A new murine ileostomy model: recycling stool prevents intestinal atrophy in the distal side of ileostomy.

Objectives: Proximal stoma creation in neonates results in growth failure and distal intestinal atrophy. "Recycling stool" consists of stool injection from the proximal limb to the distal limb of a stoma. Because this method may prevent distal bowel atrophy and increase body weight, we investigated the effects of recycling stool upon distal intestinal mucosa by generating an ileostomy model in rats.

Methods: An ileostomy was created 5 cm proximal to the cecum in male Wistar/ST rats. Discharged stool or saline was injected into the distal limb, twice per day for 7 days. The intestinal adaptation was assessed by measuring the villus height and counting goblet cell number. Proliferation and apoptosis were analyzed by Ki67 and TUNEL immunostaining.

Results: The ratios of the height of the distal villi (D) to the that of proximal villi (P) were 0.97 (median [range] of D and P length: 421 [240-729] μm and 436 [294-638] μm, <0.05) in the stool-injected group and 0.81 in the saline-injected group (442 [315-641] μm and 548 [236-776] μm, <0.05). Compared with the saline-injected group, the stool-injected group showed elevated numbers of goblet cells (3.6 [2.0-7.6] vs. 4.9 [2.4-7.5] cells/100-μm villus length) and Ki67-positive cells (26.8% [13.8%-35.4%] vs. 40.1% [31.2%-45.7%]), along with a reduced number of apoptotic cells (5.0 [2.0-14.0] vs. 4.0 [1.0-9.0] cells/100-μm villus length).

Conclusions: Recycling stool prevented distal intestinal atrophy; this experimental design may facilitate further studies concerning alternative methods to prevent intestinal atrophy and growth failure.