Systematic review: effect of probiotics on antibiotic-induced microbiome disruption.

The effectiveness of probiotics in preventing or reversing antibiotic-induced microbiome disruption remains uncertain, and claims of microbiome restoration to its pre-antibiotic state may be overestimated. In this review, we aimed to assess the efficacy of probiotics in preventing or ameliorating disruptions in microbiome composition and function induced by antibiotic treatment. We searched Medline, Embase, and CENTRAL for randomised controlled and non-randomised trials. Participants were individuals of any age who were on systemic antibiotics with a low risk of baseline dysbiosis. The intervention consisted of probiotics during or after antibiotic treatment, compared to placebo, alternative interventions, or no intervention. Outcomes included microbiome composition and diversity analysed using high-throughput molecular methods, alongside microbial function and resistome assessments. Seven studies, reported in eight papers, were reviewed. One study showed probiotics counteracting antibiotic-induced diversity changes, another showed exacerbation of these changes, and four others showed no effect. Effects on taxa abundance ranged from mitigating dysbiosis to selective modulation, no effect, or delayed recovery. One study observed no impact on the resistome, while another reported an increase in antibiotic resistance genes. In conclusion, heterogeneous results preclude a definitive conclusion on the effectiveness of any specific probiotic in restoring antibiotic-exposed microbiomes. For a clearer understanding, future research should be more standardised and long-term, employing advanced methods, such as 16S rRNA gene sequencing and metagenomic sequencing. These studies should strive to include larger, diverse populations to enhance generalisability and clearly define what constitutes a healthy microbiome. Finally, linking changes in the microbiome to specific clinical outcomes is essential for clinical decision making. PROSPERO registration number: CRD42023446214.

The influence of prenatal and intrapartum antibiotics on intestinal microbiota colonisation in infants: A systematic review.

OBJECTIVES: The intestinal microbiota develops in early infancy and is essential for health status early and later in life. In this review we focus on the effect of prenatal and intrapartum maternally administered antibiotics on the infant intestinal microbiota. METHODS: A systematic literature search was conducted in PubMed and EMBASE. All studies reporting effect on diversity or microbiota profiles were included. RESULTS: A total of 4.030 records were encountered. A total of 24 articles were included in the final analysis. Infants from mothers exposed to antibiotics during delivery showed a decreased microbial diversity compared to non-exposed infants. The microbiota of infants exposed to antibiotics was characterised by a decreased abundance of Bacteriodetes and Bifidobacteria, with a concurrent increase of Proteobacteria. These effects were most pronounced in term vaginally born infants. CONCLUSION: Maternal administration of antibiotics seems to have profound effects on the infant gut microbiota colonisation. Interpretation of microbiota aberrations in specific populations, such as preterm and caesarean born infants, is complicated by multiple confounding factors and by lack of high quality studies and high heterogeneity in study design. Further research is needed to investigate the potential short- and long-term clinical consequences of these microbial alterations.