Purpose: Short chain fatty acids are the main energy source of colonocytes and their use may be impaired in chronic radiation proctitis. The aim of the present study was to evaluate the therapeutic effect of short chain fatty acid enemas in patients with chronic radiation proctitis.
Methods: A prospective, randomized, double-blind trial comparing short chain fatty acid enemas with placebo was conducted in 19 patients with chronic radiation proctitis. Short chain fatty acid enemas contained 60 mM sodium acetate, 30 mM sodium propionate, and 40 mM sodium butyrate. The treatment period lasted five weeks and patients were followed up for six months.
Results: On admission, both groups were similar regarding all parameters evaluated. After five weeks short chain fatty acid-treated patients showed a significant decrease in the number of days with rectal bleeding from the previous week (4.4+/-1.8 to 1.4+/-2.2; P = 0.001) and an improvement of endoscopic score (4.8+/-1.4 to 2.2+/-1.2; P = 0.001). Hemoglobin values were also significantly higher in short chain fatty acid-treated patients (13.1+/-0.9 g/dl vs. 10.7+/-2.1 g/dl; P = 0.02). Mucosal DNA and protein concentrations decreased in both groups but significantly so only in placebo-treated patients (P = 0.05). Changes in histologic parameters were not significant in either group. Although short chain fatty acid-treated patients did not get worse in the next six months, placebo-treated ones gradually improved, and at the end of six months, differences between the two groups were no longer observed.
Conclusions: Short chain fatty acid enemas can accelerate the process of healing in chronic radiation proctitis, but treatment has to be continuous if a complete and sustained clinical, endoscopic, and histologic response is to be obtained.