{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T23:07:03Z","timestamp":1776294423763,"version":"3.50.1"},"reference-count":59,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,9,16]],"date-time":"2021-09-16T00:00:00Z","timestamp":1631750400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002428","name":"Austrian Science Fund","doi-asserted-by":"publisher","award":["P29608"],"award-info":[{"award-number":["P29608"]}],"id":[{"id":"10.13039\/501100002428","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"<jats:p>The heme catabolite bilirubin has anti-inflammatory, anti-oxidative and anti-mutagenic effects and its relation to colorectal cancer (CRC) risk is currently under evaluation. Although the main metabolic steps of bilirubin metabolism, including the formation of stercobilin and urobilin, take place in the human gastrointestinal tract, potential interactions with the human gut microbiota are unexplored. This study investigated, whether gut microbiota composition is altered in Gilbert\u2019s Syndrome (GS), a mild form of chronically elevated serum unconjugated bilirubin (UCB) compared to matched controls. Potential differences in the incidence of CRC-associated bacterial species in GS were also assessed. To this end, a secondary investigation of the BILIHEALTH study was performed, assessing 45 adults with elevated UCB levels (GS) against 45 age- and sex-matched controls (C). Fecal microbiota analysis was performed using 16S rRNA gene sequencing. No association between mildly increased UCB and the composition of the gut microbiota in this healthy cohort was found. The alpha and beta diversity did not differ between C and GS and both groups showed a typical representation of the known dominant phyla. Furthermore, no difference in abundance of <jats:italic>Firmicutes<\/jats:italic> and <jats:italic>Proteobacteria<\/jats:italic>, which have been associated with the mucosa of CRC patients were observed between the groups. A sequence related to the <jats:italic>Christensenella minuta<\/jats:italic> strain YIT 12065 was identified with a weak association value of 0.521 as an indicator species in the GS group. This strain has been previously associated with a lower body mass index, which is typical for the GS phenotype. Overall, sex was the only driver for an identifiable difference in the study groups, as demonstrated by a greater bacterial diversity in women. After adjusting for confounding factors and multiple testing, we can conclude that the GS phenotype does not affect the composition of the human gut microbiota in this generally healthy study group.<\/jats:p>","DOI":"10.3389\/fcimb.2021.701109","type":"journal-article","created":{"date-parts":[[2021,9,16]],"date-time":"2021-09-16T05:19:18Z","timestamp":1631769558000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":7,"title":["Gilbert\u2019s Syndrome and the Gut Microbiota \u2013 Insights From the Case-Control BILIHEALTH Study"],"prefix":"10.3389","volume":"11","author":[{"given":"Patrick A.","family":"Z\u00f6hrer","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Claudia A.","family":"Hana","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nazlisadat","family":"Seyed Khoei","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christine","family":"M\u00f6lzer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marlies","family":"H\u00f6rmann-Wallner","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anela","family":"Tosevska","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel","family":"Doberer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rodrig","family":"Marculescu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrew C.","family":"Bulmer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Craig W.","family":"Herbold","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David","family":"Berry","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Karl-Heinz","family":"Wagner","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2021,9,16]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"683","DOI":"10.1136\/gutjnl-2015-310912","article-title":"Global Patterns and Trends in Colorectal Cancer Incidence and Mortality","volume":"66","author":"Arnold","year":"2017","journal-title":"Gut"},{"key":"B2","doi-asserted-by":"publisher","first-page":"612","DOI":"10.1128\/Aem.07448-11","article-title":"Barcoded Primers Used in Multiplex Amplicon Pyrosequencing Bias Amplification (Vol 77, Pg 7846, 2011)","volume":"78","author":"Berry","year":"2012","journal-title":"Appl. Environ. Microbiol."},{"key":"B3","doi-asserted-by":"publisher","first-page":"395","DOI":"10.1146\/annurev-micro-102215-095513","article-title":"Gut Microbiota, Inflammation, and Colorectal Cancer","volume":"70","author":"Brennan","year":"2016","journal-title":"Annu. Rev. Microbiol."},{"key":"B4","doi-asserted-by":"publisher","first-page":"1942","DOI":"10.1053\/j.gastro.2010.09.003","article-title":"Loci From a Genome-Wide Analysis of Bilirubin Levels Are Associated With Gallstone Risk and Composition","volume":"139","author":"Buch","year":"2010","journal-title":"Gastroenterology"},{"key":"B5","doi-asserted-by":"publisher","first-page":"H429","DOI":"10.1152\/ajpheart.00417.2017","article-title":"Bilirubin Acts as a Multipotent Guardian of Cardiovascular Integrity: More Than Just a Radical Idea","volume":"315","author":"Bulmer","year":"2018","journal-title":"Am. J. Physiol. Heart Circ. Physiol."},{"key":"B6","doi-asserted-by":"publisher","first-page":"1857","DOI":"10.1111\/j.1476-5381.2011.01413.x","article-title":"Bile Pigment Pharmacokinetics and Absorption in the Rat: Therapeutic Potential for Enteral Administration","volume":"164","author":"Bulmer","year":"2011","journal-title":"Br. J. Pharmacol."},{"key":"B7","doi-asserted-by":"publisher","first-page":"28","DOI":"10.1016\/j.mrrev.2007.05.001","article-title":"The Anti-Mutagenic Properties of Bile Pigments","volume":"658","author":"Bulmer","year":"2008","journal-title":"Mutat. Res."},{"key":"B8","doi-asserted-by":"publisher","first-page":"193","DOI":"10.1016\/j.plipres.2012.11.001","article-title":"Bilirubin and Beyond: A Review of Lipid Status in Gilbert\u2019s Syndrome and its Relevance to Cardiovascular Disease Protection","volume":"52","author":"Bulmer","year":"2013","journal-title":"Prog. Lipid Res."},{"key":"B9","doi-asserted-by":"publisher","first-page":"3566","DOI":"10.1890\/08-1823.1","article-title":"Associations Between Species and Groups of Sites: Indices and Statistical Inference","volume":"90","author":"C\u00e1ceres","year":"2009","journal-title":"Ecology"},{"key":"B10","doi-asserted-by":"publisher","first-page":"335","DOI":"10.1038\/nmeth.f.303","article-title":"QIIME Allows Analysis of High-Throughput Community Sequencing Data","volume":"7","author":"Caporaso","year":"2010","journal-title":"Nat. Methods"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2020.615056","article-title":"The Intestinal Microbiota and Colorectal Cancer","volume":"11","author":"Cheng","year":"2020","journal-title":"Front. Immunol."},{"key":"B12","first-page":"7459","article-title":"The Role of Microbiota in Neonatal Hyperbilirubinemia","volume":"12","author":"Chen","year":"2020","journal-title":"Am. J. Transl. Res."},{"key":"B13","volume-title":"\u201cR: A Language and Environment for Statistical Computing\u201d","author":"Development Core Team","year":"2017"},{"key":"B14","doi-asserted-by":"publisher","first-page":"182","DOI":"10.1038\/s41424-018-0048-x","article-title":"Meconium Microbiome Associates With the Development of Neonatal Jaundice","volume":"9","author":"Dong","year":"2018","journal-title":"Clin. Transl. Gastroenterol."},{"key":"B15","doi-asserted-by":"publisher","first-page":"4925","DOI":"10.1038\/s41388-020-1341-1","article-title":"Gut Microbiota Modulation: A Novel Strategy for Prevention and Treatment of Colorectal Cancer","volume":"39","author":"Fong","year":"2020","journal-title":"Oncogene"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2015.00020","article-title":"Microbiota Disbiosis is Associated With Colorectal Cancer","volume":"6","author":"Gao","year":"2015","journal-title":"Front. Microbiol."},{"key":"B17","doi-asserted-by":"publisher","first-page":"169","DOI":"10.1016\/j.jbiotec.2017.06.1198","article-title":"25 Years of Serving the Community With Ribosomal RNA Gene Reference Databases and Tools","volume":"261","author":"Glockner","year":"2017","journal-title":"J. Biotechnol."},{"key":"B18","doi-asserted-by":"publisher","first-page":"789","DOI":"10.1016\/j.cell.2014.09.053","article-title":"Human Genetics Shape the Gut Microbiome","volume":"159","author":"Goodrich","year":"2014","journal-title":"Cell"},{"key":"B19","doi-asserted-by":"publisher","first-page":"5488","DOI":"10.1128\/AEM.66.12.5488-5491.2000","article-title":"Rapid Method for Coextraction of DNA and RNA From Natural Environments for Analysis of Ribosomal DNA- and rRNA-Based Microbial Community Composition","volume":"66","author":"Griffiths","year":"2000","journal-title":"Appl. Environ. Microbiol."},{"key":"B20","doi-asserted-by":"publisher","first-page":"235","DOI":"10.1038\/nmeth.1184","article-title":"Error-Correcting Barcoded Primers for Pyrosequencing Hundreds of Samples in Multiplex","volume":"5","author":"Hamady","year":"2008","journal-title":"Nat. Methods"},{"key":"B21","doi-asserted-by":"publisher","first-page":"140","DOI":"10.1016\/j.tem.2018.01.002","article-title":"Bilirubin in the Liver-Gut Signaling Axis","volume":"29","author":"Hamoud","year":"2018","journal-title":"Trends Endocrinol. Metab."},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2015.00731","article-title":"A Flexible and Economical Barcoding Approach for Highly Multiplexed Amplicon Sequencing of Diverse Target Genes","volume":"6","author":"Herbold","year":"2015","journal-title":"Front. Microbiol."},{"key":"B23","doi-asserted-by":"publisher","first-page":"257","DOI":"10.1198\/000313006X118430","article-title":"A Lego System for Conditional Inference","volume":"60","author":"Hothorn","year":"2006","journal-title":"Am. Statistician"},{"key":"B24","doi-asserted-by":"publisher","first-page":"48","DOI":"10.5534\/wjmh.190009","article-title":"Sex Differences in Gut Microbiota","volume":"38","author":"Kim","year":"2020","journal-title":"World J. Mens Health"},{"key":"B25","doi-asserted-by":"publisher","first-page":"346","DOI":"10.1016\/j.diabet.2017.07.004","article-title":"Total Serum Bilirubin and 8-Year Incident Type 2 Diabetes Mellitus: The Korean Genome and Epidemiology Study","volume":"44","author":"Kwon","year":"2018","journal-title":"Diabetes Metab."},{"key":"B26","doi-asserted-by":"publisher","first-page":"2385","DOI":"10.2337\/dc18-0253","article-title":"Gut Microbiota Differs in Composition and Functionality Between Children With Type 1 Diabetes and MODY2 and Healthy Control Subjects: A Case-Control Study","volume":"41","author":"Leiva-Gea","year":"2018","journal-title":"Diabetes Care"},{"key":"B27","unstructured":"MaechlerM.\n            RousseeuwP.\n            StruyfA.\n            HubertM.\n            HornikK.\n          \u201cFinding Groups in Data\u2019: Cluster Analysis Extended Rousseeuw Et Al.\u201d. 2.0.6 Ed.).2017"},{"key":"B28","doi-asserted-by":"publisher","first-page":"4288","DOI":"10.1093\/nar\/gks042","article-title":"Differential Expression Analysis of Multifactor RNA-Seq Experiments With Respect to Biological Variation","volume":"40","author":"McCarthy","year":"2012","journal-title":"Nucleic Acids Res."},{"key":"B29","doi-asserted-by":"publisher","first-page":"1958","DOI":"10.1021\/np4005807","article-title":"Bilirubin and Related Tetrapyrroles Inhibit Food-Borne Mutagenesis: A Mechanism for Antigenotoxic Action Against a Model Epoxide","volume":"76","author":"M\u00f6lzer","year":"2013","journal-title":"J. Nat. Prod."},{"key":"B30","doi-asserted-by":"publisher","first-page":"536","DOI":"10.1016\/j.yexcr.2012.12.003","article-title":"In Vitro DNA-Damaging Effects of Intestinal and Related Tetrapyrroles in Human Cancer Cells","volume":"319","author":"M\u00f6lzer","year":"2013","journal-title":"Exp. Cell Res."},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.1038\/srep30051","article-title":"Features of an Altered AMPK Metabolic Pathway in Gilbert\u2019s Syndrome, and its Role in Metabolic Health","volume":"6","author":"M\u00f6lzer","year":"2016","journal-title":"Sci. Rep."},{"key":"B32","doi-asserted-by":"publisher","first-page":"755","DOI":"10.1038\/s41598-017-00933-y","article-title":"Characteristics of the Heme Catabolic Pathway in Mild Unconjugated Hyperbilirubinemia and Their Associations With Inflammation and Disease Prevention","volume":"7","author":"M\u00f6lzer","year":"2017","journal-title":"Sci. Rep."},{"key":"B33","doi-asserted-by":"publisher","first-page":"144","DOI":"10.1099\/ijs.0.026989-0","article-title":"Description of Christensenella Minuta Gen. Nov., Sp. Nov., Isolated From Human Faeces, Which Forms a Distinct Branch in the Order Clostridiales, and Proposal of Christensenellaceae Fam. Nov","volume":"62","author":"Morotomi","year":"2012","journal-title":"Int. J. Syst. Evol. Microbiol."},{"key":"B34","doi-asserted-by":"publisher","first-page":"16004","DOI":"10.1038\/npjbiofilms.2016.4","article-title":"A Perspective on 16S rRNA Operational Taxonomic Unit Clustering Using Sequence Similarity","volume":"2","author":"Nguyen","year":"2016","journal-title":"NPJ Biofilms Microbiomes"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1003507","article-title":"A Product of Heme Catabolism Modulates Bacterial Function and Survival","volume":"9","author":"Nobles","year":"2013","journal-title":"PloS Pathog."},{"key":"B36","first-page":"631","article-title":"The Vegan Package","volume":"10","author":"Oksanen","year":"2007","journal-title":"Community Ecol. Package"},{"key":"B37","first-page":"593","article-title":"Gilbert\u2019s Syndrome\u2013Clinical and Pharmacological Implications","volume":"3","author":"Radu","year":"2001","journal-title":"Isr. Med. Assoc. J."},{"key":"B38","doi-asserted-by":"publisher","first-page":"89","DOI":"10.5114\/pg.2018.81072","article-title":"Epidemiology of Colorectal Cancer: Incidence, Mortality, Survival, and Risk Factors","volume":"14","author":"Rawla","year":"2019","journal-title":"Prz Gastroenterol."},{"key":"B39","doi-asserted-by":"publisher","DOI":"10.1155\/2017\/8127814","article-title":"Bacterial Community Profile of the Gut Microbiota Differs Between Hypercholesterolemic Subjects and Controls","volume":"2017","author":"Rebolledo","year":"2017","journal-title":"BioMed. Res. Int."},{"key":"B40","doi-asserted-by":"publisher","first-page":"7537","DOI":"10.1128\/AEM.01541-09","article-title":"Introducing Mothur: Open-Source, Platform-Independent, Community-Supported Software for Describing and Comparing Microbial Communities","volume":"75","author":"Schloss","year":"2009","journal-title":"Appl. Environ. Microbiol."},{"key":"B41","doi-asserted-by":"publisher","first-page":"800","DOI":"10.1038\/nrc3610","article-title":"The Microbiome and Cancer","volume":"13","author":"Schwabe","year":"2013","journal-title":"Nat. Rev. Cancer"},{"key":"B42","doi-asserted-by":"publisher","first-page":"306","DOI":"10.1016\/j.atherosclerosis.2017.12.021","article-title":"Mild Hyperbilirubinaemia as an Endogenous Mitigator of Overweight and Obesity: Implications for Improved Metabolic Health","volume":"269","author":"Seyed Khoei","year":"2018","journal-title":"Atherosclerosis"},{"key":"B43","doi-asserted-by":"publisher","first-page":"229","DOI":"10.1186\/s12916-020-01703-w","article-title":"Circulating Bilirubin Levels and Risk of Colorectal Cancer: Serological and Mendelian Randomization Analyses","volume":"18","author":"Seyed Khoei","year":"2020","journal-title":"BMC Med."},{"key":"B44","article-title":"Appendectomy Is Associated With Alteration of Human Gut Bacterial and Fungal Communities","volume-title":"Front. Microbiol.","author":"Shuntian","year":"2021"},{"key":"B45","doi-asserted-by":"publisher","first-page":"841","DOI":"10.1089\/ars.2004.6.841","article-title":"Antioxidant Activities of Bile Pigments","volume":"6","author":"Stocker","year":"2004","journal-title":"Antioxid Redox Signal"},{"key":"B46","doi-asserted-by":"publisher","first-page":"401","DOI":"10.1016\/j.tim.2020.01.001","article-title":"Microbiome in Colorectal Cancer: How to Get From Meta-Omics to Mechanism","volume":"28","author":"Ternes","year":"2020","journal-title":"Trends Microbiol."},{"key":"B47","doi-asserted-by":"publisher","first-page":"684","DOI":"10.1056\/NEJMcibr2013250","article-title":"Bilirubin, Intestinal Integrity, the Microbiome, and Inflammation","volume":"383","author":"Vitek","year":"2020","journal-title":"N. Engl. J. Med."},{"key":"B48","doi-asserted-by":"publisher","first-page":"238","DOI":"10.1016\/j.jhep.2004.10.012","article-title":"The Impact of Intestinal Microflora on Serum Bilirubin Levels","volume":"42","author":"Vitek","year":"2005","journal-title":"J. Hepatol."},{"key":"B49","doi-asserted-by":"publisher","first-page":"1939","DOI":"10.1093\/clinchem\/46.12.1939","article-title":"DNA Base Bulge vs Unmatched End Formation in Probe-Based Diagnostic Insertion\/Deletion Genotyping: Genotyping the UGT1A1 (TA)(n) Polymorphism by Real-Time Fluorescence PCR","volume":"46","author":"von Ahsen","year":"2000","journal-title":"Clin. Chem."},{"key":"B50","doi-asserted-by":"publisher","first-page":"129","DOI":"10.1080\/10408363.2018.1428526","article-title":"Diagnostic Criteria and Contributors to Gilbert\u2019s Syndrome","volume":"55","author":"Wagner","year":"2018","journal-title":"Crit. Rev. Clin. Lab. Sci."},{"key":"B51","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1042\/cs20140566","article-title":"Looking to the Horizon: The Role of Bilirubin in the Development and Prevention of Age-Related Chronic Diseases","volume":"129","author":"Wagner","year":"2015","journal-title":"Clin. Sci. (Lond)"},{"key":"B52","doi-asserted-by":"publisher","first-page":"1056","DOI":"10.1158\/1940-6207.Capr-13-0125","article-title":"Anti-Genotoxic Potential of Bilirubin In Vivo: Damage to DNA in Hyperbilirubinemic Human and Animal Models","volume":"6","author":"Wallner","year":"2013","journal-title":"Cancer Prev. Res. (Phila)"},{"key":"B53","doi-asserted-by":"publisher","first-page":"912","DOI":"10.1111\/eci.12120","article-title":"Haem Catabolism: A Novel Modulator of Inflammation in Gilbert\u2019s Syndrome","volume":"43","author":"Wallner","year":"2013","journal-title":"Eur. J. Clin. Invest."},{"key":"B54","doi-asserted-by":"publisher","first-page":"257","DOI":"10.1042\/CS20120661","article-title":"Protection From Age-Related Increase in Lipid Biomarkers and Inflammation Contributes to Cardiovascular Protection in Gilbert\u2019s Syndrome","volume":"125","author":"Wallner","year":"2013","journal-title":"Clin. Sci. (Lond)"},{"key":"B55","volume-title":"\u201cContinuous Update Project Expert Report 2018. Diet, Nutrition, Physical Activity and Cancer\u201d.","year":"2018"},{"key":"B56","doi-asserted-by":"publisher","first-page":"2738","DOI":"10.1038\/s41598-021-82538-0","article-title":"Alterations in the Gut Bacterial Microbiome in People With Type 2 Diabetes Mellitus and Diabetic Retinopathy","volume":"11","author":"Das","year":"2021","journal-title":"Sci. Rep."},{"key":"B57","doi-asserted-by":"publisher","first-page":"203","DOI":"10.1089\/10665270050081478","article-title":"A Greedy Algorithm for Aligning DNA Sequences","volume":"7","author":"Zhang","year":"2000","journal-title":"J. Comput. Biol."},{"key":"B58","doi-asserted-by":"publisher","first-page":"827","DOI":"10.1002\/hep.20407","article-title":"Serum Bilirubin Levels in the U.S. Population: Gender Effect and Inverse Correlation With Colorectal Cancer","volume":"40","author":"Zucker","year":"2004","journal-title":"Hepatology"},{"key":"B59","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.virol.2009.06.001","article-title":"The Search for Infectious Causes of Human Cancers: Where and Why","volume":"392","author":"Zur Hausen","year":"2009","journal-title":"Virology"}],"container-title":["Frontiers in Cellular and Infection Microbiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fcimb.2021.701109\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,9,16]],"date-time":"2021-09-16T05:19:26Z","timestamp":1631769566000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fcimb.2021.701109\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,16]]},"references-count":59,"alternative-id":["10.3389\/fcimb.2021.701109"],"URL":"https:\/\/doi.org\/10.3389\/fcimb.2021.701109","relation":{},"ISSN":["2235-2988"],"issn-type":[{"value":"2235-2988","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,9,16]]},"article-number":"701109"}}