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Samuel Matthew Alaish, M.D.

Photo of Dr. Samuel Matthew Alaish, M.D.
  • Surgical Director, The Hopkins Resource for Intestinal Vitality and Enhancement (THRIVE)
  • Associate Professor of Surgery


Anti-reflux Surgery, Biliary Atresia, Biliary Diseases, Biliary Tract Surgery, Chest Wall Reconstruction, Choledochal Cyst, Cholestasis, Cholestatic Liver Diseases of Childhood, Congenital Anomalies, Esophageal Surgery, Gastrointestinal Surgery, Gastrointestinal Tumors, Pectus Carinatum, Pectus Excavatum, Pediatric Oncology Surgery, Pediatric Surgery more

Research Interests

Intestinal barrier loss caused by cholestasis; short bowel syndrome; genetic predisposition to cholestatic injury; gut microbiomes more

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The Johns Hopkins Hospital (Main Entrance)

Appointment Phone: 410-955-5210
1800 Orleans St.
Baltimore, MD 21287 map

Johns Hopkins Medicine - White Marsh

Appointment Phone: 443-997-5437
4924 Campbell Boulevard
Suite 205
Nottingham, MD 21236 map

Johns Hopkins Health Care and Surgery Center

6420 Rockledge Drive
Johns Hopkins Children's Center Specialists, Suite 2300
Bethesda, MD 20817 map
Phone: 443-997-5437


Distinguished pediatric surgeon Samuel M. Alaish, M.D., joined the Johns Hopkins Children's Center in 2015 to co-lead The Hopkins Resource for Intestinal Vitality and Enhancement (THRIVE), a multidisciplinary program dedicated to the study and care of children with short bowel syndrome, a condition marked by insufficient gut tissue or poor gut function due to acquired or congenital diseases.  

Alaish, an associate professor of surgery and surgical director of THRIVE, is a leading authority on pediatric intestinal disorders. Prior to Johns Hopkins, he worked at the University of Maryland, where in 2009 he launched a pediatric intestinal rehabilitation program.

"Dr. Alaish has an impressive track record not only as a pediatric surgeon but also as a prolific researcher whose clinical encounters and surgical experiences have driven him to study the mechanisms behind the diseases he sees in clinic and in the operating room," says David Hackam, M.D., Ph.D., Johns Hopkins' pediatric surgeon-in-chief.

"This combination of clinical acumen and scientific curiosity make Dr. Alaish a perfect fit for a place like the Johns Hopkins Children's Center, the cradle of pediatric academic medicine in this country."

Alaish's interest in short bowel syndrome was sparked by his clinical encounters in the neonatal intensive care unit during his fellowship. Originally, Alaish had set out to study and develop treatments for liver damage caused by a condition known as cholestasis - the abnormal and often-corrosive backup of fat-dissolving bile in the liver that scars the organ over time. Cholestasis and related complications, which claim the lives of thousands of newborns each year, are most commonly seen in babies born with a rare condition known as biliary atresia, marked by malformed bile ducts that prevent the normal drainage of bile from the liver into the intestines. However, during his rounds Alaish noticed that bile backup was also rather common among babies with short bowel syndrome and among premature babies who require intravenous nutrition known as TPN. Some babies on TPN would develop severe cholestasis and some would do just fine, Alaish observed, and physicians had no way of predicting which course a baby would take. Suspecting that genes were at play, Alaish took his questions to the lab. There, Alaish and colleagues found that mice carrying certain genes were more prone to developing cholestasis.

Then something else caught his attention: Animals with cholestasis had leakier intestinal walls that made it easier for dangerous gut bacteria to escape into the bloodstream and cause serious invasive infections, a common and dreaded complication seen in infants. In addition, Alaish noticed that animals with such leaky walls had abnormal bacterial content in their guts. The gut harbors trillions of bacteria - some of them beneficial, some of them potentially harmful - that live in a delicate balance. However, a disruption in this equilibrium can fuel overgrowth of "bad" germs. So if leaky intestinal walls and altered bacterial population in the gut occurred hand in hand, Alaish's next question became: "Which comes first?"

Alaish says he plans to pursue that answer at Johns Hopkins, both in the lab and in clinic. The insights, he says, could lead to more effective and less toxic treatments for intestinal infections than traditional antibiotic therapy. In addition to promoting bacterial resistance and making pathogens impervious to drugs, antibiotics can encourage the growth of hard-to-treat fungal infections.

"Being at Johns Hopkins will allow me to build on my previous research and clinical expertise, take my scientific pursuits to the next level, and, hopefully, benefit more patients and have greater impact," Alaish says. "Improving patient outcomes through research in the lab and in clinic is at the very heart of THRIVE."

A native of Maryland, Alaish earned his undergraduate degree in biomedical engineering from Duke University and medical degree from the University of Maryland. He completed a surgical internship and surgical residency at the Medical College of Virginia, followed by a fellowship in pediatric surgery at New York-Presbyterian Hospital. He went on to become assistant professor of surgery at Columbia University in New York and at New York-Presbyterian Hospital. Alaish was division chief of pediatric surgery at St. Vincent's Hospital at New York until 2002.

In 2002, Alaish became director of the pediatric chest wall reconstruction program at the University of Maryland, where he also went on to found and lead the pediatric intestinal rehab program. He led the division of pediatric surgery at St. Agnes Hospital in Baltimore from 2006 until 2015.

In addition to intestinal surgery, Alaish performs a variety of surgeries for newborn anomalies as well as esophageal, gastrointestinal and biliary reconstruction and minimally invasive surgery on infants and children of all ages. He also specializes in the correction chest wall deformities.

Alaish has been voted one of "America's Top Surgeons" by the Consumers' Research Council of America five times, including most recently in 2014.

He is married to Laura M. Fayad, M.D., an associate professor of radiology and radiological science and chief of the musculoskeletal section at the Johns Hopkins University School of Medicine. They have two children, a daughter and a son. more


  • Surgical Director, The Hopkins Resource for Intestinal Vitality and Enhancement (THRIVE)
  • Program Director, Pediatric Surgery Fellowship
  • Associate Chief, Clinical Operations and Education
  • Associate Professor of Surgery

Departments / Divisions

Centers & Institutes



  • MD, University of Maryland School of Medicine (1990)


  • Virginia Commonwealth University Health System / General Surgery (1997)


  • Babies and Children's Hospital of New York Columbia University / Pediatric Surgery (1999)

Board Certifications

  • American Board of Surgery / Pediatric Surgery (2000)
  • American Board of Surgery / Surgery (1998)

Research & Publications

Research Summary

Peer-reviewed Publications

1.Alaish SM, Yager DR, Diegelmann RF, Cohen IK. Hyaluronate receptor expression in fetal fibroblasts.  Surgical Forum 1993;49.

2.Alaish SM, Yager DR, Diegelmann, Cohen IK.  Biology of fetal wound healing: hyaluronate receptor expression in fetal fibroblasts.  J Ped Surg 1994;29:1040-1043.

3.Alaish SM, Bettinger DA, Olutoye OO, Gould LJ, Yager DR, Davis A, Crossland MC, Diegelmann RF, Cohen IK.  Comparison of PVA and ePTFE (Impra) subcutaneous implants as models to evaluate wound healing potential in humans.  Wound Repair and Regeneration 1995;3:292-298.

4.Alaish SM, Yager DR, Diegelmann RF, Cohen IK.  Hyaluronic acid synthesis in keloid fibroblasts before and after treatment with triamcinolone.  Surgical Forum 1994;50.

5.Alaish SM, Yager DR, Diegelmann RF, Cohen IK.  Hyaluronic acid metabolism in keloid fibroblasts.  J Ped Surg 1995;30:949-952.

6.Alaish SM, Das Narla L, Bagwell CE.  Chronic venous access using endogenous splenic tissue: the “spleen-o-port.”  J Ped Surg 1995;30:1198-1200.

7.Olutoye OO, Alaish SM, Carr ME Jr, Paik M, Yager DR, Cohen IK, Diegelmann RF.  Aggregatory characteristics and expression of the collagen adhesion receptor in fetal porcine platelets.  J Ped Surg 1995;30:1649-1653.

8.Alaish SM, Krummel TM, Bagwell CE, Michna BA, Drucker DE, Salzberg AM.  Loop enterostomy in necrotizing enterocolitis.  J Am Coll Surg 1996;182:457-458.

9.Alaish SM, Olutoye OO, Yager DR, Liang HX, Cohen IK, Diegelmann RF.  Transforming growth factor B1 reduces expansion of open wounds in the fetal rabbit.  Wound Repair and Regeneration 1996;4:477-481.

10.Alaish SM, Torres M, Ferlito M, De Maio A.  A genetic component in cholestatic injury resulting from common bile duct ligation.  J Am Coll Surg 2004;199(3) Supplement: 53.

11.Alaish SM, Torres, M, Ferlito M, Sun C, De Maio A.  The severity of cholestatic injury is modulated by the genetic background.   Shock 2005;24(5):412-416.

12.Alaish SM, Strauch ED.  The use of alloderm in the closure of a giant omphalocele.  J Pediatr Surg 2006; 41(3):e37-e39.

13.Surgical necrotizing enterocolitis and intraventricular hemorrhage in premature infants under 1000 grams. Jen HC, Graber J, Hill JL, Alaish SM, Voigt RW, Strauch ED.  J Pediatr Surg 2006;41(8):1425-1430.

14.Alexiev BA, Alaish SM, Sun C-C.  Testicular juvenile granulosa cell tumor in a newborn: case report and review of the literature.  Int J Surg Pathol 2007;15(3):321-325.

15.Turner D, Alaish SM, Zou T, Rao JN, Wang J-Y, Strauch ED.  Bile salts induce resistance to apoptosis through NF-kB-mediated XIAP expression.  Ann Surg 2007;245(3):415-425.

16.Alaish SM, Stewart FD, Fayad LF.  Symptomatic anterior sternoclavicular joint secondary to a bicipital rib. J Ped Surg 2008;43(10):e23-26.

17.Alaish SM, Greenspon, J, Strauch ED, Sun C-C.  Intraabdominal pulmonary sequestration presenting with elevated urinary normetanephrine levels.  J Ped Surg 2009;44(3):e11-14.

18.Alaish SM, Greenspon J, Eyvazzadeh D, Shea-Donohue T, Cross A, Fasano A, Nataro J.  Intestinal permeability and bacterial translocation are modulated by the genetic background of the host.  Gastroenterology, Volume 136, Issue 5, Supplement 1, May 2009, Pages A-414.

19.Greenspon J, Perrone EE, Alaish SM.  Shoshin beriberi mimicking central line sepsis in a child with short bowel syndrome.  World J Pediatr 2010;6(4):366-8.

20.Perrone EE, Chen C, Longshore SW, Okezie O, Warner BW, Sun C-C, Alaish SM, Strauch ED.  Dietary bile acid supplementation improves intestinal integrity and survival in a murine model.  J Ped Surg 2010;45(6):1256-1265.

21.Simpson-Camp L, Richardson EJ, Alaish SM.  Streptococcus viridans tubo-ovarian abscess in an adolescent virgin.  Pediatr Int 2012;54(6):706-709.

22.Smith A, Timmons J, Murphy E, Zhao A, Cross A, Alaish SM.  Genetic Variation Regulates the Expression of Tight Junction Proteins at Baseline and Following Common Bile Duct Ligation.  J Am Coll Surg 215(3); S71-S72, 2013.

23.Alaish SM, Smith A, Timmons J, Greenspon J, Eyvazzadeh D, Murphy E, Shea-Donahue T, Cirimotich S, Mongodin E, Zhao A, Fasano A, Nataro JP, Cross A.  Gut microbiota, tight junction protein expression, intestinal resistance, bacterial translocation and mortality following cholestasis depend on the genetic background of the host.  Gut Microbes 2013;4(4):1-14.

24.Alaish SM, Strauch ED, Stylianos S.  An Updated “Historical” Algorithm for Hirschsprung Patients who Present Late or Severely Ill.  Special Issue in Pediatric Surgery, IJCM 2013;4(7A2).

25.Alaish SM, Timmons J, Smith A, Buzza M, Murphy E, Zhao A, Turner DJ, Nataro JP, Antalis T, Cross A, Dorsey SG.  Candidate genes for limiting cholestatic intestinal injury identified by gene expression profiling.  Physiol Rep 2013;1(4) e00073.

26.Alaish SM.  Imperforate anus with a proximal sigmoid colovesical fistula. Transl Med 2014, 4:3.

27.Alaish SM.  Combined duodenal atresia and pure esophageal atresia.  Int J Surg Res 2015; 2(1): 5-7.

28.Alaish SM, Mongodin E, Zhang L, and Cross A.  Intestinal dysbiosis following cholestasis is reduced by active immunization with a detoxified endotoxin vaccine. J Bacteriol Mycol 2015; 2(1):1011-1015.

29.Cappiello CD, Darwin PE and Alaish SM.  A chronic biliary stricture following blunt abdominal trauma.  J Liver Clin Res 2015; 2(2): 1016.

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