Access Type

Open Access Thesis

Date of Award

January 2018

Degree Type


Degree Name



Nutrition and Food Science

First Advisor

Yifan Zhang


The gut microbiome may play a role in the development of chronic diseases like obesity, diabetes, and heart disease. Diets including prebiotics or probiotics can alter the abundance of gut bacterial groups and have subsequent health effects. In this study we wanted to establish a method for comparing the benefits of commercial supplements that alter the microbiota by monitoring fecal microbial profiles in male C57BL/6 mice (n = 24) exposed to 15 days of dietary supplementation. A probiotic diet (VSL#3) and a prebiotic diet (potato starch) were compared to a standard diet (n = 8 for each group). Microbial profiles were obtained through qPCR using group-specific 16S RNA primers.

The potato starch group showed higher body weight than the control (p < 0.05), but was similar to the VSL#3 group. The large intestine weight of the potato starch group was higher than the control and the potato starch group (p < 0.05). Food intake remained the same across the groups. Daily water consumption was higher in the VSL#3 group (6.65 ± 1.38 mL) as opposed to the potato starch and the control group (5.55 ± 1.21 mL, 5.54 ± 0.77 mL respectively). Blood glucose levels were similar between all groups. Quantitative PCR data showed higher abundance of bifidobacteria at a significant level compared to control and VSL#3 groups. VSL#3 supplementation was associated with more lactobacillus (p < 0.05) and lower serum LBP levels (p < 0.05) compared to control and potato starch groups.

The microbiota changes observed with VSL#3 and potato starch supplementation were mostly consistent with the literature. However, VSL#3 probiotic did not demonstrate the same increase in bifidobacteria as other studies. This may suggest a need for prolonged consumption or combination with a prebiotic like potato starch. Weight increase after potato starch supplementation might have been due to slower digestion. There was a reduction in LBP levels after VSL#3 consumption, which may help prevent inflammation and obesity.