16S rRNA Sequencing Research Articles

Dietary Capsaicin Exacerbates Gut Microbiota Dysbiosis and Mental Disorders in Type 1 Diabetes Mice

Background/Objectives: Diabetes mellitus is often accompanied by mental health complications, including anxiety, depression, and cognitive decline. Recent research suggested that capsaicin, the active component of chili peppers, may influence mental health. This study aimed to determine the effect of dietary capsaicin on mental disorders in a type 1 diabetes (T1D) mouse model, while also exploring the potential involvement of the microbiota-gut-brain axis. Methods: We induced T1D in mice using streptozotocin (STZ) and administered a diet supplemented with 0.005% capsaicin for five weeks. Behavioral assessments, including the open field test (OFT), tail suspension test (TST), forced swimming test (FST), elevated plus maze (EPM) test, and Morris water maze (MWM) test, were conducted to evaluate depressive and anxiety-like behaviors as well as cognitive function. Targeted and untargeted metabolomics analyses were performed to assess neurotransmitter levels in the hippocampus and serum metabolites, while 16S rRNA sequencing was utilized to analyze gut microbiota composition. Intestinal barriers were determined using western blot detection of the tight junction proteins ZO-1 and occludin. Results: Dietary capsaicin exacerbated anxiety and depressive-like behaviors along with cognitive declines in T1D mice. Capsaicin reduced gut microbiota diversity and levels of beneficial bacteria, while broad-spectrum antibiotic treatment further intensified anxiety and depression behaviors. Metabolomic analysis indicated that capsaicin disrupted metabolic pathways related to tryptophan and phenylalanine, leading to decreased neuroprotective metabolites, such as kynurenic acid, hippurate, and butyric acid. Additionally, capsaicin diminished the expression of ZO-1 and occludin, indicating increased intestinal permeability. Conclusions: Dietary capsaicin aggravates gut microbiota and metabolic disturbances in diabetic mice, thereby worsening anxiety, depression, and cognitive decline.

Utility of 28S Ribosomal RNA Gene Domains for Molecular Classification and Phylogeny of Rhinonyssid Mites

The family Rhinonyssidae includes endoparasitic, blood-feeding mites that are parasitic on birds and that remain largely unstudied despite their potential role as vectors or reservoirs for various pathogens, like other Dermanyssoidea. Traditionally, the taxonomy of the group has been based on morphometric characteristics, which makes identification very difficult in many groups of closely related species. On the other hand, studies on the phylogenetic relationships within this group of mites have been neglected until the early years of the present century. In this study, twelve species belonging to five different species complexes were identified, and domains D1-D3 28S rRNA of each one were sequenced, for the first time, to investigate the sequence variation and its taxonomic implications for phylogenetic inference. Our data indicate that this molecular marker can effectively differentiate between species within the “motacillae”, “sairae”, “pari”, and “hirsti” complexes of the genus Ptilonyssus and the “melloi” and “columbae” complexes of the genus Tinaminyssus. Furthermore, the phylogenetic tree that can be derived from the domain D1-D3 28S rRNA sequences presented in this study is congruent with the current taxonomy of the Rhinonyssidae. This research calls for a reassessment of the taxonomic status of some group of species.

Trematode Parasite Infections in Freshwater Leeches from the Central Region of Lithuania: First Record of Posthodiplostomum (Dubois, 1936) in a Leech Host

Leeches play a critical role in the transmission of digenean trematodes, yet their parasitic infections remain understudied in the Baltic region. This study investigates the diversity, prevalence, and molecular identification of trematode infections in freshwater leeches from central Lithuania. A total of five leech species (Alboglossiphonia heteroclita, Glossiphonia complanata, Glossiphonia verrucata, Helobdella stagnalis, and Erpobdella octoculata) were examined using compression and dissection techniques to detect trematode cysts, which were predominantly found in the soft tissues rather than the intestinal tract. Molecular sequencing of 18S rRNA, COI, and ITS markers, combined with phylogenetic analyses, confirmed the presence of three trematode genera: Cotylurus, Australapatemon, and Posthodiplostomum. The overall infection rate among leeches was 40.8%, with the highest prevalence observed in G. complanata (53.3%). Cotylurus spp. were the most frequently detected parasites, with genetic analyses revealing close affinities to Cotylurus syrius and Cotylurus spp. from Poland. Australapatemon species were also identified, though species-level classification remained inconclusive. Notably, this study provides the first molecular evidence of Posthodiplostomum cuticola utilizing leeches as intermediate hosts, extending the known range of hosts for this trematode. Phylogenetic analyses demonstrated the broad geographic distribution of these parasites, with close genetic matches to isolates from Poland, Russia, Canada, and Japan. The findings highlight the ecological significance of leeches in parasite transmission networks and contribute to the understanding of trematode diversity and host interactions in the Baltic region. Further molecular and ecological studies are needed to clarify species diversity and the role of leeches in the life cycles of aquatic parasites.

16S rRNA sequencing reveals relationships among enrichment of oral microbiota in the lower respiratory tract and pulmonary nodules malignant progression.

This study is the first to elucidate the composition and interrelationships of oral and lower respiratory tract (LRT) microbiota in patients with pulmonary nodule (PN) across varying malignancy risk levels. We conducted an analysis to investigate the correlation between the malignant potential of PNs and the enrichment of oral microbiota within the LRT. Additionally, we explored the feasibility of utilizing oral-lower respiratory commensal microbiota as biomarkers to assess the benign and malignant nature of pulmonary nodules. This study aims to provide evidence supporting early diagnosis and intervention strategies for lung cancer.

Advances in metagenomic sequencing for infectious disease management: From pathogen profiling to antibiotic resistance

Metagenomics has revolutionized the study of infectious diseases by enabling the analysis of microbial communities without the need for cultivation. This approach, powered by high-throughput sequencing technologies like 16S rRNA sequencing and shotgun metagenomics, allows the identification of both culturable and unculturable microbes, providing a comprehensive view of pathogens. Metagenomics offers critical insights into microbial diversity and interactions, particularly in polymicrobial infections, respiratory and gastrointestinal infections, and bloodstream infections. Advancements in bioinformatics, artificial intelligence (AI), and machine learning have enhanced the accuracy and speed of metagenomic data interpretation, aiding pathogen detection, antibiotic resistance surveillance, and personalized treatment strategies. Despite challenges such as sample complexity, host DNA interference, and data interpretation difficulties, metagenomics continues to evolve as a crucial tool for diagnostics and therapeutic development. Future research aims to address current gaps, including integrating AI into metagenomics for more precise pathogen profiling and developing targeted therapies based on microbial communities. Ultimately, metagenomics holds the potential to transform infectious disease management, offering real-time diagnostics, better global surveillance, and the promise of personalized medicine in the fight against emerging pathogens.

Identification of disease-specific gut microbial markers in vitiligo

There is a potential correlation between vitiligo and gut microbiota, although research in this area is currently limited. The research employed high-throughput sequencing of 16S rRNA to examine the gut microbiome in the stool samples of 49 individuals with vitiligo and 49 without the condition. The study encompassed four comparison groups: (1) DI (disease) group vs. HC (healthy control) group; (2) DI_m group (disease group of minors) vs. HC_m group (healthy control group of minors); (3) DI_a group (adult disease group) vs. HC_a group (adult healthy control group); (4) DI_m group vs. DI_a group. Research findings have indicated the presence of spatial heterogeneity in the gut microbiota composition between individuals with vitiligo and healthy controls. A significant reduction in gut microbiota diversity has been observed in vitiligo patients across both minors and adult groups. However, variations have been noted in the composition of disease-related differential microbial markers among different age groups. Specifically, Bacteroides and Parabacteroides have been identified as specific markers of the intestinal microbiota of vitiligo patients in both minor and adult groups. Correlative analyses have revealed a positive correlation of these two genera with the Vitiligo Area Scoring Index (VASI) and disease duration. It is noteworthy that there are no significant differences in diversity between the DI_m group and the DI_a group, with similarities in microbiota composition and functional characteristics. Nevertheless, correlative analyses suggest a declining trend in Bacteroides and Parabacteroides with increasing age. Individuals with vitiligo exhibit distinct features in their gut microbiome when contrasted with those in the healthy control group. Additionally, the microbial marker genera that show variances between patients and healthy controls vary among different age groups. Disease-specific microbial marker genera (Bacteroides and Parabacteroides) are associated with VASI, duration of the condition, and age. These findings are essential for improving early diagnosis and developing potential treatment strategies for individuals with vitiligo.

Evaluation of Antibiotic-Sensitive Bacillus Strain as a Potential Probiotic for Enhanced Growth in Penaeus vannamei.

The safety of probiotics in aquaculture, particularly concerning the transfer of antibiotic resistance genes (ARGs), has become a significant concern. This study aims to isolate antibiotic-sensitive Bacillus strains from the gut of Penaeus vannamei and evaluate the potential for practical application in shrimp farming. The strain was tested for antibiotic sensitivity to 10 commonly used antibiotics, and the minimum inhibitory concentration (MIC) values were determined. Morphological analysis and 16S rRNA sequencing confirmed its identity. The probiotic properties, antibacterial activity, and feeding effects on P. vannamei were also assessed. The results showed that Bacillus sp. J3 and Lysinibacillus sp. R4 were generally sensitive to antibiotics but resistant to sulfapyridine and ciprofloxacin. Both strains exhibited acid and bile salt resistance in vitro and performed well in extracellular hydrolase tests. J3 demonstrated co-coagulation effects against Aeromonas veronii, Vibrio parahaemolyticus, and Vibrio alginolyticus, with coagulation rates over 35%, while R4 showed the highest co-coagulation rate (47%) against V. alginolyticus. Both strains exhibited strong antibacterial activity, with inhibition zones ranging from 20 to 22.5mm. Preliminary shrimp farming tests showed that R4 improved shrimp growth and survival rates compared to the control, and its combination with Bacillus coagulans resulted in even greater efficacy. These findings suggest that Lysinibacillus sp. R4 holds promise as a probiotic for enhancing P. vannamei growth, and future research could explore the use of multiple probiotic combinations in aquaculture.

Interleukin-21 and anti-α4β7 dual therapy during ART promotes immunological and microbiome responses in SIV-infected macaques.

Despite combination antiretroviral therapy (ART), HIV causes persistent gut barrier dysfunction, immune depletion, and dysbiosis. Further, ART interruption results in reservoir reactivation and rebound viremia. Both IL-21 and anti-α4β7 improve gut barrier functions, and we hypothesized combining them would synergize as a dual therapy to improve immunological outcomes in SIV-infected rhesus macaques (RMs). We found no significant differences in CD4+ T-cell reservoir size by intact proviral DNA assay. SIV rebounded in both dual-treated and control RMs following analytical therapy interruption (ATI), with time to rebound and initial rebound viremia comparable between groups; however, dual-treated RMs showed slightly better control of viral replication at the latest time points post-ATI. Additionally, following post-ATI, dual-treated RMs showed immunological benefits, including T-cell preservation and lower PD-1+ central memory T-cell (TCM) frequency. Notably, PD-1+ TCMs were associated with reservoir size, which predicted viral loads (VLs) post-ATI. Finally, 16S rRNA sequencing revealed better recovery from dysbiosis in treated animals, and the butyrate-producing Firmicute Roseburia predicted PD-1-expressing TCMs and VLs after ATI. PD-1+ TCMs and gut dysbiosis represent mechanisms of HIV persistence and pathogenesis, respectively. Therefore, combining IL-21 and anti-α4β7 may be an effective therapeutic strategy to improve immunological outcomes for people with HIV.

Resilience of human gut microbiomes in autism spectrum disorder: measured using stiffness network analysis.

Autism spectrum disorder (ASD) affects an estimated 1%-2% of children worldwide, but its specific etiology remains unclear. In recent years, the gut microbiome's role in ASD pathogenesis has garnered increasing attention. However, the exact relationship between microbiota and ASD-such as which microbial species significantly impact disease onset and progression-remains unresolved, and effective methods to measure microbial interactions are still lacking. In this study, we introduce an innovative stiffness network analysis (SNA) method to quantify changes in microbial network structure and identify disease-specific microbial bacteria theoretically. The SNA method was applied to reanalyze eight ASD gut microbiome data sets, encompassing 898 ASD samples and 467 healthy control (HC) samples from 16S-rRNA sequencing data. Key findings include the following: (i) an "allies" biomarker subgroup consisting of Bacteroides plebeius, Sutterella, Lachnospira, and Prevotella copri was identified; (ii) a profile monitoring score of 0.72 for the biomarker subgroup, indicating significant relationship changes between HC and ASD states, and (iii) a P/N ratio of biomarker subgroup in ASD-associated gut bacteria that was three times higher than that of HC microbiomes. Additionally, we discuss the non-monotonic relationship alterations within microbial sub-communities in the ASD gut microbiome.IMPORTANCEIt is crucial to assess alterations in network structure in different biological states in order to promote health. The stiffness network allows for the exploration of species interactions and the measurement of resilience in complex microbial networks. The objective of this study was to develop a stiffness network analysis (SNA) method for evaluating the contribution of microbial bacteria in differentiating disease samples from healthy control samples by examining changes in network stiffness parameters. Furthermore, the SNA method was employed on both simulated and real autism spectrum disorder gut microbiome data sets to identify potential microbial biomarker subgroups, with a particular focus on the relationship alterations within microbial networks.

Characterization of Lung Microbiome in Subclinical Pneumonic Thai Pigs Using 16S rRNA Gene Sequencing

Bacterial respiratory disease is one of the major concerns in the modern pig industry. To address the limitations of culture-based methods, 16S rRNA sequencing was employed to characterize the pig lung microbiome to gain a better understanding of microbial physiology and their population genetics. A batch of 510 slaughtered pigs from a farm located in Lampang province, Thailand, was selected. Individual pig weight was recorded. A total of 24 lungs (10 normal and 14 pneumonic lungs) were sampled for gross lesion examination and lung microbial communities were investigated. Poor growth performance and weight uniformity were denoted in this batch. Several pathogenic bacteria were detected in both normal and pneumonic lungs. Microbial diversity was decreased in the pneumonic group. PCoA and NMDS analysis showed a clear separation between the groups. Stenotrophomonas spp. (42.12%) was the dominant genus identified in normal lungs, while Mycoplasma hyopneumoniae (71.97%) was the most abundant in pneumonic lungs, correlating with the commonly observed consolidation lesions. The slaughterhouse serves as a key checkpoint for gathering comprehensive information on pig respiratory health, and lung is representative of the lower respiratory tract for microbiomics. Monitoring of lung lesions should be implemented routinely to gain a better understanding of regional pig respiratory health.

Multi-omics approaches reveal the therapeutic mechanism of Naoxintong Capsule against ischemic stroke.

Ischemic stroke (IS) is a leading cause of long-term disability and mortality worldwide. The Chinese Pharmacopeia 2020 lists Naoxintong Capsule (NXT), a traditional Chinese medicine prescription, as having demonstrated substantial therapeutic efficacy for IS. Our study aimed to evaluate the mechanism by which NXT treats IS by integrating the microbiome, transcriptome, and metabolomics. In a middle cerebral artery occlusion (MCAO) mouse model, the infarction rate, neurological scores, lipopolysaccharide (LPS) levels, inflammatory factor levels (IL-1β, IL-17A, and IL-6), and intestinal permeability proteins (ZO-1, MUC2, and MUC4) were measured to confirm the effect of NXT on the brain and colon. 16S rRNA sequencing, transcriptomics analysis, and targeted amino acid (AA) metabolism were employed to evaluate the mechanism by which NXT treats IS. Furthermore, the neuroprotective effects of specific AAs, identified through targeted AA metabolism, were assessed in PC12 cells following oxygen-glucose deprivation (OGD) injury. In addition, the TLR4/NF-κB pathway was evaluated by western blot (WB). NXT administration substantially alleviated brain damage and colon injury by decreasing the infarction rate, neurological scores, LPS levels, and inflammatory factors, and increasing the expression of intestinal permeability protein. Transcriptomic analysis revealed that NXT regulated "inflammatory response," "Toll-like receptor signaling pathway,", and "NF-κB signaling pathway." Furthermore, WB confirmed that NXT inhibited the brain TLR4/NF-κB pathway. 16S rRNA sequencing indicated that NXT adjusted the intestinal microbiota composition and decreased the abundance of pathogenic bacteria, including Parasutterella_massiliensis and Ihubacter_excrementihominis. Targeted AA metabolism analysis demonstrated that NXT regulated the serum levels of serine, lysine, and proline in MCAO mice. Furthermore, serine, lysine, and proline inhibited the TLR4/NF-κB pathway to protect against OGD injury in PC12 cells. Our study indicates that NXT reduces the abundance of Parasutterella_massiliensis and Ihubacter_excrementihominis, while increasing the levels of serine, lysine, and proline. These changes are significantly associated with neuroinflammation. Furthermore, NXT alleviates IS-induced neuroinflammation by inhibiting the TLR4/NF-κB pathway. Importantly, our study provides novel insights into the mechanisms underlying NXT's therapeutic effects on IS.

Screening, identification, and application of anaerobic ammonia oxidizing bacteria in activated sludge systems: A comprehensive review.

Anaerobic ammonium oxidation (Anammox) has garnered significant attention due to its ability to eliminate the need for aeration and supplementary carbon sources in biological nitrogen removal process, relying on the capacity of anaerobic ammonium oxidizing bacteria (AnAOB) to directly convert ammonium and nitrite nitrogen into nitrogen gas. This review consolidates the latest advancements in AnAOB research, outlining the mechanisms and enzymatic processes of Anammox, and summarizing the molecular biological techniques used for studying AnAOB, such as 16s rRNA sequencing, qPCR, and metagenomic sequencing. Additionally, it also overviews the currently identified AnAOB species and their distinct metabolic traits, while consolidating strategies to improve their performance. It further delineates coupled processes that utilize Anammox technology, offering practical insights for process selection. Eventually, the review concludes by suggesting future research directions and highlighting critical areas for further investigation. This review serves as a theoretical reference for the enrichment and cultivation of AnAOB, environmental impact management, and the selection of effective treatment processes.

Abstract TMP116: Gut-derived extracellular vesicles promote neurovascular damage and cognitive impairment in diabetic mice

Background and Purpose: Gut microbiota dysfunction is associated with diabetic cognitive impairment (DCI). However, the mechanisms underlying the interaction of gut microbiota dysbiosis and DCI remain poorly understood. We tested the hypothesis that extracellular vesicles generated by diabetic gut microbiota exacerbate DCI by promoting the impairment of cerebral vascular function. Methods: Gut-EVs from the stools of male non-diabetic dm (dm-gut-EVs) and diabetic (db/db mice) with DCI (db-gut-EVs) mice at 20 weeks of age (20W) were isolated and characterized by means of ultracentrifugation and 16S rRNA sequencing, respectively. Given that db/db mice develop cognitive deficits at 20W, prediabetic db/db mice at 8 weeks of age (8W) were treated with gut-EVs at a dose of 1x10 10 particles/injection intravenously twice a week for 12 weeks. Cognitive performance was assessed using a battery of behavioral tests. Results: 16S rRNA analysis revealed significant alterations in the microbiota composition of db-gut-EVs derived from 20W db/db mice with DCI compared to dm-gut-EVs (n=5/group). Db/db mice treated with db-gut-EVs extracted at 20W, but not with dm-gut-EVs, exhibited a significant decline in learning and memory function, as assayed by the Novel object recognition, Social recognition memory, and Morris water maze assay, starting at 16W and worsening at 20W, compared to db/db mice treated with saline (n=10/group). Additionally, db/db mice treated with db-gut-EVs exhibited increased cerebral vascular thrombosis (18±2 vs 11±2 Fibrin+ vessels/mm 2 in saline, p<0.05, n=5/group), whereas db/db mice treated with dm-gut-EVs showed a reduction of thrombosis (5±0.5 Fibrin+ vessels/mm 2 , p<0.05). In vitro, treatment of human cerebral endothelial cells (hCECs) with db-gut-EVs significantly (p<0.05) upregulated pro-coagulation and inflammatory proteins, including plasminogen activator inhibitor-1 (PAI-1), tissue factor (TF), NF-κB, and intercellular adhesion molecule 1 (ICAM-1), while reducing tight junction protein ZO-1 expression. Conclusions: Our findings indicate that db-gut-EVs promote DCI by inducing cerebral vascular damage, and underscore a major role for gut microbiota-brain communication in the development of DCI.

Microbiome Stability Is Linked to Acropora Coral Thermotolerance in Northwestern Philippines.

Corals associate with a diverse community of prokaryotic symbionts that provide nutrition, antioxidants and other protective compounds to their host. However, the influence of microbes on coral thermotolerance remains understudied. Here, we examined the prokaryotic microbial communities associated with colonies of Acropora cf. tenuis that exhibit high or low thermotolerance upon exposure to 33°C (heated) relative to 29°C (control). Using 16S rRNA sequencing, we show that the microbial community structure of all A. cf. tenuis colonies was similar to each other at control temperature. Thermotolerant colonies, however, had relatively greater abundance of Endozoicomonas, Arcobacter, Bifidobacterium and Lactobacillus. At elevated temperature, only thermosensitive colonies showed a distinct shift in their microbiome, with an increase in Flavobacteriales, Rhodobacteraceae and Vibrio, accompanying a marked bleaching response. Functional prediction indicated that prokaryotic communities associated with thermotolerant corals were enriched for genes related to metabolism, while microbiomes of thermosensitive colonies were enriched for cell motility and antibiotic compound synthesis. These differences may contribute to the variable performance of thermotolerant and thermosensitive corals under thermal stress. Identification of microbial taxa correlated with thermotolerance provides insights into beneficial bacterial groups that could be used for microbiome engineering to support reef health in a changing climate.

Schisandrol B alleviates depression-like behavior in mice by regulating bile acid homeostasis in the brain-liver-gut axis via the pregnane X receptor.

Depression is a widely recognized neuropsychiatric disorder. Recent studies have shown a potential correlation between bile acid disorders and depression, highlighting the importance of maintaining bile acid balance for effective antidepressant treatment. Schisandrol B (SolB), a primary bioactive compound from Schisandra chinensis (Turcz.) Baill. or Schisandra sphenanthera Rehd.etWils, is pivotal in regulating bile acid homeostasis via pregnane X receptor (PXR) in cholestasis. However, the potential of SolB in alleviating depression-like symptoms, its pharmacological effects, and the underlying mechanisms remain to be fully elucidated. We confirmed the effect of SolB against depression induced by chronic restraint stress (CRS) and chronic unpredictable mild stress (CUMS) in mice. The role of SolB in bile acid homeostasis in depression was analyzed using the metabolomic. Gene analyses and 16S rRNA sequencing were employed to investigate the involvement of PXR. Experiments with Pxr-/- mice were conducted to confirm the essential role of the PXR pathway in SolB's antidepressant effects. SolB treatment significantly increased sucrose consumption in the SPT and the locomotor activity in the OFT, while decreasing immobility time in the FST and TST in mice exposed to CRS and CUMS. Additionally, SolB treatment significantly preserved the integrity of the dendritic spine, elevated synaptic protein PSD95 levels, and augmented CREB/BDNF expression. Metabolomic and gene analyses indicated that SolB treatment significantly facilitated bile acid metabolism, promoted intestinal bile acid efflux, decreased hippocampal levels of the secondary bile acids DCA and TLCA, and upregulated expression of the PXR target proteins CYP3A11, SULT2A1, MRP2, and OATP1B1 in the liver, and MRP2 and MDR1 in hippocampus, which are integral to bile acid homeostasis. 16S rRNA sequencing revealed that SolB reduced the abundance of the bile salt hydrolase (BSH)-producing bacteria Lactobacillus johnsonii and Bacteroides fragilis and subsequently decreased the production of TLCA and DCA. Moreover, SolB failed to protect against depression induced by CRS in Pxr-null mice, suggesting that the antidepressant effect of SolB was PXR-dependent. These results provide direct evidence of the antidepressant effect of SolB via activation of PXR to regulate bile acid homeostasis in the brain-liver-gut axis, suggesting that SolB may serve as a novel potential target for preventing and treating depression.

Potential effect of the gut microbiome on tumour response to anti-cancer treatment in patients diagnosed with pancreatic ductal adenocarcinoma.

757 Background: Chemotherapy is the standard of care for pancreatic ductal adenocarcinoma (PDAC), however, recent research has identified bacteria in the human gut microbiome that may influence patient response to chemotherapy. These bacteria are also present in faeces, and are thought to be representative of the bacteria in the pancreatic ductal system. Preliminary studies have suggested that patients with more advanced PDAC demonstrate lower levels of Firmicutes, and higher levels of Proteobacteria. Additionally, research has shown bacteria in the Firmicutes phylum possess several anti-cancer properties, which may improve patient treatment response, meanwhile, Gammaproteobacteria (Proteobacteria phylum), have been shown to attenuate gemcitabine efficacy and worsen treatment response. Methods: This prospective study involved 14 participants with locally advanced PDAC. Participants received combinations of Gemcitabine, Nab-Paclitaxel, and durvalumab (immunotherapy). Participant tumours were assessed every 8 weeks using radiological imaging according to RECIST v1.1, and serum CA19-9 levels were analysed monthly. Gut microbial profiling was completed on stool samples taken pre-treatment using PacBio HiFi full-length 16S rRNA sequencing. Results: 16S rRNA sequencing identified that of the 4 patients that died due to disease progression, 3 patients had a low Firmicutes abundance, and a high Proteobacteria abundance. The rother patient demonstrated low levels of Actinobacteriota and Bacteroidota, and a low bacterial diversity. One participant showed a significant increase in CA19-9 (1066.7%), and exhibited a low abundance of Actinobacteriota and Bacteroidota, a high abundance of Proteobacteria, and a low diversity. 5 participants demonstrated a significant treatment response (according to CA19-9 and RECIST analysis), with 4 patients showing a high Firmicutes abundance, high levels of Actinobacteriota or Bacteroidota, and low levels of Proteobacteria. The remaining patient demonstrated a low abundance of Firmicutes and Proteobacteria, yet, displayed the highest abundance of Actinobacteriota and Bacteroidota. Conclusions: This exploratory study suggests an association between microbial composition and treatment response, with Firmicutes potentially being associated with an improved treatment response, and Proteobacteria with a worsened response. We believe this study to be one of the first to explore correlation of microbiome with clinical treatment response in PDAC.

Molecular survey of Hepatozoon spp. and piroplasmids in rodents and marsupials from midwestern Brazil, with evidence of a novel Piroplasmida clade (“South American Rodentia”) in the echimyid rodent Thrichomys pachyurus

The order Piroplasmida (e.g., Babesia, Theileria, Cytauxzoon, and Rangelia) and suborder Adelorina (e.g., Hepatozoon) comprise protozoa of the phylum Apicomplexa, which are related to significant economic, veterinary, and medical concerns. This study aimed to investigate the molecular occurrence and evaluate the phylogenetic placement of the Hepatozoon and Piroplasmida agents in small mammals (rodents and marsupials) in midwestern Brazil. The maximum likelihood phylogenetic inference positioned the 18S ribosomal RNA (18S rRNA) sequences of Hepatozoon obtained from Hylaeamys megacephalus with those previously detected in Didelphis aurita from Brazil; however, the sequences of Hepatozoon retrieved from Nectomys rattus and Neacomys amoenus clustered in a sub-clade sister to a clade of sequences detected in small rodents from Brazil. Phylogenetic inference positioned the piroplasmid 18S rRNA sequences detected in Thrichomys pachyurus in a single sub-clade sister to a clade containing sequences previously detected in the Phyllostomidae bat Phyllostomus discolor from midwestern Brazil. In contrast, the piroplasmid cytochrome b mitochondrial gene (cytB) sequences obtained from T. pachyurus clustered into a single clade. In conclusion, a new host record is provided for Hepatozoon spp. from the rodent N. amoenus. Furthermore, this study expanded the Piroplasmida order diversity by identifying novel genotypes in T. pachyurus rodents, which were genetically related to the piroplasmid clade found in Neotropical bats and named herein the “South American Rodentia group.”

Differential Analysis of Fecal SCFAs and Their Contribution to Adipogenesis in UCP1 Knock-In Pigs

This study aimed to investigate the changes in fecal short-chain fatty acids (SCFAs) content in UCP1 knock-in pigs (KI pigs) and their effect on adipogenesis. Fecal samples from five 6-month-old wild-type (WT) and KI pigs were collected for targeted metabolomics and 16s rRNA sequencing analyses to identify differences in SCFAs and gut microbiota that may contribute to regulating fat deposition in pigs. The metabolome of pig fecal samples targeted for an analysis of SCFAs identified seven SCFAs, with caproic acid (except isovaleric acid) being the significantly different one. The results of the fecal 16s rRNA analysis demonstrated a notable reduction in the abundance of Streptococcus spp. in the KI pigs in comparison to the WT pigs, with a statistically significant difference. Correlation analyses demonstrated a statistically significant positive correlation between the abundance of Streptococcus spp. and SCFAs, as well as pig body weight and fatness. It was postulated that the reduction in SCFAs in the intestinal tracts of KI pigs may be associated with a reduction in Streptococcus spp. abundance. Compared to WT pigs, the concentration of fecal SCFAs in KI pigs was significantly reduced, which may be related to the decreased abundance of Streptococcus. The in vitro experiments showed that caproic acid could significantly enhance the differentiation efficiency of porcine SVF cells into mature adipocytes by activating the FFAR4 gene.

Analysis of gut and mucosal microbiomes in patients with extrahepatic cholangiocarcinoma.

620 Background: Cholangiocarcinoma is an aggressive malignancy with a poor prognosis. While gut microbial dysbiosis is linked to various diseases, including biliary disorders and cancer, its association with cholangiocarcinoma remains unclear. Methods: This study compared the mucosal and gut microbiomes of patients with extrahepatic cholangiocarcinoma (n = 21) to those with cholecystitis (n = 21) and healthy individuals (n = 28). Mucosal microbiomes were collected from cancer lesions and gallbladders, with fecal samples obtained from 31 participants. The 16S rRNA gene (V3 and V4 region) was sequenced using the Illumina MiSeq platform and analyzed with QIIME 2. Results: 16S rRNA sequencing revealed Proteobacteria as the dominant taxon in the cancer cohort, with Klebsiella, Aeromonas, Staphylococcus, Fusobacterium, and Haemophilus also enriched. In contrast, Firmicutes dominated in the cholecystitis and control cohorts. β-diversity analysis highlighted significant differences between cohorts. Elevated levels of bile acids, particularly chenodeoxycholic acid and ursodeoxycholic acid, were observed in the cancer cohort and positively correlated with Proteobacteria, Aeromonas, Enterobacter, and Enterococcus. Conclusions: These findings suggest that microbiome dysbiosis contributes to cholangiocarcinoma development.

Exploring Bacterial Communities and Functions in Phytophagous Halyomorpha halys and Predatory Arma chinensis

The phytophagous Halyomorpha halys (Hemiptera: Pentatomidae) is a global agricultural pest that damages many crops. Conversely, the predatory Arma chinensis (Hemiptera: Pentatomidae) shows promise as a biological control agent against lepidopteran and coleopteran pests. Halyomorpha halys and A. chinensis are closely related species with different feeding habits, as confirmed via genomic and morphological analyses. However, no study investigating the implications of these differences has been reported. Herein, 16S rRNA sequencing technology was employed to analyze the microbiota diversity and function in different tissues (salivary glands, gut, sperm, and ovaries) of H. halys and A. chinensis to elucidate these differences from a microbial perspective. Additionally, the adult male-to-female ratio in A. chinensis organs was statistically similar, while that in H. halys was not. Based on the dominance of the symbionts in the two bug species, we inferred that Sodalis is involved in reproduction and digestion in A. chinensis, while Spiroplasma and Pantoea play essential roles in H. halys reproduction and digestion. We analyzed the data on the microbial diversity of two bug species, laying a foundation for further understanding microbial symbiosis in A. chinensis and H. halys, which may inform the development of biological control strategies.