Safety and tolerance of Lacticaseibacillus paracasei N1115 in caesarean-born young children: a randomised, placebo-controlled trial.

The administration of probiotics may help to improve dysbiosis and related health problems in children delivered by caesarean section. However, the effects are strain specific, and safety combined tolerance are considered a priority. The aim of this study was to evaluate the safety and tolerance of Lacticaseibacillus paracasei N1115 in caesarean-born children aged 6-24 months via a randomised, placebo-controlled intervention study. In total, 101 children were included and randomised to receive either a sachet of L. paracasei N1115 (2×1010 cfu/g, 2 g/day) or placebo (maltodextrin, 2 g/day) per day for 12 weeks. Anthropometric parameters were measured by trained nurses, and defecation characteristics, gastrointestinal symptoms, (serious) adverse events ((s)AEs), crying patterns and lifestyle behaviours were recorded by parents or guardians. Neurocognitive development was assessed by the Ages and Stages Questionnaires-3 (ASQ-3) before and after the intervention. The only difference between groups regarding defecation characteristics was a significant treatment × time effect on stool frequency (P=0.007), as the number of defecations was significantly higher in the probiotic group (around 1.2-1.3 times/day) than in the placebo group (around 1.0 times/day) in the later intervention period (P=0.035 at week 9; P=0.048 at week 10; P=0.026 at week 12). The use of L. paracasei N1115 also reduced the incidence rate of constipation (Incidence rate ratio (IRR): 0.120; 95% confidence interval (CI): 0.015, 0.967; P=0.046) and abdominal pain (IRR: 0.562; 95% CI: 0.358, 0.882; P=0.012). Changes in anthropometric parameters, including weight, height and head circumference, did not differ significantly between groups, nor did measures of crying, sleep, outdoor activity, temper, appetite or the ASQ-3 scores. No adverse events associated with consumption of the probiotic were reported. Thus, the administration of L. paracasei N1115 is safe and well-tolerated in caesarean-born children aged 6-24 months. Furthermore, it may ameliorate gastrointestinal function to some extent.