scholarly journals Host–microbe interactions in the gut: lessons learned from models of inflammatory bowel diseases

2014 ◽  
Vol 1 (2) ◽  
pp. 61-76
Author(s):  
Eytan Wine

The mammalian gut is the richest immune organ in the body and serves as a central location for immune system development, processing, and education. Inflammatory bowel diseases (IBD) provide excellent models for studying both innate and adaptive responses to gut microbes and the host-immune system – microbe interactions in the gut. Microbes are linked to almost all of the known disease-associated genetic polymorphisms in IBD and are critical mediators of environmental effects (through food, hygiene, and infection). Human and animal-based research supports the central role of microbes in IBD pathogenesis at multiple levels. Animal models of IBD only develop in the presence of microbes, and co-housing mice that are genetically susceptible to gut inflammation with normal mice can lead to the development of bowel injury. Recent advances in research technologies, such as deep-sequencing that enables detailed compositional analyses, have revolutionized the study of host–microbe interactions in the gut; however, knowing which bacteria are present in the bowel is likely not sufficient. The function of the microbiota as a community is recognized as a critical factor for gut homeostasis. Animal models of IBD have provided critical insight into basic biology and disease pathogenesis, especially regarding the role of microbes in IBD pathogenesis. Although many of these recent discoveries on host–microbe interactions are not yet applied to patient care, these basic observations will certainly revolutionize patient care in the future. Using such data, we may be able to predict risk of disease, define biological subtypes, establish tools for prevention, and even cure IBD using microbes or their products. A broad spectrum of therapeutic tools spanning from fecal transplantation, probiotics, prebiotics, and microbial products to microbe-tailored diets may supplement current IBD treatments.

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Yue Shan ◽  
Mirae Lee ◽  
Eugene B. Chang

Inflammatory bowel diseases (IBD) arise from a convergence of genetic risk, environmental factors, and gut microbiota, where each is necessary but not sufficient to cause disease. Emerging evidence supports a bidirectional relationship between disease progression and changes in microbiota membership and function. Thus, the study of the gut microbiome and host–microbe interactions should provide critical insights into disease pathogenesis as well as leads for developing microbiome-based diagnostics and interventions for IBD. In this article, we review the most recent advances in understanding the relationship between the gut microbiota and IBD and highlight the importance of going beyond establishing description and association to gain mechanistic insights into causes and consequences of IBD. The review aims to contextualize recent findings to form conceptional frameworks for understanding the etiopathogenesis of IBD and for the future development of microbiome-based diagnostics and interventions. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 9 (4) ◽  
pp. 697
Author(s):  
Valerio Baldelli ◽  
Franco Scaldaferri ◽  
Lorenza Putignani ◽  
Federica Del Chierico

Inflammatory bowel diseases (IBDs) are a group of chronic gastrointestinal inflammatory diseases with unknown etiology. There is a combination of well documented factors in their pathogenesis, including intestinal microbiota dysbiosis. The symbiotic microbiota plays important functions in the host, and the loss of beneficial microbes could favor the expansion of microbial pathobionts. In particular, the bloom of potentially harmful Proteobacteria, especially Enterobacteriaceae, has been described as enhancing the inflammatory response, as observed in IBDs. Herein, we seek to investigate the contribution of Enterobacteriaceae to IBD pathogenesis whilst considering the continuous expansion of the literature and data. Despite the mechanism of their expansion still remaining unclear, their expansion could be correlated with the increase in nitrate and oxygen levels in the inflamed gut and with the bile acid dysmetabolism described in IBD patients. Furthermore, in several Enterobacteriaceae studies conducted at a species level, it has been suggested that some adherent-invasive Escherichia coli (AIEC) play an important role in IBD pathogenesis. Overall, this review highlights the pivotal role played by Enterobacteriaceae in gut dysbiosis associated with IBD pathogenesis and progression.


2018 ◽  
Vol 13 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Sandra Maria Barbalho ◽  
Ricardo de Alvares Goulart ◽  
Gabriela Lombardi dos Santos Almeid Batista

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3402
Author(s):  
Barbara Borsani ◽  
Raffaella De Santis ◽  
Veronica Perico ◽  
Francesca Penagini ◽  
Erica Pendezza ◽  
...  

Carrageenan (CGN) is a high molecular weight polysaccharide extracted from red seaweeds, composed of D-galactose residues linked in β-1,4 and α-1,3 galactose-galactose bond, widely used as a food additive in processed foods for its properties as a thickener, gelling agent, emulsifier, and stabilizer. In recent years, with the spread of the Western diet (WD), its consumption has increased. Nonetheless, there is a debate on its safety. CGN is extensively used as an inflammatory and adjuvant agent in vitro and in animal experimental models for the investigation of immune processes or to assess the activity of anti-inflammatory drugs. CGN can activate the innate immune pathways of inflammation, alter the gut microbiota composition and the thickness of the mucus barrier. Clinical evidence suggests that CGN is involved in the pathogenesis and clinical management of inflammatory bowel diseases (IBD), indeed food-exclusion diets can be an effective therapy for disease remission. Moreover, specific IgE to the oligosaccharide α-Gal has been associated with allergic reactions commonly referred to as the “α-Gal syndrome”. This review aims to discuss the role of carrageenan in inflammatory bowel diseases and allergic reactions following the current evidence. Furthermore, as no definitive data are available on the safety and the effects of CGN, we suggest gaps to be filled and advise to limit the human exposure to CGN by reducing the consumption of ultra-processed foods.


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