Microbiota-host interplay at the gut epithelial level, health and nutrition

Abstract

Growing evidence suggests the implication of the gut microbiota in various facets of health and disease. In this review, the focus is put on microbiota-host molecular cross-talk at the gut epithelial level with special emphasis on two defense systems: intestinal alkaline phosphatase (IAP) and inducible heat shock proteins (iHSPs). Both IAP and iHSPs are induced by various microbial structural components (e.g. lipopolysaccharide, flagellin, CpG DNA motifs), metabolites (e.g. n-butyrate) or secreted signal molecules (e.g., toxins, various peptides, polyphosphate). IAP is produced in the small intestine and secreted into the lumen and in the interior milieu. It detoxifies microbial components by dephosphorylation and, therefore, down-regulates microbe-induced inflammation mainly by inhibiting NF-κB pro-inflammatory pathway in enterocytes. IAP gene expression and enzyme activity are influenced by the gut microbiota. Conversely, IAP controls gut microbiota composition both directly, and indirectly though the detoxification of pro-inflammatory free luminal adenosine triphosphate and inflammation inhibition. Inducible HSPs are expressed by gut epithelial cells in proportion to the microbial load along the gastro-intestinal tract. They are also induced by various microbial components, metabolites and secreted molecules. Whether iHSPs contribute to shape the gut microbiota is presently unknown. Both systems display strong anti-inflammatory and anti-oxidant properties that are protective to the gut and the host. Importantly, epithelial gene expressions and protein concentrations of IAP and iHSPs can be stimulated by probiotics, prebiotics and a large variety of dietary components, including macronutrients (protein and amino acids, especially L-glutamine, fat, fiber), and specific minerals (e.g. calcium) and vitamins (e.g. vitamins K1 and K2). Some food components (e.g. lectins, soybean proteins, various polyphenols) may inhibit or disturb these systems. The general cellular and molecular mechanisms involved in the microbiota-host epithelial crosstalk and subsequent gut protection through IAP and iHSPs are reviewed along with their nutritional modulation. Special emphasis is also given to the pig, an economically important species and valuable biomedical model.

Dietary ZnO and arginine supplementation on the dynamic change of microbiota, intestinal morphology, and immune function of weaned pigs subjected to heat stress

“…In the present study, the supplementation of ZnO remarkably decreased the mRNA expression levels of HSP27 that was involved in liver inflammation. The association between HSP expression and stress was previously reported in other studies [2,4]. The low gene expression of HSP27 in the liver and a tendency for lower blood cortisol in Zn-supplemented diets may indicate a lower stress level, however, the pigs fed high dietary Arg did not show any improvement in reducing the stress level, although Arg is reported to be an anti-stress or immunomodulatory factor by the activation of ornithine decarboxylase and generating polyamines [10].…”

“…The decrease of voluntary feed intake and being separated from mother sow increase the stress and may cause dysbiosis due to sudden microbial changes in intestine. Postwening intestinal microbiota dysbiosis is associated with some unstable situation including enteric infectious pathogens growth, leaky gut, and incomplete intestinal integrity [4].…”

Gut-Brain Axis: Probiotic,Bacillus subtilis, Prevents Aggression via the Modification of the Central Serotonergic System

“…The gut microbiota is also a key pathway to modulate brain processing the integrated information received from the peripheral nerve systems (the vagus nerve, enteric nerve, and autonomic nervous system), hormone signaling, the immune system, and microbial metabolites (short-chain fatty acids) [5,137]. Under social challenges, stress and related oxidative damage cause anatomical and functional disorders of the GI tract by: (1) disrupting the commensal bacterial populations and colonization, thus reducing beneficial bacteria and increasing pathogens; (2) increasing pathogen survivability and innovating capability; (3) disrupting absorption of nutrients and minerals, including calcium; (4) disrupting microbial neuroendocrine functions; (5) disrupting the gut epithelial barrier, thereby increasing intestinal permeability causing the gut to leak certain bacteria (leaky gut), resulting in metabolic disorder; (6) damaging epithelial cells, thus producing free radicals and reducing antioxidant efficacy; and (7) interrupting intestinal integrity, thereby leading to intestinal inflammation [142][143][144]. These changes in gut microenvironment affect brain functions, resulting in exacerbated HPA axis activity, increased chronic inflammation, and/or disrupted neurotransmitter balance, leading to emotional damage [139,145] and mental disorders [137,138].…”

Soybean Oligosaccharides Supplementation Attenuates the Fecal Odor Compounds by Modulate the Cecal Microbiota of Broilers

“…In vitro studies have revealed that SBO can improve the gut microbiota balance in colon and modulate its metabolism in pigs [7], changed in the intestinal microbiota and reduced the production of odor compounds in broilers [17,18]. Antibiotics work primarily by reshaping the intestinal microbiota [19], which is known as a unique ecosystem to play a crucial role in host health and metabolism [20][21][22]. However, the change and relationship between the compounds of major odor compounds and the intestinal microbiota are not elucidated by adding dietary SBO.…”