Ruminococcus bromii

Optimal Result: 0 - 1500000000 CFU/g stool.

Ruminococcus bromii is a keystone species, playing a large role in the digestion of resistant starches. It has been proposed that the primary role played by R. bromii is to release energy from resistant starch to other members of the microbial community, giving it an important role for maintaining microbial community balance. R. gnavus can efficiently cross-feed on starch degradation products released by R. bromii, even though it is normally a mucin degrading bacteria.

R. bromii ferments resitant starch which is correlated with increased butyrate production downstream. The major fermentation products include acetate, H2, and CO2. The byproducts of the degradation of resistant startch are used by the bacterial species. Therefore, R. bromii supports microbiome diversity through cross-feeding. One study showed that five species, including R. bromii, were significantly more abundant in stool samples from obese individuals versus non-obese individuals. R. bromii is enriched in healthy twins versus those with food allergies. An infant study showed that depletion of R. bromii and Akkermansia muciniphila was associated with reduced butyrate and theh developmenet of atopic dermatitis. 


Ze, X., Duncan, S. H., Louis, P. & Flint, H. J. Ruminococcus bromii is a keystone species for the degradation of resistant starch in the human colon microbe-microbe and microbe-host interactions. ISME J. 6, 1535–1543 (2012).

Crost, E. H. et al. Mechanistic Insights Into the Cross-Feeding of Ruminococcus gnavus and Ruminococcus bromii on Host and Dietary Carbohydrates. Front. Microbiol. 9, (2018).

Sasaki M, Schwab C, Ramirez Garcia A, Li Q, Ferstl R, Bersuch E, Akdis CA, Lauener R; CK-CARE study group; Frei R, Roduit C. The abundance of Ruminococcus bromii is associated with faecal butyrate levels and atopic dermatitis in infancy. Allergy. 2022 Aug 2;77(12):3629–40. doi: 10.1111/all.15440. Epub ahead of print. PMID: 35917214; PMCID: PMC10087690.

Bonder MJ, Tigchelaar EF, Cai X, Trynka G, Cenit MC, Hrdlickova B, Zhong H, Vatanen T, Gevers D, Wijmenga C, Wang Y, Zhernakova A. The influence of a short-term gluten-free diet on the human gut microbiome. Genome Med. 2016 Apr 21;8(1):45. doi: 10.1186/s13073-016-0295-y. PMID: 27102333; PMCID: PMC4841035.

Lee T, Clavel T, Smirnov K, Schmidt A, Lagkouvardos I, Walker A, Lucio M, Michalke B, Schmitt-Kopplin P, Fedorak R, Haller D. Oral versus intravenous iron replacement therapy distinctly alters the gut microbiota and metabolome in patients with IBD. Gut. 2017 May;66(5):863-871. doi: 10.1136/gutjnl-2015-309940. Epub 2016 Feb 4. PMID: 26848182; PMCID: PMC5531225.

David LA, Maurice CF, Carmody RN, Gootenberg DB, Button JE, Wolfe BE, Ling AV, Devlin AS, Varma Y, Fischbach MA, Biddinger SB, Dutton RJ, Turnbaugh PJ. Diet rapidly and reproducibly alters the human gut microbiome. Nature. 2014 Jan 23;505(7484):559-63. doi: 10.1038/nature12820. Epub 2013 Dec 11. PMID: 24336217; PMCID: PMC3957428.

Morrison DJ, Preston T. Formation of short chain fatty acids by the gut microbiota and their impact on human metabolism. Gut Microbes. 2016 May 3;7(3):189-200. doi: 10.1080/19490976.2015.1134082. Epub 2016 Mar 10. PMID: 26963409; PMCID: PMC4939913.

Baxter NT, Schmidt AW, Venkataraman A, Kim KS, Waldron C, Schmidt TM. Dynamics of Human Gut Microbiota and Short-Chain Fatty Acids in Response to Dietary Interventions with Three Fermentable Fibers. mBio. 2019 Jan 29;10(1):e02566-18. doi: 10.1128/mBio.02566-18. PMID: 30696735; PMCID: PMC6355990.

Rangarajan AA, Chia HE, Azaldegui CA, Olszewski MH, Pereira GV, Koropatkin NM, Biteen JS. Ruminococcus bromii enables the growth of proximal Bacteroides thetaiotaomicron by releasing glucose during starch degradation. Microbiology (Reading). 2022 Apr;168(4). doi: 10.1099/mic.0.001180. PMID: 35471195.

Kasai C, Sugimoto K, Moritani I, Tanaka J, Oya Y, Inoue H, Tameda M, Shiraki K, Ito M, Takei Y, Takase K. Comparison of the gut microbiota composition between obese and non-obese individuals in a Japanese population, as analyzed by terminal restriction fragment length polymorphism and next-generation sequencing. BMC Gastroenterol. 2015 Aug 11;15:100. doi: 10.1186/s12876-015-0330-2. PMID: 26261039; PMCID: PMC4531509.

Bao R, Hesser LA, He Z, Zhou X, Nadeau KC, Nagler CR. Fecal microbiome and metabolome differ in healthy and food-allergic twins. J Clin Invest. 2021 Jan 19;131(2):e141935. doi: 10.1172/JCI141935. PMID: 33463536; PMCID: PMC7810484.

Rosés C, Cuevas-Sierra A, Quintana S, Riezu-Boj JI, Martínez JA, Milagro FI, Barceló A. Gut Microbiota Bacterial Species Associated with Mediterranean Diet-Related Food Groups in a Northern Spanish Population. Nutrients. 2021 Feb 16;13(2):636. doi: 10.3390/nu13020636. PMID: 33669303; PMCID: PMC7920039.

Nieves-Ramírez ME, Partida-Rodríguez O, Laforest-Lapointe I, Reynolds LA, Brown EM, Valdez-Salazar A, Morán-Silva P, Rojas-Velázquez L, Morien E, Parfrey LW, Jin M, Walter J, Torres J, Arrieta MC, Ximénez-García C, Finlay BB. Asymptomatic Intestinal Colonization with Protist Blastocystis Is Strongly Associated with Distinct Microbiome Ecological Patterns. mSystems. 2018 Jun 26;3(3):e00007-18. doi: 10.1128/mSystems.00007-18. PMID: 29963639; PMCID: PMC6020473.

Zhang Y, Gu Y, Ren H, Wang S, Zhong H, Zhao X, Ma J, Gu X, Xue Y, Huang S, Yang J, Chen L, Chen G, Qu S, Liang J, Qin L, Huang Q, Peng Y, Li Q, Wang X, Kong P, Hou G, Gao M, Shi Z, Li X, Qiu Y, Zou Y, Yang H, Wang J, Xu G, Lai S, Li J, Ning G, Wang W. Gut microbiome-related effects of berberine and probiotics on type 2 diabetes (the PREMOTE study). Nat Commun. 2020 Oct 6;11(1):5015. doi: 10.1038/s41467-020-18414-8. PMID: 33024120; PMCID: PMC7538905.

What does it mean if your Ruminococcus bromii result is too low?

R. bromii decreased on a gluten-free diet in 21 healthy volunteers.

A small study on 11 healthy volunteers showed that an animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii).

Oral versus IV iron supplementation in iron deficient IBD patients resulted in decreased abundances of Faecalibacterium prausnitzii, Ruminococcus bromii, Dorea spp., and Collinsella aerofaciens. 

A study on 409 type 2 diabetes Chinese patients demonstrated the reduction of R. bromii with berberine. It is thought that the hypoglycemic effect of berberine is mediated by the inhibition of secondary bile acid biotransformation by R. bromii.

What does it mean if your Ruminococcus bromii result is too high?

R. bromii increased on a resistant starch diet.

In a study on 360 Spanish adults with different levels of adherence to a Mediterranean diet, legume consumption was shown to enhance R. bromii.

In a population study on 156 asymptomatic Mexican adults, Blastocystis colonization was strongly correlated with an increase in R. bromii.

The abundance of Ruminococcus bromii is associated with faecal butyrate levels and atopic dermatitis in infancy.

A study on 409 type 2 diabetes Chinese patients demonstrated the reduction of R. bromii with berberine. It is thought that the hypoglycemic effect of berberine is mediated by the inhibition of secondary bile acid biotransformation by R. bromii.

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