higher in Malus compared to Ribes. The ten most abundant amplicon sequence units, often referred as species, belonged to the phylum Proteobacteria. The differences between plant taxa were evident in classes Alpha- and Gammaproteobacteria, known for potential human health-benefits. Since environmental microbiota contributes to human microbiota and immunoregulation, horticultural cultivars hosting rich microbiota may have human health benefits. Further studies are needed to confirm the effectiveness of microbially-oriented plant selection in optimizing human microbiota and planetary health.

Why Symptoms Linger in Quiescent Crohn's Disease: Investigating the Impact of Sulfidogenic Microbes and Sulfur Metabolic Pathways.

Even in the absence of inflammation, persistent symptoms in patients with Crohn's disease (CD) are prevalent and worsen quality of life. We previously demonstrated enrichment in sulfidogenic microbes in quiescent Crohn's disease patients with (qCD + S) vs without persistent GI symptoms (qCD-S). Thus, we hypothesized that sulfur metabolic pathways would be enriched in stool while differentially abundant microbes would be associated with important sulfur metabolic pathways in qCD + S. We performed a multicenter observational study nested within SPARC IBD. Quiescent inflammation was defined by fecal calprotectin level < 150 mcg/g. Persistent symptoms were defined by CD-PRO2. Active CD (aCD) and non-IBD diarrhea-predominant irritable bowel syndrome (IBS-D) were included as controls. Thirty-nine patients with qCD + S, 274 qCD-S, 21 aCD, and 40 IBS-D underwent paired shotgun metagenomic sequencing and untargeted metabolomic profiling. The fecal metabolome in qCD + S was significantly different relative to qCD-S and IBS-D but not aCD. Patients with qCD + S were enriched in sulfur-containing amino acid pathways, including cysteine and methionine, as well as serine, glycine, and threonine. Glutathione and nicotinate/nicotinamide pathways were also enriched in qCD + S relative to qCD-S, suggestive of mitochondrial dysfunction, a downstream target of H2S signaling. Multi-omic integration demonstrated that enriched microbes in qCD + S were associated with important sulfur metabolic pathways. Bacterial sulfur metabolic genes, including CTH, isfD, sarD, and asrC, were dysregulated in qCD + S. Finally, sulfur metabolites with and without sulfidogenic microbes showed good accuracy in predicting the presence of qCD + S. Microbial-derived sulfur pathways and downstream mitochondrial function are perturbed in qCD + S, which implicate H2S signaling in the pathogenesis of this condition. Future studies will determine whether targeting H2S pathways results in improved quality of life in qCD + S.

Gut microbial metabolism of bile acids modifies the effect of Mediterranean diet interventions on cardiometabolic risk in a randomized controlled trial

ABSTRACT Bile acids (BAs) undergo extensive microbial metabolism in the gut and exert hormone-like functions on physiological processes underlying metabolic risk. However, the extent to which gut BA profiles predict cardiometabolic risk and explain individual responses to dietary interventions in humans is still unclear. In the DIRECT-PLUS Trial, we conducted a multi-omics analysis of 284 participants randomized into three groups: healthy dietary guidelines and two Mediterranean diet (MedDiet) groups. We longitudinally measured 44 fecal BAs using liquid chromatography-mass spectrometry, the gut microbiome through shotgun metagenomic sequencing, and body adiposity and serum lipids at baseline, 6, and 18 months. Fecal levels of 14 BAs, such as lithocholic acid and ursodeoxycholic acid, were prospectively associated with body mass index (BMI) and serum lipid profiles (false discovery rate [q]<0.05). Baseline fecal BA levels significantly modified the beneficial effects of the MedDiet; for example, BMI reduction induced by MedDiet interventions was more pronounced in individuals with lower 12-dehydrocholic acid levels (q-interaction <0.001). We confirmed that the gut microbiome is a major modifier of the secondary BA pool in humans. Furthermore, the association of fecal BAs with body adiposity and serum lipids varied significantly in individuals with different abundances of gut microbes carrying BA metabolism enzymes, e.g. several Ruminococcus spp. In summary, our study identifies novel predictive biomarkers for cardiometabolic risk and offers new mechanistic insights to guide personalized dietary interventions.

Dietary pattern and the corresponding gut microbiome in response to immunotherapy in Thai patients with advanced non-small cell lung cancer (NSCLC)

Gut microbiota is considered a key player modulating the response to immune checkpoint inhibitors (ICI) in cancer. The effects of dietary pattern on this interaction is not well-studied. A prospective multicenter cohort of 95 patients with advanced non-small cell lung cancer (NSCLC) undergoing ICI therapy were enrolled. Stool shotgun metagenomic sequencing was performed. Three-day dietary patterns before ICI were assessed. Patients were categorized as hyperprogressive disease (HPD) if they exhibited a time to treatment failure of less than 2 months. All others were categorized as non-hyperprogressive disease (non-HPD). The correlation between dietary patterns, gut microbiome, and response to ICI therapy was analyzed. In the multivariate analysis, a high abundance of Firmicutes unclassified and the Ruminococcaceae family correlated with a significantly diminished progression-free survival (PFS) with an HR of 2.40 [P = 0.006] and 4.30 [P = 0.005], respectively. More specifically, within the subset of NSCLC patients treated solely with ICI therapy, a high abundance of Intestinimonas and the Enterobacteriaceae family were associated with substantially reduced PFS with an HR of 2.61 [P = 0.02] and HR 3.34 [P = 0.005], respectively. In our comprehensive dietary pattern analysis, the HPD group showed increased consumption of cholesterol, sodium, and fats beyond recommended levels compared to the non-HPD group. This group also displayed a tendency towards higher food pattern scores characterized by a high intake of fat and dairy products. Our study revealed a distinct association between the gut microbiome composition and treatment outcomes. The overall composition of diet might be related to ICI therapeutic outcomes.