Biologics and Partial Enteral Nutrition Study

Inclusion Criteria: * Eligible participants are all adults (≥16 years old) with active CD (defined as Crohn's Disease Activity Index ≥ 150) who are due to initiate standard adalimumab (TNFα antagonist) induction treatment (160 mg day 0, 80 mg at 2 weeks and then 40 mg every 2 weeks). Exclusion Criteria: * Inability to provide written consent to participate in the study * Pregnant and/or breastfeeding individuals * Presence of stoma * Presence of short bowel syndrome * Previous treatment with an anti-TNFα inhibitor * Use of any other biologic therapy or oral small molecule therapy within the last 12 weeks * Patients currently receiving oral or intravenous steroids at a dosage \>20mg/day prednisolone or \>9mg budesonide * Introduction of or change in dose of immunomodulator (azathioprine, mercaptopurine, methotrexate) within the past 8 weeks * Use of oral antibiotics within the past 4 weeks * CD with a major fistulising or symptomatic fibrotic stricturing phenotype * Patients tested positive for blood-borne viruses such as HIV and Hepatitis * Patients with untreated tuberculosis (latent or active) * Current enrolment in other studies of an investigational product or dietary intervention * Food allergies, which do not permit participation in the study (e.g., cow's milk allergy)