|PANASEVICH, MATTHEW - University Of Missouri|
|WANKHADE, UMESH - Arkansas Children'S Nutrition Research Center (ACNC)|
|CHINTAPALLI, SREE - Arkansas Children'S Nutrition Research Center (ACNC)|
|SHANKAR, KARTIK - Arkansas Children'S Nutrition Research Center (ACNC)|
|RECTOR, R SCOTT - University Of Missouri|
Submitted to: Physiological Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2018
Publication Date: 3/9/2018
Citation: Panasevich, M., Wankhade, U.D., Chintapalli, S.V., Shankar, K., Rector, R. 2018. Cecal versus fecal microbiota in ossabaw swine and implications for obesity. Physiological Genomics. https://doi.org/10.1152/physiolgenomics.00110.2017.
Interpretive Summary: The commensal bacteria residing in the human gut have a profound influence on health and development of disease. The bacterial community is strongly influenced by nutrition and dietary patterns, and shifts to various degrees with age from infancy through adulthood. Several studies have shown that the gut microbiome plays a causal role in obesity and subsequent metabolic disease. While many studies monitor the gut microbiome by assessing changes in the fecal microbiome composition, comparative analysis between cecal and fecal changes are infrequent. This is important since interpretations of research in this area could be influenced by site of collection. Using a model of obesity and progressive form of fatty liver disease that recapitulates pediatric disease in weanling Ossabaw pigs, we compared changes in bacterial composition in both the feces and cecal contents. Obesity significantly lowered measures of bacterial richness and there were clear compositional changes between lean and obese pigs, as well as between cecal and fecal samples. Obesity dramatically increased (P<0.05) the ratio of Firmicutes-to-Bacteroidetes phyla in fecal samples. A number of differences in both composition and predicted functional capacity of the microbiome were identified between cecal and fecal samples in obese pigs. The studies highlight differences in pro-inflammatory microbiota and their metabolic capacity in cecal versus fecal samples of obese pigs, providing new insight into evaluating the microbiome in the pathogenesis of obesity and metabolic disease.
Technical Abstract: The gut microbiome plays a critical role in the onset and progression of obesity and the metabolic syndrome. However, it is not well documented whether the cecal versus the fecal microbiome is more relevant when assessing its contribution to these diseases. Here, we amplified the V4 region of the 16S rRNA gene from cecal and fecal samples of female Ossabaw swine fed a low fat control diet (10.5% fat; n=4) or Western diet (43.0% fat; 17.8% high fructose corn syrup; 2% cholesterol; n=3) for 36 weeks. Obesity significantly lowered alpha-diversity (P<0.05) and there was clear separation in beta-diversity between lean and obese pigs, as well as between cecal and fecal samples (P<0.05). Obesity dramatically increased (P<0.05) the Firmicutes:Bacteroidetes ratio in fecal samples, and Actinobacteria was higher (P<0.05) in fecal versus cecal samples in obese pigs. Cyanobacteria, Proteobacteria, and Fusobacteria were increased (P<0.05), while Spirochaetes, Tenericutes, and Verrucomicrobia were decreased (P<0.05) in obese versus lean pigs. Prevotellaceae was reduced (P<0.05) in obese fecal versus cecal samples. Moreover, cecal samples in obese had greater (P<0.05) predicted metabolic capacity for glycan biosynthesis and metabolism and LPS biosynthesis compared with fecal. Obese pigs also had greater (P<0.05) capacity for carbohydrate metabolism, which was driven by obese fecal rather than cecal samples and was opposite in lean pigs (P<0.05). The observed differences in pro-inflammatory microbiota and their metabolic capacity in cecal versus fecal samples of obese pigs provide new insight into evaluating the microbiome in the pathogenesis of obesity and metabolic disease.