Objective To evaluate the efficacy of Jianpi Yang'er Ointment for children with anorexia of spleen deficiency type in Lingnan area;To analyze its effects on children's intestinal flora and functional information by means of metagenome sequencing.Methods Totolly 144 children with anorexia in Guangzhou Women and Children Medical Center of Guangzhou Medical University from August 2022 to January 2023 were orally treated with Jianpi Yang'er Ointment,one bag per time,twice a day,after meal,for 28 d.Visits were conducted at 0 and 28 days,respectively,to measure height and body mass,record symptoms and signs,observe adverse reactions,collect feces,and fill out the"Clinical Index Scoring Table for Children with Spleen Deficiency Type Anorexia in Lingnan Area".Clinically cured children were included in the anorexia group,with healthy children as a healthy control group(HC group),perform metagenomic analysis on feces of HC group and anorexia group 0 and 28 days of treatment.Results Compared with 0 d of treatment,there was no significant difference in the height of children(P>0.05),while there was a significant difference in body mass(P<0.05),the total syndrome score,main symptom score,and secondary symptom score decreased at 28 d of treatment(P<0.05).The efficacy index was 57.03%,and the total effective rate was 99.31%(143/144).All patients did not experience symptoms such as allergies,vomiting,or diarrhea.7 clinically cured children and 6 healthy children were included in metagenome analysis on feces.PCoA showed that the structure of intestinal flora in anorexia group with 28 d treatment(JP2 group)was more similar to that in HC group at the phylum and genus levels;at the phylum level,there was no significant difference in the distribution of intestinal flora between anorexia group with 0 d treatment(JP1)group and JP2 group and HC group.At the genus level,compared with JP1 group,the abundance of Bacteroides in JP2 group decreased,but the difference was not statistically significant(P>0.05);at the species level,both JP1 and JP2 groups were mainly composed of Phocaeicola plebeius et al.and Bifidobacterium pseudocatenatum et al.The biomarker with significant differences between the two groups was s_Phascolarctobacterium_faecium,while the HC group was mainly composed of Prevotella copri and Bifidobacterium pseudocatenatum.The functional annotation results indicated that a significant change in microbial functional genes related to carbohydrate metabolism occurred after the treatment with Jianpi Yang'er Ointment.Conclusion Jianpi Yang'er Ointment can effectively improve the clinical symptoms of children with spleen deficiency anorexia in Lingnan area,adjust the structure of intestinal flora,increase the content of key probiotics,and regulate the production of intestinal microbiota short-chain fatty acids.