The interplay between the intestinal microbiota and the immune system

Abstract

Summary The relationship between commensal microbes and their hosts has been studied for many years. Commensal microorganisms are known to have a significant role in regulating the physiology of their hosts and preventing pathogenic infections while the hosts’ immune system is important in determining the composition of the microbiota. More recently, specific effects of the intestinal microbiota on the local and distal immune systems have been uncovered with important consequences for health and disease, and alterations in intestinal microbial composition has been associated with various disease states. Here, we will review the current understanding of the microbiota/immune system crosstalk, highlight the clinical consequences of changes in the microbiota and consider how to harness this symbiotic relationship to improve public health.

Chitooligosaccharides Modulate Glucose-Lipid Metabolism by Suppressing SMYD3 Pathways and Regulating Gut Microflora

“…The gut microflora is a complex microbial ecological group with important functions in immunity, anti-aging, antitumor, nutrient decomposition, and metabolism [39][40][41][42][43] that are important to maintain human health. Therefore, research on intestinal flora has received increasing attention.…”

Expresión de la Interleucina 10 (IL-10) y el Factor de Crecimiento Transformante Beta (TGF-ß) en Mucosa Intestinal de Crías de Alpaca (Vicugna pacos)

“…El calostro contiene diversos elementos como anticuerpos, leucocitos, citoquinas y nutrientes que influyen en el desarrollo del sistema inmune y protección del neonato (Brown, 2000). La colonización de microorganismos en el intestino es necesaria para el desarrollo del sistema inmune intestinal (Lei et al, 2015); sin embargo, este sistema es constantemente retado por los patógenos del entorno (Rosadio et al, 2012) modificando la estructura y función de la mucosa intestinal. Cabe resaltar que las alpacas inician la ingesta de forraje en las primeras semanas de vida, efectuándose un cambio en la microbiota intestinal y en la respuesta inmune (Bailey et al, 2001).…”

Microbial Sources of Amyloid and Relevance to Amyloidogenesis and AlzheimerÂ’s Disease (AD)

“…A remarkable variety of microbial species including bacteria and fungi of the human microbiome generate significant quantities of functional amyloid, and even early scientific interpretations suggested that secreted amyloid and other shed molecules may serve some immune-evasive and survival strategy [ 3 , 4 , 17 ]. From the 10 14 microbiota of the human microbiome it is also apparent that humans tolerate a substantial exposure to LPSs and microbial-generated amyloid, which potentially may contribute to the pathology of progressive CNS diseases with an amyloidogenic component [ 3 , 4 , 18 – 20 ]. For example, amyloids are associated with structures located on fungal surfaces and the recent observation of amyloidogenic fungal proteins and diffuse mycoses in the blood of AD patients suggest that chronic fungal infection contributes to AD risk via amyloid exposure [ 2 – 6 , 21 , 22 ].…”

“…To cite another recent example, in Escherichia coli (strain K12) extracellular bacterial amyloids known as ‘curli fibers’ and composed of the major structural curli subunit gA (CsgA) are a common secretory component used as structural materials facilitating surface attachment and adhesion, biofilm development and protection against host defenses [ 23 , 24 ]. Curli fibers typically engulf and surround bacteria forming a meshwork or ‘biofilm’ that biophysically connects large numbers of bacteria together [ 18 , 19 ]. Biofilms therefore represent a matrix of extracellular polymeric amyloids and other complex lipoproteins and LPS in various structural forms.…”