Human milk oligosaccharide secretion dynamics during breastfeeding and its antimicrobial role: A systematic review

Table 9 Extended health implications of human milk oligosaccharides antimicrobial effects

Health domain	Extended benefits	Mechanisms involved	Key HMOs
Immune development	Reduced risk of allergies (e.g., eczema, asthma) and autoimmune diseases (e.g., type 1 diabetes, IBD)	Promotes immune tolerance through Tregs; Modulates cytokine balance; Enhances GALT and sIgA production	2′-FL, 3-FL, sialylated HMOs
Gut microbiota programming	Establishes a balanced microbiota; Prevents dysbiosis and infections; Promotes long-term gut health	Selective enrichment of Bifidobacterium species; SCFA production supports gut barrier integrity and pathogen inhibition	2′-FL, 3-FL, LNT
Metabolic health	Reduced risk of obesity and type 2 diabetes; Improved lipid profiles and glucose metabolism; Prevention of metabolic disorders.	SCFA-mediated regulation of energy balance; Early microbiota influence on metabolic pathways	Fucosylated and non-fucosylated HMOs
Cognitive development	Enhanced neurodevelopment and cognitive function; Reduced risk of neurodevelopmental disorders (e.g., ASD, ADHD)	Precursors for gangliosides (myelination and synaptic plasticity); Microbiota-driven production of neuroactive compounds (e.g., serotonin)	Sialylated HMOs (3′-SL, 6′-SL)
Infection resistance	Long-term protection against infections; Reduced reliance on antibiotics, mitigating antibiotic resistance	Early microbial programming enhances innate and adaptive immunity; Pathogen exclusion through SCFA production and microbiota stability	2′-FL, 3-FL, sialylated HMOs
Chronic inflammatory diseases	Lower risk of IBD and systemic inflammation; Reduced incidence of cardiovascular diseases	Strengthens gut barrier integrity; Modulates systemic and intestinal inflammation through cytokine regulation	Fucosylated and sialylated HMOs
Non-communicable diseases	Prevention of type 2 diabetes and colorectal cancer; Improved long-term health outcomes	Anti-inflammatory and anti-carcinogenic effects of SCFAs; Early metabolic programming by microbiota	2′-FL, SCFA-producing HMOs
Neonatal-infant transition	Sustained protection during early dietary diversification; Optimized health outcomes with prolonged breastfeeding practices	Continuous microbiota support during complementary feeding; Long-term resilience against pathogenic exposures	3-FL, LNT

2'-FL: 2'-Fucosyllactose; 3-FL: 3-Fucosyllactose; 6'-SL: 6'-Sialyllactose; ADHD: Attention deficit hyperactivity disorder; ASD: Autism spectrum disorder; GALT: Gut-associated lymphoid tissue; HMOs: Human milk oligosaccharides; IBD: Inflammatory bowel disease; LNT: Lacto-N-tetraose; SCFA: Short chain fatty acids.