Bifidobacterium

{{Short description|Genus of bacteria}} {{Automatic taxobox | image = Bifidobacterium adolescentis Gram.jpg | image_caption = ''Bifidobacterium adolescentis'' | image_alt = Bifidobacterium adolescentis | taxon = Bifidobacterium | authority = Orla-Jensen 1924 (Approved Lists 1980)<ref>{{cite journal | author = Orla-Jensen S. | title = Classification des bactéries lactiques | trans-title = Classification of the lactic acid bacteria | journal = Le Lait | year = 1924 | volume = 4 | issue = 36 | pages = 468–474 | doi = 10.1051/lait:19243627| doi-access = free }}</ref> | type_species = ''Bifidobacterium bifidum'' | type_species_authority = (Tissier 1900) Orla-Jensen 1924 (Approved Lists 1980) | subdivision_ranks = Species | subdivision = See text. }}

'''''Bifidobacterium''''' is a genus of gram-positive, nonmotile, often branched anaerobic bacteria. They are ubiquitous inhabitants of the gastrointestinal tract<ref name="pmid12381787">{{cite journal | vauthors = Schell MA, Karmirantzou M, Snel B, Vilanova D, Berger B, Pessi G, Zwahlen MC, Desiere F, Bork P, Delley M, Pridmore RD, Arigoni F | title = The genome sequence of ''Bifidobacterium longum'' reflects its adaptation to the human gastrointestinal tract | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 99 | issue = 22 | pages = 14422–7 | date = October 2002 | pmid = 12381787 | pmc = 137899 | doi = 10.1073/pnas.212527599 | bibcode = 2002PNAS...9914422S | doi-access = free }}</ref><ref name= MayoB>{{cite book | veditors = Mayo B, van Sinderen D |year=2010 |title=Bifidobacteria: Genomics and Molecular Aspects |publisher= Caister Academic Press |isbn=978-1-904455-68-4}}{{page needed|date=November 2011}}</ref> though strains have been isolated from the vagina<ref>{{cite journal |last1=Albert |first1=Arianne Y. K. |last2=Chaban |first2=Bonnie |last3=Wagner |first3=Emily C. |last4=Schellenberg |first4=John J. |last5=Links |first5=Matthew G. |last6=Schalkwyk |first6=Julie van |last7=Reid |first7=Gregor |last8=Hemmingsen |first8=Sean M. |last9=Hill |first9=Janet E. |last10=Money |first10=Deborah |last11=Group |first11=VOGUE Research |title=A Study of the Vaginal Microbiome in Healthy Canadian Women Utilizing cpn60-Based Molecular Profiling Reveals Distinct Gardnerella Subgroup Community State Types |journal=PLOS ONE |date=12 August 2015 |volume=10 |issue=8 |article-number=e0135620 |doi=10.1371/journal.pone.0135620 |pmid=26266808|pmc=4534464 |bibcode=2015PLoSO..1035620A |doi-access=free }}</ref> and mouth (''B. dentium'') of mammals, including humans. Bifidobacteria are one of the major genera of bacteria that make up the gastrointestinal tract microbiota in mammals. Some bifidobacteria are used as probiotics.

Before the 1960s, ''Bifidobacterium'' species were collectively referred to as ''Lactobacillus bifidus''.

==Mode of action== Underlying most of the beneficial effects of ''Bifidobacterium'' are improved immune system function and reduction in inflammation.<ref name="pmid38055306">{{cite journal | vauthors = Gavzy SJ, Kensiski A, Bromberg JS | title = Bifidobacterium mechanisms of immune modulation and tolerance | journal = Gut Microbes | volume = 15 | issue = 2 | article-number = 2291164 | date = 2023 | pmid = 38055306 | pmc=10730214 | doi = 10.1080/19490976.2023.2291164| doi-access = free }}</ref> Notably, ''Bifidobacterium'' increases regulatory T cells and improves the intestinal barrier.<ref name="pmid38055306" /> ''Bifidobacterium'' produces essential metabolites for use by other key bacteria.<ref name="pmid38055306" /> ''Bifidobacterium'' carbohydrate fermentation produces acetate and butyrate, which can protect against various diseases.<ref name="pmid38055306" />

==History== [[Image:20101210 013757 BifidobacteriumAnimalis.jpg|thumb|right|Some of the ''Bifidobacterium animalis'' bacteria found in a sample of Activia yogurt:&nbsp; The numbered ticks on the scale are 10 micrometres apart.]] In 1899, Henri Tissier, a French pediatrician at the Pasteur Institute in Paris, isolated a bacterium characterised by a Y-shaped morphology ("bifid") in the intestinal microbiota of breast-fed infants and named it "bifidus".<ref name="tspace.library.utoronto.ca">{{cite journal|url=https://tspace.library.utoronto.ca/bitstream/1807/6600/1/jb05023.pdf|title=Potential of probiotics as biotherapeutic agents targeting the innate immune system|journal=African Journal of Biotechnology|date=February 2005|archive-date=2016-03-03|access-date=2013-07-01|archive-url=https://web.archive.org/web/20160303224906/https://tspace.library.utoronto.ca/bitstream/1807/6600/1/jb05023.pdf|url-status=live}}</ref> In 1907, Élie Metchnikoff, deputy director at the Pasteur Institute, propounded the theory that lactic acid bacteria are beneficial to human health.<ref name="tspace.library.utoronto.ca"/> Metchnikoff observed that the longevity of Bulgarians was the result of their consumption of fermented milk products.<ref>{{cite journal |url=http://mail.successmakers.com/uploads/Probiotics_-_100_years_after_Elie_Metchnikoff_PhDs_Obsevations.pdf |title=Probiotics: 100 years (1907–2007) after Elie Metchnikoff's Observation |journal=Communicating Current Research and Educational Topics and Trends in Applied Microbiology |date=February 2007 |archive-url=https://web.archive.org/web/20121004072755/http://mail.successmakers.com/uploads/Probiotics_-_100_years_after_Elie_Metchnikoff_PhDs_Obsevations.pdf |archive-date=2012-10-04 }}</ref> Metchnikoff also suggested that "oral administration of cultures of fermentative bacteria would implant the beneficial bacteria in the intestinal tract".<ref>{{cite journal|url=http://asso-epa.com/pioneers-of-probiotics/|title=Pioneers of Probiotics|journal=European Probiotic Association|date=February 2012|access-date=2013-07-01|archive-url=https://web.archive.org/web/20130722170616/http://asso-epa.com/pioneers-of-probiotics/|archive-date=2013-07-22}}</ref>

==Metabolism== The genus ''Bifidobacterium'' possesses a unique fructose-6-phosphate phosphoketolase pathway employed to ferment carbohydrates.{{cn|date=January 2021}}

Much metabolic research on bifidobacteria has focused on oligosaccharide metabolism, as these carbohydrates are available in their otherwise nutrient-limited habitats. Infant-associated bifidobacterial phylotypes appear to have evolved the ability to ferment milk oligosaccharides, whereas adult-associated species use plant oligosaccharides, consistent with what they encounter in their respective environments. As breast-fed infants often harbor bifidobacteria-dominated gut consortia, numerous applications attempt to mimic the bifidogenic properties of milk oligosaccharides. These are broadly classified as plant-derived fructooligosaccharides or dairy-derived galactooligosaccharides, which are differentially metabolized and distinct from milk oligosaccharide catabolism.<ref name="MayoB"/>

==Response to oxygen== The sensitivity of members of the genus ''Bifidobacterium'' to O₂ generally limits probiotic activity to anaerobic habitats. Recent research has reported that some ''Bifidobacterium'' strains exhibit various types of oxic growth. Low concentrations of O₂ and CO₂ can have a stimulatory effect on the growth of these ''Bifidobacterium'' strains. Based on the growth profiles under different O₂ concentrations, the ''Bifidobacterium'' species were classified into four classes: O₂-hypersensitive, O₂-sensitive, O₂-tolerant, and microaerophilic. The primary factor responsible for aerobic growth inhibition is proposed to be the production of hydrogen peroxide (H₂O₂) in the growth medium. A H₂O₂-forming NADH oxidase was purified from O₂-sensitive ''Bifidobacterium bifidum'' and was identified as a ''b''-type dihydroorotate dehydrogenase. The kinetic parameters suggested that the enzyme could be involved in H₂O₂ production in highly aerated environments.<ref name= SonomotoKYokotaA>{{cite book |editor1-last=Sonomoto |editor1-first=Kenji |editor2-last=Yokota |editor2-first=Atsushi | name-list-style = vanc |year=2011 |title=Lactic Acid Bacteria and Bifidobacteria: Current Progress in Advanced Research |publisher=Caister Academic Press |isbn=978-1-904455-82-0}}{{page needed|date=November 2011}}</ref>

==Genomes== Members of the genus ''Bifidobacterium'' have genome sizes ranging from 1.73 (''Bifidobacterium indicum'') to 3.25 Mb (''Bifidobacterium biavatii''), corresponding to 1,352 and 2,557 predicted protein-encoding open reading frames, respectively.<ref name="Milani-2016">{{cite journal | vauthors = Milani C, Turroni F, Duranti S, Lugli GA, Mancabelli L, Ferrario C, van Sinderen D, Ventura M | title = Genomics of the Genus Bifidobacterium Reveals Species-Specific Adaptation to the Glycan-Rich Gut Environment | journal = Applied and Environmental Microbiology | volume = 82 | issue = 4 | pages = 980–991 | date = February 2016 | pmid = 26590291 | pmc = 4751850 | doi = 10.1128/AEM.03500-15 | bibcode = 2016ApEnM..82..980M }}</ref>

Functional classification of ''Bifidobacterium'' genes, including the pan-genome of this genus, revealed that 13.7% of the identified bifidobacterial genes encode enzymes involved in carbohydrate metabolism.<ref name="Milani-2016" />

==Clinical uses== Adding ''Bifidobacterium'' as a probiotic to conventional treatment of ulcerative colitis has been shown to be associated with improved rates of remission and improved maintenance of remission.<ref name=Ghouri2014>{{cite journal | vauthors = Ghouri YA, Richards DM, Rahimi EF, Krill JT, Jelinek KA, DuPont AW | title = Systematic review of randomized controlled trials of probiotics, prebiotics, and synbiotics in inflammatory bowel disease | journal = Clinical and Experimental Gastroenterology | volume = 7 | pages = 473–87 | date = 9 December 2014 | pmid = 25525379 | pmc = 4266241 | doi = 10.2147/CEG.S27530 | doi-access = free }}</ref> Some ''Bifidobacterium'' strains are considered as important probiotics and used in the food industry. Different species and/or strains of bifidobacteria may exert a range of beneficial health effects, including the regulation of intestinal microbial homeostasis, the inhibition of pathogens and harmful bacteria that colonize and/or infect the gut mucosa, the modulation of local and systemic immune responses, the repression of procarcinogenic enzymatic activities within the microbiota, the production of vitamins, and the bioconversion of a number of dietary compounds into bioactive molecules.<ref name="MayoB" /> Bifidobacteria improve the gut mucosal barrier and lower levels of lipopolysaccharide in the intestine.<ref name="Pinzone-2012">{{cite journal | vauthors = Pinzone MR, Celesia BM, Di Rosa M, Cacopardo B, Nunnari G | title = Microbial translocation in chronic liver diseases | journal = International Journal of Microbiology | volume = 2012 | article-number = 694629 | year = 2012 | pmid = 22848224 | pmc = 3405644 | doi = 10.1155/2012/694629 | doi-access = free }}</ref>

Bifidobacteria may also improve abdominal pain in patients with irritable bowel syndrome (IBS) though studies to date have been inconclusive.<ref>{{Cite journal|last1=Pratt|first1=Charlotte|last2=Campbell|first2=Matthew D.|date=2019-11-18|title=The Effect of Bifidobacterium on Reducing Symptomatic Abdominal Pain in Patients with Irritable Bowel Syndrome: A Systematic Review|journal=Probiotics and Antimicrobial Proteins|volume=12|issue=3|pages=834–839|language=en|doi=10.1007/s12602-019-09609-7|pmid=31741311|pmc=7456408|issn=1867-1306|doi-access=free}}</ref>

Naturally occurring ''Bifidobacterium'' spp. may discourage the growth of Gram-negative pathogens in infants.<ref>{{cite journal | vauthors = Liévin V, Peiffer I, Hudault S, Rochat F, Brassart D, Neeser JR, Servin AL | title = Bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity | journal = Gut | volume = 47 | issue = 5 | pages = 646–52 | date = November 2000 | pmid = 11034580 | pmc = 1728100 | doi = 10.1136/gut.47.5.646 }}</ref>

A mother's milk contains high concentrations of lactose and lower quantities of phosphate (pH buffer). Therefore, when mother's milk is fermented by lactic acid bacteria (including bifidobacteria) in the infant's gastrointestinal tract, the pH may be reduced, making it more difficult for Gram-negative bacteria to grow.{{cn|date=January 2021}}

== Bifidobacteria and the infant gut == The human infant gut is relatively sterile up until birth, where it takes up bacteria from its surrounding environment and its mother.<ref>{{cite journal | vauthors = Pham VT, Lacroix C, Braegger CP, Chassard C | title = Early colonization of functional groups of microbes in the infant gut | journal = Environmental Microbiology | volume = 18 | issue = 7 | pages = 2246–58 | date = July 2016 | pmid = 27059115 | doi = 10.1111/1462-2920.13316 | bibcode = 2016EnvMi..18.2246P }}</ref> The microbiota that makes up the infant gut differs from the adult gut. An infant reaches the adult stage of their microbiome at around three years of age, when their microbiome diversity increases, stabilizes, and the infant switches over to solid foods. Breast-fed infants are colonized earlier by ''Bifidobacterium'' when compared to babies that are primarily formula-fed.<ref>{{Cite journal| vauthors = Bourlieu C, Bouzerzour K, FerretBernard S, Bourgot CL, Chever S, Menard O, Deglaire A, Cuinet I, Ruyet PL, Bonhomme C, Dupont D |date=2015|title=Infant formula interface and fat source impact on neonatal digestion and gut microbiota|journal=European Journal of Lipid Science and Technology|language=en|volume=117|issue=10|pages=1500–1512|doi=10.1002/ejlt.201500025|issn=1438-9312}}</ref> ''Bifidobacterium'' is the most common bacteria in the infant gut microbiome.<ref>{{cite journal | vauthors = Turroni F, Peano C, Pass DA, Foroni E, Severgnini M, Claesson MJ, Kerr C, Hourihane J, Murray D, Fuligni F, Gueimonde M, Margolles A, De Bellis G, O'Toole PW, van Sinderen D, Marchesi JR, Ventura M | title = Diversity of bifidobacteria within the infant gut microbiota | journal = PLOS ONE | volume = 7 | issue = 5 | article-number = e36957 | date = 2012-05-11 | pmid = 22606315 | pmc = 3350489 | doi = 10.1371/journal.pone.0036957 | bibcode = 2012PLoSO...736957T | doi-access = free }}</ref> There is more variability in genotypes over time in infants, making them less stable compared to the adult ''Bifidobacterium''. Infants and children under three years old show low diversity in microbiome bacteria, but more diversity between individuals when compared to adults.<ref>{{cite journal | vauthors = Matamoros S, Gras-Leguen C, Le Vacon F, Potel G, de La Cochetiere MF | title = Development of intestinal microbiota in infants and its impact on health | language = en | journal = Trends in Microbiology | volume = 21 | issue = 4 | pages = 167–73 | date = April 2013 | pmid = 23332725 | doi = 10.1016/j.tim.2012.12.001 | url = https://www.cell.com/trends/microbiology/abstract/S0966-842X(12)00213-2 | url-access = subscription }}</ref> Reduction of ''Bifidobacterium'' and increase in diversity of the infant gut microbiome occurs with less breast-milk intake and increase of solid food intake. Mammalian milk all contain oligosaccharides showing natural selection.{{clarification needed|date=October 2020}} Human milk oligosaccharides are not digested by enzymes and remain whole through the digestive tract before being broken down in the colon by microbiota. ''Bifidobacterium'' species genomes of ''B. longum, B. bifidum, B. breve'' contain genes that can hydrolyze some of the human milk oligosaccharides and these are found in higher numbers in infants that are breast-fed. Glycans that are produced by the humans are converted into food and energy for the ''B. bifidum.'' showing an example of coevolution.<ref>{{cite journal | vauthors = Turroni F, Milani C, Duranti S, Ferrario C, Lugli GA, Mancabelli L, van Sinderen D, Ventura M | title = Bifidobacteria and the infant gut: an example of co-evolution and natural selection | journal = Cellular and Molecular Life Sciences | volume = 75 | issue = 1 | pages = 103–118 | date = January 2018 | pmid = 28983638 | doi = 10.1007/s00018-017-2672-0 | s2cid = 24103287 | pmc = 11105234 }}</ref>

== Species ==

The genus ''Bifidobacterium'' comprises the following species:<ref name="LPSN">{{cite web |vauthors=Euzéby JP, Parte AC |url=https://lpsn.dsmz.de/family/actinomycetaceae |title=''Actinomycetaceae'' |access-date=June 17, 2021 |website=List of Prokaryotic names with Standing in Nomenclature (LPSN) |archive-date=October 26, 2022 |archive-url=https://web.archive.org/web/20221026191905/https://lpsn.dsmz.de/family/actinomycetaceae |url-status=live }}</ref> {{div col|colwidth=250px}}

Bombiscardovia Group (all cultured from the hindgut of bees)

* ''B. actinocoloniiforme'' <small>Killer et al. 2011</small> * ''B. apousia'' <small>Chen et al. 2022</small> * ''B. asteroides'' <small>Scardovi and Trovatelli 1969 (Approved Lists 1980)</small> <!-- Bifidobacterium coryneforme was reclassified as Bifidobacterium indicum. --> * ''B. choladohabitans '' <small>Chen et al. 2022</small> * ''B. indicum'' <small>Scardovi and Trovatelli 1969 (Approved Lists 1980)</small> * ''B. polysaccharolyticum'' <small>Chen et al. 2022</small> * ''B. xylocopae'' <small>Alberoni et al. 2019</small> {{div col end}}

''Bifidobacterium adolescentis'' Group * ''B. adolescentis'' <small>Reuter 1963 (Approved Lists 1980)</small> * ''B. catenulatum'' <small>Scardovi and Crociani 1974 (Approved Lists 1980)</small> * ''B. dentium'' <small>Scardovi and Crociani 1974 (Approved Lists 1980)</small> <!-- Bifidobacterium faecale was reclassified as Bifidobacterium adolescentis. --> <!-- Bifidobacterium kashiwanohense was reclassified as Bifidobacterium catenulatum subsp. kashiwanohense. --> * ''B. moukalabense'' <small>Tsuchida et al. 2014</small> * ''B. pseudocatenulatum'' <small>Scardovi et al. 1979 (Approved Lists 1980)</small> * ''B. ruminantium'' <small>Biavati and Mattarelli 1991</small> <!-- Bifidobacterium stercoris was reclassified as Bifidobacterium adolescentis. -->

''Bifidobacterium bifidium'' Group * ''B. aerophilum'' <small>Michelini et al. 2017</small> * ''B. amazonense'' <small>Lugli et al. 2021</small> * ''B. biavatii'' <small>Endo et al. 2012</small> * ''B. bifidum'' <small>(Tissier 1900) Orla-Jensen 1924 (Approved Lists 1980)</small> * ''B. goeldii'' <small>Duranti et al. 2019</small> * ''B. hapali'' <small>Michelini et al. 2016</small> * ''B. jacchi'' <small>Modesto et al. 2019</small> * ''B. leontopitheci'' <small>Duranti et al. 2020</small> * ''B. ramosum'' <small>Michelini et al. 2017</small> * ''B. samirii'' <small>Duranti et al. 2019</small> * ''B. scardovii'' <small>Hoyles et al. 2002</small>

''Bifidobacterium bombi'' Group (Milk and Honey) * ''B. aemilianum'' <small>Alberoni et al. 2019</small> * ''B. bohemicum'' <small>Killer et al. 2011</small> * ''B. bombi'' <small>Killer et al. 2009</small> * ''B. commune'' <small>Praet et al. 2015</small> * ''B. minimum'' <small>Biavati et al. 1982</small> * ''B. mongoliense'' <small>Watanabe et al. 2009</small> * ''B. subtile'' <small>Biavati et al. 1982</small> * ''B. tibiigranuli'' <small>Eckel et al. 2020</small>

''Bifidobacterium boum'' Group * ''B. apri'' <small>Pechar et al. 2017</small> * ''B. boum'' <small>Scardovi et al. 1979 (Approved Lists 1980)</small> * ''B. porcinum'' <small>(Zhu et al. 2003) Nouioui et al. 2018</small> <!-- Bifidobacterium ruminale was reclassified as Bifidobacterium thermophilum. --> * ''B. thermacidophilum'' <small>Dong et al. 2000</small> <!-- Bifidobacterium thermophilium is a misspelling of Bifidobacterium thermophilum. --> * ''B. thermophilum'' <small>corrig. Mitsuoka 1969 (Approved Lists 1980)</small>

''Bifidobacterium longum'' Group * ''B. aesculapii'' <small>Modesto et al. 2014</small> * ''B. angulatum'' <small>Scardovi and Crociani 1974 (Approved Lists 1980)</small> * ''B. avesanii'' <small>Michelini et al. 2019</small> * ''B. breve'' <small>Reuter 1963 (Approved Lists 1980)</small> * ''B. callitrichidarum'' <small>Modesto et al. 2018</small> * ''B. callitrichos'' <small>Endo et al. 2012</small> * ''B. cebidarum'' <small>Duranti et al. 2020</small> * ''B. colobi'' <small>Lugli et al. 2021</small> * ''B. erythrocebi'' <small>Neuzil-Bunesova et al. 2021</small> * ''B. eulemuris'' <small>Michelini et al. 2016</small> * ''B. felsineum'' <small>Modesto et al. 2020</small> <!-- Bifidobacterium infantis was reclassified as Bifidobacterium longum sub. infantis --> <!-- Bifidobacterium lactis was reclassified as Bifidobacterium animalis. --> * ''B. lemurum'' <small>Modesto et al. 2015</small> * ''B. longum'' <small>Reuter 1963 (Approved Lists 1980)</small> * ''B. merycicum'' <small>Biavati and Mattarelli 1991</small> * ''B. miconisargentati'' <small>Lugli et al. 2021</small> * ''B. moraviense'' <small>Neuzil-Bunesova et al. 2021</small> * ''B. myosotis'' <small>Michelini et al. 2016</small> * ''B. oedipodis'' <small>Neuzil-Bunesova et al. 2021</small> * ''B. olomucense'' <small>Neuzil-Bunesova et al. 2021</small> * ''B. panos'' <small>Neuzil-Bunesova et al. 2021</small> * ''B. parmae'' <small>Lugli et al. 2018</small> * "''B. platyrrhinorum''" <small>Modesto et al. 2020</small> * ''B. pongonis'' <small>Lugli et al. 2021</small> * ''B. reuteri'' <small>Endo et al. 2012</small> * ''B. rousetti'' <small>Modesto et al. 2021</small> * ''B. saguini'' <small>Endo et al. 2012</small> * ''B. saguinibicoloris'' <small>Lugli et al. 2021</small> * ''B. santillanense'' <small>Lugli et al. 2021</small> * ''B. scaligerum'' <small>Modesto et al. 2020</small> * ''B. simiiventris'' <small>Lugli et al. 2021</small> * ''B. stellenboschense'' <small>Endo et al. 2012</small> <!-- Bifidobacterium suis was reclassified as Bifidobacterium longum subsp. suis --> * ''B. vespertilionis'' <small>Modesto et al. 2021</small>

''Bifidobacterium pullorum'' Group (from birds and rabbits) * ''B. pullorum'' <small> Trovatelli et al. 1974 (Approved Lists 1980)</small> *''"Bifidobacterium phasiani"'' <!-- Bifidobacterium gallinarum was reclassified as Bifidobacterium pullorum subsp. gallinarum --> <!-- Bifidobacterium saeculare was reclassified as Bifidobacterium pullorum subsp. gallinarum. -->

''Bifidobacterium pseudolongum'' Group * ''B. animalis'' <small>(Mitsuoka 1969) Scardovi and Trovatelli 1974 (Approved Lists 1980)</small> * ''B. anseris'' <small>Lugli et al. 2018</small> * ''B. canis'' <small>Neuzil-Bunesova et al. 2020</small> * ''B. castoris'' <small>Duranti et al. 2019</small> * ''B. choerinum'' <small>Scardovi et al. 1979 (Approved Lists 1980)</small> * ''B. choloepi'' <small>Modesto et al. 2020</small> * ''B. criceti'' <small>Lugli et al. 2018</small> * ''B.cuniculi '' <small>Scardovi et al. 1979 (Approved Lists 1980)</small> * ''B. dolichotidis'' <small>Duranti et al. 2019</small> * ''B. gallicum'' <small>Lauer 1990</small> * ''B. italicum'' <small>Lugli et al. 2018</small> * ''B. magnum'' <small>Scardovi and Zani 1974 (Approved Lists 1980)</small> * ''B. miconis'' <small>Lugli et al. 2021</small> * ''B. pseudolongum'' <small>Mitsuoka 1969 (Approved Lists 1980)</small> <!-- Bifidobacterium globosum was reclassified as Bifidobacterium pseudolongum subsp. globosum -->

''Bifidobacterium psychroarophilum'' Group * ''B. aquikefiri'' <small>Laureys et al. 2016</small> * "''B. crudilactis''" <small>Delcenserie et al. 2007</small> * ''B. psychraerophilum'' <small>Simpson et al. 2004</small>

''Bifidobacterium tissieri'' Group (from primates) * ''B. callimiconis'' <small>Duranti et al. 2019</small> * ''B. catulorum'' <small>Modesto et al. 2018</small> * ''B.margollesii '' <small>Lugli et al. 2018</small> * ''B. pluvialisilvae'' <small>Lugli et al. 2021</small> * ''B. primatium'' <small>Modesto et al. 2020</small> * "''B. saimiriisciurei''" <small>Modesto et al. 2020</small> * ''B. simiarum'' <small>Modesto et al. 2020</small> * ''B. tissieri'' <small>corrig. Michelini et al. 2016</small> <!-- Bifidobacterium tissierii is a misspelling of Bifidobacterium tissieri. --> * ''B. vansinderenii'' <small>Duranti et al. 2017</small>

Ungrouped Bifidobacterium

* ''B. imperatoris'' <small>Lugli et al. 2018</small> <!-- Bifidobacterium denticolens was reclassified as Parascardovia denticolens. --> <!-- Bifidobacterium eriksonii was reclassified as Parascardovia dentium. --> <!-- Bifidobacterium inopinatum was reclassified as Scardovia inopinata. --> * ''B. tsurumiense'' <small>Okamoto et al. 2008</small> <!-- Bifidobacterium urinalis was never validly published. -->

== See also == * List of bacterial vaginosis microbiota * Probiotic * Proteobiotics * Prebiotics

== References == {{reflist|30em}}

== External links == * [http://microbewiki.kenyon.edu/index.php/Bifidobacterium Bifidobacterium] at [http://microbewiki.kenyon.edu/ Microbe Wiki] * [http://www.genomesonline.org Genomes Online Database] contains many Bifidobacterium genome projects * [http://bacdive.dsmz.de/index.php?search=Bifidobacterium&submit=Search ''Bifidobacterium'' at Bac''Dive'' – the Bacterial Diversity Metadatabase] * [https://biomesight.com/blog/bifidobacteria-spotlight Spotlight on Bifidobacteria] * [https://radiolab.org/podcast/the-elixir-of-life Radiolab podcast] Bifidobacterium Infantis in particular

{{wikispecies}}

{{Bacteria classification}} {{Yogurts}} {{Taxonbar|from=Q132656}} {{Authority control}}

Category:Bifidobacteriales Category:Gut flora bacteria Category:Bacterial vaginosis Category:Bacteria genera