Prebiotics: The Functional Food for Immunity

Highlights :

• Exposing a child to a group of children in daycare or school predisposes them to the infections prevailing in the group.
• Respiratory and gastrointestinal infections are common causes of sickness in daycare children.
• Prebiotics help build a robust immunity in a child by modulating the intestinal microbiota, resulting in fewer fever bouts.

Parents in developed economies often send their newborns and young children to daycare. However, it is widely established that daycare attendance increases infection risks with the number of children in a group.¹ Here, we’ll focus on what evidence suggests about supplementing kindergarten children’s nutrition with prebiotics and why that’s important.

Respiratory and gastrointestinal infections (GIs) are common causes of illness in newborns and young children in daycare, especially in developed countries. Infectious disorders explain at least 89% of illness-related absenteeism from a daycare center, with respiratory infections accounting for 60-70%. ¹ The risk of infection increases with the number of children in a ¹ In this context, the article will focus on supplementing kindergarten children with prebiotics and their effect on immunity and infections.

The first three years of life are critical for developing many organs and the immune system.¹ Acute infections in preschool children cause parents to seek medical help, significantly increasing medical expenditures and workday losses, and thus are a global public health concern. Effective preventive treatments can potentially reduce the burden and expenses for healthcare systems.²

Prebiotics: The diet-friendly ingredient for Children

The human gut microbiota actively interacts with the host, impacting metabolism and intestinal and immune system function.^2,3 Prebiotics are dietary components that aim to improve health (refer to figure 2) and reduce the risk of illness by targeting human-associated bacteria. These non-digestible dietary substances selectively encourage the production and activity of a restricted number of colon bacteria.²

MoA of prebiotics-

Prebiotics act as a substrate for commensal bacteria producing short-chain fatty acids (SCFA) and other metabolites in the intestine. They subsequently act on local and systemic immune cells and gut-associated epithelial cells, predominantly via G-protein-coupled receptor-mediated pathways.⁴

Prebiotics can also elicit a microbiota-independent impact by directly acting on the gut-associated epithelium and innate immune cells via Toll-like receptors. The cumulative effect results in epithelial barrier integrity and innate immunity regulation via pro- and anti-inflammatory cytokine release, macrophage polarization and function shifts, neutrophil recruitment and migration, dendritic cell, and regulatory T-cell development.⁴

Figure 2 shows the health benefits of prebiotics.

HMOs: Human milk oligosaccharides; GI: Gastrointestinal

Figure 2. Advantages of prebiotics supplementation in infants. (Adapted^1-3)

A 9:1 blend of short-chain galacto-oligosaccharides and long-chain fructooligosaccharides (scGOS/lcFOS) has been proven to support immune development by affecting the gut flora. It lowers the incidence and severity of upper respiratory tract infections (URTIs) in healthy infants.¹

Clinical evidence supporting the effects of prebiotics

Table 1. Studies showing the positive impact of prebiotics in reducing infections

Figure 3 compares the microbiota composition of the prebiotic and placebo groups before and after the antibiotic therapy.

Figure 3. Prebiotic and placebo microbiota composition in children at baseline (A) and following antibiotic therapy (B).

*GUM:Growing-up milk; scGOS: Short-chain galactooligosaccharides; lcFOS: Long-chain fructooligosaccharides; LCPUFA: long-chain polyunsaturated fatty acids; CI: Confidence interval