The Human Microbiota in Health and Disease

Trillions of microbes have evolved with and continue to live on and within human beings. A variety of environmental factors can affect intestinal microbial imbalance, which has a close relationship with human health and disease. Here, we focus on the interactions between the human microbiota and the host in order to provide an overview of the microbial role in basic biological processes and in the development and progression of major human diseases such as infectious diseases, liver diseases, gastrointestinal cancers, metabolic diseases, respiratory diseases, mental or psychological diseases, and autoimmune diseases. We also review important advances in techniques associated with microbial research, such as DNA sequencing, metabonomics, and proteomics combined with computation-based bioinformatics.Current research on the human microbiota has become much more sophisticated and more comprehensive.Therefore, we propose that research should focus on the host-microbe interaction and on causeeffect mechanisms, which could pave the way to an understanding of the role of gut microbiota in health and disease, and provide new therapeutic targets and treatment approaches in clinical practice.

Longitudinal gut fungal alterations and potential fungal biomarkers for the progression of primary liver disease

Liver disease,a major health concern worldwide,is a serious and progressive disorder.Herein,we not only established a mouse model of DEN+CCl4-induced primary liver disease but also collected clinical human samples to investigate longitudinal alterations in the gut mycobiome.As liver disease advanced,gut integrity was disrupted,and the mycobiota was disturbed in the mouse models.The metabolites associated with hepatocellular carcinoma(HCC)differed from those associated with the cirrhotic phase as follows:levels of stercobilin and aflatoxin B1 dialcohol were reduced,while levels of triterpenoids,bafilomycin A1,and DHEA were increased in the HCC group.The abundance of the phylum Chytridiomycota increased as the chronic liver disease progressed and was then replaced by the phylum Ascomycota in HCC.Based on the results from clinical human samples,the genus Candida(Ascomycota)(in humans)and the genus Kazachstania(Ascomycota)(in mice)occupied a dominant position in the HCC group,while other fungi were depleted.The increased abundance of C.albicans and depletion of S.cerevisiae may be hallmarks of the progression of liver cirrhosis to early HCC.Moreover,the administration of C.albicans and S.cerevisiae in the LC-HCC progression could accelerate or retard the progression of HCC.Therefore,gut fungi have the potential to serve as a noninvasive clinical biomarker and even a treatment method.