Effect of barrier microbes on organ-based inflammation

Abstract

The prevalence and incidence of chronic inflammatory disorders, including allergies and asthma, as well as inflammatory bowel disease, remain on the increase. Microbes are among the environmental factors that play an important role in shaping normal and pathologic immune responses. Several concepts have been put forward to explain the effect of microbes on the development of these conditions, including the hygiene hypothesis and the microbiota hypothesis. Recently, the dynamics of the development of (intestinal) microbial colonization, its effect on innate and adaptive immune responses (homeostasis), and the role of environmental factors, such as nutrition and others, have been extensively investigated. Furthermore, there is now increasing evidence that a qualitative and quantitative disturbance in colonization (dysbiosis) is associated with dysfunction of immune responses and development of various chronic inflammatory disorders. In this article the recent epidemiologic, clinical, and experimental evidence for this interaction is discussed.

The gut microbiota and inflammatory noncommunicable diseases: Associations and potentials for gut microbiota therapies

“…The critical role of the gut microbiota in immune development has been well documented in germ free animal models, demonstrating the failure of normal maturation and, in particular, failure of the systemic immune regulatory networks, that result in both allergic and autoimmune phenomena (as reviewed by) [5][6][7][8] . Significantly, early experiments clearly demonstrated a critical early developmental "window" during which microbial colonization could induce appropriate maturation of the Th2 response and IgE regulation, and after which this was no longer possible 22 .…”

“…The cell wall of gramnegative bacteria contains lipopolysaccharides (LPS), which induce a strong host inflammatory response to protect from infection. Under normal conditions, finely tuned regulatory responses restrict excessive inflammation and maintain tissue equilibrium [5][6][7][8] . The pattern of microbial exposure in early life appears to be important for the development of robust host immune regulation, and disruption in either the microbiota or the host response can lead to chronic inflammation.…”

Helsinki alert of biodiversity and health

“…In most studies, microbiota associated with health are more diverse than those associated with various diseases (107)(108)(109). The diversity of the indigenous microbiota is linked to diversity of microbiota and macrobiota in the living environment (39), according to the biodiversity hypothesis (10,11).…”

The human gut microbiota: a dynamic interplay with the host from birth to senescence settled during childhood

“…However, this concept, validated in healthy subjects and in patients with inflammatory bowel disease, has to be reconsidered in metabolic diseases, because gut dysbiosis can be induced within a few days or weeks by a diet change (25), allowing pathogens to penetrate the body without being destroyed by the innate and specific adaptive ISs, through a nucleotide-binding oligomerization domain 1-and LPS-cluster of differentiation 14-dependent translocation mechanism, which, when hampered, improves insulin sensitivity (26). Thereby, the blood might not be a direct route for bacterial translocation, suggesting the possibility of a tissue microbiota, also mediating allergy response (27). To identify million of bacterial genes involved in the control of metabolism is a demanding task.…”