The effects of day/night intermittent fasting and kefir administration on the levels of some energy metabolism-regulating hormones and thermogenic factors in mice

In this thesis study, two frameworks of intermittent fasting feeding model, daytime eating and nocturnal fasting, and nocturnal eating and daytime fasting, using C57BL/6 strain male mice were discussed. In addition, kefir, an important source of probiotics, was added to each of these two nutritional frameworks. It has been studied how the levels of ghrelin, leptin, adiponectin and resistin, which are known as metabolism-regulating hormones, are affected by all of them, including the kefir versions of both diets. Biochemical blood parameters such as glucose, HDL, cholesterol and triglyceride, which are known to be effective in metabolism, were also examined. In addition, the levels of UCP1, which is a thermogenic factor, and SIRT1, which can act as a thermogenic factor and a metabolic sensor, were also determined in each group. Mice were divided into 6 groups as control, kefir, daytime eating, nightly fasting, nighttime eating, daytime fasting, daytime eating, night fasting + kefir, and night eating, daytime fasting + kefir. Mice were administered intermittent fasting procedures for 4 weeks with 8 hours of eating and 16 hours of fasting in each version, day and night. At the end of the procedure, biochemical parameters and hormones affecting metabolism were measured from the blood serum of the mice, and UCP1 and SIRT1 levels were measured from the inguinal fats. Measurement of ghrelin, leptin, adiponectin, resistin, UCP1 and SIRT1 levels was done by ELISA test. As a result, it has been determined that there are many differences in the levels of hormones, biochemical parameters and thermogenic effects in which the day and night eating groups and the groups with kefir added to these groups are compared with each other, both compared to the control group and to each other, and even these differences are statistically significant in some of them. Keywords: intermittent fasting, kefir, metabolism, hormones