Ruminococcus ⇒ Ruminococcus gnavus {10000172}

Shared Reference Notes

• [1.1] [#Systemic lupus erythematosus] 
  - Many Lupus patients have little or no detectable perturbations in representation of the #Lachnospiraceae family or abundance of Ruminococcus gnavus species overtime.
• [1.2] [#Systemic lupus erythematosus] 
  - Anti-RG antibodies correlated directly with SLEDAI score and antinative DNA levels, but inversely with C3 and C4. - Intestinal expansions of Ruminococcus gnavus were directly proportional to overall disease activity and most pronounced in those with lupus nephritis. - Lupus faecal samples displayed increases in sIgA-coated Ruminococcus gnavus bacteria. - Patients with lupus nephritis displayed elevated serum IgG predominantly to Ruminococcus gnavus strain-restricted cell wall lipoglycan antigens.
• [1.3] 
  - R. gnavus is a proinflammatory species due to secretion of a polysaccharide that induces tumour necrosis factor alpha in dendritic cells.
• [1.4] [#Crohn’s disease] 
  - Gut species found to be significantly depleted in CD compared to control include: #Faecalibacterium prausnitzii , #Roseburia inulinivorans and #Alistipes senegalensis. - While #Clostridium nexile and Ruminococcus gnavus were found to be enriched.
• [1.5] [#Five-year-olds Child] 
  - The levels of Ruminococcus gnavus were lower in adults than in five-year-olds, the researchers found. - R. gnavus has been associated with conditions such as obesity and inflammatory bowel diseases
• [1.6] [#Inflamatory bowel disease] 
  - Seven bacterial species correlated with expression levels of Th17 effector cytokines, IL-17A and IL-17F. - The seven associated species include Ruminococcus gnavus, #Escherichia coli, #Lachnospiraceae bacterium, #Clostridium hathewayi, #Bacteroides faecis, #Bacteroides vulgatus, and #Akkermansia muciniphila. All of the species were positively associated with IL-17A/ IL-17F except #Akkermansia muciniphila, suggesting these species are proinflammatory, while #Akkermansia muciniphila is anti-inflammatory.
• [1.7] [#ABO Blood group, #Blood group A antigen] 
• [1.8] 
  - #Asymptomatic carriage of enteropathogens in Children infected with Campylobacter, norovirus or enteroaggregative E. coli had significant higher abundance of Ruminococcus gnavus, which has been robustly linked to Crohn disease and produced proinflammatory polysaccharides
• [1.9] [#Diabetes Type 2] [#Clostridium bolteae] 
  - These four species were #Clostridium citroniae, C. bolteae, #Tyzzerella nexilis, and Ruminococcus gnavus.
• [#Adult, #Aging] - specific bacteria can be used as markers for the development and maturation of the microbiota such as R. gnavus, which is inversely correlated to microbial richness at all ages and reduces from childhood toward adulthood.
• [1.11] 
  - Ruminococcus gnavus converts Trp into tryptamine by a Trp decarboxylase enzyme
• [1.12] [#Prostate cancer] 
  - Ruminococcus gnavus and #Bacteroides acidifaciens were enriched in the fecal microbiota of castrated (as compared to non-castrated) male mice, and that these species can metabolise androgen precursors, pregnenolone and hydroxypregnenolone, into downstream metabolites of the androgen biosynthesis pathway, dehydroepiandrosterone and testosterone.
• [1.13] [#Inflamatory bowel disease] 
  - R. gnavus, a prevalent gut microbe that proliferates in IBD, has been found to secrete a unique L-rhamnose oligosaccharide that induces tumor necrosis factor alpha (TNFα), a major pro-inflammatory cytokine.
• [1.14] [#Inflamatory bowel disease] 
  - Ruminococcocus gnavus, was shown to be increased in IBD, which could explain an increased abundance of the Ruminococcocus genus in the #Aspirin vs placebo arm observed in our study.
• [1.15] [#Aromatic amino acid] 
  - Ruminococcus gnavus is the main producer of #Tryptamine in #Infants’ gut.
• [1.16] [#Systemic lupus erythematosus] 
  - Expansions of only the anaerobic commensal, Ruminococcus (#Blautia) gnavus (RG) occurred at times of high-disease activity, and were detected in almost half of patients during lupus nephritis (LN) disease flares.
• [#Systemic lupus erythematosus] - SLE > The cell membrane-associated lipoglycans share conserved structural features documented by mass spectroscopy, and highly immunogenic repetitive antigenic-determinants, recognised by high-level serum IgG2 antibodies, that spontaneously arose, concurrent with RG blooms and lupus flares.
• [1.17] [#Systemic lupus erythematosus] 
  - Ruminococcus gnavus (RG) showed a mean 5-fold overabundance in lupus patients compared with healthy controls. And patients with high disease activity and especially lupus nephritis showed the greatest expansion of RG. - anti-RG antibodies were directly correlated with anti-DNA levels and SLEDAI scores, while they were negatively correlated with C3 and C4. - Patients with active nephritis including Class III and IV exhibited the highest levels of anti-RG strain restricted antibodies in serum. - Ruminococcus gnavus (RG) strains from lupus patients, and found that lupus-derived RG strains enhanced intestinal permeability, elevated serum levels of zonulin which is a regulator of tight junction formation between cells forming the intestinal barrier, and translocated to mesenteric lymph nodes. - The level of intestinal permeability induced by RG has a significant correlation with anti-native DNA autoantibodies and serum IgG anti RG cell-wall lipoglycan antibodies. - antigen in Ruminococcus gnavus strain CC55_001C could cross-react with anti-dsDNA antibodies.
• [1.18] [#Rheumatoid Arthritis] 
  - RA Patients with more severe symptoms had increased levels of Ruminococcus gnavus and other pro-inflammatory bacteria compared with those with milder symptom
• [1.19] [#Diabetes Type 2] 
  - The #Tyrosine decarboxylase action of bacteria Ruminococcus gnavus, #Enterococcus faecalis and #Clostridium sporogenes converts #Tyrosine (Tyr) into #Tyramine. - Its role to improve #Glucose tolerance marked it as a beneficial metabolite to T2DM.
• [#Clostridium sporogenes] [#Tryptophan] - Two gut #Bacteria C. sporogenes and Ruminococcus gnavus can convert Trp into #Tryptamine which is able to inhibit #Glucose-induced #Hyperglycemia and enhance insulin release.
• - gut inflammation in patients and murine models has been associated with increased prevalence of R. gnavus, which triggers the production of inflammatory cytokines (e.g. TNFα) by DCs via polysaccharide signaling.
• [1.21] [#Diabetes Type 2, #Irritable bowel syndrome] [#High fibre diet] 
  - fiber intervention significantly suppressed #Tryptamine and #Phenethylamine levels and abundances of R. gnavus in T2D subjects, revealing manipulation of gut microbiota-derived #Tryptamine and #Phenethylamine by dietary changes or prebiotics is a potential direction for managing #Metabolic syndrome and IBS.
• [#Diabetes Type 2, #Irritable bowel syndrome] - #Tryptamine and phenethylamine derived from the R. gnavus-mediated catabolism on dietary amino acids impaired insulin sensitivity via activation of TAAR1-MAPK/ERK signaling pathway axis, thereby contributing to insulin resistance in gut dysbiosis-associated IBS and T2D.
• [#Diabetes Type 2] - #Tryptamine/#Phenethylamine-mediated TAAR1 signaling pathway as the key molecular axis underlying R. gnavus-induced insulin resistance
• - R. gnavus has the strongest association with features of #Metabolic syndrome among 50 identified prevalent gut microbes in the species level
• - #Tryptamine and #Phenethylamine as TAAR1 ligands are the culprits and one possible way to design a therapeutic approach is to facilitate the reduction of R. gnavus or on top of blocking the #Tryptamine and #Phenethylamine production by inhibiting the bacterial TDC
• - R. gnavus reduction accompanied by downregulation of #Tryptamine and #Phenethylamine are positively correlated with the improvement of insulin resistance.
• - Among these #Tryptamine and #Phenethylamine-producing bacteria species, R. gnavus has the highest catalytic ability to transform aromatic amino acids into aromatic trace amines (#Tryptamine, #Tyramine, and #Phenethylamine) compared with other bacteria specie
• [1.22] [#High Fat Diet] 
  - non-classic amino acid conjugation of the bile acid #Cholic acid (AA-CA) increased with HFD. - AA-CAs impact intestinal stem cell growth and demonstrate that #Ileibacterium valens and Ruminococcus gnavus are able to synthesize these AA-CAs.
• [1.23] [#Anorexia nervosa] [#Berberine] 
  - BBR > decrease in Ruminococcus gnavus and Ruminococcus schinkii and an increase in #Bacteroides were observed in normal mice after treatment with BBR
• [1.24] [#Inflamatory bowel disease, #Metabolic associated fatty liver disease] 
  - Ruminococcus gnavus, which is a mucin-degrading group, in inflammatory bowel disease and in altered lipid metabolism related to non-alcoholic fatty liver disease (NAFLD) and #Obesity
• - an increased abundance of Ruminococcus gnavus was associated with decreases in intakes of trans fatty acids from baseline to 3 months.
• [1.25] [#Cognitive impairment] 
  - #Alistipes obesi, #Blautia wexlerae, and Ruminococcus gnavus were enriched or depleted in #Children with higher cognitive function scores.
• [#Cognitive impairment] - R. gnavus, which we found was negatively associated with cognitive function
• [1.26] [#Rheumatoid Arthritis, #Systemic lupus erythematosus] 
  - Ruminococcus gnavus was associated with lupus nephritis, RA and #Spondyloarthritis.
• [1.27] [#Inflamatory bowel disease] 
  - in patients with #Clostridium difficile infection (CDI), which can be a complication of IBD, R. gnavus has been found to be more abundant compared to HC and IBD patients without CDI.
• [#Crohn’s disease, #Inflamatory bowel disease, #Ulcerative Colitis] - In IBD patients, the most distinctive feature between CD and UC was a significantly higher abundance of R. gnavus in CD.
• [#Crohn’s disease, #Ulcerative Colitis] - #Pouchitis, a common complication following restorative proctocolectomy with ileal pouch-anal anastomosis for UC, is associated with increased levels of R. gnavus compared to UC and CD
• [#Crohn’s disease] - R. gnavus was found to be significantly more abundant in CD patients with a better prognosis, suggesting it may serve as a biomarker for favorable outcomes in CD.
• [#Diabetes Type 2] - R. gnavus showed significantly higher abundance in patients with type 2 diabetes mellitus (T2DM) and #Prediabetes (PreDM).
• [#Diabetes Type 2] - R. gnavus was found to have a positive correlation with #Glycine #Ursodeoxycholic acid (GUDCA) levels, which have been shown to improve metabolism by promoting fat thermogenesis
• [#Inflamatory bowel disease] [#Akkermansia muciniphila] - Active IBD often coincides with an increase in the abundance of R. gnavus, goes from an average of 0.1% in healthy controls (HC) to 69% in IBD patients with active disease. - This increase in R. gnavus abundance is associated with a decrease in Akkermansia, and this microbial shift has been proposed as a biomarker for mucosal integrity in IBD.
• [#Inflamatory bowel disease] - the absence of Methylation-Controlled J (MCJ) may contribute to an altered gut microbiota composition, such as increased levels of R. gnavus, and dysregulated immune responses, which could have implications for the pathogenesis and treatment of IBD.
• [#Inflamatory bowel disease] - In IBD, #Caprylic acid has been found to be enriched in non-IBD controls and negatively associated with the abundance of R. gnavus
• [#Inflamatory bowel disease] - R. gnavus has also been reported as a producer of #Ursodeoxycholic acid (UDCA) > It possesses an enzyme that can degrade 7-keto #Lithocholic acid (LCA) into UDCA. - Administration of UDCA has been shown to increase colonic LCA levels and inhibit caspase-3 cleavage. - Abnormal apoptosis in intestinal epithelial cells (IECs) can disrupt the integrity of the intestinal barrier, leading to bacterial infiltration and triggering an inflammatory cascade.
• [#Inflamatory bowel disease] - In patients with IBD, R. gnavus has been found to be highly abundant and positively correlated with #Tryptamine levels.
• - #Haptoglobin (Hp) expression in white adipose tissue (WAT) is increased in #Obesity rodents, and the level of Hp was found to be significantly correlated with the abundance of R. gnavus in individuals of normal weight and overweight.
• - R. gnavus is known to be highly IgA coated, regardless of the specific IgA target.
• - R. gnavus is capable of producing #Tryptamine, which can affect gut motility through several mechanisms. - First, #Tryptamine activates the #Serotonin receptor 4 (SR4) or #5-hydroxytryptamine receptor 4 (5-HT4R), leading to an increase in intracellular cyclic #Adenosine monophosphate (cAMP) concentration > This elevation in cAMP levels can enhance gut motility. - Second, #Tryptamine can also increase fluid secretion by acting on the cystic fibrosis transmembrane regulator (CFTR) > promotes the secretion of fluids into the gut, affecting gut motility.
• - R. gnavus can induce the secretion of #IL-17
• - R. gnavus has the ability to synthesize and secrete a complex glucorhamnan #Polysaccharide, which has been found to strongly induce the secretion of TNF-α through TLR4 activation.
• [#Ursodeoxycholic acid] - R. gnavus has been reported to produce UDCA.
• [#Ulcerative Colitis] - in UC patients who underwent #Fecal Microbiota Transplantation (FMT), the abundance of R. gnavus was found to be higher in donors of failed FMT and decreased after FMT.
• [1.28] [#Tryptophan] 
  - a Trp rich diet was able to shift the gut microbial composition of mice toward the increased abundance of bacteria able to produce #AHR ligands such as #Lactobacillus and Ruminococcus gnavus, thus reducing #Gluten immunopathology.
• [1.29] [#Crohn’s disease] [#Clostridioides difficile, #Clostridium paraputrificum] [#Fecal Microbiota Transplantation] 
  - Transferred fecal microbiota from healthy patients and patients with defined Crohn’s ileocolitis (CD_L3) to germ-free mice > a markedly reduced engraftment of CD_L3 microbiome compared to healthy control microbiota. - FMT from CD_L3 patients did not lead to ileitis but resulted in #Colitis with features consistent with CD: a discontinued pattern of #Colitis, more proximal colonic localization, enlarged isolated lymphoid follicles and/or tertiary lymphoid organ neogenesis, and a transcriptomic pattern consistent with epithelial reprograming and promotion of the Paneth cell-like signature in the proximal colon and immune dysregulation characteristic of CD. - The observed inflammatory response associated with persistently increased abundance of Ruminococcus gnavus, #Erysipelatoclostridium ramosum, #Faecalimonas umbilicate, #Blautia hominis, #Clostridium butyricum, and C. paraputrificum and unexpected growth of toxigenic C. difficile.

References Notes