Doctor of Philosophy (PhD)


School of Animal Science

Document Type



This study was designed to determine whether kefir accentuates the positive health benefits assessed by measures in fitness and/or body composition, as a measure of cardiovascular disease risk as well as the biomarker c-reactive protein. Sixty-seven adult males and females aged 18-35 years were assigned to one of four groups: 1) endurance training + control beverage, 2) endurance training + kefir beverage, 3) active control + control beverage or 4) active control + kefir beverage. The exercise groups completed 15 weeks of structured endurance training while the active control groups maintained their usual exercise routine. Baseline physiological and exercise measurements were collected pre-intervention and post-intervention. Blood and saliva samples were analyzed for C-reactive protein, tumor necrosis factor-alpha and secretory immunoglobulin A. Instances of sickness and illness throughout the intervention were also examined. Additionally, each group was assigned to either a kefir or a calorie/macronutrient matched placebo beverage that was consumed twice per week. The endurance training protocol was effective as demonstrated by a significant improvement (p<0.05) in the 1.5-mile times of the endurance training groups. The endurance training groups also experienced a significantly higher (p<0.05) number of sicknesses than the active control groups. There were no significant interactions among groups with respect to physiological outcome variables with the exception of serum C-reactive protein. The endurance training group receiving a control beverage demonstrated a significant increase (p<0.05) in C-reactive protein following the 15 week training program while the endurance training group receiving a kefir beverage had no significant change in C-reactive protein. Although the reported sickness was not significantly different between the endurance training group + kefir beverage and the endurance training group + control beverage, kefir supplementation may have been a factor in attenuating the increase in C-reactive protein that was observed over the course of the intervention period. This preliminary study suggests that kefir may be involved in improving the risk profile for cardiovascular disease as defined by C-reactive protein.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Boeneke, Charles