Anti-Pathogenic Functions of Non-Digestible Oligosaccharides In Vitro

Abstract

Non-digestible oligosaccharides (NDOs), complex carbohydrates that resist hydrolysis by salivary and intestinal digestive enzymes, fulfill a diversity of important biological roles. A lot of NDOs are known for their prebiotic properties by stimulating beneficial bacteria in the intestinal microbiota. Human milk oligosaccharides (HMOs) represent the first prebiotics that humans encounter in life. Inspired by these HMO structures, chemically-produced NDO structures (e.g., galacto-oligosaccharides and chito-oligosaccharides) have been recognized as valuable food additives and exert promising health effects. Besides their apparent ability to stimulate beneficial microbial species, oligosaccharides have shown to be important inhibitors of the development of pathogenic infections. Depending on the type and structural characteristics, oligosaccharides can exert a number of anti-pathogenic effects. The most described effect is their ability to act as a decoy receptor, thereby inhibiting adhesion of pathogens. Other ways of pathogenic inhibition, such as interference with pathogenic cell membrane and biofilm integrity and DNA transcription, are less investigated, but could be equally impactful. In this review, a comprehensive overview of In vitro anti-pathogenic properties of different NDOs and associated pathways are discussed. A framework is created categorizing all anti-pathogenic effects and providing insight into structural necessities for an oligosaccharide to exert one of these effects.

2′FL and LNnT Exert Antipathogenic Effects against C. difficile ATCC 9689 In Vitro, Coinciding with Increased Levels of Bifidobacteriaceae and/or Secondary Bile Acids

“…Besides the beneficial modulation of the gut microbiota, HMOs have also been shown to improve the gut barrier function [ 22 , 23 ], support immune development and modulate immune response [ 24 ], affect intestinal cell responses [ 25 ], and prevent the epithelial adhesion of intestinal pathogens [ 26 , 27 ]. HMOs are known to directly bind to epithelial receptors as well as act as soluble decoy receptors by binding to pathogens and toxins, thereby preventing pathogen attachment to mucosal surfaces and reducing infections [ 28 , 29 , 30 ]. The aforementioned selective enrichment of beneficial bacteria, modulation of local immune responses and short-chain-fatty acid (SCFA) production upon HMO consumption could additionally confer protection against pathogen colonization and infection.…”

Fighting Shigella by Blocking Its Disease-Causing Toxin

“… 27 A polyalkyne and a polyazide variant of hPG were prepared for their conjugation by employing the copper-catalyzed alkyne azide cycloaddition (CuAAC) conjugations. In addition to the synthesized compounds, commercially available oligosaccharides such as nontoxic food grade alginate, chitosan, and fructo- and galacto-oligosaccharides [alginate oligosaccharide (AOS), chitosan oligosaccharide (COS), galactose oligosaccharide (GOS), fructose oligosaccharide (FOS)] 28 were tested for Stx inhibition. These could serve as an even more viable practical alternative that could be a part of a preventative food-based approach during outbreaks with a focus on the gastrointestinal phase of the toxin-producing Shigella pathogenicity.…”

In Vitro Evaluation of Dietary Fiber Anti-Infectious Properties against Food-Borne Enterotoxigenic Escherichia coli

“…The beneficial effects of dietary fibers on human health is now well acknowledged, but their ability to exert antagonistic effects against enteric pathogens remain poorly studied [7,36,[45][46][47]. To date, the vast majority of studies investigating the potential of fibers in the fight against ETEC-associated infections have been performed on porcine ETEC strains [48][49][50][51][52], while studies involving ETEC strains from human origins are scarce [28,29,53].…”