Pharmacokinetics, Safety, and Tolerability of SYN-020

1. Subject is able to read, write, and comprehend English at a sufficient level to understand study related materials, has provided written informed consent before any study-related procedure was performed, and is willing and able to comply with all testing and study requirements.
2. Subject is a healthy male or female, aged 18 through 50 years, inclusive.
3. Subject does not use any tobacco or nicotine product (eg, cigarette, pipe, e-cigarette, vape) and has not used any tobacco or nicotine product for at least 2 months before Day -1.
4. Subject has a BMI of 18.5 to 27 kg/m2 for initial cohorts or, for exploratory cohorts, ≥ 27.1 kg/m2. For Cohorts 1 through 4, if insufficient subjects are available to meet this criterion, subjects with a BMI up to 29 kg/m2 may be included with written authorization from the Sponsor.
5. Subject is healthy based on physical examination, clinical laboratory tests, 12-lead ECG, and vital signs.
6. Subject is willing to minimize the risk of inducing pregnancy from the time of signing the informed consent form (ICF) to at least either 90 days (males) or 30 days (females) after the study drug dose.
7. If female, subject has a negative serum pregnancy test at Screening and on Day -1 (CRU admission).
8. Subject usually has at least 1 bowel movement a day based on self-reporting.

Exclusion Criteria:

1. Subject has a history or the presence of clinically significant cardiovascular, pulmonary, hepatic, renal, hematologic, gastrointestinal, endocrine, immunologic, dermatologic, neurologic, oncologic, vascular, metabolic, collagen, or psychiatric disease or any other condition that, in the opinion of the Investigator, would jeopardize the safety of the subject or the validity of the study results.
2. Subject has any known malabsorption syndrome or history of gastrointestinal surgery that could compromise the study objectives.
3. Subject has used any medication (prescription or non-prescription) or herbal supplement, other than prescription hormone replacement therapy (eg, thyroid, testosterone, estrogen) or contraception methods described in Inclusion Criterion #6, within 21 days before Day -1.
4. Subject is pregnant, breastfeeding, or not using a medically accepted method of contraception.
5. Subject is unable to abstain from artificial sweeteners (eg, aspartame, acesulfame potassium, advantame, saccharin, stevia, and sucralose) from CRU admission to the end of study participation.
6. Subject has a positive urine drug or alcohol test at Screening or CRU admission OR has a history of drug/alcohol abuse within 12 months before Screening.
7. Subject has donated more than 500 mL blood during the 3-month period before Day -1.
8. Subject has known intolerance of study drug/ingredients.
9. In the judgment of the Investigator, subject has any factor (eg, other treatment) that could invalidate the study result.
10. Subject is currently enrolled in another clinical study or has received an investigational drug or device within 30 days or within a time period consistent with a washout period of 5 half-lives before signing the ICF, whichever is longer.
11. Subject has already participated in this study.