The Role of High Sugar Diets in Colitis

• Author / Creator

  Rajaruban, Sabitha

• There is an increase in the prevalence of inflammatory bowel disease (IBD) worldwide, and this appears to be associated with an increase in the consumption of a Western diet high in fat and sugar, and low in fiber. Previous work shows that two-day exposure to high sugar diets increases the severity of Dextran Sulfate Sodium (DSS)-induced colitis and impair recovery after removal of DSS. High sugar diets were found to decrease short-chain fatty acids (SCFA), which play a role in gut barrier integrity and promote an anti-inflammatory environment. The purpose of this thesis was to determine whether the increased severity and lack of repair were due to the high sugar content or the altered fiber content of high sugar diets. Mice were given chow diet with 15% glucose, 15% fructose, or control water. Water, food, and caloric intake were assessed, as well as the concentration of SCFAs in cecum contents and stool. Intestinal permeability was measured with plasma lipopolysaccharide (LPS) levels and lactulose/mannitol ratio, and gastroduodenal permeability was assessed with sucrose excretion in the urine. Mice on the high glucose water treatment had increased water intake, making this experimental model inappropriate for use with DSS. No differences in fecal or cecal SCFA levels or small intestinal permeability were observed. Gastroduodenal permeability was higher in mice on high glucose water treatment. In a second study, mice were given chow, 50% glucose, 50% fructose or 50% sucrose diets. DSS was added to drinking water after 2 days. After 5 days, the DSS water was replaced with regular drinking water. Consumption of high sugar diets for 2 days caused a reduction in butyric acid concentration. Mice on the glucose, fructose, and sucrose diets experienced worse disease severity and histological changes and greater concentration of pro-inflammatory cytokines IL-1β and IL-6 in the colon. Significant changes in Lachnospiraceae and Enterobacteriaceae were observed. During the recovery period, high sugar diet-fed mice had greater Enterobacteriaceae and Akkermansia, and lower amounts of SCFA-producing bacteria such as Lachnospiraceae and S24-7. In conclusion, a lack of fermentable fibers in the high sugar diets was associated with microbial alterations, reduced levels of butyrate-producing microbes, increased susceptibility to DSS-induced colitis and delayed recovery. These results suggest that a lack of fiber rather than the presence of high levels of sugar was responsible for the increased disease susceptibility.

• Subjects / Keywords

  • Butyrate
  • DSS
  • High sugar diets
  • Colitis
  • Short-chain fatty acids
  • IBD

• Graduation date

  Spring 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-tthe-t208

• License

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