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Shock (Augusta, Ga.) Jan 2021Intra-abdominal hypertension (IAH), the leading complication in the intensive care unit, significantly disturbs the gut microbial composition by decreasing the relative...
Prevention of Severe Intestinal Barrier Dysfunction Through a Single-Species Probiotics is Associated With the Activation of Microbiome-Mediated Glutamate-Glutamine Biosynthesis.
INTRODUCTION
Intra-abdominal hypertension (IAH), the leading complication in the intensive care unit, significantly disturbs the gut microbial composition by decreasing the relative abundance of Lactobacillus and increasing the relative abundance of opportunistic infectious bacteria.
METHODS
To evaluate the preventative effect of Lactobacillus-based probiotics on IAH-induced intestinal barrier damages, a single-species probiotics (L92) and a multispecies probiotics (VSL#3) were introduced orally to Sprague-Dawley rats for 7 days before inducing IAH. The intestinal histology and permeability to macromolecules (fluoresceine isothiocyanate, FITC-dextran, N = 8 for each group), the parameters of immunomodulatory and oxidative responses [monocyte chemotactic protein 1 (MCP-1), interleukin-1β (IL-1β), interleukin-4 (IL-4), interleukin-10 (IL-10), malonaldehyde, glutathione peroxidase (GSH- Px), catalase (CAT), and superoxide dismutase; N = 4 for each group], and the microbiome profiling (N = 4 for each group) were analyzed.
RESULTS
Seven-day pretreatments of L92 significantly alleviated the IAH-induced increase in intestinal permeability to FITC-dextran and histological damage (P < 0.0001), accompanied with the suppression of inflammatory and oxidative activation. The increase of MCP-1 and IL-1β was significantly inhibited (P < 0.05); the anti-inflammatory cytokines, IL-4, and IL-10 were maintained at high levels; and the suppression of CAT (P < 0.05) was significantly reversed when pretreated with L92. On the contrary, no significant protective effects were observed in the VSL#3-pretreated group. Among the 84 identified species, 260 MetaCyc pathways, and 217 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, the protective effects of L92 were correlated with an increased relative abundance of Bacteroides finegoldii, Odoribacter splanchnicus, and the global activation of amino acid biosynthesis pathways, especially the glutamate-glutamine biosynthesis pathway.
CONCLUSIONS
Seven-day pretreatment with a single-species probiotics can prevent IAH-induced severe intestinal barrier dysfunction, potentially through microbial modulation.
Topics: Animals; Disease Models, Animal; Gastrointestinal Microbiome; Intestinal Absorption; Intestinal Diseases; Intra-Abdominal Hypertension; Lactobacillus; Male; Probiotics; Rats; Rats, Sprague-Dawley
PubMed: 32694391
DOI: 10.1097/SHK.0000000000001593 -
Clinical Infectious Diseases : An... Nov 2021Asymptomatic C. difficile colonization is believed to predispose to subsequent C. difficile infection (CDI). While emerging insights into the role of the commensal... (Observational Study)
Observational Study
BACKGROUND
Asymptomatic C. difficile colonization is believed to predispose to subsequent C. difficile infection (CDI). While emerging insights into the role of the commensal microbiota in mediating colonization resistance against C. difficile have associated CDI with specific microbial components, corresponding prospectively collected data on colonization with C. difficile are largely unavailable.
METHODS
C. difficile status was assessed by GDH EIA and real-time PCR targeting the toxin A (tcdA) and B (tcdB) genes. 16S V3 and V4 gene sequencing results from fecal samples of patients tested positive for C. difficile were analyzed by assessing alpha and beta diversity, LefSe, and the Piphillin functional inference approach to estimate functional capacity.
RESULTS
1506 patients were recruited into a prospective observational study (DRKS00005335) upon admission into one of five academic hospitals. 936 of them provided fecal samples on admission and at discharge and were thus available for longitudinal analysis. Upon hospital admission, 5.5% (83/1506) and 3.7% (56/1506) of patients were colonized with toxigenic (TCD) and non-toxigenic C. difficile (NTCD), respectively. During hospitalization, 1.7% (16/936) acquired TCD. Risk factors for acquisition of TCD included pre-existing lung diseases, lower GI endoscopy and antibiotics. Species protecting against hospital-related C. difficile acquisition included Gemmiger spp., Odoribacter splanchnicus, Ruminococcus bromii and other Ruminococcus spp. Metagenomic pathway analysis identified steroid biosynthesis as the most underrepresented metabolic pathway in patients who later acquire C. difficile colonization.
CONCLUSIONS
Gemmiger spp., Odoribacter splanchnicus, Ruminococcus bromii and other Ruminococci were associated with a decreased risk of C. difficile acquisition.
CLINICAL TRIALS REGISTRATION
DRKS00005335.
Topics: Bacterial Toxins; Bacteroidetes; Clostridioides; Clostridioides difficile; Clostridium Infections; Feces; Humans; Microbiota; Prospective Studies; Risk Factors; Ruminococcus
PubMed: 32589701
DOI: 10.1093/cid/ciaa871 -
Frontiers in Neuroscience 2020Attention-deficit/hyperactivity disorder (ADHD) is a neuropsychiatric condition that may be related to an imbalance of neural transmitters. The gut microbiota is the...
BACKGROUND
Attention-deficit/hyperactivity disorder (ADHD) is a neuropsychiatric condition that may be related to an imbalance of neural transmitters. The gut microbiota is the largest ecosystem in the human body, and the brain-gut axis theory proposes that the gut microbiome can affect brain function in multiple ways. The purpose of this study was to explore the gut microbiota in children with ADHD and assess the possible role of the gut microbiota in disease pathogenesis to open new avenues for ADHD treatment.
METHODS
A case-control design was used. We enrolled 17 children aged 6-12 years with ADHD who were treated in the Pediatric Outpatient Department of the First Medical Center of the Chinese PLA General Hospital from January to June, 2019. Seventeen children aged 6-12 years were selected as the healthy control (HC) group. Fecal samples of cases and controls were analyzed by shotgun metagenomics sequencing. Alpha diversity and the differences in the relative abundances of bacteria were compared between the two groups. Functional annotations were performed for the microbiota genes and metabolic pathways were analyzed using the Kyoto Encyclopedia of Genes and Genomes (KEGG).
RESULTS
There was no significant difference in the alpha diversity of gut microbiota between the ADHD and HC groups. Compared with HCs, and were significantly reduced in children with ADHD ( < 0.05), and were significantly increased [linear discriminant analysis (LDA) > 2]. At the species level, , , and were significantly reduced in the ADHD group ( < 0.05), while , , , and were increased ( < 0.05). Metabolic pathway analysis revealed significant between-group differences in the metabolic pathways of neurotransmitters (e.g., serotonin and dopamine) ( < 0.05).
CONCLUSION
Composition differences of gut microbiota in subjects with ADHD may contribute to brain-gut axis alterations and affect neurotransmitter levels, which could contribute to ADHD symptoms.
PubMed: 32132899
DOI: 10.3389/fnins.2020.00127 -
British Journal of Haematology Jun 2020We previously reported a protective association between single nucleotide polymorphisms (SNPs; rs4415345G and rs4610776A alleles) of Paneth cell α-defensin-5 against...
We previously reported a protective association between single nucleotide polymorphisms (SNPs; rs4415345G and rs4610776A alleles) of Paneth cell α-defensin-5 against acute graft-versus-host disease (aGVHD). Because dysbiosis has been associated with aGVHD, we hypothesized that these SNPs may have a gut microbiota signature. In Lasso regression analysis of 248 healthy individuals, rs4415345G was associated with a higher abundance of Odoribacter splanchnicus, an anaerobic butyrogenic commensal. In multivariable analysis of data from 613 allogeneic haematopoietic cell transplant recipients, peri-engraftment presence of O. splanchnicus was associated with ~50% lower risk for grade II-IV aGVHD (hazard ratio 0·53, 95% confidence interval 0·28-1·00, P = 0·05). O. splanchnicus may protect rs4415345G individuals against aGVHD.
Topics: Acute Disease; Adolescent; Adult; Allografts; Bacteroidetes; Bone Marrow Transplantation; Cord Blood Stem Cell Transplantation; Dysbiosis; Female; Gastrointestinal Microbiome; Graft vs Host Disease; Humans; Male; Metagenome; Paneth Cells; Peripheral Blood Stem Cell Transplantation; Polymorphism, Single Nucleotide; Risk; Symbiosis; Young Adult; alpha-Defensins
PubMed: 32086815
DOI: 10.1111/bjh.16458 -
Frontiers in Microbiology 2018The characteristics of flora in the intestine of an animal, including the number and abundance of different microbial species and their functions, are closely related to...
The characteristics of flora in the intestine of an animal, including the number and abundance of different microbial species and their functions, are closely related to the diets of the animal and affect the physical condition of the host. The Malayan pangolin () is an endangered species that specializes in myrmecophagy. Analyzing the microbiome in the intestine of the pangolin is imperative to protect this species. By sequencing the metagenomes of the feces of four pangolins, we constructed a non-redundant catalog of 211,868 genes representing 1,811 metagenomic species. Taxonomic annotation revealed that Bacteroidetes (49.9%), Proteobacteria (32.2%), and Firmicutes (12.6%) are the three main phyla. The annotation of gene functions identified 5,044 genes from 88 different glycoside hydrolase (GH) families in the Carbohydrate-Active enZYmes database and 114 gene modules related to chitin-degrading enzymes, corresponding to the catalytic domains of GH18 family enzymes, containing chitinase genes of classes III and V in the dataset. Fourteen gene modules corresponded to the catalytic domains of GH19 family enzymes, containing chitinase genes of classes I, II, and IV. These genes were found in 37 species belonging to four phyla: Bacteroidetes, Cyanobacteria, Firmicutes, and Proteobacteria. Moreover, when the metabolic pathways of these genes were summarized, 41,711 genes were associated with 147 unique KEGG metabolic pathways, and these genes were assigned to two Gene Ontology terms: metabolic process and catalytic activity. We also found several species that likely play roles in the digestion of cellulose and may be able to degrade chitin, including , and . In addition, we identified some intestinal microflora and genes related to diseases in pangolins. Twenty-seven species were identified by STAMP analysis as differentially abundant in healthy and diseased animals: 20 species, including and , were more abundant in healthy pangolins, while seven species, including , and , were more abundant in diseased pangolins. These results will support the efforts to conserve pangolins.
PubMed: 30532742
DOI: 10.3389/fmicb.2018.02793 -
Molecular Nutrition & Food Research Jan 2017Nutritional interventions based on the use of natural bioactive compounds might offer new possibilities for reshaping obesity-associated bacterial dysregulation or...
SCOPE
Nutritional interventions based on the use of natural bioactive compounds might offer new possibilities for reshaping obesity-associated bacterial dysregulation or dysbiosis and improving health. We evaluated whether pterostilbene supplementation could induce changes in gut microbiota composition and whether these modifications were associated with improvements in metabolic variables.
METHODS AND RESULTS
Zucker (fa/fa) rats were given a standard diet supplemented (n = 10) or not (n = 9) with pterostilbene (15 mg/kg body weight/day) by oral gavage for 6 weeks. Faucal samples at the beginning and at the end of the intervention period were analyzed by Illumina Mi-Seq sequencing approach. Pterostilbene exerted protective antiobesity effects, improved metabolic function (insulin sensitivity), and induced structural changes in gut microbiota composition. A decrease in the levels of Firmicutes and an increase in Verrucomicrobia phyla were detected in the pterostilbene-treated group. Bacterial species belonging to genera Akkermansia and Odoribacter were also increased. A strong inverse correlation between Akkermansia muciniphila and body weight was evidenced. Odoribacter splanchnicus showed a negative correlation with adiposity.
CONCLUSION
Pterostilbene modifies intestinal bacteria composition toward a healthier microbial profile and suggests that the antiobesity effects induced in Zucker rats could be associated with an enrichment of the mucin-degrading bacterial members, namely Akkermansia and Odoribacter genus.
Topics: Animals; Anti-Obesity Agents; Body Weight; Dietary Supplements; Dysbiosis; Gastrointestinal Microbiome; Obesity; Rats, Zucker; Stilbenes
PubMed: 27377854
DOI: 10.1002/mnfr.201500906 -
Infection and Immunity Jan 2015Capnocytophaga canimorsus, a dog mouth commensal and a member of the Bacteroidetes phylum, causes rare but often fatal septicemia in humans that have been in contact...
Capnocytophaga canimorsus, a dog mouth commensal and a member of the Bacteroidetes phylum, causes rare but often fatal septicemia in humans that have been in contact with a dog. Here, we show that C. canimorsus strains isolated from human infections grow readily in heat-inactivated human serum and that this property depends on a typical polysaccharide utilization locus (PUL), namely, PUL3 in strain Cc5. PUL are a hallmark of Bacteroidetes, and they encode various products, including surface protein complexes that capture and process polysaccharides or glycoproteins. The archetype system is the Bacteroides thetaiotaomicron Sus system, devoted to starch utilization. Unexpectedly, PUL3 conferred the capacity to acquire iron from serotransferrin (STF), and this capacity required each of the seven encoded proteins, indicating that a whole Sus-like machinery is acting as an iron capture system (ICS), a new and unexpected function for Sus-like machinery. No siderophore could be detected in the culture supernatant of C. canimorsus, suggesting that the Sus-like machinery captures iron directly from transferrin, but this could not be formally demonstrated. The seven genes of the ICS were found in the genomes of several opportunistic pathogens from the Capnocytophaga and Prevotella genera, in different isolates of the severe poultry pathogen Riemerella anatipestifer, and in strains of Bacteroides fragilis and Odoribacter splanchnicus isolated from human infections. Thus, this study describes a new type of ICS that evolved in Bacteroidetes from a polysaccharide utilization system and most likely represents an important virulence factor in this group.
Topics: Bacteroidetes; Gram-Negative Bacterial Infections; Humans; Iron; Membrane Transport Proteins; Multigene Family; Serum
PubMed: 25368114
DOI: 10.1128/IAI.02042-14