Indigenous microbiota and Leishmaniasis

Animals are colonized by their indigenous microbiota from the early days of life. The estimated number of associated bacterial cells in humans is around of 10(14) per individual, most of them in the gut. Several studies have investigated the microbiota-host relationship, and the use of germfree animals has been an important tool in these studies. These animals, when infected with a pathogen, have shown to be sometimes more resistant and other times more susceptible than conventional animals. Leishmaniasis is a worldwide public health problem and presents a spectrum of clinical manifestations. However, very few studies have addressed the role of the indigenous microbiota on the outcome of this disease. In this review, we will highlight and discuss the data available on the ways by which the microbiota can influence the outcome of the disease in murine experimental models of cutaneous infection with Leishmania.