Is Probiotic Supplementation During Pregnancy Safe for Healthy Populations? A Systematic Review of Preclinical Studies

Gut-brain axis and probiotics supplementation during gestational period have gained an especial attention in the field of neurodevelopmental disorders. However, the influence of prenatal probiotics in physiology and neurodevelopment of healthy organisms is widely unexplored and probiotics are commercially such as dietetic supplementations without the necessity of ensuring safety in healthy organisms, as is required for drugs. The aim is to present and discuss the various biochemical, developmental and behavioral effects that prenatal probiotics have on the offspring of healthy organisms in rodent models and assess their security during gestation. We included a total of 15 preclinical studies discarding all those that did not have an appropriate control for the probiotic-treated group. Results suggest that probiotics, particularly Lactobacillus strains, influenced anxiety-like behaviors in mice and GABAergic system maturation, showing an apparent biphasic effect, reducing GABA functioning in early life but increasing them in later stages; and both prenatal Lactobacillus and Bifidobacterium, influenced microbiota and general development of healthy organisms. However, the significant variations in methodologies used across studies complicate the ability to elucidate specific conclusions related to bacterial strains or doses. Further research is imperative to ensure the safety and regulation of probiotic interventions, particularly during the gestational period.