Diet-Induced Dysbiosis of the Intestinal Microbiota and the Effects on Immunity and Disease

Abstract

The gastrointestinal (GI) microbiota is the collection of microbes which reside in the GI tract and represents the largest source of non-self antigens in the human body. The GI tract functions as a major immunological organ as it must maintain tolerance to commensal and dietary antigens while remaining responsive to pathogenic stimuli. If this balance is disrupted, inappropriate inflammatory processes can result, leading to host cell damage and/or autoimmunity. Evidence suggests that the composition of the intestinal microbiota can influence susceptibility to chronic disease of the intestinal tract including ulcerative colitis, Crohn’s disease, celiac disease and irritable bowel syndrome, as well as more systemic diseases such as obesity, type 1 diabetes and type 2 diabetes. Interestingly, a considerable shift in diet has coincided with increased incidence of many of these inflammatory diseases. It was originally believed that the composition of the intestinal microbiota was relatively stable from early childhood; however, recent evidence suggests that diet can cause dysbiosis, an alteration in the composition of the microbiota, which could lead to aberrant immune responses. The role of the microbiota and the potential for diet-induced dysbiosis in inflammatory conditions of the GI tract and systemic diseases will be discussed.

Eugenol in combination with lactic acid bacteria attenuates Listeria monocytogenes virulence in vitro and in invertebrate model Galleria mellonella

“…Among the probiotic bacteria, since B. bifidum was generally more inhibitory on the various virulence factors tested, it was used in further experiments in combination with EG. The combination treatments containing EG and B. bifidum supernatant were found to be significantly more effective in down-regulating the expression of critical virulence genes compared to EG or supernatant alone (Tables 2 and 3 influencing gut microbiota physiology (Brown et al, 2012) and composition (Ley et al, 2006;Duncan et al, 2007), which in turn has been associated with attenuated pathogen virulence and reduced susceptibility of the host to foodborne infections (Dominguez-Bello & Blaser, 2008;Ghosh et al, 2011). Bomba & coworkers (2002) observed that the administration of polyunsaturated fatty acids positively influenced the adhesion of Lactobacillus spp.…”

Causal Effect of Genetic Variants Associated With Body Mass Index on Multiple Sclerosis Susceptibility

“…The intestinal immune response has also been hypothesized to explain the association between obesity and MS; an imbalance of T-helper 17 and T-regulatory cells may lead to alteration of the intestinal microbiome (32,33). It has also been shown that vitamin D deficiency is prevalent among obese individuals (34).…”

Impact of Dietary Fibers on Nutrient Management and Detoxification Organs: Gut, Liver, and Kidneys

“…This process required the presence of the SCFA receptor, FFA receptor 2 (GPCR 43) (90). DF has been recognized as a potential dietary treatment for inflammatory bowel diseases because fiber can favorably affect gut microbe and gut immune factors found to be altered in diseases such as Crohn disease and ulcerative colitis (91). In summary, DF can bolster the gut barrier by maintaining host physical barriers (mucosal layer and cellular tight junctions) as well as by altering host immune factors.…”