A total of 30 hospitalized patients with COVID-19 over 60 years old were enrolled in this study and were divided into the experimental group (n=15) and the control group (n=15) at a ratio of 1:1. Both groups were treated according to the 2022 Shanghai guidelines for Diagnosis and Treatment of COVID-19 infection and the hierarchical diagnosis and treatment process. The experimental group was treated with fecal microbiota transplantation (FMT) capsules for 1 week, and the control group was treated with empty capsules. Patients in both groups were followed up for 1 month after discharge. To observe the effect of combined FMT capsule treatment on the regulation of inflammatory factors in peripheral blood and the remodeling of intestinal flora, and to verify its safety.

Inclusion Criteria:

• 1. Over 60 years old, male or female;

  2. Meet the diagnostic criteria of COVID-19;

  3. The patient signed the informed consent, agreed to receive FMT capsule treatment, agreed to cooperate with the whole process of the clinical trial, and agreed to collect clinical data and blood, saliva, urine, stool and other samples;

  4. The patient was able to swallow 3# capsules by herself.

Exclusion Criteria:

• 1. Confirmed diagnosis of non-COVID19 pneumonia;

  2. Critically ill patients requiring mechanical ventilation, or patients who are unable to eat by mouth and swallow 3# capsules;

  3. Patients who had undergone gastrointestinal surgery;

  4. Presence of intestinal organic lesions such as congenital megacolon, intestinal obstruction, intussusception, etc.

  5. Pathological intestinal inflammatory changes, such as inflammatory bowel disease;

  6. Planned use of antacids, probiotics, antibiotics, FMT and other treatments affecting intestinal flora within the past 3 months or the following 2 months;

  7. Patients and their families did not agree to receive FMT treatment;

  8. Patients unable to cooperate with follow-up visits.