About gutsandgrowth

I am a pediatric gastroenterologist at GI Care for Kids (previously called CCDHC) in Atlanta, Georgia. The goal of my blog is to share some of my reading in my field more broadly. In addition, I wanted to provide my voice to a wide range of topics that often have inaccurate or incomplete information. Before starting this blog in 2011, I would tear out articles from journals and/or keep notes in a palm pilot. This blog helps provide an updated source of information that is easy to access and search, along with links to useful multimedia sources. I was born and raised in Chattanooga. After graduating from the University of Virginia, I attended Baylor College of Medicine. I completed residency and fellowship training at the University of Cincinnati at the Children’s Hospital Medical Center. I received funding from the National Institutes of Health for molecular biology research of the gastrointestinal tract. I have authored numerous publications/presentations including original research, case reports, review articles, and textbook chapters on various pediatric gastrointestinal problems. Currently, I am the vice chair of the section of nutrition for the Georgia Chapter of the American Academy of Pediatrics. In addition, I am an adjunct Associate Clinical Professor of Pediatrics at Emory University School of Medicine. Other society memberships have included the American Academy of Pediatrics, the Food Allergy Network, the American Gastroenterology Association, the American Association for the Study of Liver Diseases, and the Crohn’s and Colitis Foundation. As part of a national pediatric GI organization called NASPGHAN (and its affiliated website GIKids) I have helped develop educational materials on a wide-range of gastrointestinal and liver diseases which are used across the country. Also, I have been an invited speaker for national campaigns to improve the evaluation and treatment of gastroesophageal reflux disease, celiac disease, eosinophilic esophagitis, and inflammatory bowel disease (IBD). Some information on these topics has been posted at my work website, www.gicareforkids.com, which has links to multiple other useful resources. I am fortunate to work at GI Care For Kids. Our group has 15 physicians with a wide range of subspecialization, including liver diseases, feeding disorders, eosinophilic diseases, inflammatory bowel disease, cystic fibrosis, DiGeorge/22q, celiac disease, and motility disorders. Many of our physicians are recognized nationally for their achievements. For many families, more practical matters include the following: – 14 office/satellite locations – physicians who speak Spanish – cutting edge research – on-site nutritionists – on-site psychology support for abdominal pain and feeding disorders – participation in ImproveCareNow – office endoscopy suite (lower costs and easier scheduling) – office infusion center (lower costs and easier for families) – easy access to nursing advice (each physician has at least one nurse) I am married and have two sons. I like to read, walk/hike, exercise, swim, and play tennis with my free time as well as go to baseball games. I do not have any financial relationships with pharmaceutical companies or other financial relationships to disclose. I have participated in industry-sponsored research studies.

Nutritional Anemia -Expert Review

At Children’s Healthcare of Atlanta, there has been a long-standing nutritional lecture series coordinated by Kipp Ellsworth.

A recent webinar: Link to WebEx (password PmSU6JPt): Nutrition Support Colloquium featuring Dr. Parmi Suchdev: “The Prevention, Diagnosis, and Treatment of Nutritional Anemia” (30 minute lecture)

Dr. Parmi Suchdev affiliations:

  • Associate Director, Emory Global Health Institute
    Director, Global Health Office of Pediatrics
    Professor of Global Health, Rollins School of Public Health
    Professor of Pediatrics, Emory University School of Medicine

Here are a few of the slides:

Related blog posts:

Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition

COVID: Schools & Age-Related Morbidity and Mortality

JF Ludvigsson et al NEJM 2021; 384: 669-671. Full text: Open Schools, Covid-19, and Child and Teacher Morbidity in Sweden In this letter to the editor, the authors report on outcomes in Sweden, which kept schools open during the pandemic; time period: from March 1-June 30, 2020 (schools end around June 10th). Key findings:

  • Among 1-16 years of age (~1.95 million in total), 15 required ICU admission; there were no deaths in this age group
  • “Fewer than 10 pre-school teachers [1-6 years] and 20 schoolteachers received ICU care up to June 30, 2020.” Excluding health care workers, the occupational risk was similar to other occupations, with relative risk of 1.10 (0.49-2.49, 95% CI) and 0.43 (0.28-0.68, 95% CI) for preschool and school teachers respectively.

My take: This study suggests that school teachers are at similar risk for COVID-19 infection as other essential workers. In Sweden, during this timeframe, distancing but not masking was recommended. Thus, transmission rates could be lowered further.

Related article: SR Kadire et al. NEJM 2021; 384: DOI: 10.1056/NEJMclde2101987. Full text: Delayed Second Dose versus Standard Regimen for Covid-19 Vaccination This article provides rationale for both vaccine options.

Related blog posts:

Highly Prevalent Pediatric Feeding Disorders

A recent retrospective study (K Kovacic et al. J Pediatr 2021; 228: 126-131. Pediatric Feeding Disorder: A Nationwide Prevalence Study) provides epidemiologic data for pediatric feeding disorders.

The authors utilized three databases for children aged 2 months to 18 years: Medicaid Databases from Arizona (2009-2017) and Wisconsin (2005-2014) (public insurance databases) and The Truven Health Analytics MarketScan Commercial Claims and Encounters Database (2009-2015) (a nationwide private insurance database).

Key findings:

  • There were 126 002 and 367 256 children 5 years of age or younger with pediatric feeding disorders (PFD) with public and private insurance, respectively
  • In 2014, the annual prevalence of PFD was 1 in 23, 1 in 24, and 1 in 37 in children under 5 years in the publicly insured cohorts in Wisconsin, Arizona, and the privately insured cohort, respectively.
  • The prevalence of PFD in children <5 years (range: 27-44 per 1000 children) exceeds the prevalence of U.S. children with autism spectrum disorder (~17 per 1000 children at age 8 year) and eating disorders like anorexia nervosa and bulimia (8 and 13 per 100,000 persons per year).
  • In an associated editorial (pg 13-14), Rachel Rosen notes that “despite their high prevalence, the lack of studies funded by the National Institutes of Health…is striking.”

My take: This study provides useful data on PFD prevalence. PFD have a wide range of associated diseases, including prematurity, neurologic disorders/developmental delay, congenital heart disease, chronic lung disease, autism, and congenital bowel disorders. In some, PFD are related to poorly-understood feeding aversions.

Related blog posts:

Chicago, IL & Lake Michigan

Liver Shorts -February 2021 (part 2)

M Biewenga et al. Liver Transplantation 2020; 26: 1573-1581. Full text: Early Predictors of Short-Term Prognosis in Acute and Acute Severe Autoimmune Hepatitis

Key points:

  •  After the start of immunosuppressive therapy, bilirubin, albumin, and INR normalized in 70%, 77%, and 69%, respectively, in a median of 2.6 months, 3 months, and 4 weeks, respectively, in patients with A-AIH and AS-AIH
  • Deterioration of liver function (bilirubin, INR) after 2 weeks of treatment should lead to rapid evaluation for LT and consideration of second-line medication.

I Ziogas et al. J Pediatr 2021; 228: 177-182. Mortality Determinants in Children with Biliary Atresia Awaiting Liver Transplantation

Key points:

  • The cumulative incidence of waitlist mortality was 5.2%. Median waitlist time was 83 days.
  • In multivariable analysis (n = 2253), increasing bilirubin level ( P < .001), portal vein thrombosis ( P = .03), and ventilator dependence ( P < .001) at listing were associated with a higher risk, whereas weight ≥10 kg at listing ( P = .009) was associated with a lower risk of waitlist mortality. 

References Only:

HM DuBrokc, MJ Krowka. Hepatology 2020; 1455-1460. The Myths and Realities of Portopulmonary Hypertension

Related blog posts:

H Oh et al. Clin Gastroenterol Hepatol 2020; 18: 2793-2802. Full text: No Difference in Incidence of Hepatocellular Carcinoma in Patients With Chronic Hepatitis B Virus Infection Treated With Entecavir vs Tenofovir Related blog post: Is Tenofovir the Best Medication for HBV?

Evanston, IL

FMT Research & The Shawshank Redemption

In The Shawshank Redemption, Andy Dufresne (Tim Robbins) manages to escape prison by crawling through 500 yards of a filthy sewage pipe. It seems like a similar effort will be needed to find out how to benefit from fecal transplantation when given for problems like irritable bowel syndrome and metabolic disease/obesity. Some recent studies and associated editorials are noted below.

T Holvoet et al. Gastroenterol 2021; 160: 145-157. Fecal Microbiota Transplantation Reduces Symptoms in Some Patients With Irritable Bowel Syndrome With Predominant Abdominal Bloating: Short- and Long-term Results From a Placebo-Controlled Randomized Trial

  • Key finding: At week 12, 56% of patients given donor stool reported improvement in both primary endpoints compared with 26% of patients given placebo (P = .03).
  • Commentary: PW O’Toole, F Flanahan. Gastroenterol 2021; 160: 15-17. Full Text: Transplanting Microbes for Irritable Bowels or Irritated Microbes or Both?
    • This editorial stresses that trials of FMT in IBS have had inconsistent results and risks are unclear. “How many clinicians inform patients receiving FMT that the donor microbiota might include components that increase (or decrease) one’s risk of colorectal cancer?” Part of the problem is “due, in part, because a normal microbiome has not been defined.”

E Rinott et al. Gastroenterol 2021; 160: 158-173. Full text Effects of Diet-Modulated Autologous Fecal Microbiota Transplantation on Weight Regain

Key findings:

  • In this randomized controlled trial with 90 participants, autologous FMT (aFMT) significantly attenuated weight regain in the green-Mediterranean group (aFMT, 17.1%, vs placebo, 50%; P = .02) and improved insulin resistance: insulin rebound (aFMT, –1.46 ± 3.6 μIU/mL vs placebo, 1.64 ± 4.7 μIU/mL; P = .04) (Graphical abstract below)
  • In mice, Mankai-modulated aFMT in the weight-loss phase compared with control diet aFMT, significantly prevented weight regain and resulted in better glucose tolerance during a high-fat diet–induced regain phase (all, P < .05).

Commentary: M Nieurdorp, K Madsen. Gastroenterol 2021; 160: 17-19. Full text The Promise of Maintaining Diet-Induced Weight Loss by Swallowing One’s Own Feces: Time to Provide a Do-It-Yourself Manual?

  • “These findings add support to the current body of evidence that the gut microbiota have a role in weight gain and metabolism. However, many questions remain. Indeed, although studies have shown varying degrees of effectiveness of FMT in the improvement of metabolic parameters in human participants, there has been no evidence yet that FMT can induce weight loss in obese patients.”
  • “The finding that maintenance of weight loss was only seen in the one dietary group consuming the Mediterranean diet plus green tea and Mankai supplement who received autologous FMT, would suggest that specific microbial profiles may be involved and that weight loss per se may not result in the required microbial profiles.”
Figure 1 from editorial: Challenges associated with the use of fecal microbial transplantation (FMT) as treatment

My take: Both of these studies show that modulation of the fecal microbiome may be helpful under the right set of circumstances to help with both irritable bowel syndrome and metabolic syndrome. However, ‘hundreds of yards’ of more research is needed to determine if this is really feasible and to assure that the benefits outweigh the potential risks.

Related blog posts:

Supreme Court Justices “Play a Deadly Game”

A recent commentary (WE Parmet. NEJM 2021; 384: 199-201. Full text: Roman Catholic Diocese of Brooklyn v. Cuomo — The Supreme Court and Pandemic Controls) explains how a recent court decision undermines the future of many public health laws.

Key points:

  • “On November 25, 2020, … the U.S. Supreme Court, by a 5-to-4 vote, undermined states’ ability to control that pandemic.” (Roman Catholic Diocese of Brooklyn v. Cuomo)
  • Initially, most courts rejected challenges to restrictions imposed by governors during the pandemic. “Initially, most courts rejected these claims, citing the Supreme Court’s 1905 decision in Jacobson v. Massachusetts, which upheld a Cambridge, Massachusetts, regulation mandating smallpox vaccination during an outbreak.”
  • After the appointment of Justice Amy Coney Barrett, ” there was now a 5-to-4 majority willing to block limits on religious services.” This was based on the rationale that it is unlawful to “single out houses of worship for especially harsh treatment” and that “even in a pandemic, the Constitution cannot be put away and forgotten.”
  • In dissent, “Justice Stephen Breyer pointed to epidemiologic evidence that in-person worship may pose a greater risk than shopping and other activities that were less stringently regulated to argue that the Court should defer to state officials.”
  • “The Court’s eagerness to intervene even though New York’s orders were no longer in effect and its failure to consider epidemiologic evidence in determining which activities are comparable to worship will serve as a warning” against “state orders that impose tighter measures on worship…[and] suggests that states will not be able to act before super-spreader events occur or as long as other states take a more lax approach.”
  • The author note that “although courts should not abdicate their role during a pandemic, they also should not rush to assume an expertise they lack.”
  • “[The] most important legacy may be the dethroning of Jacobson…[which] has been the key precedent supporting vaccine mandates and other public health laws….With Jacobson apparently sidelined, the future of many public health laws, including and especially vaccine mandates, appears perilous.”

From The Onion:

Also, useful website via NBC: Plan Your Vaccine

Mechanisms of Postinfectious Irritable Bowel Syndrome & Functional Disorders

Aguilera-Lizarraga, J., Florens, M.V., Viola, M.F. et al. Local immune response to food antigens drives meal-induced abdominal painNature (2021). https://doi.org/10.1038/s41586-020-03118-2 (Thanks to Ben Gold’s twitter feed for this reference)

Background: “Up to 20% of people worldwide develop gastrointestinal symptoms following a meal, leading to decreased quality of life, substantial morbidity and high medical costs”

“Here we show that a bacterial infection and bacterial toxins can trigger an immune response that leads to the production of dietary-antigen-specific IgE antibodies in mice, which are limited to the intestine. Following subsequent oral ingestion of the respective dietary antigen, an IgE- and mast-cell-dependent mechanism induced increased visceral pain. This aberrant pain signaling resulted from histamine receptor H1-mediated sensitization of visceral afferents. Moreover, injection of food antigens (gluten, wheat, soy and milk) into the rectosigmoid mucosa of patients with irritable bowel syndrome induced local oedema and mast cell activation.”

My take: This study shows how innocuous food can trigger pain after an intestinal infection.

Related blog posts:

Ustekinumab Escalation in Patients with Crohn’s Disease & Healthy Lifestyle Choices for IBD Patients

JE Ollech et al. Clin Gastroenterol Hepatol 2021; 19: 104-110. Effectiveness of Ustekinumab Dose Escalation in Patients With Crohn’s Disease

In patients with Crohn’s disease, dose escalation of biologic therapy (eg. anti-TNF agents, vedolizumab) has been shown to be helpful in recapturing response to treatment. In a retrospective study with 110 patients, Ollech et al explore the outcomes in those who had their subcutaneous ustekinumab interval shortened to 4 weeks (from every 8 weeks).

Key findings:

  • Following dose interval shortening, the patients’ median Harvey Bradshaw Index (HBI) decreased from 4.5 to 3 ( P = .002), the median level of CRP decreased from 8 mg/L to 3 mg/L ( P = .031), and median level of fecal calprotectin decreased from 378 μg/g to 157 μg/g ( P = .57).
  •  Among patients with active disease (HBI >4, CRP ≥/=5mg/dL, fecal calprotectin >250ug/g, or endoscopic evidence for disease activity), dose interval shortening was associated with a 28% clinical remission (an HBI score ≤4), and 50% had reduced levels of fecal calprotectin; 36% achieved endoscopic remission.
  • The authors did not identify serious adverse events with dose shortening.

My take: Prospective studies are needed. This study indicates that more frequent dosing improves outcomes in a significant fraction of those with active disease.

Related blog posts:

Unrelated article: C-H Lo et al. Clin Gastroenterol Hepatol 2021; 19: 87-95. Healthy Lifestyle Is Associated With Reduced Mortality in Patients With Inflammatory Bowel Diseases In this study, using data from three large cohort studies, the authors assessed the impact of 5 healthy lifestyle factors: never smoking, body mass index 18.5–24.9 kg/m 2, vigorous physical activity in the highest 50% with non-zero value, alternate Mediterranean diet score ≥4, and light drinking [0.1–5.0 g/d]. Key finding:

  • Compared to patients with IBD with no healthy lifestyle factors, patients with IBD with 3–5 healthy lifestyle factors had a significant reduction in all-cause mortality (hazard ratio [HR], 0.29; 95% CI, 0.16–0.52; Ptrend < .0001). 

My take: Like the general population, healthy lifestyle choices are important in individuals with IBD; this study provides some data on the effects on outcomes.

Liver Shorts -February 2021 (part 1)

T Mayr et al. JPGN 2021; 72: 115-122. Optimized Trientine-dihydrochloride Therapy in Pediatric Patients With Wilson Disease: Is Weight-based Dosing Justified?

In this retrospective study with 31 children with Wilson’s disease (most of whom had had previous penicillamine), those who received more than 20 mg/kg/day of trientine therapy had increased adverse effects compared to those who received less than 20 mg/kg/day: 63% vs 7%; median followup was 60 months. In addition, there was not increased response to higher doses. The authors note that trientine had lower incidence of adverse effects compared to penicillamine and “appears to be the preferred” as a first-line treatment.

J Teckman et al. (ChiLDReN Network). J Pediatr 2020; 227: 81-86. Longitudinal Outcomes in Young Patients with Alpha-1-Antitrypsin Deficiency with Native Liver Reveal that Neonatal Cholestasis is a Poor Predictor of Future Portal Hypertension

In this prospective cohort with 350 participants (all with either PiZZ (90%) or PiSZ (10%) and native livers), 278 (79%) entered the cohort (in 2007 or later) without portal hypertension and 18 developed portal hypertension during follow-up. Portal hypertension was defined by development of ascites, varices or combination of splenomegaly/thrombocytopenia. Thirty participants required liver transplantation; 2 patients died during 1077 person-years of follow-up. Median length of followup was 2.5 years. My take: While most children with Alpha-1-Antitrypsin Deficiency do well, monitoring is warranted as some will develop progressive liver disease (even in the absence of neonatal cholestasis).

SA Harrison et al. Gastroenterol 2021: 160: 219-231. Full text PDF: Efficacy and Safety of Aldafermin, an Engineered FGF19 Analog, in a Randomized, Double-Blind, Placebo-Controlled Trial of Patients With Nonalcoholic Steatohepatitis

In this phase 2 double-blind study with 78 patients with NASH, at week 24, the aldafermin group had a significant reduction in absolute liver fat content (reduction of 7.7%) compared with placebo (reduction of 2.7%) (P=.002). Fibrosis improvement (1 stage) with no worsening of NASH was achieved in 38% of patients receiving aldafermin vs 18% of
patients receiving placebo (P = .10). And, NASH resolution with no worsening of fibrosis was observed in 24% of patients given aldafermin vs 9% of patients given placebo (P = .20)

A Chanpong, A Dhawan. JPGN; 2021: 72: 210-215. Long-Term Urinary Copper Excretion on Chelation Therapy in Children with Wilson Disease Key finding:  24-hour UCE decreases to ≤8 μmol/day and <6 μmol/day after 1 and 5 years of treatment, respectively.

Related blog posts:

Why Observational Studies Are Misleading & PPI Association with Kidney Stones

M Simonov et al. Clin Gastroenterol Hepatol 2021; 19: 72-79. Use of Proton Pump Inhibitors Increases Risk of Incident Kidney Stones

Commentary: P Moayyedi. Clin Gastroenterol Hepatol 2021; 19: 41-42. Full Text Link: Leaving No Stone Unturned in the Search for Adverse Events Associated With Use of Proton Pump Inhibitors

 The retrospective study by Simonov et al used data from the Women’s Veteran’s Cohort Study (1999-2017) with 465,891 patients. Key findings:

  • Overall, 2.4% of the cohort developed kidney stones. PPI use was associated with kidney stones in the unadjusted analysis, hazard ratio [HR], 1.74 (95% CI, 1.67–1.82), and persisted in the adjusted analysis with HR, 1.46 (CI, 1.38–1.55). The association was maintained in a propensity score-matched subset of PPI users and nonusers (adjusted HR, 1.25; CI 1.19–1.33).
  • H2RAs were also associated with increased risk with adjusted HR, 1.47

While this study is interesting, the editorial provides a great deal of insight into how this study and many others can be misleading. Key points:

  • “It seems that every few months a new issue arises, with the list of problems that PPIs might cause becoming ever longer, including pneumonia, fracture, heart disease, Clostridium difficile–associated diarrhea, dementia, chronic kidney disease, low B12 levels, gastric cancer, and even all-cause mortality.”
  • If the findings in the study are correct, with the unadjusted HR, “this translates to a number needed to harm (NNH) of 365 patients who need to take PPIs for 1 year to observe 1 extra episode of kidney stones…if the adjusted HR is used …the NNH was 1550.”


  • Confounding variables are hard to eliminate in an observational study. “Studies usually show that patients who are prescribed PPIs are, on average, sicker than those who are not taking these drugs.”
  • In the only large randomized controlled study (>17,000 patients over 3 years) of PPIs, there was no difference in pneumonia, Clostridium difficile infection, fracture, gastric atrophy, chronic kidney disease, dementia, cardiovascular disease, cancer, hospitalizations, and all-cause mortality in the PPI compared with the placebo arms.”Enteric infections, which were slightly more common in patients randomized to PPIs, but even there the NNH was more than 900 per year.”
  • Biases undermine the interpretation of observational studies. One example for PPIs is its association with pneumonias in prior observational studies.
    • “The effect was strongest within the first week of prescription when the odds ratio was approximately 4, although this was reduced to approximately 1.5 after 1 month. This marked reduction in risk over a relatively short period of time is not biologically plausible and a more likely explanation is that the association is the result of protopathic bias. Patients presenting to the clinician with a cough may be diagnosed with silent reflux and given a PPI. A few days later other symptoms develop, and pneumonia is made as the final diagnosis. This will not be apparent when simply interrogating a database where the researcher will observe that a PPI was prescribed before the onset of pneumonia and will imply the association is causal when this is not the case.”
  • This same type of bias could be present with the association between PPI and kidney stones.
    •  “Patients may present with abdominal pain and be given a PPI as a therapeutic trial, assuming the pain may be acid-related when subsequently it is found that the pain relates to kidney stones. Simonov et al reported that 3% were prescribed PPIs within 1 month of the diagnosis of kidney stones, but did not provide the analysis that would allow us to interpret whether protopathic bias may play a role in the associations observed”

My take: It is unlikely that PPIs cause kidney stones; however, if this is a risk factor, it is very rare. Understanding how PPIs have been incorrectly linked to a multitude of problems is a valuable lesson for any practitioner and emphasizes the need for randomized controlled studies to determine medication safety.

Related blog posts: