Herbal Supplement (Biocidin REMOVE) for Bacterial Overgrowth in Irritable Bowel Syndrome

This is a single-site, randomized, double-blind, placebo-controlled pilot feasibility trial. Forty participants will be randomized 1:1 to Biocidin REMOVE or matching placebo (20 per arm). Up to 50 participants will be consented to allow for approximately 10 screen failures. Participants and investigators are both blinded; active and placebo capsules are identical in appearance.

Study product is a commercially available herbal preparation supplied as a 665 mg capsule containing 325 mg of the active proprietary blend.

Dosing follows a 9-day titration, increasing by one capsule every three days: one capsule once daily on Days -9 to -7, one capsule twice daily on Days -6 to -4, and two capsules in the morning with one in the evening on Days -3 to -1. Participants reach the target dose of two capsules twice daily on Day 1 and continue through Day 28. Titration begins approximately 14 days after the research breath test.

Baseline procedures may occur over multiple days and may begin up to 30 days before titration. Treatment-period visits carry a ±2 day window; the post-treatment follow-up visit occurs on Day 56 with a ±7 day window.

Lactulose breath testing measures carbon dioxide, hydrogen, and methane using the Quintron BreathTracker Microlyzer, performed at the Gastroenterology Clinical Laboratories at Green Spring Station. Stool is collected at home using a DNA Genotek microbiome collection kit and analyzed at Johns Hopkins. Microbiome analysis uses targeted and metagenomic sequencing of bacterial DNA to identify changes in bacterial species; beta diversity will be assessed using Bray-Curtis dissimilarity, the Jaccard index, and UniFrac. Dietary intake is captured using the ASA24 Dietary Assessment Tool.

The primary comparison of remission proportions between arms will use a two-sample z test. The sample size of 20 per arm was chosen to detect a 40 percentage-point difference in remission, assuming 10% remission without intervention and 50% with comparable interventions, using a two-sided z test with unpooled variances, alpha of 0.05, and 80% power. Baseline characteristics will be compared between arms using Student's t-tests, Wilcoxon-Mann-Whitney tests, and chi-square or Fisher exact tests as appropriate. If randomization imbalance is suggested, propensity score-based methods and/or covariate adjustment will be explored.

Adverse events are graded using NCI CTCAE version 5.0, with causality assessed as not related, possibly related, or probably related. Study drug is discontinued for any Grade 2 or greater event considered possibly or probably related, any such event persisting more than 48 hours, or any treatment-emergent serious adverse event unless clearly unrelated. The study will be stopped if three participants experience Grade 2 or greater possibly or probably related events within the same system organ class, or if one participant experiences a severe or serious event considered possibly or probably related.

Inclusion criteria

• Age 18 years or older
• Irritable bowel syndrome by Rome IV criteria with a positive lactulose breath test for small intestinal bacterial overgrowth, defined as a rise of more than 20 parts per million of hydrogen above baseline in the first 90 minutes of testing and/or a methane level of 10 parts per million or greater at any point during the test

OR

• Irritable bowel syndrome by Rome IV criteria with a lactulose breath test showing a "flat line pattern," with exhaled gas levels remaining very low (3 parts per million or less) with no spikes
• Female participants of childbearing age who are sexually active with male partners must agree to use a highly effective method of contraception, such as abstinence, hormonal contraceptive, intrauterine device, or bilateral tubal occlusion

Exclusion criteria

• Negative SIBO breath testing at baseline
• Restricted diets (low carbohydrate, Atkins, gluten-free, low FODMAP, or others)
• Confirmed celiac disease
• Immunocompromised (chronic steroids, biologics), CD4 less than 400, AIDS not on therapy, neutropenia, acute and chronic leukemia, lymphoma
• Portal hypertension
• Chronic liver disease, defined as: ICD-10 known diagnoses of chronic liver disease; OR known or suspected liver cirrhosis, portal hypertension, or chronic hepatitis; OR serum AST and ALT elevation greater than 2 times the upper limit of normal with decreased serum albumin less than 4.0 g/dL within the last 6 months
• Pregnant or breastfeeding
• Diagnosis of inflammatory bowel disease
• Poorly controlled anxiety or depression despite medication
• Untreated significant anxiety or depression
• COVID-19 positive
• Unable to provide informed consent
• Insulin dependent or poorly controlled diabetes mellitus (HbA1c greater than 7.0%)
• Connective tissue disease such as lupus or scleroderma
• Concurrent narcotic use
• Antibiotic or probiotic use within 30 days