Current treatment options for leptospirosis: a mini-review

The microbiota plays a fundamental role on the induction, training, and function of the host immune system. In return, the immune system has largely evolved as a means to maintain the symbiotic relationship of the host with these highly diverse and evolving microbes. When operating optimally, this immune system-microbiota alliance allows the induction of protective responses to pathogens and the maintenance of regulatory pathways involved in the maintenance of tolerance to innocuous antigens. However, in high-income countries, overuse of antibiotics, changes in diet, and elimination of constitutive partners, such as nematodes, may have selected for a microbiota that lack the resilience and diversity required to establish balanced immune responses. This phenomenon is proposed to account for some of the dramatic rise in autoimmune and inflammatory disorders in parts of the world where our symbiotic relationship with the microbiota has been the most affected. Copyright © 2014 Elsevier Inc. All rights reserved. Show more

In the mucosa, the immune system's T cells and B cells have position-specific phenotypes and functions that are influenced by the microbiota. These cells play pivotal parts in the maintenance of immune homeostasis by suppressing responses to harmless antigens and by enforcing the integrity of the barrier functions of the gut mucosa. Imbalances in the gut microbiota, known as dysbiosis, can trigger several immune disorders through the activity of T cells that are both near to and distant from the site of their induction. Elucidation of the mechanisms that distinguish between homeostatic and pathogenic microbiota-host interactions could identify therapeutic targets for preventing or modulating inflammatory diseases and for boosting the efficacy of cancer immunotherapy. Show more

In the past decade, an exciting realization has been that diverse liver diseases, ranging from non-alcoholic steatohepatitis, alcoholic steatohepatitis, and cirrhosis, to hepatocellular carcinoma, are not unrelated but fall along a spectrum. Recent work on the biology of the gut-liver communication axis has assisted in understanding the basic biology of both alcoholic and nonalcoholic fatty liver disease. Of immense importance is the massive advancement in understanding of the role of the microbiome, driven by high-throughput DNA sequencing and improved computational techniques that allow the complexity of the microbiome to be interrogated, together with improved experimental designs. Here, we review the gut-liver communications of these various forms of liver disease, explore the molecular, genetic and microbiome relationships, discuss prospects for exploiting the microbiome to determine the stage of liver disease, and to predict the effects of pharmaceutical, dietary, and other interventions at a population and individual level. We conclude that although much remains to be done in understanding the relationship between the microbiome and liver disease, rapid progress towards clinical applications is being made, especially in study designs that complement human intervention studies with mechanistic work in mice that have been humanized in multiple respects, including the genetic, immunological and microbiome characteristics of individual patients. These “avatar mice” may be especially useful for guiding new microbiome-based or microbiome-informed therapies. Show more