Associate Professor Arizona State University Tempe, Arizona
Chronic intake of energy‐dense foods is known to alter gut microbial diversity and promote liver disease in adults, which may contribute to the development of cardiovascular and neurological disease. However, the effects of short-term high-fat intake are less known in adolescents. We hypothesized that high‐fat intake for 6 weeks would promote intestinal dysbiosis, hepatic lipid infiltration, and impaired cardiovascular function in six-week old male Sprague-Dawley rats. Rats were divided into two groups and fed either a standard rodent chow or a 60% high‐fat diet (HFD) for 6 weeks. Chromogenic endotoxin quantification assays indicate an increase in lipopolysaccharide concentration in the plasma of HFD rats (p = 0.032). Additionally, Western blot analyses of the cecum showed significantly greater protein expression of the transcription factor, nuclear factor kappa B (NF‐kB), (p = 0.037) and the proinflammatory cytokine, interleukin‐1β (IL‐1β), (p = 0.042) in rats fed HFD. Linear discriminate analysis of effect size (LEfSe) showed greater abundance of Firmicutes and Actinobacteria in samples collected from the cecum of HFD rats compared to chow. In addition, Oil red O staining of liver samples from HFD rats showed evidence of hepatic steatosis and increased circulating alanine aminotransferase, a marker of liver injury (p < 0.001). With respect to cardiovascular health, HFD-fed animals develop impaired vasodilation resulting from inflammation and oxidative stress. These findings show that a short-term high‐fat diet can have profound deleterious effects on gastrointestinal health and the inflammatory state of young male Sprague–Dawley rats.