Protective Microbiota: From Localized to Long-Reaching Co-Immunity

Abstract

Resident microbiota do not just shape host immunity, they can also contribute to host protection against pathogens and infectious diseases. Previous reviews of the protective roles of the microbiota have focused exclusively on colonization resistance localized within a microenvironment. This review shows that the protection against pathogens also involves the mitigation of pathogenic impact without eliminating the pathogens (i.e., “disease tolerance”) and the containment of microorganisms to prevent pathogenic spread. Protective microorganisms can have an impact beyond their niche, interfering with the entry, establishment, growth, and spread of pathogenic microorganisms. More fundamentally, we propose a series of conceptual clarifications in support of the idea of a “co-immunity,” where an organism is protected by both its own immune system and components of its microbiota.

Natural C. elegans Microbiota Protects against Infection via Production of a Cyclic Lipopeptide of the Viscosin Group

“…However, apart from this one example, the mechanisms by which the C. elegans microbiota protects the worm from pathogen infection are completely unknown. Intestinal microbiota can confer protection against intestinal pathogens in two ways: through indirect activation of the host immune response or through direct microbe-microbe competition [3,15,16]. In a first step toward exploring the molecular mechanism underlying the observed microbiota-mediated protection, we tested whether the protective effects require alive bacteria and assessed worm survival after BT247 infection in the presence of both alive and heat-inactivated microbiota isolates MYb11, MYb12, and MYb115, which strongly and consistently protected C. elegans from B. thuringiensis infection.…”

Respiratory mycobiome and suggestion of inter-kingdom network during acute pulmonary exacerbation in cystic fibrosis

“…In summary, microbial interactions are clearly complex in natural communities such as lungs, due to the impact of a multitude of microbes (bacteria, fungi, but also phages and viruses) able to interact 67,68 and to host immune response that appears dual 68,69 . We show that NGS approach combined with inference network and ecological model analysis are useful in helping to decipher physiopathology of CF lung disease, and can be considered as a promising tool for improving our therapeutic protocols.…”

The Gut-Lung Axis in Health and Respiratory Diseases: A Place for Inter-Organ and Inter-Kingdom Crosstalks

“…Beyond the local immune regulation by the site-specific microbiota, the long-reaching immune impact of gut microbiota is now being recognized, especially on the pulmonary immune system (Chiu et al, 2017). The mesenteric lymphatic system is an essential pathway between the lungs and the intestine, through which intact bacteria, their fragments, or metabolites (e.g., SCFAs) may translocate across the intestinal barrier, reach the systemic circulation, and modulate the lung immune response Bingula et al, 2017;McAleer and Kolls, 2018).…”

“…Human skin and mucosal surfaces are associated with rich and complex ecosystems (microbiota) composed of bacteria (bacteriobiota), fungi (mycobiota), viruses (virobiota), phages, archaea, protists, and helminths (Cho and Blaser, 2012). The role of the gut bacteriobiota in local health homeostasis and diseases is being increasingly investigated, but its long-distance impacts still need to be clarified (Chiu et al, 2017). Among the relevant inter-organ connections, the gut-lung axis (GLA) remains less studied than the gut-brain axis.…”