Bile acids can be categorized into primary bile acids，which are synthesized directly in liver cells，and secondary bile acids，which are formed after decomposition by intestinal bacteria. The intestinal flora is diverse and widely used，which is closely related to various functions and diseases in the human body. As one of the main metabolites of intestinal flora，bile acids have a close bidirectional regulation between them.Current research has shown a clear correlation between fecal bile acid levels and changes in gastrointestinal function.This paper will review the relationship between fecal bile acid levels and different defecation frequency in children from the perspective of changes in intestinal bile acids under diarrhea and constipation symptoms，and will provide a research direction for further exploration of the effects of different metabolites based on the composition of bile acids on defecation frequency.

Objective To analyze the changes of vitamin D in children with Henoch-Schonlein purpura(HSP).Methods 130 children with HSP from Kunming Children's Hospital between July 2022-July 2023 were selected as the study subjects and 100 healthy children were selected during the same period as the control group.The blood samples were collected from the children with HSP and the healthy children.The content of vitamin D was measured by Kunming Kingmed Institute for Clinical Laboratory.Results The content of 25(OH)D in children with HSP was lower than that in healthy children,and the difference was statistically significant(P<0.01).The proportion of vitamin D insufficiency in children with HSP was higher than that in healthy children,and the difference was statistically significant(P<0.01).Conclusion The children with HSP are prone to vitamin D insufficiency.Vitamin D supplementation may provide a new method for the treatment of HSP.

Short-chain fatty acids are metabolites produced by anaerobic bacteria fermenting undigested carbohydrates in the cecum and colon.After being absorbed in the colon，they can regulate intestinal energy metabolism，maintain intestinal mucosal barrier function，regulate intestinal immune function，affect intestinal secretion and absorption，and regulate intestinal microecology through the above functions，thereby changing the frequency of defecation in children.With the in-depth understanding of intestinal microecology，it has been found that the metabolites of intestinal flora also play an important role in the human body.When the frequency of defecation in children changes，the composition of intestinal flora changes，and the content of short-chain fatty acids produced by intestinal flora metabolism also changes.This article reviews the role and mechanism of short-chain fatty acids in children's different defecation frequencies，and provides treatment ideas for children's different defecation frequencies.

There are the largest and most complex microbial groups in the human gastrointestinal tract，which constantly adapt to the host environment and provide multiple key functions for the host.Currently，many diseases are closely related to gastrointestinal motility disorders，including diarrhea，constipation，irritable bowel syndrome and so on.Increasing evidence indicates that the gut microbiota and their metabolites are able to influence gastrointestinal motility，which subsequently influences the development of diseases，and the relationship between them has become a research topic.This article reviews the mechanisms of gut microbiota and their metabolites as well as the mechanisms of probiotics in regulating gastrointestinal motility，in an attempt to provide valuable clues for developing therapies that rely on gut microbiota to improve gastrointestinal motility.

Following the principles of evidence-based medicine,in accordance with the structure and drafting rules of standardized documents,based on literature research,according to the characteristics of chronic cough in children and issues that need to form a consensus,the TCM Guidelines for Diagnosis and Treatment of Chronic Cough in Children was formulated based on the Delphi method,expert discussion meetings,and public solicitation of opinions.The guideline includes scope of application,terms and definitions,eti-ology and diagnosis,auxiliary examination,treatment,prevention and care.The aim is to clarify the optimal treatment plan of Chinese medicine in the diagnosis and treatment of this disease,and to provide guidance for improving the clinical diagnosis and treatment of chronic cough in children with Chinese medicine.

Human breast milk oligosaccharides are a kind of complex carbohydrates widely existing in human breast milk, which is the third major nutrient in human breast milk and is closely related to the growth and development of infants and some diseases.More than 200 different functional oligosaccharides have been identified for their role in regulating intestinal flora, regulating immunity and promoting brain development.This article reviews the structural composition, biological function, application and development trend of breast milk oligosaccharides, to provide reference for the application of oligosaccharides in functional food.

Chronic enteropathy associated with solute carrier organic anion transporter family member 2A1 gene(CEAS)is an autosomal recessive disease caused by SLCO2A1 gene mutation.Characterized by Persistent, intractable, nonspecific intestinal ulcers that lead to chronic loss of blood and protein.At present, pathogenesis of CEAS is still unclear.Endoscopic examination shows specific intestinal ulcers and intestinal stenosis, which mainly involves ileum.Due to its rare occurrence and similar clinical manifestations with Crohn′s disease and non-steroidal anti-inflammatory drug related bowel disease, it is easy to be confused clinically.No effective treatment has been established, and iron supplementation, blood transfusion and parenteral or enteral nutrition can be given symptomatic treatment.Surgical treatment is feasible in serious condition, however, all of them can only get a temporary effect.Usually, after the end of treatment, the disease relapses, and the life prognosis is not clear.

It is the hotspot that studying the interplay and mechanism between intestinal flora metabolites and diseases.Deoxycholic acid, one of the intestinal flora metabolites, is one of the most abundant secondary bile acids in human intestinal tract, which is corelated with many diseases, while the mechanisms remain unclear.The imbalance of deoxycholic acid is connected with the intestinal flora disorder and high fat diet, which could result in several immunoreaction and inflammatory reaction.In this review, the interaction between deoxycholic acid and digestive diseases in children, such as non-alcoholic fatty liver disease, inflammatory bowel disease and irritable bowel syndrome, is discussed to explore their related mechanism, so as to clarify the direction of further study on the influence of intestinal microbiota metabolites deoxycholic acid on the human body.

During coronavirus disease 2019 epidemic, the treatment of severe trauma has been impacted. The Consensus on emergency surgery and infection prevention and control for severe trauma patients with 2019 novel corona virus pneumonia was published online on February 12, 2020, providing a strong guidance for the emergency treatment of severe trauma and the self-protection of medical staffs in the early stage of the epidemic. With the Joint Prevention and Control Mechanism of the State Council renaming "novel coronavirus pneumonia" to "novel coronavirus infection" and the infection being managed with measures against class B infectious diseases since January 8, 2023, the consensus published in 2020 is no longer applicable to the emergency treatment of severe trauma in the new stage of epidemic prevention and control. In this context, led by the Chinese Traumatology Association, Chinese Trauma Surgeon Association, Trauma Medicine Branch of Chinese International Exchange and Promotive Association for Medical and Health Care, and Editorial Board of Chinese Journal of Traumatology, the Chinese expert consensus on emergency surgery for severe trauma and infection prevention during coronavirus disease 2019 epidemic ( version 2023) is formulated to ensure the effectiveness and safety in the treatment of severe trauma in the new stage. Based on the policy of the Joint Prevention and Control Mechanism of the State Council and by using evidence-based medical evidence as well as Delphi expert consultation and voting, 16 recommendations are put forward from the four aspects of the related definitions, infection prevention, preoperative assessment and preparation, emergency operation and postoperative management, hoping to provide a reference for severe trauma care in the new stage of the epidemic prevention and control.

Objective:To explore the mid-term efficacy of liquid nitrogen-inactivated autologous tumor segment bone replantation for repairing bone defects after resection of malignant tumors in the long bone shaft.Methods:A retrospective analysis was performed on the clinical data of 16 patients treated with liquid nitrogen-inactivated autologous bone graft at Beijing Jishuitan Hospital from July 2015 to June 2017 to repair defects caused by malignant tumour resection of the diaphysis. There were 10 males and 6 females with a mean age of 23.4±11.6 years (range, 8-44 years), including 8 classic osteosarcoma, 2 high-grade surface osteosarcoma, 4 Ewing's sarcoma, 1 periosteal osteosarcoma, and 1 undifferentiated pleomorphic sarcoma. Tumors were located in the humerus in 2 cases, in the femur in 8 cases and in the tibia in 6 cases. The mean length of tumor was 12.4±4.8 cm (range, 5.5-26 cm). Postoperative imaging examination was performed every 6 months, and the healing status of the transplanted bone-host bone was evaluated based on the imaging assessment method of the International Society of Limb Salvage (ISOLS) imaging assessment after allogeneic bone transplantation, and the complications were assessed using the Henderson classification. The five-year survival rate for patients and grafted bone was calculated using the Kaplan-Meier survival curve.Results:The median follow-up was 64 (60.3, 69.8) months. At the end of follow-up, 13 patients were tumour free and 3 patients died of multiple metastases at 19, 20 and 33 months after surgery. There were 32 osteotomy ends in 16 patients, of which 30 healed, including 11 metaphyseal osteotomy ends, and the healing time was 9 (6, 12) months after replantation of the tumour segment with liquid nitrogen-inactivated autologous bone; 19 osteotomy ends in the diaphysis took 13 (9, 21) months to heal, with a statistically significant difference in healing time between different sites ( Z=-2.25, P=0.025). Sixteen patients had six complications, including two cases of non-union at the diaphyseal site, one case of failure of internal fixation due to non-union, three cases of recurrence, and no soft tissue complications or infections. One patient with failed internal fixation was treated with a vascularized tip iliac bone graft that healed 6 months after surgery. Another patient died of multiple metastases with 1 unhealed diaphysis left. Three cases of recurrence were all located in the extracranial soft tissue of the autologous tumor segment inactivated by liquid nitrogen. Among them, one case underwent reoperation and local radiotherapy, and there was still no tumor survival after 65 months of surgery, and two cases died due to multiple metastases. The five-year survival rate of patients was 81% as calculated using the Kaplan-Meier survival curve, and the graft survival rate was 100%. There was no amputation and the limb salvage rate was 100%. Conclusion:The use of liquid nitrogen-inactivated autologous tumor segment bone replantation for reconstruction of bone defects after resection of malignant tumors in the shaft has advantages of higher healing rate, shorter healing time at the metaphyseal end compared to the osteotomy end, fewer complications, and higher survival rate of the replanted bone.