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Navigating the microbial seas: a global analysis of gut microbiota in marine mammals

Published online by Cambridge University Press:  23 June 2025

Dalma Belén Soñez*
Affiliation:
Laboratorio de Zoología Vertebrados, Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
Diana Szteren
Affiliation:
Laboratorio de Zoología Vertebrados, Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
*
Corresponding author: Dalma Belén Soñez; Email: dsonez@fcien.edu.uy

Abstract

The gastrointestinal microbiota of mammals plays a crucial role in host health, influencing nutrient absorption, lipid metabolism, and immune system regulation. This study examines the current state of research on gut microbiota in pinnipeds and cetaceans, significant indicators of ocean health. To this end, a bibliometric and an in-depth analysis was conducted using the Scopus database. A total of 83 articles published between 1994 and 2023 were found on this topic. In this period, publications showed a 6.9% annual increase, reflecting a growing interest in this field. The USA and China lead in research output, reflecting their high investment in research funding. Study topics were classified in characterization, characterization and comparison, bacterial isolation, and others. Regarding the origin of the samples, faecal samples predominated over gastrointestinal tissues and oral swabs. The most abundant bacterial phyla were Firmicutes, Proteobacteria, Fusobacteria, and Bacterioidetes. The research also highlights the presence of pathogenic bacteria underscoring the need to better understand the health implications for these species. The analysis also reveals that studies focus on a few species, such as Phoca vitulina (Harbor seal) and Tursiops truncatus (Bottlenose dolphin), reflecting a bias towards more accessible and studied species. To advance in this area, it is recommended to broaden the range of species and countries studied, improve sampling methodologies, and foster international collaborations. Research on marine mammal gut microbiota remains an expanding field, offering significant insights into the biology and ecology of these animals.

Information

Type
Research Article
Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of Marine Biological Association of the United Kingdom.

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References

Abdelrhman, KFA, Ciofini, A, Bacci, G, Mancusi, C, Mengoni, A and Ugolini, A (2020) Exploring the resident gut microbiota of stranded odontocetes: High similarities between two dolphin species Tursiops truncatus and Stenella coeruleoalba. Journal of the Marine Biological Association of the United Kingdom 100, 11811188.10.1017/S0025315420000983CrossRefGoogle Scholar
Aksnes, DW and Browman, HI (2016) An overview of global research effort in fisheries science. ICES Journal of Marine Science 73, 10041011.10.1093/icesjms/fsv248CrossRefGoogle Scholar
Apprill, A (2017) Marine animal microbiomes: toward understanding host–microbiome interactions in a changing ocean. Frontiers in Marine Science 4, 222.10.3389/fmars.2017.00222CrossRefGoogle Scholar
Aria, M and Cuccurullo, C (2017). Bibliometrix: An R-Tool for Comprehensive Science Mapping Analysis. Journal of Informetrics 11, 959975.10.1016/j.joi.2017.08.007CrossRefGoogle Scholar
Bai, S, Zhang, P, Lin, M, Lin, W, Yang, Z and Li, S (2021) Microbial diversity and structure in the gastrointestinal tracts of two stranded short-finned pilot whales (Globicephala macrorhynchus) and a pygmy sperm whale (Kogia breviceps). Integrative Zoology 16, 324335.10.1111/1749-4877.12502CrossRefGoogle Scholar
Banks, JC, Cary, SC and Hogg, ID (2014) Isolated faecal bacterial communities found for Weddell seals, Leptonychotes weddellii, at White island, McMurdo Sound, Antarctica. Polar Biology 37, 18571864.10.1007/s00300-014-1567-xCrossRefGoogle Scholar
Bik, EM, Costello, EK, Switzer, AD, Callahan, BJ, Holmes, SP, Wells, RS, Carlin, KP, Jensen, ED, Venn-Watson, S and Relman, DA (2016) Marine mammals harbor unique microbiotas shaped by and yet distinct from the sea. Nature Communications 7, 10516.10.1038/ncomms10516CrossRefGoogle ScholarPubMed
Bossart, GD (2011) Marine mammals as sentinel species for oceans and human health. Veterinary Pathology 48, 676690.10.1177/0300985810388525CrossRefGoogle ScholarPubMed
Broadus, RN (1987) Toward a definition of “bibliometrics.” Scientometrics 12, 373379.10.1007/BF02016680CrossRefGoogle Scholar
Burns, JJ (2009) Harbor Seal and Spotted Seal: Phoca vitulina and P. largha. In Perrin William, F, Bernd, W and Thewissen, JGM ((eds)), Encyclopedia of Marine Mammals.Second Edition. London: Academic Press, 533542.10.1016/B978-0-12-373553-9.00126-7CrossRefGoogle Scholar
Cicala, F, Ramírez-Delgado, D, Gómez-Reyes, R, Martínez-Porchas, M, Rojas-Vargas, J, Pardo-López, L and Licea-Navarro, AF (2022) Detection of human pathogenic bacteria in rectal DNA samples from Zalophus californianus in the Gulf of California, Mexico. Scientific Reports 12(1), 14859.10.1038/s41598-022-18903-4CrossRefGoogle ScholarPubMed
Colombino, E, Prieto-Botella, D and Capucchio, MT (2021) Gut health in veterinary medicine: A bibliometric analysis of the literature. Animals 11, 1997.10.3390/ani11071997CrossRefGoogle ScholarPubMed
Delport, TC, Power, ML, Harcourt, RG, Webster, KN and Tetu, SG (2016) Colony location and captivity influence the gut microbial community composition of the Australian sea lion (Neophoca cinerea). Applied and Environmental Microbiology 82, 34403449.10.1128/AEM.00192-16CrossRefGoogle ScholarPubMed
Dudek, NK, Galaz-Montoya, JG, Shi, H, Mayer, M, Danita, C, Celis, AI, Viehboeck, T, Wu, GH, Behr, B, Bulgheresi, S, Huang, KC, Chiu, W and Relman, DA (2023) Previously uncharacterized rectangular bacterial structures in the dolphin mouth. Nature Communications 14(1), 2098.10.1038/s41467-023-37638-yCrossRefGoogle ScholarPubMed
Fossi, MC, Baini, M and Simmonds, MP (2020) Cetaceans as Ocean Health Indicators of Marine Litter Impact at Global Scale. Frontiers in Environmental Science 8, 586627.10.3389/fenvs.2020.586627CrossRefGoogle Scholar
Foster, G, Holmes, B, Steigerwalt, AG, Lawson, PA, Thorne, P, Byrer, DE, Ross, M, Xerry, J, Thompson, P and Collins, MD (2004) Campylobacter insulaenigrae sp. nov., isolated from marine mammals. International Journal of Systematic and Evolutionary Microbiology 54(6), 23692373.10.1099/ijs.0.63147-0CrossRefGoogle ScholarPubMed
Glad, T, Kristiansen, VF, Nielsen, KM Brusetti, L, Wright ADG and Sundset, MA (2010) Ecological characterization of the colonic microbiota in Arctic and sub-Arctic seals. Microbial Ecology 60, 32033010.1007/s00248-010-9690-xCrossRefGoogle ScholarPubMed
González, MJ, Villanueva, MP, Latif, F and Fernández, H (2009) Aislamiento de plesiomonas shigelloides y aeromonas veronii biotipo sobria en heces de lobo marino común sudamericano, otaria flavescens (Shaw, 1800). Revista de Biología Marina y Oceanografía 44, 763765.10.4067/S0718-19572009000300021CrossRefGoogle Scholar
Grosser, S, Sauer, J, Paijmans, AJ, Caspers, BA, Forcada, J, Wolf, JBW and Hoffman, JI (2019) Fur seal microbiota are shaped by the social and physical environment, show mother–offspring similarities and are associated with host genetic quality. Molecular Ecology 28, 24062422.10.1111/mec.15070CrossRefGoogle ScholarPubMed
Hoyles, L, Pascual, C, Falsen, E, Foster, G, Grainger, JM and Collins, MD (2001) Actinomyces marimammalium sp. nov., from marine mammals. International Journal of Systematic and Evolutionary Microbiology 51(1), 151156.10.1099/00207713-51-1-151CrossRefGoogle ScholarPubMed
Huang, Z, Liu, K, Ma, W, Li, D, Mo, T and Liu, Q (2022) The gut microbiome in human health and disease—Where are we and where are we going? A bibliometric analysis. Frontiers in Microbiology 13, 1018594.10.3389/fmicb.2022.1018594CrossRefGoogle Scholar
Indrawati, A, Safika, S, Ningrum, S, Aulia, K, Maheshwari, H and Andriyono, S (2023) Fecal and gastric fluid microbiome profiles in the indopacific bottlenose dolphins (Tursiops aduncus). Journal of Veterinary Sciences 37(1), 151159.Google Scholar
IOC-UNESCO (Intergovernmental Oceanographic Commission, United Nations Educational, Scientific and Cultural Organization), 2020. Global ocean science report 2020 - charting capacity for ocean sustainability. Paris: UNESCO Publishing. https://coilink.org/20.500.12592/xwdbvsw (accessed 11 July 2024).Google Scholar
Jarić, I, Knežević-Jarić, J and Gessner, J (2015) Global effort allocation in marine mammal research indicates geographical, taxonomic and extinction risk-related biases. Mammal Review 45, 5462.10.1111/mam.12032CrossRefGoogle Scholar
Kulkarni, SS and Edwards, DJ (2022) A bibliometric review on the implications of renewable offshore marine energy development on marine species. Aquaculture and Fisheries 7, 211222.10.1016/j.aaf.2021.10.005CrossRefGoogle Scholar
Kuziel, GA and Rakoff-Nahoum, S (2022) The gut microbiome. Current Biology: CB 32, R257R264.10.1016/j.cub.2022.02.023CrossRefGoogle ScholarPubMed
Leatherwood, S and Reeves, RR (1990) The Bottlenose Dolphin. Academic Press, San Diego.Google Scholar
Ley, RE, Hamady, M, Lozupone, C, Turnbaugh, PJ, Ramey, RR, Bircher, JS, Schlegel, ML, Tucker, TA, Schrenzel, MD, Knight, R and Gordon, JI (2008) Evolution of Mammals and their gut microbes. Science 320, 16471651.10.1126/science.1155725CrossRefGoogle ScholarPubMed
Marchesi, JR, Adams, DH, Fava, F, Hermes, GDA, Hirschfield, GM, Hold, G, Quraishi, MN, Kinross, J, Smidt, H, Tuohy, KM, Thomas, LV, Zoetendal, EG and Hart, A (2016) The gut microbiota and host health: A new clinical frontier. Gut 65, 330339.10.1136/gutjnl-2015-309990CrossRefGoogle Scholar
Marine Mammal Science, 2024. List of marine mammal species and subspecies. https://marinemammalscience.org/science-and-publications/list-marine-mammalspecies-subspecies/ (accessed 26 July 2024).Google Scholar
Marón, CF, Kohl, KD, Chirife, A, Di Martino, M, Fons, MP, Navarro, MA, Beingesser, J, McAloose, D, Uzal, FA, Dearing, MD, Rowntree, VJ and Uhart, M (2019) Symbiotic microbes and potential pathogens in the intestine of dead southern right whale (Eubalaena australis) calves. Anaerobe 57, 107114.10.1016/j.anaerobe.2019.04.003CrossRefGoogle ScholarPubMed
Medeiros, AW, Giongo, A, Valdez, FP, Blaese De Amorin, D, Tavares, M, d’Azevedo, PA, Franco, AC, Frazzon, J and Frazzon, APG (2016) Characterization of the faecal bacterial community of wild young South American (Arctocephalus australis) and Subantarctic fur seals (Arctocephalus tropicalis). FEMS Microbiology Ecology 92(3), fiw029.10.1093/femsec/fiw029CrossRefGoogle ScholarPubMed
Miller, CA, Holm, HC, Horstmann, L, George, JC, Fredricks, HF, Van Mooy, BA and Apprill, A (2020) Coordinated transformation of the gut microbiome and lipidome of bowhead whales provides novel insights into digestion. The ISME Journal 14, 688701.10.1038/s41396-019-0549-yCrossRefGoogle ScholarPubMed
Moya-Anegón, FD and Herrero-Solana, V (1999) Science in America Latina: A comparison of bibliometric and scientific-technical indicators. Scientiometrics 46, .Google Scholar
Nelson, TM, Apprill, A, Mann, J, Rogers, TL and Brown, MV (2015) The marine mammal microbiome: Current knowledge and future directions. Microbiology Australia 1(1), 813.10.1071/MA15004CrossRefGoogle Scholar
Nelson, TM, Rogers, TL and Brown, MV (2013) The Gut Bacterial Community of Mammals from Marine and Terrestrial Habitats. Plos ONE 8(12), e83655.10.1371/journal.pone.0083655CrossRefGoogle ScholarPubMed
Nelson, TM, Rogers, TL, Carlini, AR and Brown, MV (2013) Diet and phylogeny shape the gut microbiota of Antarctic seals: A comparison of wild and captive animals. Environmental Microbiology 15, 11321145.10.1111/1462-2920.12022CrossRefGoogle Scholar
Nishida, AH and Ochman, H (2018) Rates of gut microbiome divergence in mammals. Molecular Ecology 27, 18841897.10.1111/mec.14473CrossRefGoogle ScholarPubMed
Olmstead, ARB, Mathieson, OL, McLellan, WA, Pabst, DA, Keenan, TF, Goldstein, T and Erwin, PM (2023) Gut bacterial communities in Atlantic bottlenose dolphins (Tursiops truncatus) throughout a disease-driven (Morbillivirus) unusual mortality event. FEMS Microbiology Ecology 99(9), fiad097.10.1093/femsec/fiad097CrossRefGoogle ScholarPubMed
Olsen, MA, Aagnes, TH and Mathiesen, SD (1994) Digestion of Herring by Indigenous Bacteria in the Minke Whale Forestomach. Applied and Environmental Microbiology 60, 44454455.10.1128/aem.60.12.4445-4455.1994CrossRefGoogle ScholarPubMed
Ost, KS and Round, JL (2018) Communication between the microbiota and mammalian immunity. Annual Review of Microbiology 72, 399422.10.1146/annurev-micro-090817-062307CrossRefGoogle ScholarPubMed
Pacheco-Sandoval, A, Lago-Lestón, A, Abadía-Cardoso, A, Solana-Arellano, E and Schramm, Y (2022) Age as a primary driver of the gut microbial composition and function in wild harbor seals. Scientific Reports 12, 14641.10.1038/s41598-022-18565-2CrossRefGoogle ScholarPubMed
Palacios, DM, Martins, CCA and Olavarría, C (2011) Aquatic mammal science in Latin America: A bibliometric analysis for the first eight years of the Latin American Journal of Aquatic Mammals (2002-2010). Latin American Journal of Aquatic Mammals 9, 4264.10.5597/lajam00174CrossRefGoogle Scholar
Pan, RK, Kaski, K and Fortunato, S (2012) World citation and collaboration networks: Uncovering the role of geography in science. Scientific Reports 2, 902.10.1038/srep00902CrossRefGoogle ScholarPubMed
Ramirez-Delgado, D, Cicala, F, Gonzalez-Sanchez, RA, Avalos-Tellez, R, Solana-Arellano, E and Licea-Navarro, A (2022) Multi-locus evaluation of gastrointestinal bacterial communities from Zalophus californianus pups in the Gulf of California, México. PeerJ 10, e13235.10.7717/peerj.13235CrossRefGoogle ScholarPubMed
Reddy, LM, Dierauf, LA and Gulland, FM (2001) Marine mammals as sentinels of ocean health. Marine Mammal Medicine. In Dierauf, LA, and Gulland, FM (eds). Vol. 27 CRC Press Boca Raton, Florida 313Google Scholar
Sanders, J, Beichman, A, Roman, J, Scot, JJ, Emerson, D, McCarthy, JJ and Girguis, PR (2015) Baleen whales host a unique gut microbiome with similarities to both carnivores and herbivores. Nature Communications 6, 8285.10.1038/ncomms9285CrossRefGoogle Scholar
Sehnal, L, Brammer-Robbins, E, Wormington, AM, Blaha, L, Bisesi, J, Larkin, I, Martyniuk, CJ, Simonin, M and Adamovsky, O (2021) Microbiome composition and function in aquatic vertebrates: small organisms making big impacts on aquatic animal health. Frontiers in Microbiology 12, 567408.10.3389/fmicb.2021.567408CrossRefGoogle ScholarPubMed
Sender, R, Fuchs, S and Milo, R (2016) Revised estimates for the number of human and bacteria cells in the body. PLoS Biology 14(8), e1002533.10.1371/journal.pbio.1002533CrossRefGoogle ScholarPubMed
Sepulveda, J and Moeller, AH (2020) The effects of temperature on animal gut microbiomes. Frontiers in Microbiology 11, 384.10.3389/fmicb.2020.00384CrossRefGoogle ScholarPubMed
Szteren, D , and Lercari, D (2022) Marine mammal research in South America: 30 years of publication efforts and collaborative networks. Latin American Journal of Aquatic Research 50, 251266.10.3856/vol50-issue2-fulltext-2810CrossRefGoogle Scholar
Tian, J, Du, J, Lu, Z, Han, J, Wang, Z, Li, D and Guan, X and Wang Z (2020). Distribution of microbiota across different intestinal tract segments of a stranded dwarf minke whale, Balaenoptera acutorostrata. Microbiology Open 9(10), e1108.10.1002/mbo3.1108CrossRefGoogle ScholarPubMed
Van Cise, AM, Switzer, AD, Apprill, A, Champagne, CD, Chittaro, PM, Dudek, NK, Gavery, MR, Hancock‐Hanser, BL, Harmon, AC and Jaffe, AL (2024) Best practices for collecting and preserving marine mammal biological samples in the ‘omics era. Marine Mammal Science 40, e13148.10.1111/mms.13148CrossRefGoogle Scholar
Van Eck, N J and Waltman, L (2010) Software Survey: VOSviewer, a Computer Program for Bibliometric Mapping. Scientometrics 84, 523538.10.1007/s11192-009-0146-3CrossRefGoogle ScholarPubMed
Van Nunen, K, Li, J, Reniers, G and Ponnet, K (2018) Bibliometric analysis of safety culture research. Safety Science 108, 248258.10.1016/j.ssci.2017.08.011CrossRefGoogle Scholar
Wan, X, Li, J, Ao, M, McLaughlin, RW, Fan, F, Wang, D and Zheng, J (2023) The intestinal microbiota of a Risso’s dolphin (Grampus griseus): Possible relationships with starvation raised by macro-plastic ingestion. International Microbiology 26, 10011007.10.1007/s10123-023-00355-zCrossRefGoogle ScholarPubMed
Wan, X-L, McLaughlin, RW, Zheng, J-S, Hao, Y-J, Fan, F, Tian, R-M and Wang, D (2018) Microbial communities in different regions of the gastrointestinal tract in East Asian finless porpoises (Neophocaena asiaeorientalis sunameri). Scientific Reports 8, 14142.10.1038/s41598-018-32512-0CrossRefGoogle ScholarPubMed
World Bank, 2024. GDP (current US$). https://data.worldbank.org/indicator/NY.GDP.MKTP.CD (accessed 20 July 2024).Google Scholar
Wang, B, Pan, S-Y, Ke, R-Y, Wang, K and Wei, Y-M (2014) An overview of climate change vulnerability: A bibliometric analysis based on Web of Science database. Natural Hazards 74, 16491666.10.1007/s11069-014-1260-yCrossRefGoogle Scholar
Xiaofei, Z, Zhou, Z and Pan, X (2024) Research reviews and prospects of gut microbiota in liver cirrhosis: A bibliometric analysis (2001–2023). Frontiers in Microbiology 15, 1342356.Google Scholar
Xiuqing, Z, Hu, J, Deng, S, Tan, Y, Qiu, C, Zhang, M, Ni, X, Lu, H, Wang, Z, Li, L, Chen, H, Huang, S, Xiao, T, Shang, D and Wen, Y (2021) Bibliometric and visual analysis of research on the links between the gut microbiota and depression from 1999 to 2019. Frontiers in Psychiatry 11, 587670.Google Scholar
Zyoud, SH, Shakhshir, M, Abushanab, AS, Al-Jabi, SW, Koni, A, Shahwan, M, Jairoun, AA and Abu Taha, A (2022) Mapping the global research landscape on nutrition and the gut microbiota: Visualization and bibliometric analysis. World Journal of Gastroenterology 28, 29812993.10.3748/wjg.v28.i25.2981CrossRefGoogle ScholarPubMed
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