Small intestinal bacterial overgrowth (SIBO) can cause symptoms like bloating, stomach pain, and changes in bowel movements, significantly affecting quality of life. Many people with irritable bowel syndrome (IBS) also have SIBO, and there is growing recognition of how important it is to address this condition. Artemisia annua has shown potential in managing SIBO based on early reports and studies suggesting it can fight bacteria like *E. coli* and *Klebsiella*, which are linked to a type of SIBO that produces hydrogen gas.

This study aims to test if Artemisia annua is safe and well-tolerated for adults with hydrogen-type SIBO. Over five weeks, participants will take either 5 grams of dried Artemisia annua leaves or a placebo. Researchers will monitor safety through blood tests, vital signs, and adverse events, and they will assess symptom changes using questionnaires and breath tests.

The trial will include up to 32 participants from the Portland, Oregon area. Participants will be randomly assigned to treatment groups, and neither they, the researchers, nor the test administrators will know who is receiving the herb or the placebo. Results will be analyzed using standard statistical methods.

This study addresses the lack of research on herbal treatments for SIBO. If successful, the findings could lead to larger studies and help expand treatment options for people with SIBO.

Background: Small intestinal bacterial overgrowth (SIBO) often leads to bloating, abdominal pain, and stool change, and has significant impacts on quality of life. There is a high prevalence of SIBO among irritable bowel syndrome patients in particular and a growing awareness in the medical community of the impact of this condition. Anecdotal reports indicate that Artemisia annua, traditionally used against malaria, has shown promise in individuals with SIBO and previous studies suggest it has antimicrobials effects against E. coli and Kelbsiella, the bacteria associated with the hydrogen subtype of SIBO. This protocol describes the design of a phase II triple blind placebo controlled trial aiming to evaluate the safety and tolerability of 5g a day of dried leaf Artemisia annua in treating adults with hydrogen subtype SIBO over a 5 week period. Secondary objectives include the impact on symptom severity and exploratory outcomes include hydrogen and methane gas response.

Methods: A triple-blind, placebo-controlled, parallel-arm trial will enroll up to 32 participants from the Portland Oregon metropolitan area. Participants will undergo two lactulose breath tests, biweekly blood tests, and regular symptom assessments. Randomization will be computer-generated, stratified by symptom severity, with adherence closely monitored. Outcomes will measure changes in laboratory toxicology indicators, vital statistics, adverse events, and symptom severity. Data will be analyzed using appropriate statistical tests with a significance level set at p<.05.

Discussion: This is a protocol for a phase II trial of Artemisia annua in individuals with hydrogen subtype SIBO. This study helps address the dearth of formal studies of herbal treatments for SIBO and the results could provide a basis for larger trials and contribute to broader treatment strategies for this condition.

Inclusion Criteria:

• Adults 18 years of age or older
• IBS-SSS score >175
• Meets North American Consensus criteria for H2 SIBO
• Willing to take Artecinua™ or placebo as a dietary supplement for 5 weeks
• Willing to have two lactulose breath tests and do the prep diet 24 hours before and fast overnight before the test
• Willing to have three blood drawstests and fast overnight before the draw
• Able to speak, read, and understand English
• Able to provide informed consent
• For individuals of child-bearing potential, willing to use an intrauterine device or two other concurrent forms of birth control to prevent pregnancy while enrolled

Exclusion Criteria:

• Use of antibiotic pharmaceuticals or supplements 14 days before baseline breath test
• Initiation of change in diet, medication, or supplement regime within 30 days
• Hospitalization within the past 3 months
• Women who are breastfeeding, pregnant, or planning pregnancy in the next 4 months
• Allergies to any of the ingredients in the study products.
• Individuals with chronic kidney or liver disease, cancer, colorectal disease and/or other rare disorders that at the discretion of the PI or Clinical *Investigator may impact their safety or confound trial results
• The use of any high-risk medications with narrow therapeutic indices metabolized by CYP450 enzymes: Warfarin (CYP2C9), Tacrolimus/Cyclosporine (CYP3A4), Efavirenz (CYP2B6), and Codeine (CYP2D6).
• Drugs requiring activation for efficacy: Clopidogrel (CYP2C19), Codeine (CYP2D6), and Tamoxifen (CYP2D6) (citations).
• GFR: <30 mL/min/1.73m²
• Hepatitis from any cause.
• Excessive alcohol use (> seven drinks/week in women and > fourteen in men).
• Hepatic (ALT, AST, bilirubin) and renal (creatinine, estimated GFR) parameters outside of normal range at screening.