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Alexa Evenson


Background: Gluten and inulin type fibers have been shown to impact satiety, breath hydrogen, GI symptoms, and properties of different food products. Stress is often thought to play a role in breath hydrogen and gastrointestinal symptoms. Additional lifestyle factors are often related to increased GI symptoms including fiber consumption, increased high-intensity exercise, higher rates of anxiety, and disrupted sleep behaviors. Furthermore, individuals with irritable bowel syndrome (IBS) often display differences in GI symptoms based on consumption of gluten and inulin and lifestyle factors.

Objective: The objective of this panel will be to describe the findings from a year-long study examining the impact of consumption of gluten and inulin (a FODMAP) on gastrointestinal (GI) symptoms, breath hydrogen, satiety, perceived stress, cortisol levels, and a variety of lifestyle factors including anxiety, diet, physical activity, and sleep in adults with and without IBS.

Methods: A blinded, randomized, controlled crossover design was conducted with 24 non-IBS participants. Fasted participants consumed a control low FODMAP smoothie and treatment smoothies that consisted of the low FODMAP base (control) with gluten (5g) or inulin (5g). Cortisol and breath hydrogen were measured at baseline (0), 1, 2, and 3 hours. GI symptoms were measured at baseline (0), 0.5, 1, 1.5, 2, 3, 12, and 24 hours. VAS was collected at baseline (0), 10 min, 30 min, 1, 1.5, 2, and 3 hours. Perceived stress, State and Trait Anxiety, and Physical activity were measured for each treatment. Dietary intake and Sleep were analyzed at one time point as these measures assessed behaviors over the past 30 days. Salimetrics ELISA assays were used to determine cortisol values. Variables were analyzed by the Area Under the Curve using the trapezoidal rule, Spearman rho correlation coefficients, Independent T-tests, Repeated Measures ANOVA, and Simple-Effects Tests with significance set at p<.05.

Results: There were no differences between non-IBS and IBS groups in any diet variable, including fruits, vegetables, fiber, dairy, added sugar, whole grains, physical activity variables, or sleep (p>0.05). There were no differences in state-somatic, trait-somatic, trait-cognitive, or trait-total in either treatment for non-IBS and IBS groups (p>0.05), except for the inulin treatment had a difference in state-cognitive between non-IBS and IBS groups (MD=3.5714; p=0.035) with the IBS group having more state-cognitive anxiety. The IBS group had more total GI symptoms to begin with (p=.001), however, there were no differences in change in breath hydrogen between treatments or groups (p>0.05). More details will be provided during the panel discussion.

Conclusion: In this sample of participants, the restriction of gluten and inulin in the diet (at 5 grams) is not warranted for those with and without IBS, as neither treatment produced a significant increase in breath hydrogen or GI symptoms for either group. In those with IBS, there were increased GI symptoms to start with, indicating more GI distress but not related to the consumption of gluten or inulin at the 5-gram level.