With obesity and type 2 diabetes on the rise, research is trying to find ways to reverse or slow its progress. Soy diets have been shown to be effective in doing so but have variable results. One variable that may affect soy's effectiveness is intestinal microflora. This experiment used female Zucker Diabetic Fatty (ZDF) rats that develop type 2 diabetes when fed high-fat diet and is similar to that of human development of type 2 diabetes. This study used soy diets designed to modify intestinal bacteria with probiotics or prebiotics: control, 2.5% fructooligosaccharide (FOS), 2.5% B. lactis, or 2.5% L. acidophilus. Food intake, body weight, and glucose levels were evaluated weekly throughout the study. At the end of a 23 day period total body lipids were assessed, as well as, glucose levels. The percent body lipids in the B. lactis group were higher than all other groups (p>0.05). The B. lactis and L. acidophilus groups had seemingly higher glucose levels; however, the statistical analysis was insignificant due to high variation between groups. Urine samples showed B. lactis and L. acidophilus groups had three rats with glucose levels of 500 mg/dl or above while control and FOS groups had one rat each in this category. This study showed no improvement to obesity and diabetic parameters through the microflora modifications used. In fact, some parameters worsened indicating a need for continuing research of soy with intestinal microflora modification.