Table 1.

Potential benefits of probiotics, prebiotics, synbiotics and fibre on different life stages.

Life Stage	Probiotics	Prebiotics/Oligosaccharides	Synbiotics	Fibre
Pregnancy/Lactating Mother	—Reduce incidence of aGDM [37] —Reduce risk of preeclampsia [40,41,42] —Lower risk of preterm delivery [42] —Prevent infectious mastitis [44] —Reduce incidence of bacterial vaginosis [43] —Alter immunologic composition of breast milk [56,57]	—Reduce abundance of faecal Bacteroides in women with GDM [34] —Alter immunologic composition of breast milk [60]	—Decrease serum insulin levels and positively influence other insulin actions [35] —Reduce blood pressure in women with GDM [36] —Alter immunologic composition of breast milk [61] —Positively impact mineral levels in breast milk [62]	—Reduce abundance of faecal Bacteroides in women with GDM [34]
Infant	—Reduce risk of all-cause mortality, bNEC ≥ Stage II, late onset sepsis and feeding intolerance in preterm infant [69] —Increase faecal bifidobacteria, reduce Proteobacteria and Clostridia in breast-fed caesarean born infants [84] —Treat infant colic in breast fed infants [88]	—Decrease incidence of mortality, sepsis, hospital stay duration and time to full enteral feeding in preterm infant [78] —Soften infant stool in formula-fed healthy infants [89]	—Reduce incidence of NEC in preterm infant [80,81,82] —Reduce incidence of sepsis in preterm infants [81] —Increase stool frequency in formula-fed infants [90] —Beneficially modulate gut microbiota, reduce incidence of ear infections and use of dermatological medication in infants with non-cIgE-mediated cow’s milk allergy on amino acid based formula [91] —Reduce infantile crying and colic, functional constipation and daily regurgitation in infants on starter formula [92] —Reduce cumulative incidence of lower respiratory tract infections in weaned infants [93] —Beneficially modulate gut microbiota in caesarean born infants [94]
Adult–Physical Activity	—Improve immunity [147,151,153,161,164] —Reduce incidence of dURTI [147,151,159,164] —Relieve morbidity and symptoms of URTI [153] —Reduce severity of gastrointestinal illness and reduce load of lower respiratory illness symptoms in male competitive cyclists [156] —Reduce number of athletes experiencing URTI and reduce number of illness days [158] —Reduce duration of URTI [160] —Decrease fatigue accumulation during consecutive high intensity exercise [153] —Reduce exercise-induced tryptophan degradation rates [159] —Improve endurance performance [165] —Alleviate oxidative stress, increase plasma-branched amino acids and elevate exercise performance [166]		—Reduce plasma endotoxin unit levels, maintain intestinal permeability, reduce gastrointestinal symptoms [167] Note: Study used probiotic/prebiotic antioxidant intervention.
Adult–Stress	—Decrease anxiety symptoms in eCFS patients [189] —Relieve psychological stress in healthy volunteers [191] —Reduce Black Depression Inventory scores in individuals with major depressive disorder [192] —Reduce postpartum depression symptoms [193] —Reduce salivary cortisol and plasma tryptophan levels in healthy medical students at examination time and increase faecal serotonin levels after exams [194] —Reduce rate of subjects experiencing abdominal and cold symptoms and number of days of such symptoms in pre-exam period [194] —Beneficially modulate gut microbiota [189]	—Improve anxiety scores in individuals with fIBS [196,198] —Beneficially modulate gut microbiota [196,198] —Reduce salivary cortisol awakening response in healthy volunteers [197] —Decrease attentional vigilance to negative versus positive information in a dot-probe task [197]
Elderly	—Improve immunity [121,122] —Beneficially modulate gut microbiota [122,123,124,125,126,127]	—Beneficially modulate gut microbiota [128,129] —Immunomodulation [129] —Improve exhaustion and handgrip [132] —Reduce frailty index levels [133]	—Beneficially modulate gut microbiota, improve innate immunity and reduce total and gLDL-cholesterol [134]	—Improve bowel function, improve nutrient density of diet [119]

^aGDM, gestational diabetes mellitus; ^bNEC, necrotizing enterocolitis; ^cIgE, immunoglobulin E; ^dURTI, upper respiratory tract infection; ^eCFS, chronic fatigue syndrome; ^fIBS, irritable bowel syndrome; ^gLDL, low density lipoprotein.