Shaping the Infant Microbiome With Non-digestible Carbohydrates

Abstract

Natural polysaccharides with health benefits are characterized by a large structural diversity and differ in building blocks, linkages, and lengths. They contribute to human health by functioning as anti-adhesives preventing pathogen adhesion, stimulate immune maturation and gut barrier function, and serve as fermentable substrates for gut bacteria. Examples of such beneficial carbohydrates include the human milk oligosaccharides (HMOs). Also, specific non-digestible carbohydrates (NDCs), such as galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS) are being produced with this purpose in mind, and are currently added to infant formula to stimulate the healthy development of the newborn. They mimic some functions of HMO, but not all. Therefore, many research efforts focus on identification and production of novel types of NDCs. In this review, we give an overview of the few NDCs currently available [GOS, FOS, polydextrose (PDX)], and outline the potential of alternative oligosaccharides, such as pectins, (arabino)xylo-oligosaccharides, and microbial exopolysaccharides (EPS). Moreover, state-of-the-art techniques to generate novel types of dietary glycans, including sialylated GOS (Sia-GOS) and galactosylated chitin, are presented as a way to obtain novel prebiotic NDCs that help shaping the infant microbiome.

Effects of Human Milk Oligosaccharides on the Adult Gut Microbiota and Barrier Function

“…HMOs are best known for their prebiotic effects in breast-fed infants, where they exert a strong bifidogenic effect, characterized by the proliferation of Bifidobacterium infantis, B. breve, or B. bifidum strains [12]. HMO metabolism into short chain fatty acids (SCFAs) in infants has drawn a lot of attention in recent years [13][14][15]. HMOs, through cross feeding with butyrate-producing bacteria, induce butyrate production in the colon [16], an essential SCFA metabolite in the human colon.…”

Fermentation of Chicory Fructo‐Oligosaccharides and Native Inulin by Infant Fecal Microbiota Attenuates Pro‐Inflammatory Responses in Immature Dendritic Cells in an Infant‐Age‐Dependent and Fructan‐Specific Way

“…These formula are supplemented with nondigestible carbohydrates (NDCs) such as galacto-oligosaccharides and inulin to mimic the health effects offered by HMOs. [7,8] A class of NDCs, commonly used in infant formulas are inulin-type fructans. Inulin-type fructans are generally isolated from chicory roots and composed of linear chains of (2-1)-linked fructose monomers with varying degree of polymerization (DP).…”

The Impact of Dietary Fucosylated Oligosaccharides and Glycoproteins of Human Milk on Infant Well-Being

“…In contrast to the main milk sugar lactose, which is broken down in the small intestine by lactase into simple sugars, HMOs and the glycan part of glycoproteins are not digested and pass through the gastrointestinal tract of breastfed newborns [83,84]. In the lumen of the intestine, non-digestible milk oligosaccharides contribute to human health by shaping the newborn's microbiome and inhibit colonization by pathogenic bacteria [5,9,[84][85][86]. However, some species, namely bifidobacteria, are able to utilize HMOs and glycans of milk glycoconjugates [85,[87][88][89].…”

“…The mechanism of anti-bacterial and anti-viral activity of fucosylated HMOs is based on the structural similarity of individual HMOs to sugar chains of glycoproteins present on the surface of neonatal/infant epithelial cells. Thanks to this, HMOs "mimic" surface glycans of epithelial cells [5,9,50,86]. Soluble fucosylated human milk oligosaccharides "passing" through the newborn's digestive tract "rinse" the epithelial cells of the throat, esophagus and intestines of the newborn and can be recognized and bound by (1) fucose-specific lectin receptors present on the surface of host epithelial cells and/or via (2) lectin receptors of fucose-dependent bacteria.…”