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Methanobrevibacter smithii

Methanobrevibacter smithii is the predominant archaeon in the microbiota of the human gut. M. smithii has a coccobacillus shape. It plays an important role in the efficient digestion of polysaccharides (complex sugars) by consuming the end products of bacterial fermentation. Methanobrevibacter smithii is a single-celled microorganism from the Archaea domain. M. smithii is a methanogen, and a hydrogenotroph that recycles the hydrogen by combining it with carbon dioxide to methane. The removal of hydrogen by M. smithii is thought to allow an increase in the extraction of energy from nutrients by shifting bacterial fermentation to more oxidized end products.[1]

Methanobrevibacter smithii
Scientific classification
Domain: Archaea
Kingdom: Euryarchaeota
Class: Methanobacteria
Order: Methanobacteriales
Family: Methanobacteriaceae
Genus: Methanobrevibacter
Species:
M. smithii
Binomial name
Methanobrevibacter smithii
Balch and Wolfe 1981

Methanobrevibacter smithii is also found in dental plaque and in the vagina (with vaginosis).[2]

Importance in the human gut edit

The human gut microbiota consists of three main groups of hydrogen-consuming microorganisms or hydrogenotrophs: methanogens including M. smithii; various acetogenic bacteria; and sulfate-reducing bacteria. The different roles of these microorganisms are helpful in understanding how hydrogen metabolism affects the efficiency of dietary fermentation.[3] Accumulation of hydrogen in the gut reduces the efficiency of microbial fermentation as well as the yield of energy. Methanogenic archaea are therefore particularly significant for the human gut, because they are pivotal in the removal of excess hydrogen.[1] M. smithii is the most common methanogenic archaeon in the human gut microbiota. M. smithii is paramount in digestive processes, and has a high prevalence in human feces.[4]

The gut microbiota is dominated by gram-negative Bacteroidota, and Bacillota (mostly gram-positive). Archaea are most prominently represented by the methanogenic M. smithii. M. smithii is believed to be a therapeutic target for manipulation and an adaptation to the gut ecosystem.[5]

M. smithii has significant enrichment of genes involved in the utilization of carbon dioxide (CO2), hydrogen gas (H2), and formate (HCO2) for methanogenesis. It also has an intact pathway to allow for CO2 utilization gene cluster for the methanogenic consumption of Bacteroides thetaiotaomicron-produced metabolite.[5]

M. smithii supports methanogenic and nonmethanogenic removal of diverse bacterial end products of fermentation.[5]

The dominant archaeon in the human gut ecosystem affects the specificity and efficiency of bacterial digestion of dietary polysaccharides. This influences the person’s calorie harvest and body fat.[5] M. smithii, along with certain bacteria, is more often found in lean individuals than in those who are overweight.[6] Researchers have sequenced M. smithii genome, indicating that M. smithii may be a therapeutic target for reducing energy harvest in obese humans.[5]

Cell wall and cell membrane compared to bacteria edit

The cell wall and cell membrane of Methanobrevibacter smithii determine susceptibility to antibiotics and statins. The cell wall is composed of pseudopeptidoglycan (and not peptidoglycan as in bacteria) which makes archaea resistant to lysozyme and many antibiotics that interfere with cell wall synthesis. The cell membrane consists of a lipid bilayer or monolayer, the backbone of which is composed of isoprene units that are linked to glycerol by ether bonds. In contrast, the lipid bilayer of bacteria consists of a fatty acid backbone that is linked to glycerol by an ester bond. The presence of statin-sensitive isoprene units in the cell membrane of archaea allows statins to selectively interfere with the growth of archaea while leaving the cell membrane of bacteria unaffected. While bacteria do not use isoprene units in their cell membrane they are still required elsewhere. These bacterial isoprene units are, however, synthesized by the mevalonate pathway (MEP) that is not inhibited by statins. [7]

In anorexic patients edit

In 2009, the largest human study concerning obesity and gut microbiota to date was conducted. Obesity disorders are the result of an imbalance and have serious consequences such as cardiovascular disease, type 2 diabetes, and colon cancer. The gut microbiota and environment contributes to the energy imbalance because of its involvement in energy intake, conversion and storage. Culture-independent methods have shown that high proportions of methanogens can comprise up to 10% of all anaerobes in the colons of healthy adults. The quantification average of M. smithii for the anorexic group was much greater than the lean and obese group. Thus, higher amounts of M. smithii were found in anorexic patients than lean patients.

The development of Methanobrevibacter in anorexia patients may be associated with an adaptive attempt towards optimal exploitation of the low caloric diet of anorexic patients. Hence, an increase in M. smithii leads to the optimization of food transformation in low caloric diets. M. smithii could also be related to constipation, a common condition for anorexic patients.[1]

M. smithii and constipation edit

Observational studies show a strong association between delayed intestinal transit and the production of methane. Experimental data suggest a direct inhibitory activity of methane on the colonic and ileal smooth muscle and a possible role for methane as a gasotransmitter. Statins can inhibit archaeal cell membrane biosynthesis apparently without affecting bacterial numbers as demonstrated in livestock and humans. This opens the possibility of a therapeutic intervention that targets a specific etiological factor of constipation while protecting the intestinal microbiome. While it is generally believed that statins inhibit methane production via their effect on cell membrane biosynthesis, mediated by inhibition of the HMG-CoA reductase, there is accumulating evidence for an alternative or additional mechanism of action where statins inhibit methanogenesis directly. It appears that this other mechanism may predominate when the lactone form of statins, particularly lovastatin, is administered.[7]

References edit

  1. ^ a b c Armougom F; Henry M; Vialettes B; Raccah D; et al. (2009). "Monitoring Bacterial Community of Human Gut Microbiota Reveals an Increase in Lactobacillus in Obese Patients and Methanogens in Anorexic Patients". PLOS ONE. 4 (9): e7125. Bibcode:2009PLoSO...4.7125A. doi:10.1371/journal.pone.0007125. PMC 2742902. PMID 19774074.
  2. ^ Belay, N; Mukhopadhyay, B; Conway de Macario, E; Galask, R; Daniels, L. 1990. Methanogenic bacteria in human vaginal samples. Journal of Clinical Microbiology, 28 (7), 1666–1668.
  3. ^ Hansen, Elizabeth E.; Lozupone, Catherine A.; Rey, Federico E.; Wu, Meng; Guruge, Janaki L.; Narra, Aneesha; Goodfellow, Jonathan; Zaneveld, Jesse R.; McDonald, Daniel T. (2011-03-15). "Pan-genome of the dominant human gut-associated archaeon, Methanobrevibacter smithii, studied in twins". Proceedings of the National Academy of Sciences of the United States of America. 108 Suppl 1 (Suppl 1): 4599–4606. Bibcode:2011PNAS..108.4599H. doi:10.1073/pnas.1000071108. ISSN 1091-6490. PMC 3063581. PMID 21317366.
  4. ^ Bedis, D., Mireille, H. (2009). "High Prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae Detected in the Human Gut Using an Improved DNA Detection Protocol." PLOS One 4(9) e7063.
  5. ^ a b c d e Buck, S., Hansen, E., (2007). "Genomic and metabolic adaptations of Methanobrevibacter smithii to the human gut." Proceedings of the National Academy of Sciences of the United States of America 104, 10643-10648.
  6. ^ Stenman LK, Burcelin R, Lahtinen S (2016). "Establishing a causal link between gut microbes, body weight gain and glucose metabolism in humans - towards treatment with probiotics". Beneficial Microbes. 7 (1): 11–22. doi:10.3920/BM2015.0069. PMID 26565087.
  7. ^ a b Gottlieb, K., Wacher, V., Sliman, J., & Pimentel, M. (2015). Review article: inhibition of methanogenic archaea by statins as a targeted management strategy for constipation and related disorders. Alimentary Pharmacology & Therapeutics.

Further reading edit

Bang, Corinna; Weidenbach, Katrin; Gutsmann, Thomas; Heine, Holgar; Schmitz, Ruth A. (2014). "The Intestinal Archaea Methanosphaera stadtmanae and Methanobrevibacter smithii Activate Human Dendritic Cells". PLOS ONE. 9 (6): e99411. Bibcode:2014PLoSO...999411B. doi:10.1371/journal.pone.0099411. PMC 4051749. PMID 24915454.

Kim, Gene; Deepinder, Fnu; Morales, Walter; Hwang, Laura; Weitsman, Stacy; Chang, Christopher; Gunsalus, Robert; Pimentel, Mark (December 2012). "Methanobrevibacter smithii Is the Predominant Methanogen in Patients with Constipation-Predominant IBS and Methane on Breath". Digestive Diseases and Sciences. 57 (12): 3213–3218. doi:10.1007/s10620-012-2197-1. PMID 22573345. S2CID 207113756.

External links edit

  • Paul B. Eckburg, Paul W. Lepp, and David A. Relman Archaea and Their Potential Role in Human Disease
  • Dermoumi, Heide L.; Ansorg, Rainer A.M. (2001). "Isolation and Antimicrobial Susceptibility Testing of Fecal Strains of the Archaeon Methanobrevibacter smithii". Chemotherapy. 47 (3): 177–183. doi:10.1159/000063219. PMID 11306786. S2CID 29227943.
  • LSPN page for Methanobrevibacter
  • Samuel BS; Hansen EE; Manchester JK; Coutinho PM; et al. (2007). "Genomic and metabolic adaptations of Methanobrevibacter smithii to the human gut". Proc Natl Acad Sci U S A. 104 (25): 10643–8. Bibcode:2007PNAS..10410643S. doi:10.1073/pnas.0704189104. PMC 1890564. PMID 17563350.
  • Vianna ME; Conrads G; Gomes BP; Horz HP. (2006). "Identification and Quantification of Archaea Involved in Primary Endodontic Infections". J Clin Microbiol. 44 (4): 1274–82. doi:10.1128/JCM.44.4.1274-1282.2006. PMC 1448633. PMID 16597851.
  • Ridlon JM; McGarr SE; Hylemon PB. (2005). "Development of methods for the detection and quantification of 7alpha-dehydroxylating clostridia, Desulfovibrio vulgaris, Methanobrevibacter smithii, and Lactobacillus plantarum in human feces". Clin Chim Acta. 357 (1): 55–64. doi:10.1016/j.cccn.2005.02.004. PMID 15963794.
  • Type strain of Methanobrevibacter smithii at BacDive - the Bacterial Diversity Metadatabase
  • Methanobrevibacter - What we know about the most abundant archaea in the human gut

methanobrevibacter, smithii, predominant, archaeon, microbiota, human, smithii, coccobacillus, shape, plays, important, role, efficient, digestion, polysaccharides, complex, sugars, consuming, products, bacterial, fermentation, single, celled, microorganism, f. Methanobrevibacter smithii is the predominant archaeon in the microbiota of the human gut M smithii has a coccobacillus shape It plays an important role in the efficient digestion of polysaccharides complex sugars by consuming the end products of bacterial fermentation Methanobrevibacter smithii is a single celled microorganism from the Archaea domain M smithii is a methanogen and a hydrogenotroph that recycles the hydrogen by combining it with carbon dioxide to methane The removal of hydrogen by M smithii is thought to allow an increase in the extraction of energy from nutrients by shifting bacterial fermentation to more oxidized end products 1 Methanobrevibacter smithii Scientific classification Domain Archaea Kingdom Euryarchaeota Class Methanobacteria Order Methanobacteriales Family Methanobacteriaceae Genus Methanobrevibacter Species M smithii Binomial name Methanobrevibacter smithiiBalch and Wolfe 1981 Methanobrevibacter smithii is also found in dental plaque and in the vagina with vaginosis 2 Contents 1 Importance in the human gut 2 Cell wall and cell membrane compared to bacteria 3 In anorexic patients 4 M smithii and constipation 5 References 6 Further reading 7 External linksImportance in the human gut editThe human gut microbiota consists of three main groups of hydrogen consuming microorganisms or hydrogenotrophs methanogens including M smithii various acetogenic bacteria and sulfate reducing bacteria The different roles of these microorganisms are helpful in understanding how hydrogen metabolism affects the efficiency of dietary fermentation 3 Accumulation of hydrogen in the gut reduces the efficiency of microbial fermentation as well as the yield of energy Methanogenic archaea are therefore particularly significant for the human gut because they are pivotal in the removal of excess hydrogen 1 M smithii is the most common methanogenic archaeon in the human gut microbiota M smithii is paramount in digestive processes and has a high prevalence in human feces 4 The gut microbiota is dominated by gram negative Bacteroidota and Bacillota mostly gram positive Archaea are most prominently represented by the methanogenic M smithii M smithii is believed to be a therapeutic target for manipulation and an adaptation to the gut ecosystem 5 M smithii has significant enrichment of genes involved in the utilization of carbon dioxide CO2 hydrogen gas H2 and formate HCO 2 for methanogenesis It also has an intact pathway to allow for CO2 utilization gene cluster for the methanogenic consumption of Bacteroides thetaiotaomicron produced metabolite 5 M smithii supports methanogenic and nonmethanogenic removal of diverse bacterial end products of fermentation 5 The dominant archaeon in the human gut ecosystem affects the specificity and efficiency of bacterial digestion of dietary polysaccharides This influences the person s calorie harvest and body fat 5 M smithii along with certain bacteria is more often found in lean individuals than in those who are overweight 6 Researchers have sequenced M smithii genome indicating that M smithii may be a therapeutic target for reducing energy harvest in obese humans 5 Cell wall and cell membrane compared to bacteria editThe cell wall and cell membrane of Methanobrevibacter smithii determine susceptibility to antibiotics and statins The cell wall is composed of pseudopeptidoglycan and not peptidoglycan as in bacteria which makes archaea resistant to lysozyme and many antibiotics that interfere with cell wall synthesis The cell membrane consists of a lipid bilayer or monolayer the backbone of which is composed of isoprene units that are linked to glycerol by ether bonds In contrast the lipid bilayer of bacteria consists of a fatty acid backbone that is linked to glycerol by an ester bond The presence of statin sensitive isoprene units in the cell membrane of archaea allows statins to selectively interfere with the growth of archaea while leaving the cell membrane of bacteria unaffected While bacteria do not use isoprene units in their cell membrane they are still required elsewhere These bacterial isoprene units are however synthesized by the mevalonate pathway MEP that is not inhibited by statins 7 In anorexic patients editIn 2009 the largest human study concerning obesity and gut microbiota to date was conducted Obesity disorders are the result of an imbalance and have serious consequences such as cardiovascular disease type 2 diabetes and colon cancer The gut microbiota and environment contributes to the energy imbalance because of its involvement in energy intake conversion and storage Culture independent methods have shown that high proportions of methanogens can comprise up to 10 of all anaerobes in the colons of healthy adults The quantification average of M smithii for the anorexic group was much greater than the lean and obese group Thus higher amounts of M smithii were found in anorexic patients than lean patients The development of Methanobrevibacter in anorexia patients may be associated with an adaptive attempt towards optimal exploitation of the low caloric diet of anorexic patients Hence an increase in M smithii leads to the optimization of food transformation in low caloric diets M smithii could also be related to constipation a common condition for anorexic patients 1 M smithii and constipation editObservational studies show a strong association between delayed intestinal transit and the production of methane Experimental data suggest a direct inhibitory activity of methane on the colonic and ileal smooth muscle and a possible role for methane as a gasotransmitter Statins can inhibit archaeal cell membrane biosynthesis apparently without affecting bacterial numbers as demonstrated in livestock and humans This opens the possibility of a therapeutic intervention that targets a specific etiological factor of constipation while protecting the intestinal microbiome While it is generally believed that statins inhibit methane production via their effect on cell membrane biosynthesis mediated by inhibition of the HMG CoA reductase there is accumulating evidence for an alternative or additional mechanism of action where statins inhibit methanogenesis directly It appears that this other mechanism may predominate when the lactone form of statins particularly lovastatin is administered 7 References edit a b c Armougom F Henry M Vialettes B Raccah D et al 2009 Monitoring Bacterial Community of Human Gut Microbiota Reveals an Increase in Lactobacillus in Obese Patients and Methanogens in Anorexic Patients PLOS ONE 4 9 e7125 Bibcode 2009PLoSO 4 7125A doi 10 1371 journal pone 0007125 PMC 2742902 PMID 19774074 Belay N Mukhopadhyay B Conway de Macario E Galask R Daniels L 1990 Methanogenic bacteria in human vaginal samples Journal of Clinical Microbiology 28 7 1666 1668 Hansen Elizabeth E Lozupone Catherine A Rey Federico E Wu Meng Guruge Janaki L Narra Aneesha Goodfellow Jonathan Zaneveld Jesse R McDonald Daniel T 2011 03 15 Pan genome of the dominant human gut associated archaeon Methanobrevibacter smithii studied in twins Proceedings of the National Academy of Sciences of the United States of America 108 Suppl 1 Suppl 1 4599 4606 Bibcode 2011PNAS 108 4599H doi 10 1073 pnas 1000071108 ISSN 1091 6490 PMC 3063581 PMID 21317366 Bedis D Mireille H 2009 High Prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae Detected in the Human Gut Using an Improved DNA Detection Protocol PLOS One 4 9 e7063 a b c d e Buck S Hansen E 2007 Genomic and metabolic adaptations of Methanobrevibacter smithii to the human gut Proceedings of the National Academy of Sciences of the United States of America 104 10643 10648 Stenman LK Burcelin R Lahtinen S 2016 Establishing a causal link between gut microbes body weight gain and glucose metabolism in humans towards treatment with probiotics Beneficial Microbes 7 1 11 22 doi 10 3920 BM2015 0069 PMID 26565087 a b Gottlieb K Wacher V Sliman J amp Pimentel M 2015 Review article inhibition of methanogenic archaea by statins as a targeted management strategy for constipation and related disorders Alimentary Pharmacology amp Therapeutics Further reading editBang Corinna Weidenbach Katrin Gutsmann Thomas Heine Holgar Schmitz Ruth A 2014 The Intestinal Archaea Methanosphaera stadtmanae and Methanobrevibacter smithii Activate Human Dendritic Cells PLOS ONE 9 6 e99411 Bibcode 2014PLoSO 999411B doi 10 1371 journal pone 0099411 PMC 4051749 PMID 24915454 Kim Gene Deepinder Fnu Morales Walter Hwang Laura Weitsman Stacy Chang Christopher Gunsalus Robert Pimentel Mark December 2012 Methanobrevibacter smithii Is the Predominant Methanogen in Patients with Constipation Predominant IBS and Methane on Breath Digestive Diseases and Sciences 57 12 3213 3218 doi 10 1007 s10620 012 2197 1 PMID 22573345 S2CID 207113756 External links editPaul B Eckburg Paul W Lepp and David A Relman Archaea and Their Potential Role in Human Disease Dermoumi Heide L Ansorg Rainer A M 2001 Isolation and Antimicrobial Susceptibility Testing of Fecal Strains of the Archaeon Methanobrevibacter smithii Chemotherapy 47 3 177 183 doi 10 1159 000063219 PMID 11306786 S2CID 29227943 Methanogens Photo Gallery Methanobrevibacter smithii LSPN page for Methanobrevibacter Samuel BS Hansen EE Manchester JK Coutinho PM et al 2007 Genomic and metabolic adaptations of Methanobrevibacter smithii to the human gut Proc Natl Acad Sci U S A 104 25 10643 8 Bibcode 2007PNAS 10410643S doi 10 1073 pnas 0704189104 PMC 1890564 PMID 17563350 Vianna ME Conrads G Gomes BP Horz HP 2006 Identification and Quantification of Archaea Involved in Primary Endodontic Infections J Clin Microbiol 44 4 1274 82 doi 10 1128 JCM 44 4 1274 1282 2006 PMC 1448633 PMID 16597851 Ridlon JM McGarr SE Hylemon PB 2005 Development of methods for the detection and quantification of 7alpha dehydroxylating clostridia Desulfovibrio vulgaris Methanobrevibacter smithii and Lactobacillus plantarum in human feces Clin Chim Acta 357 1 55 64 doi 10 1016 j cccn 2005 02 004 PMID 15963794 Type strain of Methanobrevibacter smithii at BacDive the Bacterial Diversity Metadatabase Methanobrevibacter What we know about the most abundant archaea in the human gut Retrieved from https en wikipedia org w index php title Methanobrevibacter smithii amp oldid 1224108232, wikipedia, wiki, book, books, library,

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