A Study of the Gut Barrier and Blood Vessel Inflammation in Individuals With and Without HIV

Inclusion Criteria: 1. Men and women age 21-65 with previously diagnosed HIV disease 2. Stable anti-retroviral therapy (ART) as defined by no changes in ART regimen for \>6 months 3. HIV viral load \< 200 copies/mL 4. To be eligible for colonoscopy procedure, laboratory values that meet the following criteria: 1. Hemoglobin \> 9.0 g/dL 2. Absolute neutrophil count ≥ 1000/mm3 3. Platelet count ≥ 100,000/mm3 4. Prothrombin time (PT) \< 1.2 x upper limit of normal (ULN) 5. Partial thromboplastin time (PTT) \< 1.5 x ULN 4\. Ability and willingness to give written informed consent and to comply with study requirements Exclusion Criteria: 1. History of clinically significant gastrointestinal disease including but not limited to: colon cancer, intestinal obstruction, ulcerative colitis, Crohn's disease, or history of C. difficile within the past 3 months 2. First-degree relative with history of colon cancer 3. Active gall bladder, biliary or pancreatic disease 4. Female subject who is pregnant, nursing or less than 8 weeks post partum. 5. Use of any immunomodulatory agents within 30 days prior to study enrollment 6. History of intolerance, sensitivity, allergy or anaphylaxis to benzodiazepines or other narcotics to be used during the colonoscopy or upper endoscopy procedure 7. Contraindication to beta-blocker (including moderate to severe asthma or heart block) or nitroglycerin use as these drugs are given as part of the standard cardiac CT protocol. Previous allergic reaction to beta blocker or nitroglycerin. 8. Patients with previous allergic reactions to iodine-containing contrast media 9. Renal disease or creatinine \>1.5 mg/dL (contrast will be administered during CT angiography of the heart) 10. History of requiring antibiotic prophylaxis for invasive procedures 11. History of myocardial infarction, decompensated cirrhosis, or any other condition that in the opinion of the investigator will compromise ability to participate in the study 12. Currently taking anticoagulants including but not limited to: heparin, warfarin (Coumadin), tinzaparin (Innohep), enoxaparin (Lovenox), danaparoid (Orgaran), dalteparin (Fragmin), clopidogrel (Plavix), prophylactic aspirin, and regular NSAID use 13. Subject taking any of the following medications: statins, systemic steroids (inhaled or nasal steroid therapy is permitted), interleukins, systemic interferons (e.g. local injection of interferon alpha for treatment of human papilloma virus is permitted), systemic chemotherapy including oral chemotherapeutic agents, methotrexate, octreotide, growth hormone, antiarrhythmics including digoxin, antiepileptics, immunosuppressants, vancomycin, rifampin, aminoglycosides, clonidine, prazosin, lithium and ritonavir-boosted lopinavir (Kaletra). 14. Subject has had two or more endoscopy procedures (sigmoidoscopy, upper endoscopy or colonoscopy) within the past 12 months for clinical purposes or other research studies. 15. Body weight greater than 300 lbs due to CT scanner table limitations 16. Active illicit drug use 17. Patients who report any significant radiation exposure over the course of the year prior to randomization. Significant exposure is defined as: 1. More than 2 percutaneous coronary interventions (PCI) within 12 months of randomization 2. More than 2 myocardial perfusion studies within the past 12 months 3. More than 2 CT angiograms within the past 12 months 4. Any subjects with history of radiation therapy 18. Patients already scheduled or being considered for a procedure or treatment 1. requiring significant radiation exposure (e.g., radiation therapy, PCI, or catheter 2. ablation of arrhythmia) within 12 months of randomization 19. History of malignancy 20. Prior recipient of a HIV vaccine