The aim of this study is to investigate how bacteria and fibre interact with the epithelial cells of the gastrointestinal mucosa to reduce inflammation and to diminish tissue damage caused by radiation therapy to patients diagnosed with rectal cancer.

Thirty patients diagnosed with rectal cancer receiving short term radiation therapy 25 Gray (Gy) during one week preoperatively will be examined. The patients will be divided into three groups with ten patients in each group. One control group without no treatment/study product, one group receiving a test product of 45 g of oat bran and freezing medium only, and one group having a probiotic bacteria, Lactobacillus plantarum HEAL 19 (1010 CFU/g), freezed dried blueberry husks (13 g) and oat bran (22 g), corresponding to 8 g fibre per day in each of the two treated groups. The patients will consume the test product once a day 1 week before and during radiotherapy (2 weeks in total). Mucosal biopsies for microflora analysis and blood samples for analysis of SCFAs and cytokines will be collected at inclusion as well as faecal samples. After radiation therapy, at surgery, blood samples, faecal samples and mucosal biopsies are collected. Fresh faecal samples, blood samples and mucosal biopsies are stored at -80°C until analysis.

Inclusion Criteria:

• Rectal cancer/Adenocarcinoma recti
• Informed Consent explained orally and written, understood, agreed and signed

Exclusion Criteria:

• Diabetes Mellitus
• Inflammatory bowel disease
• Previous radiation to pelvis area
• Ongoing steroid or immunosuppressive therapy
• Ongoing antibiotics therapy