LMN-201 for Prevention of C. Difficile Infection Recurrence

Inclusion Criteria:

1. Male or female, aged 18 or older.

2. Diagnosis of CDI defined as a new or recent history of 3 or more bowel movements perday with a loose or watery consistency (Bristol Stool Scale 5, 6, or 7); a positivestool C. difficile toxin B immunoassay (stool collected no more than 7 days beforefirst dose of LMN-201/placebo), and no other likely explanation for diarrhea. NOTE:Diarrhea is not required to be present on the day of enrollment.

3. Provision of signed and dated informed consent form.

4. Scheduled to receive or planning to receive a ≤28-day course of SOC antibiotictherapy for CDI. Participant must have been diagnosed with CDI for 7 or fewer daysat time of initial study drug administration. SOC antibiotic therapy is defined asthe receipt of oral fidaxomicin or oral metronidazole or oral vancomycin (seeSection 8.2.6)

5. May be on systemic antibiotics for an infection unrelated to the gastrointestinaltract.

6. Ability to take oral medication and willingness to adhere to the study medicationregimen.

7. Stated willingness and ability to comply with all study procedures and availabilityfor the duration of the study and investigator believes individual will complete thestudy.

8. Access to a mobile smartphone.

9. For females of reproductive potential: use of highly effective contraception for atleast 4 weeks prior to screening and agreement to use such a method during studyparticipation and for an additional 4 weeks after the end of study drugadministration.

10. For males of reproductive potential: agreement to use condoms or other methods toensure effective contraception with partner during study participation and for anadditional 4 weeks after the end of study drug administration.

Exclusion Criteria:

1. Fulminant C. difficile colitis.

2. Admitted or expect to be admitted to an intensive care unit.

3. Underlying gastrointestinal disorder characterized by diarrhea including but notlimited to chronic ulcerative colitis, Crohn's disease, celiac sprue, short bowelsyndrome, dumping syndrome following gastrectomy, pancreatic insufficiency, entericparasitic infection, viral enteritis, bacterial enteritis (salmonella, shigella,ETEC, etc.).

4. Neutropenia (absolute neutrophil count of < 1000 per microliter for any reason).

5. Current or previous treatment in past 3 months with any therapy likely to influencethe outcome of this study, including but not limited to the following:

6. Bezlotoxumab (Zinplava, Merck & Co.), or another antibody against C. difficiletoxin(s)

7. C. difficile vaccine

8. SER-109 (Seres Therapeutics)

9. CP101 (Finch Therapeutics)

10. VE303 (Vedanta Therapeutics)

11. Fecal microbiota transplant

12. Current therapy with oral exchange resins

13. Protracted exposure to mu-agonist opioids and/or anticholinergic medicationprescribed for diarrheal symptoms (unable to stop mu-agonist opioid treatmentunless on a stable dose as of onset of diarrhea and no increase in dose plannedfor the duration of the study.)

14. Treatment with SOC antibiotic therapy is planned for longer than a 28-day period.

15. Pregnancy, anticipated pregnancy, or breastfeeding.

16. Inability or unwillingness to swallow numerous, relatively large capsules containingstudy drug or placebo because of a swallowing disorder or dysphagia.

17. Inability to pass swallowed capsules into the distal small intestine because ofgastroparesis, repetitive vomiting, or anatomic narrowing in the esophagus, stomach,or small intestine.

18. Psychiatric illness that would affect compliance with medications, study capsules,or follow-up.

19. Status as an inmate, residential mental health program, or residential substanceabuse program.

20. Terminal illness with limited life expectancy of less than 24 weeks.

21. Poor concurrent medical risks with clinically significant co-morbid disease suchthat, in the opinion of the investigator, the patient should not be enrolled.

22. Any other condition that, in the opinion of the investigator, would jeopardize thesafety or rights of the individual, would make it unlikely for the individual tocomplete the study, or would confound the results of the study.

• Note: Use of probiotics and other food supplements (e.g., yogurt, kefir,kimchi, etc.) are not exclusionary.

• Note: Assuming participants meet all of the inclusion criteria and none of theexclusion criteria, participants with underlying malignancy with a good lifeexpectancy in the study are not excluded.