Gut Microbiota Characteristics in Children After the Use of Proton Pump Inhibitors.

BACKGROUND/AIMS: Prolonged acid suppression from proton pump inhibitor (PPI) has been shown to cause gut microbiota alteration which may increase risk of various infections in adults. We aimed to characterize gut microbiota profiles in children after a short-term use of PPI. MATERIALS AND METHODS: Children aged 1-18 years who underwent PPI therapy were included during April-December 2017. We excluded children who previously used antibiotics or acid suppressants, had a history of acute gastroenteritis or specific food avoidance one month prior to the enrolment. The stool samples before and after the PPI use were collected for gut microbiota composition. The 16S ribosomal RNA gene sequencing was performed by using Illumina MiSeq. The differences in gut microbiota profile after the use of PPI were compared to pre-PPI period. RESULTS: We completed stool collection in 20 children (median age of 5.8 years and 60% were female). No significant changes in the overall number of species-level taxonomy categories or predominant bacteria phylum (Bacteroidetes) were noted. We found a trend increase in the proportion of phylum Firmicutes among children living in the metropolitan/suburban area (P=.07) and among males (P=.11). In four children with infection-related adverse effects, we noted a non-significant increase in the proportion of phylum Firmicutes after the PPI use (from 35 to 52%, P = .14). CONCLUSION: Even the total number and predominant gut microbiota did not significantly change after a four- to eight-week course of PPI therapy; we found a trend of increased proportion of phylum Firmicutes in certain groups of children.

Various initial presentations of Epstein-Barr virus infection-associated post-transplant lymphoproliferative disorder in pediatric liver transplantation recipients: Case series and literature review.

PTLD is a rare but potentially life-threatening condition, which shows a higher prevalence in children than in adults. From 129 children who underwent LT, we reported 5 cases with biopsy-proven PTLD at a single teaching hospital. Four patients had shared clinical presentations including fever, lymphadenopathy, and splenomegaly. They were noted to be given a prolonged course of IS due to the management of comorbid complications such as acute cellular rejection or severe food allergy or eosinophilic gastrointestinal disease. The other one patient presented with upper gastrointestinal bleeding from gastric mass during an early post-transplantation period. Notably, hypoalbuminemia was noted in all reported patients. Similar to previous studies, both EBV serology mismatch between the donor and recipient with high EBV viral load were noted in all except one case, whose EBV serology was unknown before LT. At least one episode of CMV reactivation was also observed in 3 of 5 patients prior to the PTLD diagnosis. The histopathology revealed 1 of 5 early PTLD, 1 of 5 polymorphic PTLD, and 3 of 5 monomorphic PTLD. The treatment included IS withdrawal, chemotherapy, and/or rituximab. One patient died of multiorgan dysfunction, one remains in complete remission, and three patients are either still on treatment or await response evaluation. Even though most of our reported PTLD cases had shared manifestations with fever, lymphadenopathy, splenomegaly, EBV serology mismatch, and high EBV viral load, various initial presentations such as respiratory symptoms, hypoalbuminemia, and prolonged use of IS from other causes such as significant food allergy were noted.