At six to 7 weeks of age, C57BL/6 female mice started receiving either a low-fibre (0.2% cellulose) or high-fibre diets including 5% psyllium, 5% psyllium plus 10% RS or 5% psyllium plus 10% inulin for a maximum time of 9 weeks followed by normal chow for another 12 weeks. All diets are isocaloric, approximately 4 kcal/g, and details of the diet formulae are listed in Supplementary Table S
5 (Research Diets Inc, USA). For acute toxicity experiment, two and a half weeks after commencing the modified diets, mice were treated supine with 10, 12 or 14 Gy of X-rays (220 kVp, 13.0 mA copper filtered beam with a measured half-value layer (HVL) of 0.84 mmCu) to the lower abdomen, including the lower small intestine using a
SARRP irradiator (Xstrahl Ltd, Camberley, UK). For late toxicity experiments, 2 weeks after commencing the modified diets, mice were treated supine using a SARRP with 5 Gy for 5 consecutive days, using a 356° arc treatment and 8.5-mm collimator, with the isocentre positioned at the posterior caudal bladder wall covering the lower large intestine, to avoid the small intestine. In both experiments, small and large intestines were collected using the ‘Swiss roll technique’ described in (Moolenbeek and Ruitenberg, 1981) [67 (
link)].
Then C.K., Paillas S., Moomin A., Misheva M.D., Moir R.A., Hay S.M., Bremner D., Roberts (nee Nellany) K.S., Smith E.E., Heidari Z., Sescu D., Wang X., Suárez-Bonnet A., Hay N., Murdoch S.L., Saito R., Collie-Duguid E.S., Richardson S., Priestnall S.L., Wilson J.M., Gurumurthy M., Royle J.S., Samuel L.M., Ramsay G., Vallis K.A., Foster K.R., McCullagh J.S, & Kiltie A.E. (2024). Dietary fibre supplementation enhances radiotherapy tumour control and alleviates intestinal radiation toxicity. Microbiome, 12, 89.
