Effect of Preoperative Bowel Preparation and Diet on Anastomotic Healing and the Colon Microbiota: An Experimental Model.

Intestinal microbiota members, particularly Enterococcus faecalis, play significant roles in the pathogenesis of anastomotic leaks (ALs), with key mechanisms involving collagenase production and matrix metalloproteinase-9 (MMP-9) activation. Diet strongly affects microbiota composition, with Western diets (WDs) promoting dysbiosis, which may exacerbate AL. The effects of mechanical bowel preparation (MBP) and oral antibiotics on AL remain unclear. This experimental study explored the impact of preoperative diet and MBP on AL, focusing on the intestinal microbiota. Sixty-four female Wistar albino rats were fed a WD or standard diet (SD) for 3 weeks before surgery. The rats were subsequently divided into subgroups according to MBP or oral antibiotic administration. Enterococcus colonies were analyzed throughout the procedure, and their correlation with AL was evaluated by assessing collagenase activity and MMP-9 tissue concentrations. Enterococcus colony collagenase activity was significantly greater in the WD group than in the SD group (P = 0.024). Moreover, anastomotic burst pressures were nonsignificantly lower in the WD group. Finally, MMP-9 levels and collagenase activity were significantly lower in the groups that received either diet with oral antibiotics and MBP than in other subgroups (P = 0.045 and P = 0.007, respectively). An SD, especially combined with MBP and oral antibiotics, plays a critical role in reducing the risk of AL by modulating collagenase activity in E faecalis and MMP-9 tissue concentrations in rats. Thus, dietary interventions may improve surgical outcomes; however, further clinical studies are necessary to validate these results in human populations.