The human microbiota plays a vital role in overall health, particularly in influencing immune function, managing inflammation, and reducing disease susceptibility. Recent research has underscored the potential of postbiotics—non-viable microbial cells or their metabolic by-products—as effective tools for supporting gut health, particularly in newborns and children. Postbiotics offer distinct safety advantages over probiotics, such as eliminating the risks of bacterial translocation and overstimulation of inflammation. This makes them especially suitable for vulnerable groups, including preterm infants.
The maternal microbiota contributes significantly to foetal immune development even before birth. Following delivery, the colonisation of the infant gut is influenced by factors such as delivery mode and breastfeeding, which encourage the growth of beneficial bacteria like Lactobacilli and Bifidobacteria. Disruptions to this early microbial environment can lead to inflammation, reduced immune tolerance, and a heightened risk of developing allergies or gastrointestinal disorders.
Postbiotics are defined as non-viable bacteria and their fermentation products, including short-chain fatty acids (SCFAs), vitamins, and other metabolites that positively affect the host. Their beneficial effects occur both locally in the gut and systemically. Locally, postbiotics strengthen the gut barrier by stimulating mucin production, modulate cytokines to reduce inflammation, and exhibit antimicrobial properties that prevent pathogen overgrowth. Systemically, SCFAs such as acetate and propionate regulate metabolism and immune responses in organs beyond the gut, including the liver and muscles.
The advantages of postbiotics are particularly significant in paediatric care. Unlike probiotics, postbiotics pose no risk of bacterial translocation or infection, making them safer for neonates and preterm infants whose intestinal barriers are still developing. Clinical applications of postbiotics demonstrate their effectiveness in improving gut health and immunity. Studies have shown that postbiotics enhance gut barrier integrity and lower inflammatory markers such as faecal calprotectin. They have also been associated with reduced incidences of common infections, including respiratory and gastrointestinal illnesses, in infants supplemented with fermented formulas. Furthermore, postbiotics derived from Lactobacilli strains have been shown to alleviate symptoms of allergic rhinitis and improve tolerance to cow’s milk allergy. In neonatal care, compounds such as butyrate promote intestinal development and may help prevent necrotising enterocolitis (NEC), a serious condition affecting preterm infants.
Evidence supporting these benefits includes studies on fermented infant formulas (FIFs) containing strains such as Lactobacillus paracasei and Bifidobacterium breve. These formulas have demonstrated clinical improvements in immunity, reduced colic, and better stool consistency in infants.
Postbiotics represent a safe and effective supplement for supporting gut health and immunity in children and newborns. Their ability to reduce inflammation, strengthen the intestinal barrier, and improve clinical outcomes makes them particularly valuable for neonates and preterm infants. While the current evidence is promising, further large-scale clinical trials are needed to optimise formulations, determine effective dosages, and establish clear clinical guidelines for postbiotic use in paediatrics.
