Igloo‑CF is a prospective, multi‑centre cohort study involving pancreatic‑insufficient adults with cystic fibrosis, conducted across four UK sites: Leeds, Manchester, Royal Papworth, and Birmingham.

The study is ongoing and investigates how the gut microbiome is influenced by diet, medication use, and CFTR modulator therapy.

Early findings from the cohort have already been published, providing initial insights into microbiome diversity, treatment‑related shifts, and potential clinical implications. Further analyses are ongoing.

A summary of what has been published to date

  • Dietary protein intake and overall diet quality in adults with cystic fibrosis following elexacaftor/tezacaftor/ivacaftor therapy.Morgan PT, Ellis TJ, Smeuninx B, Breen L, Kinsey L, Tomlinson OW, White H, Caley LR, Peckham DG. Br J Nutr. 2025 Jun 28;133(12):1497-1505. doi: 10.1017/S0007114525103760.  
  • Longer term follow-up of abdominal symptoms (CFAbd-Score) after initiation of Elexacaftor / Tezacaftor / Ivacaftor in adults with cystic fibrosis.Caley LR, Gillgrass L, Zagoya C, Saumtally H, Duckstein F, H W, Mainz JG, Peckham DG. J Cyst Fibros. 2025 Jul;24(4):787-791.
  • Heightened mitochondrial respiration in CF cells is normalised by triple CFTR modulator therapy through mechanisms involving calcium.Jarosz-Griffiths HH, Caley LR, Lara-Reyna S, Savic S, Clifton IJ, McDermott MF, Peckham DG. Heliyon. 2024 Oct 11;10(20):e39244. doi: 10.1016/j.heliyon.2024.e39244. 
  • The gut microbiota in adults with cystic fibrosis compared to colorectal cancer. Caley LR, Wood HM, Bottomley D, Fuentes Balaguer A, Wilkinson L, Dyson J, Young C, White H, Benton S, Brearley M, Quirke P, Peckham DG. J Cyst Fibros. 2024 Mar;23(2):262-268. doi: 10.1016/j.jcf.2023.12.004.
  • Body mass index and nutritional intake following Elexacaftor/Tezacaftor/Ivacaftor modulator therapy in adults with cystic fibrosis.Caley LR, Jarosz-Griffiths HH, Smith L, Gale L, Barrett J, Kinsey L, Davey V, Nash M, Jones AM, Whitehouse JL, Shimmin D, Floto RA, White H, Peckham DG.J Cyst Fibros. 2023 Nov;22(6):1002-1009. 
  • Butyrate regulates neutrophil homeostasis and impairs early antimicrobial activity in the lung. Dang AT, Begka C, Pattaroni C, Caley LR, Floto RA, Peckham DG, Marsland BJ. Mucosal Immunol. 2023 Aug;16(4):476-485. 
  • Diabetes is associated with increased burden of gastrointestinal symptoms in adults with cystic fibrosis. Caley LR, Zagoya C, Duckstein F, White H, Shimmin D, Jones AM, Barrett J, Whitehouse JL, Floto RA, Mainz JG, Peckham DG. J Cyst Fibros. 2023 Mar;22(2):275-281. 
  • Cystic Fibrosis-Related Gut Dysbiosis: A Systematic Review. Caley LR, White H, de Goffau MC, Floto RA, Parkhill J, Marsland B, Peckham DG. Dig Dis Sci. 2023 May;68(5):1797-1814. 
  • Time to change course and tackle CF related obesity. Caley L, Peckham D. J Cyst Fibros. 2022 Sep;21(5):732-734.
  • Elexacaftor-Tezacaftor-Ivacaftor Treatment Reduces Abdominal Symptoms in Cystic Fibrosis-Early results Obtained With the CF-Specific CFAbd-Score.Mainz JG, Zagoya C, Polte L, Naehrlich L, Sasse L, Eickmeier O, Smaczny C, Barucha A, Bechinger L, Duckstein F, Kurzidim L, Eschenhagen P, Caley L, Peckham D, Schwarz C. Front Pharmacol. 2022 Jun 3;13:877118.
  • Average rate of lung function decline in adults with cystic fibrosis in the United Kingdom: Data from the UK CF registry. Caley L, Smith L, White H, Peckham DG. J Cyst Fibros. 2021 Jan;20(1):86-90.
  • Anti-inflammatory effects of elexacaftor/tezacaftor/ivacaftor in adults with cystic fibrosis heterozygous for F508del. Jarosz-Griffiths HH, Gillgrass L, Caley LR, Spoletini G, Clifton IJ, Etherington C, Savic S, McDermott MF, Peckham D. PLoS One. 2024 May 31;19(5):e0304555.