Effect of Milk Fat Globule Membrane (MFGM) on Gut Barrier Protection in Runners

A randomized, double-blind cross-over exercise trial was conducted with 14 runners on Utah State University campus. This population of 14 runners was selected from a larger population of 20 that was recruited to complete two initial trials. In two preliminary visits, the parameters necessary for conducting the experimental trial were determined. During the first visit, a baseline value was determined for gut permeability as well as aerobic capacity of runners. In the second visit the capacity to complete a run at 80% VO2max was tested and the effect of the exercise stress on gut permeability, plasma LPS and core temperature were measured.

Once a test population was selected, a randomized, double-blind, cross-over trial was conducted in which MFGM was tested for the ability to prevent a change in the exercise induced gut permeability.

During each testing session heart rate (HR), work output and core temperature (CT) were monitored. HR and CT were monitored by a CorTemp™ temperature pill which was ingested by the athletes prior to the trial (http://www.hqinc.net/pages/pill_page.html). In addition, blood was drawn at baseline (before depletion trial), immediately after the time trial, and again at 1h and 5h. Blood was analyzed for indices of training intensity (lactate), muscle damage (creatine kinase, cytokines), and gut barrier dysfunction (lipopolysaccharide, cytokines). In addition, immediately after the run athletes consumed a beverage with two carbohydrates (lactulose, and rhamnose). During the following six hours urine was collected and these sugars were measured via gas chromatography to determine the permeability of the gut.

Subject Recruitment Twenty, runners (ages 18-50) were initially recruited via campus flyers, advertisements in the local paper and weekly sports guide. Participants who had medical histories including: heart disease, uncontrolled hypertension, diabetes, Crohn's Disease, irritable bowel syndrome, colitis, Celiac disease, inflammatory or autoimmune diseases or lactose intolerance were excluded from the study. All subjects were instructed to avoid all anti-inflammatory medications for at least 24 h prior to any testing activity. On the morning of the first visit, approved subjects had body composition measured by BodPod (Life Measurement, Inc., Concord, CA). Participants were asked to refrain from any heavy exercise for 48 hrs before the first visit. Subjects were given a 50 ml tube containing the 5 g lactulose and 2 g rhamnose sugar probe and instructed to drink the probe 4hrs after they have finished breakfast to determine baseline gut permeability. Subjects were given a urine collection container and instructed to collect all urine for 6 hrs after ingestion of the probe. Subjects were not to eat lunch until 1.5 hrs after drinking the sugar probe. After 6 hrs of urine collection, subjects returned to the test site and performed a running VO2 max test.

Second Visit (approximately one week after first visit) Approximately 3 hrs after completion of breakfast, subjects reported to the test site to have blood drawn (to determine baseline plasma LPS), weight measured and to ingest a temperature probe. Participants started the exercise challenge (60 minute run at 80% VO2 max) approximately 4 hrs after completion of breakfast. The exercise challenge was conducted in a climate-controlled room at 22 °C without a fan. Subjects were monitored to ensure they were running at 80% VO2 max and were not allowed to consume water during the challenge. Immediately after the exercise challenge, participants consumed the sugar probes. Weight was measured, blood drawn (post-exercise plasma LPS) and subjects were instructed to collect their urine for the next six hrs. To facilitate re hydration and urine production, subjects were instructed to replace 150% of their fluid losses (pre to post exercise weight) by water intake.