Marion graduated from the University of Galway with an Honours degree in Physiology, followed by a Postgraduate Diploma and MSc in Human Nutrition and Dietetics from the University of Ulster, Coleraine.

With over 20 years of clinical experience in Gastroenterology and Surgery, Marion has worked within the NHS and private healthcare. As Lead Dietitian for the Nutrition Support Team and Home Parenteral Nutrition Team at Oxford University Hospitals NHS Trust, Marion managed complex inpatient and outpatient cases requiring enteral and intravenous feeding.

Subsequently, Marion was appointed Lead Dietitian for the Oxford Intestinal Transplant Team, playing a key role in establishing and delivering a national service supporting hospitals across the UK and Northern Ireland.

Since 2001, Marion has operated a successful private practice, initially providing services to inpatients and outpatients across Oxfordshire and Berkshire. Since relocating to Northern Ireland in 2014, Marion continues to accept outpatient referrals from across the UK and Ireland.

Marion has presented at local, regional, and international meetings. Marion has a strong clinical interest in gut health, with a particular focus on the role of the gut microbiome in health and disease.