Tu2032 VSL#3 Probiotic Treatment Prevents Ritonavir-Induced Gastrointestinal Barrier Dysfunction and Dyslipidemia in Mice

1.20x105cfu/ml (range=0-8.6x105cfu/ml) (p,0.01 by Wilcoxon Rank Sum test for matched pairs). Interestingly, in the rats followed for 30 additional days, the stool Staphylococcal counts continued to drop to near non-detectable levels. In the case of coliforms, atbaseline, rats had a median of 1.86x104cfu/ml. By day 10 of rifaximin, stool coliform counts dropped to 2.2x103cfu/mL (P,0.01, Wilcoxon Rank sum test for matched pairs). However, complete recovery of stool coliforms was seen by 3 days after cessation of therapy. After dissection, coliforms were rare in the duodenum and jejunum as expected in normal animals. However, rifaximin did not affect the large number of coliforms in the colon. Using qPCR for total bacteria, only the duodenum demonstrated a significant reduction in bacteria (P=0.05). Interestingly, there was a trend for continued decline in bacteria in the duodenum even after cessation of rifaximin (P=0.08). Conclusions: Rifaximin has no durable effect on stool colonic coliform bacteria although durable reductions in stool Staphylococcal species are seen. Using qPCR, rifaximin has a durable effect on the total flora of the duodenum in normal rats.