Abstract
Early-life colonization of Lactobacillus in the gut is crucial for immediate and lifelong health. The intestinal mucosa is a key interface of host-microbiota interaction, but the colonization patterns of Lactobacillus within this niche remain unclear. In this study, nine newborn piglets per litter (ten litters total) were randomly assigned (three piglets per group per litter; n = 30 per group across all litters) to receive daily oral doses of 2'-fucosyllactose (2'-FL, 100 mg/(kg·d)), galactooligosaccharides (GOS, 1 g/(kg·d)), or saline (control) during the 21 day suckling period. The results revealed significant age-associated shifts in Lactobacillus composition, with the higher Lactobacillus abundance observed during the suckling period and decreasing after weaning (P < 0.05). On postnatal day 8, Lactobacillus delbrueckii was the dominant species, followed by Limosilactobacillus reuteri, Limosilactobacillus mucosae, Lactobacillus amylovorus, and Lactobacillus johnsonii. From days 8 to 21, the levels of L. johnsonii, L. amylovorus, L. mucosae, and L. reuteri notably declined on the jejunal mucosa (P < 0.05), whereas the quantities of L. amylovorus increased on the ileal mucosa (P = 0.001). By day 49, L. mucosae showed a lower level on the duodenal and jejunal mucosa (P < 0.05). Compared with the control group, 2'-FL enriched more Lactobacillus (e.g. L. delbrueckii and L. johnsonii) on the jejunal mucosa on day 21 (P < 0.05), and reduced total Lactobacillus on day 49 (P < 0.05). Relative to 2'-FL, the impact of GOS was less significant (P > 0.05). These results highlight the role of 2'-FL and GOS in selectively modulating the development of intestinal Lactobacillus, offering insights into their potential for regulating mucosal function during critical growth phases. These findings provide a mechanistic basis for targeted prebiotic interventions in neonatal piglets.