Nutrition and foodA glance at … dietary emulsifiers, the human intestinal mucus and microbiome, and dietary fiber
Section snippets
Human intestinal mucus
Human intestinal mucus contains >1300 identifiable proteins, most of which are O-glycosylated mucin (MUC) proteins (predominantly MUC2) that share similar large domains enriched in proline, threonine, and serine (PTS domains) [4], [5], [6], [7], [8], [9]. Although O-glycosylation tends to confer a rodlike conformation to the glycosylated mucins [4], the hydroxyls, carboxyl, and sulfate groups of the O-glycans form hydrogen bonds with water, forming complex cross-linked branching structures [5]
Mucus–microbiome ecological equilibrium
The relative balance between the rates of mucin protein replacement and glycosylation and the rates of microbial mucus proteolysis, hydrolysis, and digestion determines the degree of homeostatic mucus maintenance and the functional balance between protection against bacterial invasion and facilitation of nutrient penetration and absorption. This balance determines the status of the human intestinal microbial-epithelial system, or “microbiome,” consisting of the intestinal epithelial tissues,
Human microbiome, intestinal mucus, and soluble dietary fiber
The normal microbiologic residents of the healthy human gut generate and sustain conditions in the gut that disfavor colonization by enteric pathogenic organisms (“colonization resistance”). The composition of the microbiota determines, in part, the level of resistance to specific infections and the susceptibility to specific inflammatory diseases of the intestinal tract [33]. The very dense beneficial human commensal gut microbiota exhibits more variability in species and abundance between
Emulsifiers and the microbiome—case in point: carboxymethylcellulose
Carboxymethylcellulose is one of the principal cellulose ethers manufactured worldwide (especially in India and China). It is an artificial hydrophilic, water-soluble, cellulose-based emulsifier that is used in the food and beverage (e.g., dry pet foods, frozen dairy foods, diet soft drinks, white and sparkling wines, and tortillas), paper, pharmaceutical, personal care cosmetics, oil drilling, mineral ore mining, wallpaper, paper bag, textile, and detergent industries [63], [64], [65], [66].
Human intestinal mucus and inflammatory bowel disease
A possible causal association between human intestinal mucus deficiency and inflammatory bowel disease (IBD) is suggested by the results of early studies that reported that patients with symptomatic IBD exhibited decreased glycosylation of intestinal mucus that was accompanied by thinning of the inner mucus layer of the colon [86]. Consistent with these reports, children diagnosed with IBD exhibit reductions in goblet cell density, hypoglycosylation of the intestinal mucus, and thinning of the
Emulsifiers, phytochemicals, and IBD
Interestingly, there is interest in exploiting the mucus-degrading properties of emulsifiers to increase the accessibility of the intestinal epithelium to putatively health-promoting dietary phytochemicals. In one such investigation, the ability of the phytochemical curcumin to penetrate the intestinal mucus was nearly doubled in the presence of the emulsifier, Tween-80 (polysorbate 80) [94]. In the face of concern that dietary emulsifiers may potentiate the initiation or progression of IBD [90]
Conclusions
Dietary emulsifiers contribute to the desirable characteristics of many processed foods and beverages, while remaining indigestible, unabsorbable, and unfermentable, thereby conferring no benefits on the human digestive tract. Furthermore, the consumption of emulsifiers (such as carboxymethylcellulose) weakens the mucus barrier of the intestinal epithelium and facilitates bacterial translocation into the intestinal tissues. In contrast, the consumption of soluble dietary fiber supports the
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Cited by (21)
Gut barrier disruption and chronic disease
2022, Trends in Endocrinology and MetabolismCitation Excerpt :The Western diet also induces systemic inflammation associated with changes in bile acid synthesis and signaling [34]. Bile acids are emulsifiers that affect mucus properties [35] and increase gut permeability in intestinal cell monolayers [36] and mice [37]. Emulsifiers are also added to processed foods to improve lipid–water mixing and food texture.
Food obesogens as emerging metabolic disruptors; A toxicological insight
2022, Journal of Steroid Biochemistry and Molecular BiologyCitation Excerpt :Their market rate is hiked robustly after regulatory bodies let the industries bring several chemicals into GRAS category [126] due to which emulsifiers in common foods now became enormous [67,134]. Growing number of research suggests that emulsifiers ubiquitously used in processed foods could contribute to the development of obesity and MetS [135]. The association between emulsifier intake and altered gut microbial population has been continuously recorded.
Crude fiber modulates the fecal microbiome and steroid hormones in pregnant Meishan sows
2019, General and Comparative EndocrinologyCitation Excerpt :And, whether this account for the inconsistent changes of estradiol concentration in saliva and stool remain unclear, further studies are needed. Dietary fiber can alter the gut microbiota composition (Song et al., 2015; Glade and Meguid, 2016; Jiang et al., 2017). Consistently, here the pyrosequencing analysis showed that the 7.5% CF diet obviously increased the diversity and the richness of the fecal microbiome, enriched the proportion of Butyrivibrio, Fibrobacter, Lactobacillus and Ruminococcus in stool microbiota.
Mucoadhesive role of tamarind xyloglucan on inflammation attenuates ulcerative colitis
2018, Journal of Functional FoodsCitation Excerpt :Animals deprived of fermentable dietary fibers lead to deprivation of short-chain fatty acid energy substrates ultimately leading to thinning of the inner mucus layer of the colon with increased proximity of colonic microbes to the colon epithelium. A shift in the balance of colonic microbial species in favor of increased mucus-consuming and epithelial barrier weakening bacterial species is also found (Glade & Meguid, 2016). Dextran sodium sulfate (DSS)-induced colitis in mice is known to mimic the morphological and pathophysiologic features observed in human UC.
Gut microbiome-based medical methodologies for early-stage disease prevention
2017, Microbial PathogenesisCitation Excerpt :An investigation published by Science in 2016 systematically associated 110 exogenous and intrinsic factors with 125 bacterial species in the gut microbiome and puts forward a better understanding of environmental and dietary factors that are implicated in the microbe-human interaction [52]. Several other studies tried to give some explanations of how high fat diet, western diet, dietary fiber, ethanol, and probiotics alter the bacterial compositions and physiological functions of gut microbiome in animal models and humans [35,53–57]. Moreover, Kim et al. showed that the Capsicum and Curcuma longa oleoresins modified the gut microbiome and had an impact on the development of necrotic enteritis, Monteagudo-Mera et al. described that galacto-oligosaccharides enhanced the Bifidobacterium species that play a metabolic role in the intestines of mice, and Kirpich et al. elucidated that an ethanol and fat diet caused bacterial variations in the gut microbiome of a mouse model of alcoholic liver disease [58–60].
The One Health approach for allergic diseases and asthma
2023, Allergy: European Journal of Allergy and Clinical Immunology
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