Blander et al. specifically review the role of the multi-kingdom gut microbiome in innate and adaptive immunity, including direct effects on immune and nonimmune cells, disease development and progression due to chronic inflammation, modulation of inflammation at distal sites (including the hygiene hypothesis), and effects on host immune response to vaccines and cancer therapies.

The study of the intestinal microbiota has begun to shift from cataloging individual members of the commensal community to understanding their contributions to the physiology of the host organism in health and disease. Here, we review the effects of the microbiome on innate and adaptive immunological players from epithelial cells and antigen-presenting cells to innate lymphoid cells and regulatory T cells. We discuss recent studies that have identified diverse microbiota-derived bioactive molecules and their effects on inflammation within the intestine and distally at sites as anatomically remote as the brain. Finally, we highlight new insights into how the microbiome influences the host response to infection, vaccination and cancer, as well as susceptibility to autoimmune and neurodegenerative disorders.

Author Info: (1) Jill Roberts Institute for Research in Inflammatory Bowel Disease, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New Y

Author Info: (1) Jill Roberts Institute for Research in Inflammatory Bowel Disease, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA. Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, USA. Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, Cornell University, New York, New York, USA. (2) Jill Roberts Institute for Research in Inflammatory Bowel Disease, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA. Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, USA. (3) Jill Roberts Institute for Research in Inflammatory Bowel Disease, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA. Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, USA. (4) Jill Roberts Institute for Research in Inflammatory Bowel Disease, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA. Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, USA. Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, Cornell University, New York, New York, USA. (5) Jill Roberts Institute for Research in Inflammatory Bowel Disease, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA. Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, New York, USA. Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, Cornell University, New York, New York, USA.