Investigating microbial therapies to combat intestinal mucositis and dysbiosis in a mouse model for pelvic irradiation

Throughout their cancer treatments, around half of the patients will undergo irradiation that is accompanied by several side effects reducing their quality of life and leading to interruption or extension of their treatment course. Pelvic irradiation is characterized by the triggering of mucositis and dysbiosis further impairing the daily life of the patients. Bacterial food supplements have been investigated for their ability to mitigate the discomfort experienced following pelvic irradiation. In this work, we address the ability of Limnospira indica and Lacticaseibacillus rhamnosus in alleviating the above-mentioned side effects triggered by a local pelvic irradiation of 12 Gy applied on a mice model. We found that the combinatorial administration of these food supplements was able to confer tight junction protection to a certain extent while it failed to reduce the cellular apoptosis occurring in the intestinal crypts following pelvic irradiation; Also, the bacterial translocation towards the mesenteric lymph nodes was found to be identical between the control group and treated group. However, a shift in microbiome alpha and beta diversity was detected between the different groups, while the supplemented group did not present any significant shift in the microbial composition following pelvic irradiation. This indicates that the present original bacterial formulation could prevent the mice microbiome to reach a dysbiotic state following pelvic irradiation as it was observed in the control group. These very promising results will be further completed by investigating the mode of action/active molecules mediating the beneficial effects of both L. indica and L. rhamnosus making use of human gut organoids derived bioreactor technology.