Oral supplementation with Bifidobacterium longum ssp. infantis and 2'-fucosyllactose revives gut microbiota perturbation and intestinal and immune developmental delay following early-life antibiotic challenge in BALB/c mice.

Probiotics and synbiotics can mitigate the negative health consequences of early-life antibiotic exposure. This study aimed to determine whether supplementation with Bifidobacterium longum ssp. infantis 79 (B79) or synbiotics composed of B79 and 2'-fucosyllactose (2'-FL) could mitigate the negative impact of ceftriaxone exposure in early life. We found that antibiotic-treated mice exhibited lower BW, crypt depth, short-chain fatty acid content, and α-diversity indices at weaning, whereas they had increased relative abundance of opportunistic pathogens (such as Enterococcus and Staphylococcus) and decreased relative abundance of intestinal commensal bacteria. Supplementation with B79 and 2'-FL revived these antibiotic-induced negative effects and reduced the mRNA expression of IL-6, IL-12p40, and TNF-α in the spleen at weaning. Moreover, B79 and 2'-FL supplementation persistently improved crypt depth, propionic acid synthesis, and IgG and secretory IgA production, as well as revived the gut microbiota structure and composition in adulthood. Overall, our study suggests that early-life supplementation with B79 alone or in combination with 2'-FL can mitigate ceftriaxone-induced negative effects on the gut microbiota and intestinal and immune development of mice, and these improvements can partially last into adulthood.