fructooligosaccharide and Food-Hypersensitivity

The WHO refers to human milk as the nutritional gold standard for term infants. Human milk contains many immunomodulatory compounds, including oligosaccharides. Human-milk oligosaccharides can serve as prebiotics because the nondigestible oligosaccharides present in human milk show a clear bifidogenic effect on the gut microbiota. Dietary oligosaccharide structures that have prebiotic effects similar to human-milk oligosaccharides include galacto-oligosaccharides, fructo-oligosaccharides, and pectin-derived acidic oligosaccharides. Both animal studies and human clinical trials showed that dietary intervention with these dietary oligosaccharides in early life could lead to the prevention of atopic dermatitis, food allergy, and allergic asthma. The immune-modulating effects of these oligosaccharides are likely assisted via alteration of the intestinal microbiota or in a microbiota-independent manner by direct interaction on immune cells or both. In this review, an overview of the prebiotic role of dietary oligosaccharides on the microbiota and the microbiota-independent immune modulation by these prebiotics is provided. In addition, recent publications that report on the pathways by which the oligosaccharides might exert their direct immunomodulatory effect are summarized.

Topics: Animals; Asthma; Clinical Trials as Topic; Dermatitis, Atopic; Diet; Food Hypersensitivity; Gastrointestinal Tract; Humans; Immunologic Factors; Infant; Metagenome; Milk, Human; Models, Animal; Oligosaccharides; Prebiotics; Probiotics; Trisaccharides

Fructooligosaccharides (FOS) can change gut microbiota composition and play a protective role in food allergy (FA). Furthermore, the protective mechanism of FOS against FA is unclear. In this study, intestinal flora and tryptophan (Trp) metabolites were investigated in a mouse model with FA supplemented with FOS. Meanwhile, we injected aryl hydrocarbon receptor antagonists (AhR-A) into a mouse model of FA supplemented with FOS to investigate whether T helper cell (Th) 17/regulatory T (Treg) cell balance was affected. Our research studies showed that dietary intake of FOS provided moderate protection from the intestinal inflammation induced by ovalbumin (OVA). This protective effect disappeared in AhR-A mice. The OVA mice manifestations had significantly lower bacterial richness, when compared to the normal control (NC) mice. Among fecal bacteria, the abundance of Akkermansiaceae (family level) and Verrucomicrobia (phylum level) increased and Ruminococcacere (phylum level) decreased in the feces of allergic mice. These changes were reversed by FOS treatment. FOS modulated the gut microbiome profiles that were altered in OVA mice, which showed an increase in the abundance of Ruminococcacere (phylum level) and a decrease in the abundance of Akkermansiaceae (family level) and Verrucomicrobia (phylum level). Liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis of Trp metabolites showed significant reductions in the level of kynurenine (kyn) in the serum of OVA mice, as compared to NC and FOS mice. Conversely, the levels of Trp and 5-hydroxytryptamine (5-HT) were significantly increased in OVA mice. Correlation analysis revealed a negative relationship between the relative abundance of Verrucomicrobiae (class level) and Akkermansiaceae (family level) with kyn, and a positive relationship with 5-HT. FOS significantly reduced interleukin-17A (IL-17A) and retinoic acid-associated nuclear orphan receptor-γt (RORγt) in FOS mice but not in AhR-A mice. FOS increased the level of interleukin-10 (IL-10) and Forkhead box P3 (Foxp3) in FOS mice but not in AhR-A mice. These findings suggest that FOS ameliorates allergic symptoms and impacts Th17/Treg balance in mice by modulating the gut microbiota composition and Trp metabolites. FOS may serve as an effective tool for the treatment of FA by regulating immune and gut microbiota.

Topics: Animals; Disease Models, Animal; Food Hypersensitivity; Male; Mice; Mice, Inbred BALB C; Oligosaccharides; Ovalbumin; T-Lymphocytes, Regulatory; Th17 Cells; Tryptophan

Fructooligosaccharides (FOS) in prebiotic foods can alter intestinal immune responses. The combination of probiotics with oligosaccharides has been reported to alter intestinal flora and suggested to be beneficial against food allergy in humans.. All male Nc/jic mice used in this 8-week study were 6 weeks of age and were allotted to the following three groups: (1) the nonsensitization group; (2) the ovalbumin (OVA) sensitization +5% fructose-containing control food administration group; and (3) the OVA sensitization +5% FOS-containing food administration group. Duodenal tissues were collected and then immunohistochemically stained with monoclonal antibodies to CCR4 and CCR5. The number of mast cells and the villus edema formation rate in the duodenum were determined by image analysis.. The number of CCR4-positive cells increased significantly in Group 2 as compared with Group 1 and tended to decrease in Group 3 as compared with Group 2. Relatively few CCR5-positive cells were observed in the duodenum. FOS tended to reduce the number of CCR4-positive cells but significantly reduced the number of mast cells and the edema formation rate in the duodenum.. This study demonstrated a correlation between the number of CCR4-positive cells and villus edema formation rate. Therefore, FOS, which we inferred to show antiallergic activity for food allergy in this study and which has already been established to be safe for use as food in humans, can be considered to be potentially useful for the prevention of food allergy in pediatric patients with allergy.

Topics: Animals; Anti-Allergic Agents; Cell Count; Disease Models, Animal; Duodenal Diseases; Duodenum; Edema; Food Hypersensitivity; Immunoglobulin E; Male; Mast Cells; Mice; Microvilli; Oligosaccharides; Ovalbumin; Probiotics; Receptors, CCR4; Receptors, CCR5; Receptors, Chemokine; T-Lymphocytes, Helper-Inducer