Differences In Microbial Composition Research Articles

Stability in fecal metabolites amid a diverse gut microbiome composition: a one-month longitudinal study of variability in healthy individuals

ABSTRACT An extensive network of microbial-host interactions exists in the gut, making the gut microbiome a complex ecosystem to untangle. The microbial composition and the fecal metabolites are important readouts to investigate intricate microbiota-diet-host interplay. However, this ecosystem is dynamic, and it is of interest to understand the degree and timescale of changes occurring in the gut microbiota, during disease as well as in healthy individuals. Cross-sectional study design is often used to investigate the microbiome, but this design provides a static snapshot and cannot provide evidence on the dynamic nature of the gut microbiome. Longitudinal studies are better suited to extrapolate causation in a study or assess changes over time. This study investigates longitudinal change in the gut microbiome and fecal metabolites in 14 healthy individuals with weekly sampling over a period of one-month (four time points), to elucidate the temporal changes occurring in the gut microbiome composition and fecal metabolites. Utilizing 16S rRNA amplicon sequencing for microbiome analysis and NMR spectroscopy for fecal metabolite characterization, we assessed the stability of these two types of measurable parameters in fecal samples during the period of one month. Our results show that the gut microbiome display large variations between healthy individuals, but relatively lower within-individual variations, which makes it possible to uniquely identify individuals. The fecal metabolites showed higher stability over time compared to the microbiome and exhibited consistently smaller variations both within and between individuals. This relative higher stability of the fecal metabolites suggests a balanced, consistent output even amid individual’s differences in microbial composition and they can provide a viable complementary readout to better understand the microbiome activity.

Gut Microbiota Composition Positively Correlates with Sports Performance in Competitive Non-Professional Female and Male Runners

There is still a pressing need for further investigation to bridge the gap in understanding the differences in gut microbiota composition between female runners and their male counterparts. We aimed to determine the gut microbiota composition in competitive non-professional female and male runners and to correlate the gut bacteria to performance. Our study included 40 subjects, of which 22 were runners (13 males and 9 females) and 18 control subjects (9 males and 9 females, representing the general population who perform light physical activity with a weekly running volume of ≤5 km per week). Fecal specimens were collected and analyzed for taxonomic profiling to compare species’ relative abundances between males and females based on the results of 16SrRNA analysis. Bacterial alpha and beta diversity were assessed to determine the differences in microbial composition between runners and controls, and between sexes. Each participant underwent a maximal oxygen consumption test and a time-to-exhaustion test at 85% of the measured VO2max. Blood lactate was collected every 5 min during the tests. Bacterial alpha diversity showed a significant difference (p = 0.04) between runners and controls. Taxonomic analysis of gut microbiota composition showed a lower Enterobacteriaceae abundance and a higher Methanosphaera abundance in runners compared with the control group. Ten different bacteria (Methanosphaera, Mitsuokella, Prevotellaceae, Megamonas, Rothia, Oscillospira, Bacteroides, Odoribacter, Blautia massiliensis, Butyricicoccus_pullicaecorum) were positively correlated with exercise (VO2max, lactate blood levels, time to exhaustion, and weekly training volume). We found no significant differences in the gut microbiota composition between male and female runners. Gut microbiota composition positively correlates with sports performance in competitive non-professional female and male runners, and female runners show similar gut microbiome diversity to male runners.

Gut Microbiota and Parkinson’s disease - a prospective analysis of the FINRISK 2002 Study

Abstract Background Parkinson’s disease (PD) is a neurodegenerative movement disorder with mainly unknown etiology. Constipation is a common symptom, and changes in gut microbiota may play role in PD pathogenesis. Previous studies exploring microbial associations to PD have been mostly cross-sectional, and the role of microorganisms in PD etiology remains unclear. Thus, we examined the association between microbiota features and incident PD in a prospective cohort design. Methods In the FINRISK 2002 Study, 7231 participants gave a stool sample that underwent shotgun metagenomic sequencing. Participants with missing stool sample, incomplete covariate data, pregnancy, antibiotic use, and prevalent cases were excluded (final n = 5562). Cox regression models, adjusted for age, sex, education, smoking, coffee consumption, diabetes, cardiovascular events, and constipation, were used to assess associations between incident PD and microbiota features, ie. alpha diversity (the number of different species present in a sample), beta diversity (the differences in microbial composition between individuals), and abundance of 381 core taxa (compositional detection rate of at least 0.1% and a prevalence of 1%). 120 incident cases of PD, identified through register linkage, occurred during a median follow-up of 17.8 years. Results In the multivariate models, PD incidence was not associated with the Shannon index, a measure on alpha diversity, (p-value 0.81), or with the ten first principal component axes in beta diversity analysis (p-values ranging between 0.49-0.91). In permutational analysis, PD did not explain differences in the composition of the gut microbiota (R2 <0.001, p-value 0.46)). None of the core species were associated with PD incidence (all FDR-corrected p-values > 0.05). Conclusions This prospective study showed no support for an association between gut microbiota features and incident PD. Key messages • Previous findings associating gut microbiota with PD may be due to the cross-sectional design, ie. PD affecting the gut microbiota. • Suggestions to screen gut bacteria to identify people at high risk of Parkinson’s disease are vastly premature as the scientific evidence is inconclusive.

Probiotic Mixtures Consisting of Representatives of Bacteroidetes and Selenomonadales Increase Resistance of Newly Hatched Chicks to Salmonella Enteritidis Infection

There are extensive differences in the caecal microbiota of chicks from hatcheries and those inoculated with faecal material from adult hens. Besides differences in microbial composition, the latter chickens are highly resistant to Salmonella Enteritidis challenges, while the former are susceptible. In this study, we tested whether strains from genera Bacteroides, Megamonas, or Megasphaera can increase chicken resistance to Salmonella and Campylobacter jejuni when defined microbial mixtures consisting of these bacterial genera are administered. Mixtures consisting of different species and strains from the above-mentioned genera efficiently colonised the chicken caecum and increased chicken resistance to Salmonella by a factor of 50. The tested mixtures were even more effective in protecting chickens from Salmonella in a seeder model of infection (3–5 log reduction). The tested mixtures partially protected chickens from C. jejuni infection, though the effect was lower than that against Salmonella. The obtained data represent a first step for the development of a new type of probiotics for poultry.

Impact of propionic acid-rich diets on microbial composition of the murine gut microbiome

Propionic acid (PPA), an anti-fungal agent and common food additive, has been shown to induce atypical neurodevelopment in mice, accompanied by gastrointestinal dysfunction potentially resulting from gut dysbiosis. A putative association between dietary PPA exposure and gut dysbiosis is suggested but has not been explored directly. Here, we investigated PPA-associated alteration in gut microbial composition that may result in dysbiosis. Using long-read metagenomic sequencing, gut microbiomes of mice fed an untreated (n=9) or PPA-rich (n=13) diet were sequenced to assess differences in microbial composition and bacterial metabolic pathways. Dietary PPA was associated with an increased abundance of notable taxa, including several species of Bacteroides, Prevotella, and Ruminococcus, whose member species have previously been associated with PPA production. Microbiomes of PPA exposed mice also possessed a greater abundance of pathways related to lipid metabolism and steroid hormone biosynthesis. Our findings demonstrate PPA’s effect in altering the gut microbiota and associated metabolic pathways. These observed changes highlight how preservatives listed as safe for consumption may affect gut microbiome composition with implications for one’s health.

Parvimonas micra forms a distinct bacterial network with oral pathobionts in colorectal cancer patients

BackgroundMounting evidence suggests a significant role of the gut microbiota in the development and progression of colorectal cancer (CRC). In particular, an over-representation of oral pathogens has been linked to CRC. The aim of this study was to further investigate the faecal microbial landscape of CRC patients, with a focus on the oral pathogens Parvimonas micra and Fusobacterium nucleatum.MethodsIn this study, 16S rRNA sequencing was conducted using faecal samples from CRC patients (n = 275) and controls without pathological findings (n = 95).ResultsWe discovered a significant difference in microbial composition depending on tumour location and microsatellite instability (MSI) status, with P. micra, F. nucleatum, and Peptostreptococcus stomatis found to be more abundant in patients with MSI tumours. Moreover, P. micra and F. nucleatum were associated with a cluster of CRC-related bacteria including Bacteroides fragilis as well as with other oral pathogens such as P. stomatis and various Porphyromonas species. This cluster was distinctly different in the control group, suggesting its potential linkage with CRC.ConclusionsOur results suggest a similar distribution of several CRC-associated bacteria within CRC patients, underscoring the importance of considering the concomitant presence of bacterial species in studies investigating the mechanisms of CRC development and progression.

Dynamic changes in dissolved oxygen concentration, microbial communities, and volatile compounds during industrial oak-barrel fermentation of Sauvignon Blanc wine

Oak-barrel fermentation is used in white wine production to enhance aroma and flavor complexity. However, the dynamics of microbial communities and their impact on the formation of flavor compounds during barrel fermentation remain unclear. This study investigated the changes in dissolved oxygen concentrations, microbial communities, and volatile compounds during Sauvignon Blanc wine fermentation in various oak barrels (new and two-year-old Francois Freres and new Taransaud) and stainless-steel tanks. We found that oak barrels had higher dissolved oxygen levels than steel tanks, with new barrels exhibiting higher levels than the old ones during fermentation. The dominant bacterial genera across all the vessels during the fermentation included Ralstonia, Pantoea, Gluconobacter, and Mesorhizobium, whereas the dominant fungal genera were Saccharomyces, Aspergillus, Alternaria, and Aureobasidium. The fermentation environment altered the microbial composition as the fermentation progressed in various vessels. Compared with steel tanks, difference in microbial composition between oak barrels was less significant. The new oak barrels increased the levels of esters, alcohols, and acids in the wine, while only minor differences were observed between old barrels and steel tanks. Correlation analysis showed that Ralstonia, Gluconobacter, Mesorhizobium, and Saccharomyces were positively correlated with the production of wine volatiles. Structural equation modeling indicated the interactions between dissolved oxygen, microbial communities, and wine aromas. The impact of dissolved oxygen on fungal communities during fermentation differed significantly between new and old oak barrels, indirectly influencing aroma. Conversely, in stainless-steel tanks, dissolved oxygen weakly influenced the bacterial and fungal communities, with the influence on wine aroma primarily dependent on the fungal communities. These findings provide valuable insights for optimizing the Sauvignon Blanc wine fermentation in oak barrels

Comparing microbial communities in mucilage and seawater samples: Metagenomic insights into mucilage formation in the Marmara Sea.

Marine environments are subject to various naturally occurring phenomena, including marine snow and mucilage. In 2021, the rapid emergence of mucilage in the Marmara Sea raised concerns about its environmental impact. This study investigates the microbial communities in mucilage and seawater samples from the Marmara Sea using metagenomic-scale comparative analyses. The results indicate significant differences in microbial composition and diversity, with mucilage samples showing higher levels of polysaccharide biosynthesis-related enzymes. Over 50% of reads in mucilage samples remained unclassified (dark matter), highlighting unknown microbial taxa. Clean seawater was characterized by a higher presence of Euryarchaeota, Proteobacteria, and Rhodothermaeota, while Chlamydiae and Fusobacteria were dominant in mucilage. The study underscores the necessity for comprehensive metagenomic analyses to understand microbial roles in mucilage formation and persistence. Early detection of microbial shifts could serve as a warning system for mucilage outbreaks, aiding in the development of management strategies.

Mucosal microbiota characterization in gastric cancer identifies immune-activated-related transcripts relevant gastric microbiome signatures.

Tumor microenvironment (TME) immune cells and gastric mucosal microbiome constitute two vital elements of tumor tissue. Increasing evidence has elucidated their clinicopathological significance in predicting outcomes and therapeutic efficacy. However, comprehensive characterization of immune cell-associated microbiome signatures in the TME is still in the early stages of development. Here, we characterized the gastric mucosa microbiome and its associations with immune-activated related transcripts (IATs) in 170 GC tumor tissues and matched non-tumor tissues using 16s rRNA gene sequencing and quantitative reverse transcription-PCR. Microbial diversity and richness were significantly higher in GC tumor tissues than in non-tumor tissues. Differences in microbial composition between the groups were evident, with Firmicutes, Proteobacteria, Bacteroidota, Campilobacterota, Actinobacteria, Fusobacteriota, Verrucomicrobiota, Acidobacteriota, and Cyanobacteria being the dominant phyla in the gastric mucosal microbiota. Microbial interaction network analysis revealed distinctive centralities of oral bacteria (such as Fusobacterium, Porphyromonas, Prevotella, etc.) in both tumor and normal mucosae networks, suggesting their significant influence on GC microbial ecology. Furthermore, we analyzed the expression of IATs (CXCL9, CXCL10, GZMA, GZMB, PRF1, CD8A, IFNG, TBX2, and TNF) and characterized IAT-relevant gastric microbiome signatures in GC patients. Our results showed that the expression of CXCL9, CXCL10, GZMA, GZMB, PRF1 and IFNG was significantly higher in tumor tissues than in adjacent normal tissues in GC patients. Notably, high expression of IATs in tumor tissues was associated with improved survival in GC patients and could serve as a powerful predictor for disease-free survival. Additionally, analysis of IAT levels and mucosal microbiota diversity revealed a correlation between higher IAT expression and increased microbiota richness and evenness in the IATs high group, suggesting potential interactions between mucosal microbiota and tumor immunopathology. Spearman correlation analysis showed positive associations between IAT expression and specific mucosal bacterial species. Notably, Akkermansia muciniphila demonstrated potential involvement in modulating GZMB expression in the GC mucosal microenvironment. These findings underscore the importance of mucosal microbiota alterations in GC and suggest potential therapeutic targets focusing on modulating the tumor microbiota for improved clinical outcomes. The detailed characterization of these elements has profound implications for both treatment and survival prediction in GC. We observed that microbial diversity and richness were significantly higher in GC tumor tissues compared to non-tumor tissues. These differences highlight the unique microbial landscape of GC tumors and suggest that the microbiome could influence tumor development and progression. Importantly, our study demonstrated that high expression levels of IATs in GC tumor tissues were associated with improved patient survival. This suggests that IATs not only reflect immune activation but also serve as valuable biomarkers for predicting disease-free survival. The potential of IATs as predictive markers underscores their utility in guiding therapeutic strategies and personalizing treatment approaches. Moreover, the correlation between higher IAT expression and increased microbiota richness and evenness suggests that a diverse and balanced microbiome may enhance immune responses and contribute to better clinical outcomes. These findings highlight the critical need to consider mucosal microbiota alterations in GC management. Targeting the tumor microbiota could emerge as a promising therapeutic strategy, potentially leading to more effective treatments and improved patient outcomes. Understanding and modulating the microbiome's role in GC opens new avenues for innovative therapeutic interventions and personalized medicine.

The Hidden Relationship between Intestinal Microbiota and Immunological Modifications in Preeclampsia Pathogenesis.

Preeclampsia is a multifactorial gestational syndrome characterized by increased blood pressure during pregnancy associated with multiorgan involvement. The impact of this disease on maternal and neonatal health is significant, as it can lead to various fetal comorbidities and contribute to the development of maternal comorbidities later in life. Consistent evidence has shown that the microbiota acts as a regulator of the immune system, and it may, therefore, influence the development of preeclampsia by modulating immune factors. This narrative review aims to investigate the role of the immune system in the pathogenesis of preeclampsia and to summarize the most recent literature on the possible link between preeclampsia and alterations in the intestinal microbiota. To this end, we conducted a literature search, aiming to perform a narrative review, on PubMed and Embase from January 1990 to March 2024, focusing on the latest studies that highlight the main differences in microbial composition between patients with and without preeclampsia, as well as the effects of microbial metabolites on the immune system. From the review of 28 studies assessing the intestinal microbiota in preeclamptic women, preeclampsia could be associated with a state of dysbiosis. Moreover, these patients showed higher plasmatic levels of endotoxin, pro-inflammatory cytokines, and T helper 17 cells; however, the findings on specific microbes and metabolites that could cause immune imbalances in preeclampsia are still preliminary.

Characterization of Intestinal Flora in Osteoporosis Patients Based on 16S rDNA Sequencing.

This study investigated differences in gut flora between osteoporosis (OP) patients and healthy individuals using 16S rDNA sequencing. The correlation between differential flora abundance and bone mineral density (BMD) was analyzed, and key flora and potential mechanisms associated with OP were explored. Forty-three OP patients and twenty-four healthy volunteers were recruited. Gender, age, height, weight, and BMD data were collected. DNA from fecal samples was extracted for 16S rDNA sequencing. The Kruskal-Wallis test assessed differences in gut flora composition, while LEfSe analysis identified significant flora. Spearman correlation analysis examined the relationship between differential flora and BMD, and PICRUSt predicted pathways involved in OP. Significant differences in microbial composition were found between the two groups. Klebsiella, Escherichia-Shigella, and Akkermansia were biomarkers in OP patients, with Faecalibacterium in the healthy group. Akkermansia abundance negatively correlated with lumbar BMD, while Klebsiella and Escherichia-Shigella negatively correlated with femoral neck and hip BMD. Faecalibacterium showed a positive correlation with BMD. Functional predictions indicated differences in metabolism-related pathways between the groups. Gut flora differed significantly between OP patients and healthy individuals. Akkermansia, Klebsiella, and Escherichia-Shigella could serve as diagnostic biomarkers for OP, highlighting the potential of gut flora in OP diagnosis and treatment.

Alterations of gut microbiome in eosinophilic chronic rhinosinusitis.

A growing body of evidence has elucidated that the gut microbiota has a crucial impact on the pathophysiological process of atopic diseases. Eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP) is a local atopic disease of the systemic immune response. Alterations in the gut microbiome in eCRSwNP patients remain largely undefined. 16S rRNA gene sequencing was performed in a cross-sectional study of 17 eCRSwNP patients, 9 noneCRSwNP patients and 13 healthy controls, and gut microbiota DNA sequencing between each pair of groups was compared using bioinformatic methods. Compared with that of healthy controls, the gut microbiomes of eCRSwNP patients were characterised by a distinct overall microbial composition. However, no significant differences were found in the alpha diversity of the gut microbiota between patients and healthy controls. The distinct differences in microbial composition were significantly correlated with the severity of disease. At the genus level, the abundance of Faecalibacterium positively correlated with Lund-Mackay CT scores. Similarly, the abundance of Turicibacter positively correlated with the percentage of tissue eosinophils. We found alterations in the gut microbiome in eCRSwNP patients, and the alterations in the gut microbiome were correlated with the severity of disease.

Mosquitoes reared in distinct insectaries within an institution in close spatial proximity possess significantly divergent microbiomes.

The microbiome affects important aspects of mosquito biology and differences in microbial composition can affect the outcomes of laboratory studies. To determine how the biotic and abiotic conditions in an insectary affect the composition of the bacterial microbiome of mosquitoes we reared mosquitoes from a single cohort of eggs from one genetically homogeneous inbred Aedes aegypti colony, which were split into three batches, and transferred to each of three different insectaries located within the Liverpool School of Tropical Medicine. Using three replicate trays per insectary, we assessed and compared the bacterial microbiome composition as mosquitoes developed from these eggs. We also characterised the microbiome of the mosquitoes' food sources, measured environmental conditions over time in each climate-controlled insectary, and recorded development and survival of mosquitoes. While mosquito development was overall similar between all three insectaries, we saw differences in microbiome composition between mosquitoes from each insectary. Furthermore, bacterial input via food sources, potentially followed by selective pressure of temperature stability and range, did affect the microbiome composition. At both adult and larval stages, specific members of the mosquito microbiome were associated with particular insectaries; and the insectary with less stable and cooler conditions resulted in slower pupation rate and higher diversity of the larval microbiome. Tray and cage effects were also seen in all insectaries, with different bacterial taxa implicated between insectaries. These results highlight the necessity of considering the variability and effects of different microbiome composition even in experiments carried out in a laboratory environment starting with eggs from one batch; and highlights the impact of even minor inconsistencies in rearing conditions due to variation of temperature and humidity.

Exploring the Microbial Diversity and Composition of Three Cigar Product Categories

Cigars and cigarillos are emerging as popular tobacco alternatives to cigarettes. However, these products may be equally harmful to human health than cigarettes and are associated with similar adverse health effects. We used 16S rRNA gene amplicon sequencing to extensively characterize the microbial diversity and investigate differences in microbial composition across 23 different products representing three different cigar product categories: filtered cigar, cigarillo, and large cigar. High throughput sequencing of the V4 hypervariable region of the 16 s rRNA gene revealed 2124 Operational Taxonomic Units (OTUs). Our findings showed that the three categories of cigars differed significantly in observed richness and Shannon diversity, with filtered cigars exhibiting lower diversity compared to large cigars and cigarillos. We also found a shared and unique microbiota among different product types. Firmicutes was the most abundant phylum in all product categories, followed by Actinobacteria. Among the 16 genera shared across all product types were Bacillus, Staphylococcus, Pseudomonas, and Pantoea. Nine genera were exclusively shared by large cigars and cigarillos and an additional thirteen genera were exclusive to filtered cigars. Analysis of individual cigar products showed consistent microbial composition across replicates for most large cigars and cigarillos while filtered cigars showed more inter-product variability. These findings provide important insights into the microbial diversity of the different cigar product types.

Analysis of nasopharyngeal microbiota revealing microbial disturbance associated with ovine respiratory complex

The ovine respiratory complex (ORC) is a complex respiratory disease process in ovine causing a significant health concern with substantial morbidity and mortality. It poses a significant threat of impacting animal health, leading to severe health consequences and considerable economic loss. Research on the upper respiratory tract (URT) microbiota is critical for offering insights into pathogenesis, prevention, and treatment strategies of ORC. The goal of this study is to compare the nasopharyngeal microbiota of clinically healthy Hu sheep (Group H) and sheep with ORC (Group P). The 16S rDNA gene amplicon high-throughput sequencing technique was applied to identify the microbial composition in the nasopharyngeal samples. The results showed that there was no significant difference in the microbiota diversity and richness between ORC and healthy sheep. However, there were significant differences in microbial composition, such as the relative abundance of Enterobacteriaceae, Moraxellaceae, Pasteurellaceae, and Streptococcaceae between the two groups. The abundance of aerobes in sheep with ORC increased significantly, while the abundance of anaerobes and facultative anaerobes decreased significantly. There were also differences in the taxa phenotypes associated with biofilm forming, mobile element-containing, oxidative stress-tolerance, and potential pathogens between the two groups. Our study showed the nasopharyngeal microbiota composition and its associated shifts between clinically healthy sheep and ORC sheep in China. These findings suggest that shifts in the nasopharyngeal microbiota could be a contributing factor to the pathogenesis of ORC, offering a potential avenue for the development of targeted interventions and treatments for this condition in sheep.

Evaluating urine volume and host depletion methods to enable genome-resolved metagenomics of the urobiome.

The gut microbiome has emerged as a clear player in health and disease, in part by mediating host response to environment and lifestyle. The urobiome (microbiota of the urinary tract) likely functions similarly. However, efforts to characterize the urobiome and assess its functional potential have been limited due to technical challenges including low microbial biomass and high host cell shedding in urine. Here, to begin addressing these challenges, we evaluate urine sample volume (100 ml - 5 mL), and host DNA depletion methods and their effects on urobiome profiles in healthy dogs, which are a robust large animal model for the human urobiome. We collected urine from seven dogs and fractionated samples into aliquots. One set of samples was spiked with host (canine) cells to model a biologically relevant host cell burden in urine. Samples then underwent DNA extraction followed by 16S rRNA gene and shotgun metagenomic sequencing. We then assembled metagenome assembled genomes (MAGs) and compared microbial composition and diversity across groups. We tested six methods of DNA extraction: QIAamp BiOstic Bacteremia (no host depletion), QIAamp DNA Microbiome, Molzym MolYsis, NEBNext Microbiome DNA Enrichment, Zymo HostZERO, and Propidium Monoazide. In relation to urine sample volume, 3 3.0 mL resulted in the most consistent urobiome profiling. In relation to host depletion, individual (dog) but not extraction method drove overall differences in microbial composition. DNA Microbiome yielded the greatest microbial diversity in 16S rRNA sequencing data and shotgun metagenomic sequencing data, and maximized MAG recovery while effectively depleting host DNA in host-spiked urine samples. As proof-of-principle, we then mined MAGs for core metabolic functions and environmental chemical metabolism. We identified long chain alkane utilization in two of the urine MAGs. Long chain alkanes are common pollutants that result from industrial combustion processes and end up in urine. This is the first study, to our knowledge, to demonstrate environmental chemical degradation potential in urine microbes through genome-resolved metagenomics. These findings provide guidelines for studying the urobiome in relation to sample volume and host depletion, and lay the foundation for future evaluation of urobiome function in relation to health and disease.

Adult Outpatients with Long COVID Infected with SARS-CoV-2 Omicron Variant. Part 1: Oral Microbiota Alterations

BackgroundMany individuals experience long COVID after SARS-CoV-2 infection. As microbiota can influence health, it may change with COVID-19. This study investigated differences in oral microbiota between COVID-19 patients with and without long COVID. MethodsBased on a prospective follow-up investigation, this nested case-control study evaluated the differences in oral microbiota in individuals with and without long COVID (Symptomatic and Asymptomatic groups), which were assessed by 16S rRNA sequencing on tongue coating samples. A predictive model was established using machine learning based on specific differential microbial communities. ResultsOne-hundred-and-eight patients were included (n=54 Symptomatic group). The Symptomatic group had higher Alpha diversity indices (observed_otus, Chao1, Shannon, and Simpson indices), differences in microbial composition (Beta diversity), and microbial dysbiosis with increased diversity and relative abundance of pathogenic bacteria. Marker bacteria (c__Campylobacterota, o__Coriobacteriales, o__Pseudomonadales, and o__Campylobacterales) were associated with long COVID by linear discriminant analysis effect size and receiver operating characteristic curves (AUC 0.821). ConclusionThere were distinct variations in oral microbiota between COVID-19 patients with and without long COVID. Changes in oral microbiota may indicate long COVID.

Meta-analysis identifies common gut microbiota associated with multiple sclerosis

BackgroundPrevious studies have identified a diverse group of microbial taxa that differ between patients with multiple sclerosis (MS) and the healthy population. However, interpreting findings on MS-associated microbiota is challenging, as there is no true consensus. It is unclear whether there is gut microbiota commonly altered in MS across studies.MethodsTo answer this, we performed a meta-analysis based on the 16S rRNA gene sequencing data from seven geographically and technically diverse studies comprising a total of 524 adult subjects (257 MS and 267 healthy controls). Analysis was conducted for each individual study after reprocessing the data and also by combining all data together. The blocked Wilcoxon rank-sum test and linear mixed-effects regression were used to identify differences in microbial composition and diversity between MS and healthy controls. Network analysis was conducted to identify bacterial correlations. A leave-one-out sensitivity analysis was performed to ensure the robustness of the findings.ResultsThe microbiome community structure was significantly different between studies. Re-analysis of data from individual studies revealed a lower relative abundance of Prevotella in MS across studies, compared to controls. Meta-analysis found that although alpha and beta diversity did not differ between MS and controls, a higher abundance of Actinomyces and a lower abundance of Faecalibacterium were reproducibly associated with MS. Additionally, network analysis revealed that the recognized negative Bacteroides-Prevotella correlation in controls was disrupted in patients with MS.ConclusionsOur meta-analysis identified common gut microbiota associated with MS across geographically and technically diverse studies.

Chloroquine Downregulation of Intestinal Autophagy Changed Intestinal Microbial Community Compositions and Metabolite Profiles in Piglets.

Our previous study demonstrated that moderate inhibition of intestinal autophagy was beneficial to alleviate early weaning stress in piglets, but the detailed mechanism behind this was unclear. Microbiota-mediated enterocyte autophagy helps maintain intestinal homeostasis. This study investigated the effects of inhibition or activation of autophagy in intestinal microbial community compositions and metabolite profiles in piglets. Eighteen 24-day-old weaned piglets were divided into three groups (each treatment of six piglets) and treated daily with rapamycin (RAPA), chloroquine (CQ) or a control volume of normal saline (CON group). Before the formal trial, the piglets were allowed to acclimatize for 3 days, and then the trial period was 14 days. Collected samples from the ileum and colon underwent 16S rRNA gene sequencing and metabolite analysis. Significant differences in microbial composition were observed in both the ileum and colon of the RAPA and CQ groups compared to the CON group (p < 0.05). In addition, the relative levels of abundance of Peptostreptococcus, Fusobacterium, Dialister, Selenomonas and Oceanobacillus in the ileum and Porphyromonas, Bacteroides, unidentified_Lachnospiraceae, Akkermansia, Sharpea, Peptococcus, Pseudoalteromonas, Peptoclostridium and unidentified_Acidobacteria in the colon were improved in piglets fed the RAPA diet, whereas the relative levels of abundance of Turicibacter, Rickettsiella and Sarcina in the ileum and Roseburia and Kroppenstedtia in the colon were enhanced in the CQ group (p < 0.05). Meanwhile, metabolomic analysis showed that there were significant differences in metabolites among all groups (p < 0.05), and KEGG enrichment analysis revealed that differential metabolites were mainly enriched in the ABC transporters and biosynthesis of amino acids pathways. Furthermore, these metabolites were closely related to differential microorganisms (p < 0.05). Overall, autophagy inhibition regulates the composition of intestinal microorganisms and their metabolites, and these differential metabolites are significantly correlated with differential intestinal microorganisms, which may in turn affect the production performance of weaned piglets.

Profiling of bacterial community’s dynamics inhibiting the intestinal tract of broiler chickens growing in naturally ventilated house

An experiment was conducted to evaluate the relative abundance of gastrointestinal microbial structures in different gut sections of Cobb500 broiler chickens reared in naturally ventilated houses and fed a standard diet for 35 days under the ambient environment of Oman. In this research, sequences from 1,179,068 16S rDNA analyses were grouped into 253 operational taxonomic units with a sequence similarity threshold of 97%. These units revealed the presence of seven phyla and twenty-six families. Firmicutes were found to be the dominant phylum in the duodenum (96.4%), jejunum (88.8%), ileum (96.8%), and cecum (96.8%). In contrast, Tenericutes and Thermi were the least prevalent phyla across these gut regions, accounting for between 0.01% and 0.12% of the total sequences. Actinobacteria, Bacteroidetes, and Cyanobacteria showed higher prevalence in the cecum (accounted for 6.59%, 7.42%, and 7.50%, respectively) than in duodenum, jejunum, and ileum. Lactobacillaceae were notably observed as the predominant family in the four gut segments, accounting for 73.87% in the duodenum, 43.30% in the jejunum, 77.81% in the ileum, and 46.30% in the caecum, collectively comprising a substantial portion of the sequencing data. Lachnospiraceae and Ruminococcaceae emerged as dominant families, comprising 28.61% and 30.8% of the sequencing data across all four intestinal sections, respectively. Statistical analysis of the 16S rDNA libraries showed that each section of the intestine contains a unique bacterial community with an increase in bacterial diversity parallel to age increase. The study's findings reveal the temporal dynamics of the chicken's gut microbiota in a naturally ventilated housing environment. The results obtained provide a unique perspective on the diversity of bacterial communities, highlighting significant differences in microbial composition across different segments of the intestine and offering practical insights for the management of broiler chicken health.