Patient description: The patient is a 24-year-old man who has had type 1 diabetes for 11 years. He presents to the emergency room with hyperglycemia and concern for possible diabetic ketoacidosis after not taking his insulin for 3 days. The patient reports that he is currently homeless and has lost his supply of insulin, syringes, glucometer, and glucose testing supplies. The patient states that at the time of his initial diagnosis with type 1 diabetes he was hospitalized with a glucose value >1000 mg/dL. At the time, he was experiencing polyuria, polydipsia, and polyphagia. He reports that he has been on insulin since the time of his diagnosis, and he has never been prescribed oral agents for diabetes management. Most recently, he has been using insulin glargine 55 units once daily, and insulin aspart sliding scale 3 times daily. The patient has had previous episodes of diabetic ketoacidosis, for which he was hospitalized. With this episode of hyperglycemia, he is not experiencing any nausea, vomiting, or abdominal discomfort, and he appears well. His lab studies showed: A1c: 11.3% Creatinine: 0.9 mg/dL with eGFR >60 mL/min Aspartate aminotransferase (AST): 17 U/L Alanine aminotransferase (ALT): 14 U/L Beta-hydroxybutyrate: 0.1 mmol/L Bicarbonate: 25 mEq/L Anion

Clinical trial eligibility criteria: eligible ages (years): 18.0-45.0,  Healthy Volunteers An understanding, ability, and willingness to fully comply with study procedures and restrictions Ability to voluntarily provide written, signed, and dated informed consent and assent as applicable to participate in the study Aged 18 inclusive at the time of consent. The date of signature of the informed consent is defined as the beginning of the screening period. This criterion will only be assessed at the first screening visit Male, or non-pregnant, non-lactating female who agrees to comply with any applicable contraceptive requirements of the protocol or females of non-childbearing potential Considered "healthy" by the investigator. Healthy status is defined by absence of evidence of any active or chronic disease following a detailed medical and surgical history, a full physical examination including vital signs, 12-lead electrocardiogram (ECG), hematology, coagulation (as appropriate), serum chemistry, and urinalysis Body mass index (BMI) >= 18.0 and l<=32.0 kilogram per square meter (kg/m^2) at screening. Body weight for a participant in Cohort 1 will be >= 40.0 kg to <= 75.0 kg, and body weight for a participant in Cohort 2 will be > 75.0 kg to <= 120.0 kg, inclusive. This criterion will be assessed at the screening visit and confirmed at first check-in  History of any hematological, hepatic, respiratory, cardiovascular, renal, neurological or psychiatric disease, gall bladder removal, or current or recurrent disease that could affect the action, absorption, or disposition of the investigational product, or clinical or laboratory assessments Current or relevant history of physical or psychiatric illness, any medical disorder that may require treatment or make the participant unlikely to fully complete the study, or any condition that presents undue risk from the investigational product or procedures Positive PCR (polymerase chain reaction) test for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), either with the absence or presence of the clinical symptoms of Coronavirus disease 2019 (COVID-19) Known or suspected intolerance or hypersensitivity to teduglutide, closely-related compounds, or any of the stated ingredients Significant illness, as judged by the investigator, within 2 weeks of the first dose of teduglutide Known history of alcohol or other substance abuse within the last year prior to screening Donation of blood or blood products (e.g. plasma or platelets) within 60 days prior to receiving the first dose of teduglutide Pregnant or lactating female Within 30 days prior to the first dose of teduglutide: 1. Have used an investigational product (if elimination half-life is lesser than [<] 6 days, otherwise 5 half-lives) 2. Have been enrolled in a clinical study (including vaccine studies) that, in the investigator's (or designee's) opinion, may impact this study 3. Have had any substantial changes in eating habits, as assessed by the investigator (or designee) Use of dipeptidyl peptidase 4 inhibitors within 30 days or 5 half-lives, whichever is greater, prior to administration of the first dose of teduglutide