Ma Somsouk, MD, MAS


1. Leveraging digital health and care coordination to improve health services delivery to vulnerable populations. We embrace big data and technology to design, develop, and deliver economic and effective services for patients in the area of cancer screening and follow-up.

2. Development of intestinal organoids from humans to understand barrier function, systemic inflammation, inflammatory bowel disease, HIV persistence, infection, and microbiome. Approaches employed: organoid models, isolation of epithelial cells, lymphocytes, microbiota, and interventional trials such as fecal transplant.
M.A.S., 2008 - , UCSF, Epidemiology and Biostatistics
Fellowship, 2008 - , UCSF, Gastroenterology & Hepatology
Residency, 2005 - , UCLA-Harbor Medical Center
M.D., 2002 - , Harvard Medical School
Fellowship, 2001 - , Beijing Medical University, Research Scholar
B.A., 1997 - , Pomona College, Chemistry
Honors and Awards
  • Dean M. Craig Endowed Chair in Gastrointestinal Medicine, UCSF, 2016
  • AGA Fellow, American Gastroenterology Association, 2015
  • Distinction in Mentoring, UCSF Academic Senate Nomination, 2015
  • Paul Dudley White / Andrew Sellard Fellowship, Harvard, 2001
  • Magna Cum Laude, Pomona College, 1997
  1. Colorectal Cancer Screening and COVID-19.
  2. Phenotypic analysis of the unstimulated in vivo HIV CD4 T cell reservoir.
  3. Mechanistic differences underlying HIV latency in the gut and blood contribute to differential responses to latency-reversing agents.
  4. Distinct viral reservoirs in individuals with spontaneous control of HIV-1.
  5. Advanced Notification Calls Prior to Mailed Fecal Immunochemical Test in Previously Screened Patients: a Randomized Controlled Trial.
  6. Changes in gastrointestinal microbial communities influence HIV-specific CD8+ T-cell responsiveness to immune checkpoint blockade.
  7. Obesity and metabolic outcomes in a safety-net health system.
  8. A Root Cause Analysis of Barriers to Timely Colonoscopy in California Safety-Net Health Systems.
  9. Antiretroviral Therapy Concentrations Differ in Gut vs. Lymph Node Tissues and Are Associated With HIV Viral Transcription by a Novel RT-ddPCR Assay.
  10. Standardized Workflows Improve Colonoscopy Follow-Up After Abnormal Fecal Immunochemical Tests in a Safety-Net System.
  11. Effectiveness and cost of organized outreach for colorectal cancer screening: A Randomized Controlled Trial.
  12. Human Immunodeficiency Virus (HIV)-Infected CCR6+ Rectal CD4+ T Cells and HIV Persistence On Antiretroviral Therapy.
  13. HIV-1-induced cytokines deplete homeostatic innate lymphoid cells and expand TCF7-dependent memory NK cells.
  14. The impact of antiretroviral therapy duration on the HIV-1 infection of T-cells within anatomic sites.
  15. Disparities in Hepatocellular Carcinoma Incidence in California: An Update.
  16. TFF3 interacts with LINGO2 to regulate EGFR activation for protection against colitis and gastrointestinal helminths.
  17. Fecal Microbiota Transplantation in Pouchitis: Clinical, Endoscopic, Histologic, and Microbiota Results from a Pilot Study.
  18. HIV and the Gut Microbiota: Composition, Consequences, and Avenues for Amelioration.
  19. CD32-RNA Co-localizes with HIV-RNA in CD3+ Cells Found within Gut Tissues from Viremic and ART-Suppressed Individuals.
  20. Serum Bovine Immunoglobulins Improve Inflammation and Gut Barrier Function in Persons with HIV and Enteropathy on Suppressive ART.
  21. Fecal microbiota transplant for Crohn disease: A study evaluating safety, efficacy, and microbiome profile.
  22. Increased mucosal neutrophil survival is associated with altered microbiota in HIV infection.
  23. Cellular HIV Reservoirs and Viral Rebound from the Lymphoid Compartments of 4'-Ethynyl-2-Fluoro-2'-Deoxyadenosine (EFdA)-Suppressed Humanized Mice.
  24. Low Literacy Level Instructions and Reminder Calls Improve Patient Handling of Fecal Immunochemical Test Samples.
  25. Gut and blood differ in constitutive blocks to HIV transcription, suggesting tissue-specific differences in the mechanisms that govern HIV latency.
  26. Population health interventions to improve colorectal cancer screening by fecal immunochemical tests: A systematic review.
  27. Macrophage Activation Marker Soluble CD163 is a Dynamic Marker of Liver Fibrogenesis in HIV/HCV Coinfection.
  28. Colorectal Cancer Incidence Trends by Age, Stage, and Racial/Ethnic Group in California, 1990-2014.
  29. Race/ethnicity is an independent risk factor for autoimmune hepatitis among the San Francisco underserved.
  30. Yield of Colonoscopy After a Positive Result From a Fecal Immunochemical Test OC-Light.
  31. A20 upregulation during treated HIV disease is associated with intestinal epithelial cell recovery and function.
  32. Increased HIV-1 transcriptional activity and infectious burden in peripheral blood and gut-associated CD4+ T cells expressing CD30.
  33. Hospitalizations for Autoimmune Hepatitis Disproportionately Affect Black and Latino Americans.
  34. Differential Expression of CD8+ T Cell Cytotoxic Effector Molecules in Blood and Gastrointestinal Mucosa in HIV-1 Infection.
  35. Missed Opportunities in Colorectal Cancer Prevention in Patients With Inadequate Bowel Preparations.
  36. Colorectal Cancer Screening Among South Asians: Focus Group Findings on Attitudes, Knowledge, Barriers and Facilitators.
  37. The San Francisco Cancer Initiative: A Community Effort To Reduce The Population Burden Of Cancer.
  38. Risk factors for postpolypectomy bleeding in patients receiving anticoagulation or antiplatelet medications.
  39. Detection of HIV-1-specific gastrointestinal tissue resident CD8+ T-cells in chronic infection.
  40. An Optimized and Validated Method for Isolation and Characterization of Lymphocytes from HIV+ Human Gut Biopsies.
  41. Evaluation of oral serum-derived bovine immunoglobulins in HIV-infected patients with chronic idiopathic diarrhea.
  42. A Randomized Controlled Trial of Lisinopril to Decrease Lymphoid Fibrosis in Antiretroviral-Treated, HIV-infected Individuals.
  43. Circulating LOXL2 Levels Reflect Severity of Intestinal Fibrosis and GALT CD4+ T Lymphocyte Depletion in Treated HIV Infection.
  44. Limited engraftment of donor microbiome via one-time fecal microbial transplantation in treated HIV-infected individuals.
  45. Human Immunodeficiency Virus Persistence and T-Cell Activation in Blood, Rectal, and Lymph Node Tissue in Human Immunodeficiency Virus-Infected Individuals Receiving Suppressive Antiretroviral Therapy.
  46. Replication of CMV in the gut of HIV-infected individuals and epithelial barrier dysfunction.
  47. Mucosal stromal fibroblasts markedly enhance HIV infection of CD4+ T cells.
  48. Urgent colonoscopy in patients with lower GI bleeding: a systematic review and meta-analysis.
  49. Inadequate Utilization of Diagnostic Colonoscopy Following Abnormal FIT Results in an Integrated Safety-Net System.
  50. Predominance of weakly cytotoxic, T-betLowEomesNeg CD8+ T-cells in human gastrointestinal mucosa: implications for HIV infection.
  51. Bacteroides are associated with GALT iNKT cell function and reduction of microbial translocation in HIV-1 infection.
  52. Protective association of colonoscopy against proximal and distal colon cancer and patterns in interval cancer.
  53. Longitudinal Genetic Characterization Reveals That Cell Proliferation Maintains a Persistent HIV Type 1 DNA Pool During Effective HIV Therapy.
  54. Gut epithelial barrier and systemic inflammation during chronic HIV infection.
  55. The immunologic effects of mesalamine in treated HIV-infected individuals with incomplete CD4+ T cell recovery: a randomized crossover trial.
  56. Lymphoid fibrosis occurs in long-term nonprogressors and persists with antiretroviral therapy but may be reversible with curative interventions.
  57. The CD8? memory stem T cell (T(SCM)) subset is associated with improved prognosis in chronic HIV-1 infection.
  58. HIV-infected individuals with low CD4/CD8 ratio despite effective antiretroviral therapy exhibit altered T cell subsets, heightened CD8+ T cell activation, and increased risk of non-AIDS morbidity and mortality.
  59. Esophageal varices on computed tomography and subsequent variceal hemorrhage.
  60. Challenges and possible solutions to colorectal cancer screening for the underserved.
  61. Non-physician performance of lower and upper endoscopy: a systematic review and meta-analysis.
  62. Adverse events in older patients undergoing ERCP: a systematic review and meta-analysis.
  63. Discordance between peripheral and colonic markers of inflammation during suppressive ART.
  64. A comparison of methods for measuring rectal HIV levels suggests that HIV DNA resides in cells other than CD4+ T cells, including myeloid cells.
  65. Commentary: Towards an effective and safe treatment of small intestine bacterial overgrowth - Authors' reply.
  66. The HIV-1 reservoir in eight patients on long-term suppressive antiretroviral therapy is stable with few genetic changes over time.
  67. Prospective antiretroviral treatment of asymptomatic, HIV-1 infected controllers.
  68. Helicobacter pylori: evidence-based review with a focus on immigrant populations.
  69. Comparison of HIV DNA and RNA in gut-associated lymphoid tissue of HIV-infected controllers and noncontrollers.
  70. Meta-analysis: antibiotic therapy for small intestinal bacterial overgrowth.
  71. Dysbiosis of the gut microbiota is associated with HIV disease progression and tryptophan catabolism.
  72. The immunologic effects of maraviroc intensification in treated HIV-infected individuals with incomplete CD4+ T-cell recovery: a randomized trial.
  73. Late presentation of colorectal cancer in a vulnerable population.
  74. Comparative analysis of measures of viral reservoirs in HIV-1 eradication studies.
  75. Activation, exhaustion, and persistent decline of the antimicrobial MR1-restricted MAIT-cell population in chronic HIV-1 infection.
  76. Short communication: HIV+ viremic slow progressors maintain low regulatory T cell numbers in rectal mucosa but exhibit high T cell activation.
  77. Adherence to colorectal cancer screening: a randomized clinical trial of competing strategies.
  78. Adverse events in older patients undergoing colonoscopy: a systematic review and meta-analysis.
  79. Prevalence of gastric cancer versus colorectal cancer in Asians with a positive fecal occult blood test.
  80. Increased frequency of regulatory T cells accompanies increased immune activation in rectal mucosae of HIV-positive noncontrollers.
  81. Moderate ascites identifies patients with low model for end-stage liver disease scores awaiting liver transplantation who have a high mortality risk.
  82. Ascites improves upon [corrected] serum sodium plus [corrected] model for end-stage liver disease (MELD) for predicting mortality in patients with advanced liver disease.
  83. New model for end stage liver disease improves prognostic capability after transjugular intrahepatic portosystemic shunt.
  84. Understanding liver health using the National Center for Health Statistics.
  85. A cost-utility analysis of ablative therapy for Barrett's esophagus.
  86. Management of obscure occult gastrointestinal bleeding: a cost-minimization analysis.
  87. Actinomycosis mimicking a pancreatic head neoplasm diagnosed by EUS-guided FNA.
  88. A cost-identification analysis of screening and surveillance of hepatitis C infection in a prospective cohort of dialysis patients.
  89. Will virtual colonoscopy replace optical colonoscopy for colorectal cancer screening?
  90. Proton pump inhibitors and hip fracture: cause for alarm?
  91. Determination of the three-dimensional, solution-phase structure of the macrolide antibiotic oxolide in CD2Cl2 and D2O from NMR constraints.
  92. Constitutive activation of Stat3 signaling pathway in human colorectal carcinoma.
  93. Hepatitis C virus is independently associated with increased insulin resistance after liver transplantation.
  94. Critical elements of the immunoglobulin heavy chain gene enhancers for deregulated expression of bcl-2.
  95. Spontaneous resolution of chronic hepatitis C virus disease after withdrawal of immunosuppression.
  96. Promoter structure and cell cycle dependent expression of the human methylpurine-DNA glycosylase gene.
  97. Partial functional deficiency of E160D flap endonuclease-1 mutant in vitro and in vivo is due to defective cleavage of DNA substrates.