Phase 1 trial tests probiotic treatment for radiation side effects in the gut

Bailey Nelson, MD, has been awarded a $50,000 pilot grant from the Cancer Center to open a Phase 1 trial testing if a probiotic supplement can reduce gastrointestinal (GI) symptoms for patients undergoing whole pelvis radiotherapy.

Pelvic radiation therapy, a common treatment for GI, genitourinary (GU) and gynecologic cancers, uses high-energy rays to destroy cancer cells in the pelvic area — but it can lead to acute and chronic side effects that include diarrhea, fecal urgency, abdominal cramping and malabsorption.

“The exact mechanism of gastrointestinal symptoms is elusive, but there is sufficient data to suggest that the intestinal microbiome plays a role in radiation-induced GI injury,” said Nelson, associate member of the Cancer Center and assistant professor in the Department of Radiation Oncology in UC’s College of Medicine. “The microbiome likely plays a much larger role in cancer development and treatment toxicity than we ever imagined.”

The intestinal microbiome is populated by trillions of microorganisms such as bacteria, viruses, fungi and parasites. This includes “bad” bacteria that can cause illness and “good” bacteria like Akkermansia muciniphila, which helps break down mucus in the intestines to maintain the intestinal lining.

Previous studies and preclinical models have shown A. muciniphila was protective of radiation-induced GI toxicity by enhancing intestinal repair, Nelson said. “In our previous institutional retrospective study, A. muciniphila was enriched in patients with no-to-mild diarrhea after whole pelvic radiotherapy compared to patients with moderate-to-severe diarrhea, indicating that it may be protective against radiation-induced GI toxicity.”