biostudies-literatureGao Xthe National Key Research and Development Program of China25https://www.ebi.ac.uk/biostudies/studies/S-EPMC12913845biostudies-literatureUnknown13(1)Radiation enteritis is a common complication in patients undergoing abdominal radiotherapy. Current management strategies face significant limitations: clinical agents like amifostine are hindered by systemic side effects and demanding administration; direct supplementation with radioprotective metabolites such as propionate suffers from low bioavailability and transient action; and conventional probiotics lack targeted therapeutic output. To address these challenges, we engineered Escherichia coli Nissle 1917 to function as a living therapeutic that continuously produces and delivers propionate directly in the gut. This propionate-engineered probiotic achieved a production yield of 181.33 ± 4.27 mg/L in vitro. In a mouse model of abdominal irradiation, this engineered bacterium alleviatedBioresources and bioprocessingPropionate-engineered probiotics reduce radiation-induced intestinal damage.PMC129138452024YFA0918500Wu JZhu ZGuo YLu XHuang HJi KLiu QZhao ZWang LWang PKang GGao MWang QJia XGao XfalsePropionate-engineered probiotics reduce radiation-induced intestinal damage.Radiation enteritis is a common complication in patients undergoing abdominal radiotherapy. Current management strategies face significant limitations: clinical agents like amifostine are hindered by systemic side effects and demanding administration; direct supplementation with radioprotective metabolites such as propionate suffers from low bioavailability and transient action; and conventional probiotics lack targeted therapeutic output. To address these challenges, we engineered Escherichia coli Nissle 1917 to function as a living therapeutic that continuously produces and delivers propionate directly in the gut. This propionate-engineered probiotic achieved a production yield of 181.33 ± 4.27 mg/L in vitro. In a mouse model of abdominal irradiation, this engineered bacterium alleviated2026-01-01T00:00:00Z2026 Feb2026-07-16T06:58:14.118Z2026-07-09T13:10:59.852ZS-EPMC129138454170129510.1186/s40643-026-01020-9