This study investigated the oral microbiota of children younger than 3 years with febrile seizures (FS). Oral swab samples were collected from 48 children with FS and 47 healthy controls, and the V4 region of the bacterial 16 S rRNA gene was sequenced. The Shannon index did not differ significantly between groups, whereas the ACE index was significantly lower in the FS group. Although beta-diversity analysis based on weighted and unweighted UniFrac distances showed no significant between-group differences, partial least squares discriminant analysis provided an exploratory supervised visualization showing apparent separation between the FS and control groups. Among the key genera, Streptococcus, Prevotella, and Granulicatella were significantly enriched in the FS group, whereas Neisseria, Haemophilus, Porphyromonas, and Capnocytophaga were significantly depleted. Predicted functional analysis showed increased relative abundances of pathways related to translation, replication and repair, nucleotide metabolism, cell growth and death, and bacterial infectious diseases, whereas pathways related to energy metabolism, cell motility, signaling molecules and interaction, and transport and catabolism were reduced. These findings suggest that FS is associated with selective ecological reconfiguration of the early-life oral microbiota, mainly reflected by altered proportions of key resident genera.

Non-peptidic thrombopoietin receptor agonists (TPO-RAs), including eltrombopag, avatrombopag and hetrombopag, are used as second-line therapies for immune thrombocytopenia (ITP). However, concerns regarding their hepatic safety persist. The present study conducted a meta-analysis by searching PubMed, Web of Science and the Chinese Medical Association Journal Database for randomized controlled trials evaluating non-peptidic TPO-RAs in ITP that reported hepatic enzyme outcomes, specifically alanine aminotransferase and/or aspartate aminotransferase. The present meta-analysis therefore assessed data from 13 randomized controlled trials involving 1,480 patients (1,034 in the intervention arm and 446 in the control arm) to evaluate the risk of hepatic enzyme abnormalities associated with these aforementioned agents. The results revealed that non-peptidic TPO-RAs did not significantly increase the incidence of hepatic enzyme elevation events in the intervention group compared with that in the control group [odds ratio (OR)=1.30; 95% CI, 0.82-2.07; P=0.27]. The risk of hepatic enzyme elevation events in patients receiving TPO-RAs remained non-significant when analyses were restricted to studies with a treatment duration of ≥6 weeks (OR=1.28; 95% CI: 0.78-2.08; P=0.33), to studies that exclusively enrolled adults (OR=1.24; 95% CI, 0.77-1.99; P=0.37, and to studies reporting severe transaminase elevations defined as ≥3 times the upper limit of that considered normal (OR=1.66; 95% CI, 0.59-4.65; P=0.34). Subgroup analyses also showed no significant increase in hepatic enzyme elevation events with eltrombopag (OR=1.68; 95% CI, 0.93-3.04; P=0.09), avatrombopag (OR=0.88; 95% CI, 0.09-8.46; P=0.91) or hetrombopag (OR=1.04; 95% CI, 0.30-3.65; P=0.95). These findings suggest that non-peptidic TPO-RAs did not significantly increase the incidence of hepatic enzyme elevation events in patients with ITP compared with that in controls and support their continued clinical use with appropriate liver function monitoring. The present meta-analysis was registered in the International Prospective Register of Systematic Reviews (registration no. CRD420251084782).

To construct a computed tomography (CT) based radiomics signature and assess its performance in predicting vascular endothelial growth factor (VEGF) expression in pediatric patients with nephroblastoma. A total of 73 pediatric nephroblastomaL patients were enrolled (51 in the training cohort and 22 in the test cohort). The region of interest manually marked on the CT images served as the basis for the automatic extraction of radiomics features. A radiomics score was generated utilizing the radiomics signature based formula after retaining a subset of radiomics features to create a radiomics signature. Clinical elements, such as clinicopathological information and CT imaging characteristics, were used to create a clinical model. With the inclusion of a radiomics signature and clinical characteristics, a composite nomogram was created. Decision curve analysis (DCA) was used to evaluate the prediction performance. 5 carefully chosen radiomics features were used to create the radiomics signature. Next, the radiomics score was determined. In the training cohort and the test cohort, the logistic regression model’s area under the curve was 0.761 and 0.791, respectively. Based on the radiomics signature and clinical variables, the clinical radiomics nomogram demonstrated its ability to accurately predict the level of VEGF expression. DCA verified the clinical value of the clinical radiomics nomogram. In pediatric patients with nephroblastoma, the radiomics model based on the CT radiomics signature may accurately predict the level of VEGF expression.

Mitochondrial 3-hydroxy-3-methylglutaryl-coenzyme A synthase 2 (HMGCS2) deficiency is an exceptionally rare autosomal recessive metabolic disorder that impairs ketogenesis. It is typically characterized by hypoketotic hypoglycemia during periods of fasting or metabolic stress. Notably, severe hyperglycemia as an initial presenting symptom has not been previously reported. We report the case of a 6-month-old girl who suddenly developed coma after 1 day of fasting due to repeated vomiting during pneumonia. At presentation, she had hyperglycemia (25.8 mmol/L), ketonuria (1+), glucosuria (3+), metabolic acidosis (pH 6.90), elevated serum alanine transaminase and aspartate aminotransferase levels, increased blood ammonia levels, and liver enlargement on ultrasound. However, fasting insulin, glucagon, and glycated hemoglobin levels were all within the normal range. Whole-exome sequencing identified compound heterozygous mutations in the HMGCS2 gene—c.1175C>T (p.S392L) inherited from the father and c.719A>T (p.A240V) inherited from the mother—thereby confirming the diagnosis of HMGCS2 deficiency. This case highlights severe hyperglycemia as an atypical clinical feature of HMGCS2 deficiency. Increased awareness of such rare manifestations may assist in improving early diagnosis and treatment of this condition.

Extrauterine growth restriction (EUGR), prevalent and severe in very preterm infants (< 32 weeks’ gestation), means discharge growth values (weight, head circumference, or length) are ≤ 10th percentile on the Fenton 2013 chart. Many of these infants fast or have delayed oral feeding soon after birth. Oropharyngeal colostrum administration, using a syringe or sterile swab, is an alternative to early enteral colostrum feeding. As the effectiveness of oropharyngeal colostrum administration in reducing the incidence of EUGR in preterm infants remains unclear, a randomized trial design is crucial for addressing this question. This proposed study protocol investigates the impact of oropharyngeal colostrum administration on the time to regain birth weight and postnatal growth in very preterm infants, based on the interaction between early gut microbiota and the host. We plan to perform this multicenter randomized controlled trial by recruiting 260 very preterm infants from September 2025 to August 2028. The study will be conducted at five neonatal intensive care units (NICUs) in Jiangsu Province, China. The study population will be randomly assigned to either the oropharyngeal colostrum administration group or the placebo (normal saline) group. The intervention will commence within 48–72 h of birth and and will be administered continuously for a duration of 5 days, with stool samples collected from the preterm infants before and after the intervention. The primary outcome measure is the incidence of EUGR at discharge, while the secondary outcome measures include differences in the time to regain birth weight and gut microbiota between groups. This study will use a multivariate logistic regression to evaluate the association between oropharyngeal colostrum administration and EUGR, multiple tests (T-test, Wilcoxon, repeated measures analysis of variance) for gut microbial diversity differences, and a generalized linear model for the association between the intervention and gut microbiota composition. This study aims to provide a scientific basis for the clinical application of oropharyngeal colostrum administration in preterm infants through rigorous clinical trials and intestinal flora analyses and to provide new insights into intervention strategies for EUGR in preterm infants. ClinicalTrials.gov identifier: NCT07082881. Registered 16 July 2025.

Purpose:The gut microbiota plays a crucial role in bilirubin metabolism in neonates. The phototherapy threshold assesses the need for clinical intervention in neonatal hyperbilirubinemia (NH). This study aimed to investigate gut microbiota alterations in neonates with NH meeting the phototherapy threshold. Patients and Methods:A total of 75 neonates with NH who met the phototherapy threshold (NH group), and 67 healthy neonates (control group) were included. Fecal samples were collected within one hour before initiating phototherapy for 16S rRNA gene sequencing and bioinformatic analysis. Results:In contrast to healthy controls, the NH group showed significantly higher Shannon (p<0.001) and abundance-based coverage estimator (p<0.05) indices, as well as significant differences in both unweighted and weighted UniFrac values (p<0.001 for each). In addition, linear discriminant analysis effect size revealed significant taxonomic shifts in the gut microbiota of the NH group at multiple levels, including phylum, class, order, family, and genus. Among the key differential genera, the abundance of Streptococcus (p<0.001) was significantly reduced, whereas Escherichia (p<0.001) and Klebsiella (p<0.001) were markedly enriched. Conclusion:Neonates meeting the phototherapy threshold exhibit altered gut microbiota composition, characterized by increased diversity, richness, and an elevated abundance of opportunistic pathogenic genera. These results offer valuable preliminary insights into the gut microbiome changes associated with NH requiring phototherapy.

Background and Objectives: Utilizing the Surveillance, Epidemiology, and End Results (SEER) database, the present study aimed to evaluate the most recent survival rates for parosteal osteosarcoma (POS) and to identify risk factors affecting survival. Additionally, the incidence of POS in recent years was determined. Methods: Data on age, sex, race, SEER stage, surgery, radiation, chemotherapy, and survival were extracted from the SEER database, along with additional predictive variables. Survival curves were generated using Kaplan-Meier estimates, adjusted for various parameters. Predictive nomograms and multivariable Cox regression models were also developed. Results: A total of 127 patients were included. The overall survival rates at 1, 3, and 5 years were 99.21%, 95.23%, and 86.66%, respectively. Survival analysis revealed that patients with distant SEER stage (P < O.OO1), no surgery (P = 0.025), and chemotherapy (P = 0.009) had worse outcomes. Multivariate analysis identified surgical treatment as the only independent predictor of a favorable outcome [HR, 0.163; 95% CI, (0.031-0.863)]. A nomogram was constructed to predict prognosis, and calibration curves demonstrated good agreement between predicted and actual survival outcomes. Conclusions: Poor overall survival was associated with advanced SEER stage, absence of surgery, and receipt of chemotherapy. The nomogram accurately predicted survival likelihood, showing strong concordance with observed outcomes.

Mechanical ventilation was frequently conducted in late preterm and term newborn infants because of their severity of neonatal respiratory distress syndrome (NRDS), but the level of positive end expiratory pressure (PEEP) used was not explicit. This study aimed to investigate the efficacy and safety of higher-PEEP in the treatment of NRDS in these infants. Initially, 80 newborn late preterm and term infants diagnosed with NRDS were enrolled, a total of 26 infants were excluded because they were not within the gestational age range of 34+ 0 to 39+ 6 weeks or did not receive mechanical ventilation. Of 54 eligible infants, 6 were excluded: 3 for pre-existing pneumothorax before mechanical ventilation, 1 for hospital transfer, 1 for withdrawal of treatment, and 1 for misdiagnosis with transient tachypnea. Ultimately, 48 infants remained. Following a simple randomization procedure, 23 were assigned to higher-PEEP group and 25 to the control group. The duration of mechanical ventilation was regarded as the primary outcome. We also collected and analyzed data of other clinical factors. We found that higher-PEEP group had significantly shorter durations of mechanical ventilation (P = 0.008) and oxygen inhalation (P = 0.002) compared to the control. Additionally, the fraction of inspired oxygen (FiO2) (P = 0.001) and oxygenation index (OI) (P = 0.048) at 24 h after birth were lower in higher-PEEP group compared to the control. Furthermore, higher-PEEP group had a shorter duration of hospitalization (P = 0.033). However, no significant differences were observed in the comparisons of complications between the two groups. In summary, higher PEEP could reduce the duration of mechanical ventilation by preserving adequate functional residual capacity, without increasing rates of adverse effects.

Phototherapy is the most commonly used treatment for neonatal hyperbilirubinemia (NH). Gut microbiota is involved in bilirubin metabolism; however, it is uncertain whether this is affected by phototherapy. The present study included 43 newborns with hyperbilirubinemia and collected fecal samples for high-throughput sequencing before and after phototherapy. Selection alpha diversity analysis was used to determine the differences in diversity and abundance between the two groups, whereas similarity was determined using beta diversity analysis. Linear discriminant analysis effect size analysis was used to screen for markedly different bacteria. The structure of the gut microbiota in newborns with hyperbilirubinemia changed after phototherapy, with a significant decrease in abundance and diversity. The changes in the key bacterial species were characterized by an increase in the abundance of Streptococcus salivarius and a decrease in the abundance of Escherichia, Klebsiella pneumoniae, Rothia mucilaginosa and Streptococcus oralis. These changes mainly manifested as an increase in beneficial bacteria and a decrease in opportunistic bacteria, which may not be related to the side effects of phototherapy. These results can provide theoretical assistance for microbiological research on the later stages of NH.

This study aimed to develop a novel scoring system utilizing circulating interleukin (IL) levels to predict resistance to intravenous immunoglobulin (IVIG) in Chinese patients with Kawasaki disease (KD). We further compared this scoring system against six previously established scoring methods to evaluate its predictive performance. A retrospective analysis was conducted on KD patients who were treated at the cardiovascular medical ward of our institution from January 2020 to December 2022. Six scoring systems (Egami, Formosa, Harada, Kobayashi, Lan and Yang) were analyzed, and a new scoring system was developed based on our data. In our study, 521 KD patients were recruited, 42 of whom (8.06

The association between alterations in the oral microbiome and hand, foot, and mouth disease (HFMD) has been observed in previous studies. Our study, therefore, aimed to identify the structural changes in the oral microbiota and biomarkers in children with HFMD caused by enterovirus A 71 (EV-A71). Children diagnosed with EV-A71 HFMD and healthy children recruited from April 2021 to September 2023 were included in the present study, and were categorized into EV-A71 and control groups, respectively. Oral swabs were collected and microbiota information was obtained using 16 S rRNA gene sequencing technology. Alpha-diversity and partial least squares discriminant analyses were conducted to compare microbial diversity, richness, and similarity between the two groups. Linear discriminant analysis effect size was employed to identify microbial taxa with significant differences, and determined the key genera among them. The study included a total of 80 children, with 50 assigned to the EV-A71 group and 30 to the control group. No significant differences were found between the two groups in terms of age (2.2 ± 1.2 vs. 2.7 ± 1.2 years; age range: 1–5 years; P = 0.114) or sex (56

OBJECTIVE:To diagnose and explore the genetic etiology of a neonate with Hereditary epidermolysis bullosa.METHODS:A neonate who was admitted to Suqian Hospital Affiliated to Xuzhou Medical University on July 10, 2021 was selected as the study subject. Peripheral blood samples were collected from the child and his parents for the extraction of genomic DNA. And target gene capture and next-generation sequencing were carried out. Candidate variants were verified by Sanger sequencing and pathogenicity analysis.RESULTS:The child was found to harbor compound heterozygous variants of the COL17A1 gene, namely c.997C>T (p.Q333X) and c.3481dupT (p.Y1161fs*2), which were respectively inherited from his father and mother. Both variants were predicted to be pathogenic.CONCLUSION:The child was diagnosed with Generalized atrophic benign epidermolysis bullosa due to the compound heterozygous variants of the COL17A1 gene.

According to clinical evidence, type 2 diabetes mellitus (T2D) and osteomyelitis (OM) are currently the 2 major causes of mortality and morbidity in humans. Despite accounts of their coexistence, there is still no understanding of their fundamental connection. We attempted to assess the causal effect of T2D on OM using the two-sample Mendelian randomization method. The whole gene-wide association study’s aggregate data were examined. Single-nucleotide polymorphisms, which have a substantial correlation with T2D, were used as instrumental variables in a two-sample Mendelian randomization (MR) analysis to assess the causal relationship between T2D and OM risk using the inverse variance weighting, MR-egger regression, and weighted median approaches, respectively. A total of 114 single-nucleotide polymorphism were used as instrumental variables in this analysis. The inverse variance-weighted analysis showed a significant causal relationship between T2D and OM, indicating that T2D has a detrimental effect on OM risk. The odds ratio for the causal effect of T2D on OM was 1.317, with a 95% confidence interval of (1.140, 1.522) (P < .001). To assess heterogeneity, Cochran Q test statistics and MR-Egger regression were applied in the inverse variance-weighted technique. The P-value of .737 indicated a considerable level of heterogeneity was not absent in the data. This study used Mendelian randomization analysis to establish a causal relationship between T2D and OM. The findings suggest that T2D may increase the risk of OM.

Introduction: To investigate the predictive value of plasma sodium at the onset of necrotizing enterocolitis (NEC) diagnosis in distinguishing surgical NEC from medical NEC.Methods: A retrospective review of all NEC neonates treated at our hospital between 2008 and 2022. Patients were divided into two groups based on treatment methods: surgical intervention and medical treatment. Patient demographics, laboratory parameters, and outcomes were all documented. The values of laboratory parameters were collected at the onset of NEC and after treatment. To identify potential predictors of surgical NEC, multivariate logistic regression analyses were used. The receiver operating characteristic curve was applied to determine predictive factors.Results: Surgical treatment was performed in 111 infants (44.6%), and medical treatment in 138 cases (55.4%). Of 249 infants with NEC, 22 patients exhibited Bell stage I, 91 infants had Bell stage II, and 136 patients displayed Bell stage III. We discovered that white blood cell (WBC), C-reactive protein (CRP), fibrinogen, and sodium were independent predictors of NEC receiving surgery based on the results of the multivariate logistic regression analysis. Hyponatremia was found in 122 of the 249 patients (49%). At the onset of NEC diagnosis, hyponatremia was found in 83.8% of surgical intervention group and in 21.0% of medical treatment group (P < 0.001). Sensitivity, specificity, positive predictive value, and negative predictive value for WBC, CRP, fibrinogen, and sodium were calculated. The cutoff values were determined using receiver operating characteristic analysis. The area under the curve of hyponatremia for surgical intervention was 0.875, with 84% sensitivity, 80% specificity, 77% positive predictive value, and 86% negative predictive value, which had a greater specificity (0.80) for predicting surgical intervention than WBC (0.67), CRP (0.50), and fibrinogen (0.70).Conclusions: When a surgical evaluation is necessary, hyponatremia can effectively distinguish surgical NEC from medical NEC. It could be used as a predictive marker to guide parental counseling for surgical intervention and rapid transfer of patients to tertiary centers when they have a surgical condition.(c) 2023 Elsevier Inc. All rights reserved.

Although little is known about the regulatory mechanisms underlying the pathogenesis of osteomyelitis caused by Staphylococcus aureus (S. aureus), hypoxia-inducible factor-1α (HIF-1α) and STIP1 homology and U-box containing protein 1 (STUB1) have been found to be up-regulated in both S. aureus infected MC3T3-E1 cells and in patients with osteomyelitis. HIF-1α directly targets STUB1 to induce its expression. In MC3T3-E1 cells infected with S. aureus, silencing HIF-1α and STUB1 and administering the hypoxia inhibitor IDF-11774 consistently increased the expression of OSX and RUNX2, as well as the levels of alizarin Red S and alkaline phosphatase activity. In a mouse model of osteomyelitis, S. aureus infection elevated HIF-1α expression and serum STUB1 levels. Interleukin (IL)-6, IL-1β, and C-reactive protein levels in serum were reduced after treatment with the hypoxia inhibitor IDF-11774. Following an infection with S. aureus, hypoxia was activated to cause STUB1 overexpression by directly targeting HIF-1α, ultimately causing osteomyelitis symptoms such as osteogenesis and mineralization defected and increased inflammation. This study presents a novel signaling cascade in the pathogenesis of osteomyelitis involving hypoxia/HIF-1α/STUB1. This signaling cascade may be a target for therapeutic interventions.

Thrombopoietin receptor agonists (TPO-RAs) have a role in second-line immune thrombocytopenic purpura (ITP) treatment, binding to and activating thrombopoietin receptors on megakaryocyte membranes in the bone marrow. This promotes megakaryocyte maturation and increases platelet production. Despite a 2-6% incidence of thrombotic events during TPO-RA treatment, it remains uncertain whether TPO-RAs elevate thrombosis rates. A comprehensive search of electronic databases was conducted using the relevant search criteria. To assess the risk of bias, the included studies were assessed using the revised Cochrane Risk of Bias Assessment Tool 2.0, and a meta-analysis was performed using RevMan 5.4.1. A total of 1,698 patients with ITP were included from randomized controlled trials (RCTs). There were 26 thromboembolic events in the TPO-RAs group and 4 in the control group. However, there was no significant difference in the incidence of thrombotic events between the two groups [odds ratio (OR)=1.76, 95% confidence interval (CI): 0.78-4.00, P=0.18], even if the duration of treatment was >12 weeks (OR=2.46, 95% CI: 0.81-7.43, P=0.11). Subgroup analysis showed that none of the four drugs significantly increased the incidence of thrombotic events (romiplostim: OR=0.92, 95% CI: 0.14-6.13, P=0.93; eltrombopag: OR=2.32, 95% CI: 0.64-8.47, P=0.20; avatrombopag: OR=4.15, 95% CI: 0.20-85.23, P=0.36; and hetrombopag: OR=0.76, 95% CI: 0.03-18.76, P=0.87). There was also no significant difference in the results of the double-blinded placebo-controlled RCTs (OR=1.21, 95% CI: 0.41-3.58, P=0.73). Compared to patients with ITP who did not receive TPO-RA treatment, those receiving TPO-RA treatment did not exhibit a significantly increased risk of thrombotic events.

ObjectiveThe objective of this meta-analysis was to illustrate the clinical outcomes and safety of two different management options for Song stage 2-4 lateral condyle humeral fractures in children.MethodIn January 2023, a systematic computer-based search was conducted. Data were retrieved for patients with two different management options for lateral condyle humeral fractures in children. The primary endpoints were clinical outcomes based on infection, avascular necrosis, and nonunion. After testing for publication bias and heterogeneity between studies, the data was aggregated for stochastic effect models when necessary.ResultsEight clinical studies with 742 patients were eventually included in the meta-analysis. There was no significant difference between the closed reduction and percutaneous pinning, and open reduction and internal fixation in terms of the clinical outcomes based on infection, avascular necrosis, and nonunion (P > 0.05).ConclusionsClosed reduction and percutaneous pinning, as well as open reduction and internal fixation of lateral condyle humeral fractures in children, resulted in similar structural stability and functional outcomes. More high-quality randomized controlled trials are needed to determine this conclusion.

Self-improving collodion ichthyosis (SICI) is a relatively rare subtype of autosomal recessive congenital ichthyosis (ARCI) that is often characterized by a collodion baby (CB) phenotype at birth. A newborn girl, just 1 hour old, presented with taut, shiny, thick yellow crusts, like parchment, and scales on her trunk and upper limbs. The tightening effect had caused both upper eyelids to appear everted, and her lips and auricles were deformed. Based on whole-exome sequencing and examination of the clinical phenotype, the patient was diagnosed with ARCI. After admission, the exposed mucosa was covered with a sterile Vaseline gauze dressing, and she was placed in an incubator set to a temperature of 32°C with a humidity level of 75%. One week later, the parchment-like scales had begun to flake off, and at the age of 3 weeks, all bodily skin appeared normal. SICI was diagnosed. After discharge, the patient was followed up to 3 months of age, at which time her growth and development were comparable to those of her peers. Clinicians should consider SICI as a possible diagnosis when analyzing the prognosis of patients with CB. Reducing water loss and maintaining the electrolyte balance are particularly important for SICI treatment.

The aim of the present study was to analyze the safety of non-peptide thrombopoietin receptor agonists (TPO-RAs) for immune thrombocytopenia (ITP) treatment. All studies reporting adverse events (AEs) in relation to ITP treatment with eltrombopag, avatrombopag, and hetrombopag were retrieved from PubMed, Web of Science, and Embase databases. RevMan 5.4.1 was used for meta-analysis, heterogeneity and bias analyses. A total of 1,078 patients from seven eligible studies were enrolled. In the enrolled clinical trials, the double-blind period was between 6 weeks and 6 months. The results revealed that the chances of any AEs [relative risk (RR)=1.16; 95% confidence interval (CI), 0.90-1.51; I2=78%; P=0.26], grade 3/4 AEs (RR=1.07; 95% CI, 0.63-1.80; I2=0%; P=0.81), elevated transaminase levels (RR=1.09; 95% CI, 0.68-1.74; I2=0%; P=0.72), thrombosis (RR=1.92; 95% CI, 0.55-6.66; I2=0%; P=0.31) and cataracts (RR=0.83; 95% CI, 0.38-1.83; I2=0%; P=0.65) were not significantly higher in patients with ITP that received non-peptide TPO-RAs compared with patients with ITP treated with a placebo. The present study indicated that non-peptide TPO-RAs were relatively safe for patients with ITP, at least within 6 months of administration.

This study aimed to clarify the characteristics of intestinal microbiota in children with hand, foot, and mouth disease (HFMD) under 3 years old. Fresh feces were collected from 54 children with HFMD and 30 healthy children. All of them were <3 years old. Sequencing of the 16S rDNA amplicons was performed. Between the 2 groups, the richness, diversity, and structure of the intestinal microbiota were analyzed by α-diversity and β-diversity. Linear discriminant analysis and LEfSe analyses were used to compare different bacterial classifications. The sex and age of the children in the 2 groups were not statistically significant (P = .92 and P = .98, respectively). Compared to healthy children, the Shannon index, Ace index, and Chao index were lower in children with HFMD (P = .027, P = .012, and P = .012, respectively). Based on the weighted or unweighted UniFrac distance analysis, the structure of the intestinal microbiota in HFMD was also significantly changed (P = .002 and P < .001, respectively). Linear discriminant analysis and LEfSe analysis showed that the changes of key bacteria were manifested as a decrease in Prevotella and Clostridium_XIVa (P < .001 and P < .001, respectively), while Escherichia and Bifidobacterium increased (P = .025 and P = .001, respectively). Children with HFMD under 3 years of age have intestinal microbiota disorder and show a decrease in diversity and richness. The decrease in the abundance of Prevotella and Clostridium, which can produce short-chain fatty acids, is also one of the characteristics of the change. These results can offer a theoretical foundation for the pathogenesis and microecological treatment of HFMD in infants.