The role of histopathology in diagnosing protracted diarrhea of infancy

Qingjie decoction attenuated E.coli-induced diarrhea by regulating energy metabolism and alleviating inflammation based on network analysis and metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Diarrhea is a frequently encountered gastrointestinal complication in clinical practice, and E. coli is one of the main causative agents. Although Qingjie decoction (QJD) has been shown to be highly effective in treating diarrhea by eliminating heat-toxin, the underlying molecular mechanisms and pathways of QJD remain unclear.

AIM OF REVIEW

The aim of this research was to explore the effects and fundamental mechanism of QJD on diarrhea induced by E.coli in rats.

MATERIALS AND METHODS

Initially, we used UHPLC-MS/MS analysis to identify the chemical composition of QJD. Then, we constructed a visualization network using network pharmacology. Next, we utilized metabolomics to identify differentially expressed metabolites of QJD that are effective in treating diarrhea.

RESULTS

The chemical composition of QJD was analyzed using UHPLC-MS/MS, which identified a total of 292 components. Using a network pharmacology approach, 127 bioactive compounds of QJD were screened, targeting 171 potential diarrhea treatment targets. TNF-α, IL-6, IL-1β, and CAT were identified as important targets through visualizing the PPI network. Enrichment analysis demonstrated significant enrichment in the TNF signaling pathway, IL-17 signaling pathway, and PI3K-Akt signaling pathway. QJD showed beneficial effects, such as increased body weight, decreased fecal water content, and reduced inflammatory cell infiltration in the duodenum and colon, as well as maintaining the structure of the duodenum and colon. Metabolomic analysis revealed 32 differentially expressed metabolites in the control, model and QJD-H groups, including glucose, valine, and cysteine. Functional analysis indicated that differential metabolites were related to energy metabolism, including glucose metabolism, TCA cycle, and amino acid metabolism.

CONCLUSION

QJD significantly increased body weight, decreased water content in feces, relieved inflammatory cell infiltration, maintained the structure of duodenum and colon. Combining network analysis and metabolomics, QJD exerted therapeutic effects by inhibiting inflammation and oxidative stress, regulating glucose metabolism, tricarboxylic acid metabolism, and amino acid metabolism.

Emodin Improves Intestinal Health and Immunity through Modulation of Gut Microbiota in Mice Infected by Pathogenic Escherichia coli O1

The effect of emodin on the intestinal mucosal barrier of a mouse E. coli O₁-induced diarrhea model was observed. Following successful establishment of a diarrhea model, the mice were treated with drugs for seven days. Intestinal lesions and the shape and the number of goblet cells were assessed via hematoxylin-eosin and periodic-acid-Schiff staining, while changes in inflammatory factors, ultrastructure of the small intestine, expression of MUC-2, and changes in the intestinal microbiota were analyzed via RT-PCR, electron microscopy, immunofluorescence, and 16S rRNA sequencing. Examination showed that emodin ameliorated pathological damage to the intestines of diarrheic mice. RT-PCR indicated that emodin reduced TNF-α, IL-β, IL-6, MPO, and COX-2 mRNA levels in duodenal tissues and increased the levels of sIgA and MUC-2 and the number of goblet cells. Microbiome analysis revealed that Escherichia coli O₁ reduced bacterial richness and altered the distribution pattern of bacterial communities at the phylum and order levels in cecum contents. Notably, pathogenic Clostridiales and Enterobacteriales were significantly increased in diarrheic mice. However, emodin reversed the trend. Thus, emodin protected against intestinal damage induced by E. coli O₁ and improved intestinal mucosal barrier function in mice by increasing the abundance of beneficial intestinal microbiota and inhibiting the abundance of harmful bacteria, thereby alleviating diarrhea.

Escherichia coli O101-induced diarrhea develops gut microbial dysbiosis in rats

Enterotoxigenic Escherichia coli (ETEC)-induced diarrhea is a devastating disease and one of the third leading causes of infectious disease-associated mortalities worldwide. Despite recent advances in the identification of the association between gut microbiota and diarrhea, a lack of understanding exists on the status of gut microbiota in rats treated with ETEC. In the present study, a rat model of Escherichia (E.) coli O₁₀₁-induced diarrhea was established. The diarrhea incidence and index, as well as histological changes, were assessed. In addition, Illumina MiSeq sequencing of V3-V4 hypervariable regions of 16S ribosomal RNA was employed to investigate the changes in the gut microbiota profiles in the feces of the diarrhea rats. The results indicated that E. coli O₁₀₁ increased the diarrhea index and injury in the intestinal tissues, whereas it decreased the bacterial richness and shifted the distribution pattern of the bacterial communities in the phylum, order and genus levels in the fecal samples. Notably, the proportion of bacteria Prevotella, Enterococcus and Akkermansia was significantly decreased, while the pathogenic bacteria Escherichia/Shigella were significantly increased in diarrhea rats. Taken together, the gut microbiota is closely associated with E. coli O₁₀₁-induced diarrhea in lower microbial diversity and dysbiosis of gut microbiota at different taxonomical levels.

Prolonged tacrolimus for pediatric gastrointestinal disorder: Double-edged sword?

BACKGROUND

Although tacrolimus (TAC) can induce remission in children with refractory inflammatory bowel disease (IBD) or autoimmune gastroenteropathy (AGE), its use in maintenance therapy remains controversial. The aim of this study was to investigate the potential nephrotoxic nature of prolonged TAC use.

METHODS

This retrospective study reviewed children with gastrointestinal disorder who underwent kidney biopsy for the evaluation of renal damage during TAC therapy for >1 year. The clinical and histological features of renal damage were evaluated in this single-institution cohort.

RESULTS

Eighteen of 121 children with IBD and two children with AGE followed at a national children hospital in Tokyo, Japan, received TAC between August 2006 and April 2013. Among them, five (Crohn's disease, n = 3; autoimmune gastropathy, n = 1; autoimmune enteropathy, n = 1) received TAC for >1 year, and underwent kidney biopsy. All five had achieved remission on TAC, but had histological evidence of chronic nephrotoxicity. Renal damage in one patient with relatively low TAC trough level remained mild. Estimated glomerular filtration rate (eGFR) at the time of kidney biopsy was lower than at the initiation of TAC in all four available patients. Among them, eGFR improved in one patient after the decrease or discontinuation of TAC.

CONCLUSIONS

TAC appeared to be effective in children with refractory gastrointestinal disorder, but long-term use seems to cause irreversible renal damage. Rigorous monitoring of eGFR and kidney biopsy in selected cases should be considered for the proper adjustment of TAC.

Diarrheal Illness in the Pediatric Population: A Review of Neonatal Enteropathies and Childhood Idiopathic Inflammatory Bowel Disease

In the clinical context of pediatric diarrheal illness, the interpretation of endoscopic mucosal biopsies varies significantly from that in adults. This review outlines these differences by first describing a host of diarrheal illnesses that are nearly exclusive to the pediatric age group. The final portion of this article describes salient pathologic differences between adult and pediatric idiopathic inflammatory bowel disease. The goal of this review is to provide a brief description of each disease process and focus on practical aspects of diagnosis that are applicable for pathologists working in general practice settings.

Autoimmune enteropathy: a review and update of clinical management

Autoimmune enteropathy (AIE) is a rare condition characterized by intractable diarrhea, histologic changes on small intestinal biopsy, and failed response to dietary manipulation that also may present with extraintestinal manifestations. In many patients, immunosuppressive therapies are necessary. Although AIE is more common in infants, adult involvement has also been documented. Much of what is known about AIE has been gathered from case reports and small case series; therefore, more research in this evolving field is needed. IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked syndrome) and APECED (autoimmune phenomena, polyendocrinopathy, candidiasis, and ectodermal dystrophy) are systemic forms of AIE.

Autoimmune enteropathy: a review and update of clinical management

Autoimmune enteropathy (AIE) is a rare condition characterized by intractable diarrhea, histologic changes on small intestinal biopsy, and failed response to dietary manipulation that also may present with extraintestinal manifestations. In many patients, immunosuppressive therapies are necessary. Although AIE is more common in infants, adult involvement has also been documented. Much of what is known about AIE has been gathered from case reports and small case series; therefore, more research in this evolving field is needed. IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked syndrome) and APECED (autoimmune phenomena, polyendocrinopathy, candidiasis, and ectodermal dystrophy) are systemic forms of AIE.

Gastrointestinal endoscopy and mucosal biopsy in the first year of life: indications and outcome

OBJECTIVES

Lower threshold and widening indications for paediatric gastrointestinal endoscopy have resulted in a significant increase in the numbers of endoscopic procedures performed in infants. Despite this, knowledge of gastrointestinal mucosal findings in this age group is limited and data on the clinical usefulness of endoscopy are lacking.

METHODS

All of the children younger than 1 year referred to a single tertiary paediatric gastroenterology unit during the period June 1987 to August 2007 who underwent gastrointestinal endoscopy were identified and the clinical indications and histological outcomes were reviewed.

RESULTS

A total of 933 gastroesophageal duodenoscopies and 439 colonoscopies were performed in 1024 cases in a total of 823 infants. In order of frequency, clinical indications were diarrhoea (51%), failure to thrive (41.2%), symptoms of reflux (27.1%), and rectal bleeding (8.5%). Mucosal biopsies were insufficient for assessment in only 2.4% of cases. Mucosal histology was normal in 33.8%, whereas histological abnormalities were identified in 63.8%. Specific histological diagnoses included microvillous inclusion disease, autoimmune enteropathy, graft-versus-host disease post-bone marrow transplantation, tufting enteropathy, and disaccharidase deficiency. There was only 1 colonic perforation complicating endoscopy in a total of 889 cases for which relevant information was available (0.1%).

CONCLUSIONS

In two-thirds of cases, histological abnormalities were detected that influenced management following endoscopic examination and mucosal biopsy in infants. Endoscopy with biopsies is a greatly informative test with low failure and complication rates in the first year of life.