The aim of the study is to demonstrate, under clinical conditions, the effectiveness of the standard product 'Nutridrink' enriched with a mixture of plant extracts rich in polyphenolic compounds in the aspect of supporting the recovery of oncology patients undergoing surgical resection of tumours.

Oncology patients undergoing the procedure are exposed to various postoperative complications. Nutridrink with a mixture of extracts with anti-inflammatory and antioxidative properties aims to provide the patient with essential nutrients and bioactive substances that can reduce the inflammatory state, protect cells from oxidative damage, and decrease the risk of complications while supporting tissue healing processes after the surgical procedure. The study group are oncology patients undergoing surgical resection of gastrointestinal tumour. During the study, the effects of the mixture on levels of oxidative stress and inflammation markers will be assessed, as well as the subjective evaluation of patients' quality of life and well-being after surgical surgical tumor resection.

Inclusion Criteria:

• Women and men, 18-80 years old
• Patients diagnosed with resectable gastrointestinal tract cancer undergo the resection procedure no later than one month after being enrolled in the study
• Signed informed consent

Exclusion Criteria:

• Intake of supplements containing plant extracts, polyphenols or anthocyanins
• Participation in another clinical trial
• Inability to consume the investigational product in liquid form as medication/placebo
• Women who are pregnant, planning to become pregnant during the study or breastfeeding
• Autoimmune disease, severe liver dysfunction, inflammatory bowel disease, tuberculosis, multiple sclerosis, AIDS, rheumatoid arthritis, organ transplantation
• Hypersensitivity/allergy to any of the ingredient