The purpose of this investigation is to test the hypothesis that chronic supplementation with a dairy-based beverage containing a mixture of blueberry, green tea, and cocoa flavonoids (non-nutritive natural plant compounds) will ameliorate exercise-related changes in gut permeability and inflammation. In a previous feeding study in humans, (NCT02728570) a high flavonoid diet (flavonoids at 340 mg/1000kcal) was effective in mitigating gut permeability and inflammation in overweight and obese adults compared to a low flavonoid diet (10mg/1000 kcal). To test this hypothesis, 20 trained cyclists will complete a randomized crossover study with supplementation for 2 weeks with a dairy-based sports beverage containing either a high flavonoid (approximately 620 mg) or low flavonoid (approximately 5mg) beverage. After the two week intervention, cyclists will complete a 1 hour cycling trial (45 min at 65% VO2 max then 15 minute time trial). The primary endpoints will be gut permeability as measured by plasma intestinal fatty acid binding protein (I-FABP) and the differential sugar test. Secondary endpoints will include gut inflammation (measured via fecal calprotectin), plasma cytokines (IL-6, IL-10 and TNFα) and plasma LPS. In addition, the distance completed in the time trial is a secondary endpoint.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
12
A low flavonoid, sports nutrition recovery beverage will be prepared from milk (78%), sugar (8.6%), maltodextrin (8.6%), placebo blueberry powder (2.4%), alkalized cocoa powder (1.6%), and whey protein isolate (0.6%). The beverage will contain approximately 5mg flavonoids per serving.
A high flavonoid, sports nutrition recovery beverage will be prepared from milk (78%), sugar (8.6%), maltodextrin (8.6%), blueberry powder (2.4%), cocoa powder (1.6%), green tea extract (0.1%) and whey protein isolate (0.6%). The beverage will contain approximately 620 mg flavonoids per serving.
Center for Human Nutrition Studies
Logan, Utah, United States
Urinary lactulose:mannitol ratio by gas chromatography
Measure of gut permeability from mouth to end of small intestine. Ratio of urinary lactulose to mannitol after subject consumes a beverage containing these sugars. Sugars in urine are measured by gas chromatography with flame ionization detection.
Time frame: Three weeks
Plasma intestinal fatty acid binding protein (i-FABP) by ELISA
Marker of gut wall integrity. i-FABP is measure by enzyme-linked immunosorbent assay in plasma of subjects after the time trial.
Time frame: Three weeks
Fecal calprotectin by ELISA
Secondary endpoint for intestinal inflammation. Calprotectin is measured in fecal samples by enzyme-linked immunosorbent assay.
Time frame: Three weeks
Urinary sucralose:mannitol ratio by gas chromatography
Secondary measure of gut permeability from mouth to end of colon. Ratio of urinary lactulose to mannitol after subject consumes a beverage containing these sugars. Sugars in urine are measured by gas chromatography with flame ionization detection.
Time frame: Three weeks
Serum soluble tumor necrosis factor (TNFa) by ELISA
One of four secondary endpoints for systemic inflammation. The cytokine, TNFa, is measured in plasma by enzyme-linked immunosorbent assay.
Time frame: Three weeks
Serum soluble interleukin-6 (IL-6) by ELISA
One of four secondary endpoints for systemic inflammation. The cytokine, IL-6, is measured in plasma by enzyme-linked immunosorbent assay.
Time frame: Three weeks
Serum soluble interleukin-10 by ELISA
One of four secondary endpoints for systemic inflammation. The cytokine, IL-10, is measured in plasma by enzyme-linked immunosorbent assay.
Time frame: Three weeks
Serum endotoxin by ELISA.
One of four secondary endpoint for systemic inflammation. The bacterial cell wall product is measured in plasma by enzyme-linked immunosorbent assay.
Time frame: Three weeks
Distance ridden in time trial
Subjects will complete a 15m time trial on a bike after each dietary intervention. The distance covered in each time trial will be measured by the computer on the exercise bike.
Time frame: One Day
Rating of perceived exertion by questionnaire.
Subjects will complete a 15m time trial on a bike after each dietary intervention. This measure is a subjective measure of the difficulty of the work. Subjects will provide the ratings orally during the time trial.
Time frame: One Day
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