1. Background The use of high-dose radiotherapy, chemotherapy and preventive antibiotics in the preconditioning regimen before allogeneic hematopoietic stem cell transplantation can easily lead to damage to the gastrointestinal mucosa, resulting in malnutrition, and even progression to cachexia, which directly leads to multiple organ failure; The damage of the intestinal mucosal barrier, secondary to the translocation of intestinal-derived bacteria, leads to bloodstream infection and lung infection (drug-resistant Enterobacteriaceae, especially carbapenem-resistant Enterobacteriaceae infection) is one of the challenges faced in clinical treatment. A major problem that affects the long-term survival rate of patients. Nutrition therapy based on the support and guidance of the intelligent nutrition management system aims to improve the compliance and compliance rate of patients with nutritional support therapy through scientific and accurate monitoring and intervention, thereby improving the nutritional status of patients and improving the tolerance of patients to radiotherapy and chemotherapy. Reduce the incidence of adverse reactions. At the same time, it is hoped that nutritional support therapy will protect the integrity of the intestinal mucosal barrier of patients, reduce the incidence of Enterobacteriaceae bacterial infections (mainly drug-resistant Klebsiella pneumoniae and Escherichia coli infections), and ultimately improve the long-term survival rate.
2. Purposes To investigate the effect of continuous nutritional therapy on the nutritional status of allogeneic HSCT recipients based on an intelligent nutritional management system, and to reduce the incidence of malnutrition during peri-transplantation.
3. Conditions to be met to participate in a study/trial Inclusion criteria: 1. Age 12-55 years old; 2. Patients who are about to receive allo-HSCT (1-2 weeks before pretreatment) ; 3. No serious medical and surgical complications, no mental and psychological diseases; 4. . Those who voluntarily participate in the study and sign the informed consent in writing. 4. No serious allergic diseases, especially those with milk protein allergy; Exclusion criteria: 1. Physical discomfort during the test; 2. Complicated with severe infection or other serious underlying diseases, and the duration of hemodynamic instability is ≥5 days; 3. Severe liver and kidney dysfunction and coagulation disorders persist Time ≥ 5 days; 4. Intractable cachexia phase/refractory phase: tumor continues to progress, no response to treatment; catabolism is active, and body weight continues to lose weight that cannot be corrected 5. Being unable to understand or comply with the research protocol due to clinical symptoms of brain dysfunction or severe mental illness; 6. drug abuse, medical, psychological or social conditions that may interfere with the subject's participation in the research or the evaluation of the research results; 7. Those who cannot be followed up as scheduled; 8. The investigator believes that the subject has any clinical or laboratory abnormalities or compliance problems that are not suitable for participation in this clinical study.
4. Number of trail subjects This clinical trial is a randomized controlled trial, and plans to recruit a total of 106 subjects, with 53 subjects in the experimental group and 53 in the control group .
5. Research/Trial Process This study is a randomized controlled clinical trial. After signing the informed consent, the subjects who meet the inclusion and exclusion criteria will be randomly assigned to the experimental group and the control group at a ratio of 1:1. The control group only receives conventional treatment, while the experimental group receives precise nutritional intervention with the assistance of an intelligent nutrition system. The intervention period of the experimental group will be 100 days after being enrolled and receiving the transplantation. The patients in the control group and experimental group will be followed up at -5d before transplantation and +6d, +30d, +60d, +100d, +180d, and +360d after transplantation. .

Randomized trial : The grouping is randomly performed by the computer, so that the bias caused by the grouping can be avoided. Each subject had a 50% chance of being assigned to both the experimental group and the control group.