This study is a randomized, double-blind, placebo controlled clinical study to assess the efficacy, safety, pharmacokinetics (PK) and pharmacodynamics (PD) of FB102 in adult participants with well controlled (on a strict GFD) CeD following an oral gluten challenge.

Inclusion Criteria:

1. Men and women aged 18 to 70 years at Screening.
2. Has documented diagnosis of CeD confirmed by intestinal biopsy and positive celiac serology at least 12 months prior to Screening (intestinal biopsy and serology do not have to be performed concurrently).
3. Body mass index (BMI) between 16.0 and 40.0 kg/m2, inclusive.
4. Self-reported to be on a GFD for at least 12 months prior to Screening and must be willing to remain on a GFD for the duration of study participation, with the exception of the oral gluten challenge administered as a study procedure. Prior acute and resolved accidental exposures are not exclusionary.

Exclusion Criteria:

1. Uncontrolled CeD and/or active signs/symptoms of CeD, in the opinion of the Investigator.
2. History of or current neuropsychiatric manifestations specifically related to gluten exposure including ataxia, seizures, severe peripheral neuropathy, cognitive impairment, and depression.