**The Gut Microbiota and Diabetes: Research, Translation, and Clinical Applications—2023Diabetes,Diabetes Care, andDiabetologiaExpert Forum**

Byndloss, Mariana
Devkota, Suzanne
Duca, Frank
Niess, Jan Hendrik
Nieuwdorp, Max
Orho-Melander, Marju
Sanz, Yolanda
Tremaroli, Valentina
Zhao, Liping

¹Vanderbilt University Medical Center, Nashville, TN
²Howard Hughes Medical Institute, Vanderbilt University Medical Center, Nashville, TN
³Human Microbiome Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
⁴University of Arizona, Tucson, AZ
⁵Department of Biomedicine, University of Basel, Basel, Switzerland
⁶Department of Gastroenterology and Hepatology, University Digestive Healthcare Center, Clarunis, Basel, Switzerland
⁷Department of Internal and Vascular Medicine, Amsterdam University Medical Centers, Amsterdam, the Netherlands
⁸Amsterdam Diabeter Center, Amsterdam University Medical Centers, Amsterdam, the Netherlands
⁹Department of Clinical Sciences in Malmö, Lund University Diabetes Centre, Lund University, Malmö, Sweden
¹⁰Institute of Agrochemistry and Food Technology, Spanish National Research Council (IATA-CSIC), Valencia, Spain
¹¹Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
¹²Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ

Corresponding author: Yolanda Sanz, [email protected]

Received March 26, 2024 and accepted May 23, 2024

See accompanying article, p. 1389.

This article is being simultaneously published in Diabetes (https://doi.org/10.2337/dbi24-0028), Diabetes Care (https://doi.org/10.2337/dci24-0052) and Diabetologia (https://doi.org/10.1007/s00125-024-06198-1) by the ADA and the EASD.

This article is featured in a podcast available at diabetesjournals.org/diabetes/pages/diabetesbio.

Acknowledgments. Editorial support services for this article were provided by Debbie Kendall of Kendall Editorial in Richmond, VA. The authors also thank Robert Caesar and Anna Hallen of Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden, for their help with the figures.

Funding. The 2023 Diabetes, Diabetes Care, and Diabetologia expert forum “The Microbiome and Diabetes: Research, Translation and Clinical Applications,” including a subsequent symposium presented on this topic and the preparation of this article, was supported by a grant from the Novo Nordisk Foundation (NNF23SA0085453). M.B. is a Howard Hughes Medical Institute Freeman Hrabowski Scholar and is supported by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) grant NIDDK R01DK131104, the Pew Charitable Trusts (2022-A-19568), and the Burroughs Wellcome Fund Investigators in the Pathogenesis of Infectious Disease (022792). S.D. is supported by NIDDK grants NIDDK R01DK123446 and 1DP1 DK130687. J.H.N. is supported by Swiss National Science Foundation (SNSF) grant 310030_219210. M.N. is supported by a personal ZONMW-VICI grant 2020 (09150182010020) and a DFN-DON grant 2020 (2020.10.002). Y.S. is supported by grants from the Spanish Ministry of Science, Innovation and Universities MICIU/AEI (PID2020-119536RB-I00) and Severo Ochoa Center of Excellence (Ref. CEX2021-001189-S/10.13039/501100011033). V.T. is a co-principal investigator of a research project funded by the European Union's Innovative Medicines Initiative (IMI grant 875534).

Duality of Interest. J.H.N. has served as an advisor for Abbvie, Bristol Myers Squibb, Falk, Janssen, Roche, and Takeda. M.N. is the founder and a scientific advisory board member of Caelus Pharmaceuticals and Advanced Microbiome Interventions in Amsterdam, the Netherlands. Y.S. is co-author of patents based on the use of intestinal bacteria for obesity and metabolic comorbidities. V.T. holds a patent for the use of microbiota in type 2 diabetes. L.Z. is a co-founder of Notitia Biotechnologies, a microbiome company providing products related to diabetes. No other potential conflicts of interest relevant to this article were reported.

Author Contributions. All authors contributed to writing, reviewing, and revising the manuscript and approved the final version for submission. M.O.-M. is the guarantor of this work and, as such, takes responsibility for the integrity of the review.

Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Diabetes 73(9):p 1391-1410, September 2024. | DOI: 10.2337/dbi24-0028

This article summarizes the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organized by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: 1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g., genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomization in humans; 2) the highly individualized nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; 3) because single-time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and 4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.