// Workers AI · dad joke modeWhy was segmented filamentous bacteria good at sports? It had a lot of segments to its team.
| Segmented filamentous bacteria | |
|---|---|
Scientific classification  (Candidatus) | |
| Domain: | Bacteria |
| Kingdom: | Bacillati |
| Phylum: | Bacillota |
| Class: | Clostridia |
| Order: | Eubacteriales |
| Family: | Clostridiaceae |
| Genus: | Candidatus Savagella Thompson et al. 2012[1] non Foerste 1920 non Geis 1932 |
| Type species | |
| "Ca. Savagella gallinara" Gilroy et al. 2021 | |
| Species | |
| |
| Synonyms | |
| |
Segmented filamentous bacteria (SFB) are members of the gut microbiota of mammals, fish, and birds, and have been shown to potently induce immune responses in mice.[2] They have a distinct morphology and form their own clade within the Clostridiaceae. The SFB genus is known as Anisomitus, for "uneven thread", with A. miae as the nomenclature type (seqco.de/r:zlg3gn05). [3]
Previously, the name Candidatus Savagella was proposed for this lineage[1] after they had been referred to as Candidatus Arthromitus due to their morphological resemblance to bacterial filaments previously observed in the guts of insects by Joseph Leidy[4].
Despite the fact that they have been widely referred to as segmented filamentous bacteria, this term is somewhat problematic as it does not allow one to distinguish between different bacterial species that colonize various hosts. In mice, these bacteria grow primarily in the terminal ileum in close proximity to the intestinal epithelium where they are thought to help induce T helper 17 cell responses.[5] Mouse studies indicate SFB-induced Th17 cells can convert to Th1-like cells, enhancing anti-PD-1 tumor control against tumors sharing an SFB antigen.[6]
Intriguingly, Segmented Filamentous Bacteria were found to expand in AID-deficient mice, which lack the ability to mount an appropriate humoral immune response because of impaired somatic hypermutation; parabiotic experiments revealed the importance of IgA in eliminating Segmented Filamentous Bacteria.[7] This goes hand in hand with an earlier study demonstrating the ability of monocolonization with Segmented Filamentous Bacteria to dramatically increase mucosal IgA levels.[8] Segmented Filamentous Bacteria are species specific, and may be important to immune development.
See also
[edit]References
[edit]- 1 2 Thompson, C. L.; Vier, R.; Mikaelyan, A.; Wienemann, T.; Brune, A. (2012). "'Candidatus Arthromitus' revised: Segmented filamentous bacteria in arthropod guts are members of Lachnospiraceae". Environmental Microbiology. 14 (6): 1454–65. Bibcode:2012EnvMi..14.1454T. doi:10.1111/j.1462-2920.2012.02731.x. PMID 22436008.
- ↑ Ivanov, I. I.; Littman, D. R. (2010). "Segmented filamentous bacteria take the stage". Mucosal Immunology. 3 (3): 209–212. doi:10.1038/mi.2010.3. PMC 3010405. PMID 20147894.
- ↑ Kiran, Shashi; Cruz, Ana Raquel; Daniau, Alice; Ma, Bing; Marbouty, Martial; Pipoli Da Fonseca, Juliana; Legrand, Agnes; Baudry, Lyam; Cokelaer, Thomas; Bensussan, Matthieu; Moya-Nilges, Maryse; Garneau, Julian; Monot, Marc; Ochieng, John B; Antonio; Tamboura, Boubou; de Vos, Willem M; Salonen, Anne; Hossain, Jahangir; Omore, Richard; Sow, Samba O; Sansonetti, Philippe J; Ravel, Jacques; Cerf-Bensussan, Nadine; Schnupf, Pamela (March 2026). "Segmented filamentous bacteria are worldwide human gut commensals". Nature Communications. 17 (4174). doi:10.1038/s41467-026-70010-4.
- ↑ Leidy, J. 1849. On the existence of entophyta in healthy animals, as a natural condition. Proc. National Academy of Sciences. USA 4:225–233
- ↑ Ivanov, I.; Atarashi, K.; Manel, N.; Brodie, E.; Shima, T.; Karaoz, U.; Wei, D.; Goldfarb, K.; Santee, C.; Lynch, S. V.; Tanoue, T.; Imaoka, A.; Itoh, K.; Takeda, K.; Umesaki, Y.; Honda, K.; Littman, D. R. (2009). "Induction of intestinal Th17 cells by segmented filamentous bacteria". Cell. 139 (3): 485–498. doi:10.1016/j.cell.2009.09.033. PMC 2796826. PMID 19836068.
- ↑ Najar, Tariq A.; Hao, Yuan; Hao, Yuhan; Romero-Meza, Gabriela; Dolynuk, Alexandra; Almo, Emma; Littman, Dan R. (March 2026). "Microbiota-induced T cell plasticity enables immune-mediated tumour control". Nature. 651 (8104): 201–210. doi:10.1038/s41586-025-09913-z. ISSN 1476-4687.
- ↑ Suzuki, K.; Meek, B.; Doi, Y.; Muramatsu, M.; Chiba, T.; Honjo, T.; Făgărășan, S. (2004). "Aberrant expansion of segmented filamentous bacteria in IgA-deficient gut". Proceedings of the National Academy of Sciences of the United States of America. 101 (7): 1981–1986. Bibcode:2004PNAS..101.1981S. doi:10.1073/pnas.0307317101. PMC 357038. PMID 14766966.
- ↑ Klaasen, H. L.; Van Der Heijden, P. J.; Stok, W.; Poelma, F. G.; Koopman, J. P.; Van Den Brink, M. E.; Bakker, M. H.; Eling, W. M.; Beynen, A. C. (1993). "Apathogenic, intestinal, segmented, filamentous bacteria stimulate the mucosal immune system of mice". Infection and Immunity. 61 (1): 303–306. doi:10.1128/IAI.61.1.303-306.1993. PMC 302719. PMID 8418051.
- Gut Immune Maturation Depends on Colonization with a Host-Specific Microbiota (Cell Volume 149, Issue 7 2012 1578 – 1593)
Further reading
[edit]Two review articles
- Ivanov II; Littman DR (May 2010). "Segmented filamentous bacteria take the stage". Mucosal Immunol. 3 (3): 209–12. doi:10.1038/mi.2010.3. PMC 3010405. PMID 20147894.
- Klaasen HL; Koopman JP; Poelma FG; Beynen AC (June 1992). "Intestinal, segmented, filamentous bacteria". FEMS Microbiol. Rev. 8 (3–4): 165–80. doi:10.1016/0378-1097(92)90801-t. PMID 1515159.