Year: 2026
Type: article
Abstract: BACKGROUND Gut microbiota dysbiosis plays an important role in functional gastrointestinal disorders. While the effectiveness of Limosilactobacillus reuteri (L. reuteri ) DSM 17938 has been evidenced in several pediatric gastrointestinal conditions, its effects on gut microbiota modulation in exclusively breastfed infants remain unclear. AIM To evaluate the effect of L. reuteri DSM 17938 supplementation on gut microbiota diversity and gastrointestinal symptoms in healthy, exclusively breastfed infants. METHODS Healthy, term infants born at King Chulalongkorn Memorial Hospital (March 2024 to January 2025) were randomized to receive L. reuteri DSM 17938 or a placebo, five drops daily for up to 8 weeks. Fecal samples were collected at 1, 2, and 4 months. The stool microbiota was characterized using 16S rRNA sequencing (Nanopore technology) to assess taxonomic classification, microbial diversity, and relative abundance. RESULTS Stool samples from 34 exclusively breastfed infants (17 receiving probiotics, 17 placebo-treated) were analyzed. Baseline characteristics and gastrointestinal symptoms were comparable between groups. Gut microbiota diversity significantly differed with the mode of delivery during the first two months; a higher alpha diversity was observed in neonates born through normal delivery than in babies born through cesarean section (P = 0.028) (Chao 1 index, P = 0.07 and Shannon index, P = 0.01). By 2 months, the probiotic-treated group showed greater alpha diversity than the placebo, particularly in infants born by vaginal delivery (Chao 1 index, P = 0.38 and Shannon index, P = 0.05). In addition, beta diversity differed significantly between the groups (P = 0.04). However, no significant differences in alpha- or beta-diversity were observed at the 4-month time point. Probiotic supplementation was associated with an increased relative abundance of Bifidobacterium , regardless of delivery mode. Higher abundances of Parabacteroides and Hungatella hathewayi were observed in infants born via normal delivery or cesarean section, respectively. No differences in gastrointestinal symptoms were detected. CONCLUSION L. reuteri DSM 17938 supplementation during early infancy induced modest and transient changes in gut microbiota composition, particularly increasing Bifidobacterium abundance, without sustained microbiota alterations or significant effects on gastrointestinal symptoms.
DOI: 10.5409/wjcp.122122
Language: English
Subfield: Food Science
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W7165031343