The primary research question to be addressed is: Does a 2'-FL-containing dietary supplement impact stool microbiota composition in adults with IBS? The primary measure for determining potential impacts of the 2'-FL-containing dietary supplement on stool microbiota composition is stool abundance of Faecalibacterium prausnitzii, a commensal intestinal bacteria. Additional measures related to determining potential impacts of the 2'-FL-containing dietary supplement on gut microbiota composition are stool levels of additional commensal intestinal bacteria and measures of intestinal microbial diversity.

Inclusion Criteria:

• Adults age 18-70 years (inclusive)
• Existing diagnosis of IBS
• Willing to take the 2'-FL-containing dietary supplement (or a control supplement) three times per day for 6 weeks
• Willing to attend 4 in-person study visits
• Willing to collect 3 stool samples at home
• Willing to periodically monitor stool form/consistency (and log the information on a diary)
• Willing to complete IBS symptom focused questionnaires
• Willing to refrain from making changes in dietary supplements and medications for the duration of the study
• Willing to maintain current dietary pattern for the duration of the study
• Willing to maintain current exercise pattern for the duration of the study
• Able to speak, read, and understand the English language
• Able to provide written informed consent

Exclusion Criteria:

• Do not have an active primary care provider or specialist managing their IBS
• Initiation of or changes to supplements or medications within 2 weeks prior to screening and/or enrollment (changes include stopping or changing the dose of supplements or medications)
• Intake of prebiotic or fiber supplement(s) (current intake or intake within 2 weeks prior to screening and/or enrollment)
• Intake of probiotic supplement(s) (current intake or intake within 2 weeks prior to screening and/or enrollment)
• Use of antibiotic, antiparasitic, or antifungal medications orally or intravenously (current use or use within 2 weeks prior to screening and/or enrollment)
• Initiation of or changes to an exercise regimen within 2 weeks prior to screening and/or enrollment
• Initiation of or changes to a food plan within 2 weeks prior to screening and/or enrollment
• Current involvement or within 2 weeks prior to screening and/or enrollment of a significant diet or weight loss program (such as NutriSystem, Jenny Craig, Atkin's or other low-carb diet programs) or very low-calorie liquid diet programs (such as Optifast, Medifast, and/or HMR)
• Current or previous history of chronic gastrointestinal illness other than IBS (e.g. inflammatory bowel disease, celiac disease, diverticulitis, cirrhosis, hepatitis, etc.)
• History of gastrointestinal surgery other than appendectomy (e.g. weight loss surgery, cholecystectomy, splenectomy, etc.)
• Major medical or surgical event requiring hospitalization (for any reason other than a minor scheduled medical procedure) within 3 months prior to screening
• Cancer diagnosis or treatment within the last 5 years (with the exception of basal cell carcinoma, squamous cell carcinoma, and/or carcinoma in situ of the cervix)
• Currently participating in another interventional research study or participated in another interventional study within 2 weeks prior to screening
• Known intolerance or allergy to ingredients that may be in the study supplement or control supplement (Collinsonia root, beet root, okra, date powder, sucanat, rice hull concentrate, rice bran extract, cellulose, calcium stearate, calcium phosphate, gum arabic, or a trace amount of lactose)
• Women who are lactating, pregnant or planning pregnancy within the next 3 months