Fecal human β-defensin-2 (hBD-2) levels and gut microbiota patterns in preterm neonates with different feeding patterns

BACKGROUND AND OBJECTIVES: Human β-defensin-2 (hBD-2) is an essential antibacterial peptide involved in innate immunity and is expressed in breast milk and intestinal mucosa. The aim of this study was to investigate fecal hBD-2 levels and gut microbiota in preterm neonates with different feeding patterns. MATERIALS AND METHODS: This study was cross-sectionally designed and included 44 preterm neonates categorized into four groups as follows: breast milk only, breast milk predominant, formula milk predominant, formula milk only. The study was conducted at the Neonatology Ward, National Center Hospital Cipto Mangunkusumo, Jakarta from November 2016 to April 2017. hBD-2 levels were measured by ELISA. Intestinal bacteria were quantified by qPCR. RESULTS: hBD-2 levels were significantly different between groups (one-way ANOVA, p=0.004) and the highest value of hBD-2 was found in the formula milk predominant group (344.87±61.2 ng/mL). hBD-2 levels were positively correlated with feeding pattern (Spearman correlation test, p=0.009, r=0.391). There were no significant differences in the total number of specific intestinal microbiota (Bifidobacterium, Lactobacillus and Klebsiella) among groups (one-way ANOVA, p>0.05). Interestingly, the formula milk only group had the highest amount of Klebsiella compared with other groups. hBD-2 levels were not correlated with the quantity of Bifidobacterium, Lactobacillus and Klebsiella (Pearson correlation test, p>0.05). CONCLUSION: hBD-2 levels were significantly higher in the formula milk predominant group compared with the breast milk only group. Gut microbiota patterns showed that Bifidobacterium and Lactobacillus were higher in the breast milk only group, while Klebsiella was higher in formula milk group, although this difference was not statistically significant.