The human gut microbiome, crucial for health, can be disrupted by antibiotic treatment, leading to various health issues and the rise of antimicrobial resistance (AMR). This study investigates the impact of a probiotic on the gut microbiome’s composition and antimicrobial resistance genes (ARGs) content following antibiotic treatment. Conducted as a single-centre, double-blind, randomized, placebo-controlled trial, adults taking oral antibiotics were allocated into a probiotic or placebo group. Evaluations included viable cell enumeration and shotgun metagenomic sequencing for microbiome analysis, along with ARG assessment. The probiotic maintained the numbers of lactobacilli, significantly increased the Bacteroides population and decreased numbers of enterobacteria. The lactobacilli and enterococci numbers decreased in the placebo. The alpha diversity remained stable in the probiotic group throughout the study, but significant reductions were observed in the placebo group post antibiotic treatment. There was significant spatial separation in beta diversities between groups at the end of the study. Compared to baseline levels, there was a significant reduction in the abundance of ARGs in the probiotic group at the end of the study, while ARG abundance in the placebo group was comparable with baseline levels at the end of the study. Co-occurrence network analysis observed consistent betweenness centrality and node degree within group in the probiotic group whereas scores decreased in the placebo group. This study suggests that the probiotic may minimize the disruption of antibiotic treatment on the gut microbiome by preserving microbial diversity and reducing ARG abundance.

The effects of probiotics on the gut microbiota and microbial metabolites in healthy individuals are not well understood. Faecal and serum samples were collected at the start and end of a 3-month, double-blind, placebo-controlled, randomised study with three different probiotic formulations in free-living, healthy adults. The composition of the faecal microbiota and levels of faecal and/or serum short-chain fatty acids (SCFA) and bile acids (BA) were measured and the probiotic formulations were found to impart differing effects including shifts in the composition and structure of the faecal microbiota, enhanced levels of circulating short chain fatty acids such as butyrate and propionate, and elevated levels of sulphated bile acids in faeces. This was in contrast to the outcomes for the placebo population where very little change occurred over the study. These findings demonstrate that probiotic supplementation elicits formulation specific effects and that there are potential benefits for healthy individuals.

The gut microbiota is a vast community of microorganisms that forms part of a complex communication network linking the gastrointestinal tract with the immune system and central nervous system.1 Th...

Early-life establishment of the gut microbiota plays a role in lifelong health, with disruptions linked to heightened risks of metabolic and immune disorders. Probiotic supplementation may be used to modulate the infant gut microbiome to promote favourable development. Here, we evaluate how Lab4B probiotic supplementation shapes the development of the infant gut microbiome over the first 6 months. Faecal samples collected from infants enrolled in PROBAT (ISRCTN26287422), a randomised, double-blind, placebo-controlled trial, were analysed using culture-dependent and -independent (16S rDNA and metagenomic shotgun sequencing) techniques to examine the composition, diversity, and metabolic capabilities of the microbiome, as well as the abundance of antimicrobial resistance genes (ARGs). Probiotic supplementation encouraged the development of a microbiome with a distinct composition characterised by elevated abundances of Bifidobacteriaceae in the first 6 weeks (p = 0.006) and Lactobacillaceae throughout the first 6 months (p < 0.05 at every 6-week time point), accelerated microbial diversification, reduced abundance of beta-lactam- and cephalosporin-resistance genes, and differences in predicted metabolic capabilities at the start and end points. Supplementation of this neonatal population, which is at high risk of atopy, with the Lab4B probiotic significantly influenced the development of the infant gut microbiota during the first 6 months.

Early-life gut microbiota establishment plays a role in lifelong health, with disruptions linked to heightened risks of metabolic and immune disorders. Probiotic supplementation may be used to modulate the infant gut microbiome to promote favourable development and here we evaluate how Lab4B probiotic supplementation shapes infant gut microbiota development over the first six months. Faecal samples collected from infants enrolled in the PROBAT (ISRCTN26287422) randomised, double-blind, placebo-controlled trial were analysed using culture-dependent, and independent (16S rDNA and metagenomic shotgun sequencing) techniques to examine the composition, diversity, antimicrobial resistance gene (ARG) abundance, and metabolic capabilities of the microbiotas. Probiotic supplementation encouraged the development of a distinct microbiota composition: characterised by elevated abundances of Bifidobacteriaceae in the first 6 weeks (p = 0.006) and Lactobacillaceae throughout the first 6 months (p < 0.05 at every 6-week time point), accelerated microbial diversification, reduced abundance of beta-lactam and cephalosporin resistance genes and differences in predicted metabolic capabilities at start and end points. Supplementation of this high atopy risk neonatal population with the Lab4B probiotic significantly influenced the development of the infant gut microbiota during the first 6 months.