Edible insects have been eaten by people throughout human history and are consumed today across the globe. Insects are also currently being incorporated into a number of food products in the United States, Canada, and Europe due to their unique nutritional and sustainability attributes. Insects have been touted as an environmental alternative to conventional meat products, but they are unique in containing dietary fiber. The investigators have recently demonstrated in a population of healthy individuals that two weeks of consuming 25 g/day cricket powder may be associated with prebiotic effects by stimulating the growth of Bifidobacterium in the gut. In addition, participants had reduced inflammatory markers in the blood after the cricket intervention. Crickets and other edible insects contain a unique form of fiber called chitin. They would like to explore whether chitin may be responsible for these previously observed effects and particularly if chitin consumption can mitigate symptoms and inflammation associated with the gastrointestinal disorder Irritable Bowel Syndrome (IBS). This project aims to examine the impact of consuming 4 grams of cricket-derived chitin daily for 30 days on the gut microbiota, intestinal and systemic markers of inflammation, and symptom severity and quality of life in individuals with IBS.

The study will take place in the Food and Nutrition Clinical Research Laboratory (FNCRL) located in the Gifford Building Room 216 on the Colorado State University campus. The time commitment for the study is approximately two and a half months, during which participants will spend ~1 hour (15-20 min/visit) at clinic appointments, eat small chocolate bars containing either the cricket chitin or a maltodextrin placebo daily for 30 days each, and collect four stool and four blood samples. (The two-and-a-half-month study will be broken into three parts: one 30-day fiber consumption period, one 14-day break, and a 30-day placebo consumption period.). The participant will be randomly assigned to Group A or Group B, but the treatment schedule for each is the same. One group will be given the small chocolate patties containing the insect chitin for 30 days, and the other group will be given the patties containing the placebo. However, neither the participant nor the research personnel will know whether participants are consuming the placebo or the treatment bars during a specific period until after the study is complete and all data is analyzed.

One group will eat insect fiber-filled chocolate patty for 30 days and then take at least a 14-day break (called a wash-out), followed by 30 days of eating the placebo bars. The other group will eat the placebo patties for 30 days and then take a break of at least 14 days (wash-out), followed by 30 days of eating the cricket fiber patties. During the treatment periods, the participant will consume either 4g of cricket fiber or 4g of maltodextrin (a type of sugar) included in the chocolate patties.

At the baseline visits, as well as at the end of each treatment period, fasted blood and stool samples will be collected by trained research personnel at the FNCRL. This means that participants will have a total of four (4) clinic visits during the study. The participant will be required to drop off the first stool sample at a specified location after the first visit. Subsequent stool kits will be returned at the scheduled clinic visit. Additionally, at each visit, the participant will be weighed, and hip and waist circumference will be measured. The participant will also fill out several forms, including questionnaires about any IBS-related symptoms and about their quality of life. Finally, the participant will take home a form to track their daily bowel movements and a 3-day diet diary to record what the participant eats at the beginning and end of each treatment period.

All blood samples will be collected at Colorado State University by a trained professional. The research team will provide the participant with collection materials and instructions, and the participant will perform fecal sample collection.

Inclusion Criteria:

• Participants must be 18 years of age or older with a medical diagnosis of Irritable Bowel Syndrome (IBS) and/or recurrent abdominal pain greater than 1 time per week persistent for at least 3 months while also meeting 2 of the 3 criteria for IBS diagnosis according to the Rome IV assessment. Both adult males and females of any race or ethnicity will be included in this study. (Rome IV Diagnostic Criteria for IBS link: www.mdcalcl.com/rome-iv-diagnostic-criteria-irritable-bowel-syndrome-ibs)

Exclusion Criteria:

• pregnant and lactating women,
• individuals taking antibiotics or who have recently taken antibiotics (within 60 days of the study start date),
• individuals with any self-reported shellfish, milk, or soy allergies
• individuals with a current diagnosis of inflammatory bowel disease, gastrointestinal cancers, other cancers, liver or kidney disease,
• individuals reporting current medication and dietary supplement use, along with the presence of other metabolic diseases, will be assessed on a case-by-case basis and may result in study exclusion
• individuals who feel that they will not be able to adhere to study requirements