The microbiome plays an important role in maintaining human health. Despite multiple factors being attributed to the shaping of the human microbiome, extrinsic factors such diet and use of medications including antibiotics appear to dominate. Mucosal surfaces, particularly in the gut, are highly adapted to be able to tolerate a large population of microorganisms while still being able to produce a rapid and effective immune response against infection. The intestinal microbiome is not functionally independent from the host mucosa and can, through presentation of microbe-associated molecular patterns and generation of microbial-derived metabolites, fundamentally influence mucosal barrier integrity and modulate host immunity. In a healthy gut there is an abundance of beneficial bacteria that help to preserve intestinal homeostasis, promote protective immune responses and limit excessive inflammation. The importance of the microbiome is further highlighted during dysbiosis where a loss of this finely-balanced microbial population can lead to mucosal barrier dysfunction, aberrant immune responses, and chronic inflammation that increases the risk of disease development. Improvements in our understanding of the microbiome are providing opportunities to harness members of a healthy microbiome to help reverse dysbiosis, reduced inflammation and ultimately prevent disease progression.

Diet is an important lifestyle factor that is known to contribute in the development of human disease. It is well established that poor diet plays an active role in exacerbating metabolic diseases, such as obesity, diabetes and hypertension. Our understanding of how the immune system drives chronic inflammation and disease pathogenesis has evolved in recent years. However, the contribution of dietary factors to inflammatory conditions such as inflammatory bowel disease, multiple sclerosis and arthritis remain poorly defined. A western diet has been associated as pro-inflammatory, in contrast to traditional dietary patterns that are associated as being anti-inflammatory. This may be due to direct effects of nutrients on immune cell function. Diet may also affect the composition and function of gut microbiota, which consequently affects immunity. In animal models of inflammatory disease, diet may modulate inflammation in the gastrointestinal tract and in other peripheral sites. Despite limitations of animal models, there is now emerging evidence to show that anti-inflammatory effects of diet may translate to human gastrointestinal and inflammatory diseases. However, appropriately designed, larger clinical studies must be conducted to confirm the therapeutic benefit of dietary therapy.

Background Despite improved postoperative management, endoscopic recurrence after surgery remains common in Crohn’s disease (CD) patients [1]. It is widely accepted that patients receiving preoperative nutrition supplementation are less likely to experience postoperative complications [2]. However, little is known about the long-term effects of preoperative nutrition supplementation on surgery. In this study we aimed to assess the long-term effects of preoperative nutrition supplementation on endoscopic recurrence. Methods Single centre retrospective data was collected between 2015 and 2021 on patients who had surgical resection with ileocolonic anastomosis. Follow up data was retrospectively collected at 12 months after surgery. Endoscopic recurrence was defined as a Rutgeerts score of 2 or more. Statistical analysis included demographics and inferential analyses. Missing data was attributed to the absence in clinic notes. Results This study included 50 CD patients [50.0% male, median age of 31.0 (18.0-68.0), 81.8% non-smokers] who had ileocolonic anastomosis. Most patients had ileocolonic CD (76.0%, 38/50) and either stricturing (46.0%, 23/50) or penetrating (26.0%, 13/50) disease behaviour. Almost half (49.0%, 24/49) of CD patients received preoperative nutrition supplementation prior to surgery, with 61.9% on oral nutrition supplementation. No statistical difference was found between the demographics of patients receiving nutrition supplementation and patients without nutrition supplementation, p>0.05 (table 1). Endoscopic recurrence was observed in 43.5% (10/23) of patients at 12 months. 80.0% (8/10) of patients who experienced endoscopic recurrence did not receive preoperative nutrition supplementation (figure 1). Logistic regression indicated that patients receiving nutrition supplementation may be 84.4% less likely to experience endoscopic recurrence at 12 months compared to patients without nutrition supplementation (OR 0.16 (CI 0.023-1.056)(p=0.057)). The type of preoperative nutrition supplementation did not significantly impact endoscopic recurrence (p>0.05). Conclusion Preoperative nutrition supplementation may reduce the risk of endoscopic recurrence one year after surgical resection. The use of preoperative nutrition is highly recommended for all CD patients undergoing surgery. More extensive research is needed to confirm study findings.