Major Research Achievement Published on Gastroenterology

　　 　　

On March 4th,  Gastroenterology , an authoritative journal of digestive tract (impact factor: 22.682), published an online paper entitled "Fecal Mycobiota Combined with Host Immune Factors Distinguish Clostridioides Difficile Infection from Asymmetric Carriage", which was completed by the innovative team of animal nutrition and healthy breeding of the Institute of Animal Science and Technology in cooperation with Harvard Medical School in the United States. Our university is the first unit to complete the thesis, with Associate Professor Cao Yangchun from the College, Dr. Wang Lamei from the College of Life Sciences and Dr. Shanlin Ke from Harvard Medical School as the co-first authors, Professor Yao Junhu and Professor Chen Yulin as co-authors, and Dr. Yang-Yu Liu and Dr. Xinhua Chen from Harvard Medical School as correspondent authors.

Clostridium difficile is a specific anaerobic gram-positive bacillus, which widely exists in nature, human and animal intestines and feces. The imbalance of intestinal flora leads to the overgrowth of Clostridium and the release of toxins, which leads to Clostridium infection. With the wide application of antibiotics, the incidence of Clostridium infection is increasing year by year in the world, especially the emergence and prevalence of high-yield strains, which makes Clostridium become one of the important pathogens related to medical and health care in recent years. However, there are still many unknown problems about the accurate prevention, diagnosis and treatment of Clostridium infection.

Intestinal flora imbalance is an important factor of Clostridium difficile infection (CDI). Studies have shown that bacterial flora imbalance affects the incidence and severity of Clostridium difficile infection, but the role of intestinal fungi in it is still unclear. Feces and serum samples of 118 hospitalized patients were collected and divided into CDI group, carrier (asymptomatic) group and control group according to Clostridium infection and diarrhea. Immunofluorescence and liquid chromatography were used to detect clostridium and its toxin in feces, ITS2 diversity sequencing combined with high-throughput information algorithm was used to study intestinal fungi group, and immunofluorescence and enzyme-linked immunosorbent assay were used to detect serum immune indexes. This study found that there were significant differences in α and β diversity between CDI patients and carriers. Cladosporium and Aspergillus were enriched in carriers, while the ratio of Ascomycetes/Basidiomycetes in CDI patients was significantly higher than that in carriers and controls. Compared with carriers, the association between serum immune factors and fungal group characteristics of CDI patients was weak; The diagnostic model based on 4 fungal OTU+6 host immune markers can be used to distinguish CDI patients from carriers (AUC: 92.38%). In this study, a diagnostic model based on fungi and immune indexes was established for the first time, which can accurately distinguish CDI patients from asymptomatic carriers, and also find the potential important role and application value of intestinal fungi in CDI.

The first aid of this study is supported by the National Key Research and Development Plan (2017YFD0500500) in the 13th Five-Year Plan chaired by Professor Yao Junhu.

Article link: https://www.gastrojournal.org/article/S0016-5085 (21) 00475-3/fulltext