The gut microbiome is a significant risk factor for future chronic lung disease.

"custom code for analysis in this study is available at https://github com/dpredprj/gut_respiratory_link ."

"Disclosure of potential conflict of interest: V. Salomaa has received honoraria from Sanofi for consulting and also has ongoing research collaboration with Bayer Ltd (all outside this study). The rest of the authors declare that they have no relevant conflicts of interest."

"V.S. was supported by the 10.13039/501100005633Finnish Foundation for Cardiovascular Research and by 10.13039/501100004037Juho Vainio Foundation. M.I. was supported by the Munz Chair of Cardiovascular Prediction and Prevention. A.S.H. was supported by the 10.13039/501100002341Academy of Finland (grant no. 321356). L.L. was supported by the 10.13039/501100002341Academy of Finland (grant nos. 295741 and 328791). T.N. was supported by the 10.13039/501100004756Emil Aaltonen Foundation, the 10.13039/501100005633Finnish Foundation for Cardiovascular Research, the Sigrid Jusélius Foundation, and the 10.13039/501100002341Academy of Finland (grant no. 321351). This study was supported by the Victorian government’s Operational Infrastructure Support program and by core funding from the 10.13039/501100000274British Heart Foundation (grant nos. RG/13/13/30194 and RG/18/13/33946) and the NIHR Cambridge Biomedical Research Centre (grant no. BRC-1215-20014). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. This work was supported by Health Data Research UK, which is funded by the UK 10.13039/501100000265Medical Research Council, the 10.13039/501100000266Engineering and Physical Sciences Research Council, the 10.13039/501100000269Economic and Social Research Council, the Department of Health and Social Care (England), the 10.13039/501100000589Chief Scientist Office of the Scottish Government Health and Social Care Directorates, the 10.13039/501100010756Health and Social Care Research and Development Division (10.13039/100015846Welsh Government), the 10.13039/501100001626Public Health Agency (Northern Ireland), the 10.13039/501100000274British Heart Foundation, and Wellcome."