Characterisation of Gut Microbiota in Ossabaw and Gottingen Minipigs as Models of Obesity and Metabolic Syndrome

Background: Recent evidence suggests that the gut microbiota is an important contributing factor to obesity and obesity related metabolic disorders, known as the metabolic syndrome. The aim of this study was to characterise the intestinal microbiota in two pig models of obesity namely Gottingen minipigs and the Ossabaw minipigs. Methods and Findings: The cecal, ileal and colonic microbiota from lean and obese Osabaw and Gottingen minipigs were investigated by Illumina-based sequencing and by high throughput qPCR, targeting the 16S rRNA gene in different phylogenetic groups of bacteria. The weight gain through the study was significant in obese Gottingen and Ossabaw minipigs. The lean Gottingen minipigs' cecal microbiota contained significantly higher abundance of Firmicutes (P<0.006), Akkermensia (P<0.01) and Methanovibribacter (P<0.01) than obese Gottingen minipigs. The obese Gottingen cecum had higher abundances of the phyla Spirochaetes (P<0.03), Tenericutes (P<0.004), Verrucomicrobia (P<0.005) and the genus Bacteroides (P<0.001) compared to lean minipigs. The relative proportion of Clostridium cluster XIV was 7.6-fold higher in cecal microbiota of obese Gottingen minipigs as compared to lean. Obese Ossabaw minipigs had a higher abundance of Firmicutes in terminal ileum and lower abundance of Gottingen in colon than lean Ossabaw minipigs (P<0.01). Obese Ossabaws had significantly lower abundances of the genera Prevotella and Lactobacillus and higher abundance of Clostridium in their colon than the lean Ossabaws. Overall, the Gottingen and Ossabaw minipigs displayed different microbial communities in response to diet-induced obesity in the different sections of their intestine. Conclusion: Obesity-related changes in the composition of the gut microbiota were found in lean versus obese Gottingen and Ossabaw minipigs. In both pig models diet seems to be the defining factor that shapes the gut microbiota as observed by changes in different bacteria divisions between lean and obese minipigs.