Emu Oil-Modulated Faecal Microbiota Transplantation Improves Disease Indicators in a Mouse Model of Crohn’s-Like Colitis

Objectives: Faecal microbiota transplantation (FMT) studies have revealed variable therapeutic efficacy in Crohn's disease (CD) management. Orally administered Emu Oil (EO) has demonstrated anti-inflammatory and reparative properties in models of intestinal disease. The current study aimed to determine whether EO-modulated FMT could reduce disease severity in a mouse model of trinitrobenzene sulfonic acid (TNBS)-induced Crohn's-like colitis. Methods: Female ARC(s) mice were assigned to FMT donor (n=5/group) and recipient (n=10/group) groups. Donor mice were orally administered either Water (80μl), Olive Oil (OO) or EO (160μl) daily (days -7 to 0); fresh faeces were collected (days -1 to 3) and group pooled. Recipient mice intrarectally received TNBS (3mg; day 0) and donor faecal supernatant (120μl; day 3) and killed on day 6. Daily bodyweight (BW) and disease activity index (DAI), colonoscopically-assessed disease severity, organ weights, intestinal permeability (fluorescein isothiocyanate [FITC]-dextran), histologically-assessed colonic damage (disease severity, crypt depth), intestinal barrier function (mucin-secreting cells), acute inflammation (myeloperoxidase [MPO]) and faecal microbiome (16S rRNA amplicon sequencing) were assessed. p< 0.05 was considered significant. Results: TNBS induced BW loss in all groups, which normalised to day 0 values on the day of kill. Daily DAI remained elevated throughout the trial in all groups; only EO FMT normalised DAI on day 6 compared with day 0 (p< 0.05). TNBS increased colonoscopically-assessed disease severity scores (p< 0.05), with no significant EO nor OO FMT effect. EO FMT resulted in decreased liver weights and greater small intestinal weights relative to BW, reduced histologically-assessed disease severity and increased colonic mucin counts compared with Water and OO FMT (p< 0.05). The most abundant genera across groups were Muribaculaceae, Eisenbergiella and Bacteroides; while alpha and beta diversity, taxonomic profiles, FITC-dextran, crypt depth and MPO activity remained unchanged (p >0.05). Conclusions: Compared with Water and OO FMT, EO FMT improved clinically- and histologically-assessed indicators of colonic disease and barrier function. EO-modulated FMT may enhance current FMT treatment, improving CD management. Funding Sources: The author(s) received no funding for this research.