P496 - SARCOPENIA AND MICROBIOTA COMPOSITION IN CROHN’S DISEASE PATIENTS STARTING BIOLOGIC THERAPY

P496

SARCOPENIA AND MICROBIOTA COMPOSITION IN CROHN’S DISEASE PATIENTS STARTING BIOLOGIC THERAPY

S. Inniss^1,2,*, S. Rath^1,2, A. Smith¹, F. Rahman^1,2

¹Eastman Dental Institute, University College London, ²Gastrointestinal Services, University College London Hospitals NHS Foundation Trust, London, United Kingdom

Rationale: Sarcopenia, the loss of muscle mass and function, is increasingly recognised in Crohn’s disease (CD), particularly in those with advanced disease. Although gut microbiota alterations have been independently linked to both Crohn’s disease and sarcopenia in other populations, their association has not yet been investigated within the CD population. This study aimed to explore the association between the microbiome and sarcopenia in CD patients initiating biologic therapy.

Methods: Seventy-five CD patients were prospectively recruited from a tertiary IBD centre. Sarcopenia was assessed using skeletal muscle index at the L3 vertebral level from MRI or CT scans, analysed with TomoVision software. Nutritional status was evaluated using MUST and anthropometric measurements such as handgrip strength (HGS). Stool and saliva samples underwent 16S rRNA gene sequencing (V3–V4 region, Illumina MiSeq®) and were processed using the nf-core/ampliseq pipeline. Limited scan availability among patients with stool samples prevented gut microbiota analysis in relation to sarcopenia.

Results: The cohort was 57.3% male with a mean age of 36 years. Most had ileocolonic disease, and 42.7% presented with complications (stricturing 24.0%, penetrating 18.7%). Stool microbiota did not differ by nutritional status (p ≥ 0.05). However, sarcopenic patients showed higher salivary Streptococcus abundance than non-sarcopenic patients (26.1% vs 18.9%, p = 0.008). In contrast, oral microbiota diversity and composition did not differ by HGS or malnutrition status (p ≥ 0.05).

Conclusion: Sarcopenic CD patients initiating biologic therapy showed increased salivary Streptococcus abundance. Larger studies are needed to confirm this potential link between the oral microbiome and muscle loss in CD.

Disclosure of Interest: None declared