This clinical food study aims to explore the effect of KB195, a novel mixture of oligosaccharides, on the metabolism of nitrogen by the microbiome in patients with urea cycle disorders (UCDs). This will be done using a stable isotope to assess nitrogen metabolism in the blood, urine, and stool. The study will also assess the safety and tolerability of KB195 in patients with UCDs.

Inclusion Criteria:

• Confirmed UCD patient at any age ≥ 14 years
• Parental/legal guardian permission or patient's written informed consent or assent, as applicable
• Be willing and able to comply with study requirements

Exclusion Criteria:

• Any medical condition unrelated to the sequelae of UCD
• Patient has N-acetylglutamate synthase (NAGS) deficiency
• Recent hospitalization or risk for metabolic decompensation
• Liver transplantation
• Systemic antibiotics, probiotics or prebiotics that do not align with study guidances
• Change in dose or frequency of any drug or other compound to modulate GI motility
• Contraindications or known allergy/sensitivity to the use of the study products
• Use of an investigational drug, product or device within 30 days prior to Screening Visit, or current enrolment in another investigational drug, product, or device study
• Considered to be at risk for noncompliance or unlikely for any reason to be able to comply with the study procedures