Oligosaccharides, particularly those classified as prebiotics (e.g., fructooligosaccharides [FOS] and galactooligosaccharides [GOS]), have been investigated for their potential to support gut health in individuals with Crohn's Disease. The rationale is based on their ability to selectively stimulate the growth of beneficial gut bacteria such as Bifidobacterium and Lactobacillus, which may help modulate the immune system and reduce intestinal inflammation. Several small clinical studies and pilot trials have examined prebiotic supplementation in Crohn's Disease. Some results indicate modest improvements in disease activity indices and reductions in pro-inflammatory markers, but these findings are inconsistent and often limited by small sample sizes, short durations, and methodological differences.

Major clinical guidelines do not currently recommend oligosaccharide supplementation as a standard therapy for Crohn's Disease due to insufficient and inconclusive evidence. While the theoretical basis and some pilot data are promising, larger, high-quality randomized controlled trials are needed to establish efficacy, optimal dosing, and safety. Therefore, the use of oligosaccharides for Crohn's Disease is supported by preliminary scientific investigation, but evidence remains weak to moderate (rated 2/5), and their use should not replace established medical therapies.