A Study to Evaluate the Effect of Ustekinumab on Cytochrome P450 Enzyme Activities Following Induction and Maintenance Dosing in Participants With Moderate to Severe Crohn's Disease

Inclusion Criteria For Crohn's Disease (CD) Participants

- Participant must have a body weight in the range of 45 to 110 kilogram (kg) inclusive
and have a body mass index (BMI) of 18 to 35 kilogram per meter square (kg/m^2)
inclusive

- Have moderate to severe CD or fistulizing CD of at least 3 months duration, with
colitis, ileitis, or ileocolitis, confirmed at any time in the past by histology,
and/or endoscopy

For Healthy Volunteers

- Healthy on the basis of physical examination, medical history, vital signs, and
12-lead electrocardiogram (ECG) performed at screening

- Healthy on the basis of clinical laboratory tests performed at screening and Day-1

- If a woman of childbearing potential, she must have a negative serum beta-human
chorionic gonadotropin (hCG) pregnancy test at screening; and a negative urine
pregnancy test at Day -1

Exclusion Criteria For CD Participants

- Has complications of CD such as symptomatic strictures or stenoses, short gut
syndrome, or any other manifestation that might be anticipated to require surgery in
the next 3 months, could preclude the use of the Crohn's Disease Activity Index (CDAI)
to assess response to therapy, would possibly confound the ability to assess the
effect of treatment with ustekinumab, or would alter the absorption of the probe
cocktail

- Currently has or is suspected to have an abscess. Recent cutaneous and perianal
abscesses are not exclusionary if drained and adequately treated at least 3 weeks
prior to baseline, or 8 weeks prior to baseline for intra-abdominal abscesses,
provided that there is no anticipated need for any further surgery. Participants with
active fistulas may be included if there is no anticipation of a need for surgery and
there are currently no abscesses identified

For Healthy Volunteers Participants

- Has an abnormal C-reactive protein (CRP) greater than (>) 2* upper limit of normal
(ULN)

- Has had major surgery (example, requiring general anesthesia) within 8 weeks before
screening, or will not have fully recovered from surgery, or has surgery planned
during the time the participant is in screening or is expected to participate in the
study (5 weeks)

- Is pregnant, nursing, or planning a pregnancy (both men and women) during the study