Table 2.

Summary of early-life gut microbiome on health and diseases.

Subjects	Baseline Gut Microbiome Composition Compared to Control Group	Intervention	Key Findings of the Study	Reference
Necrotising entercolitis (NEC)
Preterm infants	Proteobacteria most abundant phylum	N.A.	There was a significant change observed in the gut microflora. Increased Proteobacteria, Clostridium, and Bacteroides, and decreasing Staphylococcus and Haemophilus were observed over time	[180]
Full-term vaginal delivered breast-fed infants (FTVDBF) and VLBW preterm infants	Higher levels of Firmicutes and Proteobacteria, and decreased levels of Bacteroidetes and Actinobacteria	N.A.	There was a significant change observed between the full-term vaginal delivered breast-fed infants (FTVDBF) and VLBW preterm infants	[181]
Preterm infants	Lower level of Clostridia	N.A.	There was a significant change observed and this is associated with an increased risk and severity of NEC	[182]
Infants diagnosed with NEC withing first 30 days of life	N.A.	Human milk	Infants who received human milk for >7 days had decreased risk of NEC compared to infants who received human milk for less than 1 week	[183]
Preterm infants	N.A.	Human milk	Total SCFA concentrations were higher for human milk-fed infants than those for preterm-formula milk-fed infants. This is associated with reduced risk of NEC	[184]
		Preterm-formula milk
Very low birthweight infants (VLBW)	N.A.	Human milk	A lower concentration of disialyllacto-N-tetraose in human milk samples received by VLBW infants who developed NEC. Eight infants in the cohort developed NEC (Bell stage 2 or 3)	[185]
Very low birthweight infants (VLBW)	N.A.	Human milk and formula milk (for full feeds) supplemented with probiotic	Bifidobacterium bifidum and Lactobacillus acidophilus is associated with a reduction in the risk of NEC, late-onset sepsis, and mortality irrespective feeding mode	[186]
Preterm babies <32 weeks and VLBW	N.A.	Human milk or formula milk supplemented with S.boulardii	Saccharomyces boulardii supplementation at a dose of 250 mg/day was not effective at reducing the incidence of death or NEC in VLBW infants, it improved feeding tolerance and reduced the risk of clinical sepsis	[187]
Preterm infants	N.A.	Human milk or formula milk supplemented with probiotic	No difference in the incidence of NEC between infants receiving human milk or formula milk supplemented with Bifidobacterium bifidum and Lactobacillus acidophilus and the group that did not receive probiotics supplementation	[188]
Obesity
Termed infants	Bacteroides fragilis	N.A.	Colonization with B. fragilis group was borderline significantly associated with a higher BMI	[189]
Infants	Streptococcus	N.A.	Colonization of Streptococcus was significantly higher in the first months of life and has been associated with higher adiposity and BMI	[190]
Atopy
Newborns with a single or double heredity for atopy	Clostridia	N.A.	Clostridium colonization in neonates is associated with an increased risk of atopic dermatitis	[191]
10 children with IgE-associated eczema and 10 nonallergic children	Ruminococcaceae	N.A.	Relative abundance of Gram-positive Ruminococcaceae was lower at one week of age in infants developing IgE-associated eczema, compared with controls	[192]
2–6 months infants who are breastfed	N.A.	Human milk	Shorter breastfeeding duration was associated with an overall increased risk of eczema	[193]
Healthy term infants at risk of atopy	N.A.	Formula milk	Hydrolysed whey formula supplemented with short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (9:1; 8 g/L) significantly decreased the risk of atopic	[194]
Mother–infant pairs	N.A.	Lactobacillus rhamnosus LPR + Bifidobacterium longum BL999 or Lactobacillus paracasei ST11 + Bifidobacterium longum BL999 for the maternal until delivery. Then babies are breast-fed	The risk of developing eczema during the first 24 months of life was significantly reduced in infants of mothers receiving LPR + BL999 (odds ratio [OR], 0.17; 95% CI, 0.08–0.35; p < 0.001) and ST11+BL999	[195]
Infants	N.A.	Lactobacillus rhamnosus HN001	Maternal supplementation from 35 weeks gestation until 6 months of breastfeeding and infant supplementation until two years with Lactobacillus rhamnosus HN001 reduced the prevalence of eczema	[196]

N.A.: Not applicable.