Effect of Lactobacillaceae Probiotics on Colonic Microbiota and Metabolite Production in Cystic Fibrosis: A Comparative In Vitro Study.

Cystic Fibrosis-related gut dysbiosis (CFRGD) has become a recognised complication in children with this condition, and current evidence remains insufficient to guide the selection of probiotic strains for supplementation treatments. The aim of this study was to characterise the effect of three probiotic strains on CFRGD by means of a dynamic in vitro simulation of the colonic fermentation (SHIME). The configuration of the system included three bioreactors colonised with the faecal inoculum of a child with cystic fibrosis. For 20 days, each bioreactor was supplied daily with either (ATCC 53103 TM), (DSM 17938) or (DSM 22266). The baseline microbiota was characterised by a high abundance of , and genera. After 20 days of supplementation, and reduced significantly, and the three strains led to increased and and decreased , with some of these changes being maintained 10 days after ceasing supplementation. The metabolic activity remained unaltered in terms of short-chain fatty acids, but branched-chain fatty acids showed a significant decrease, especially with . Additionally, ammonia decreased at 20 days of supplementation, and lactate continuously increased with the three strains. The effects on colonic microbiota of , or were established, including increased beneficial bacteria, such as , and beneficial metabolites such as lactate; and on the other hand, a reduction in pathogenic genera, including or and branched-chain fatty acids, overall supported their use as probiotics in the context of CFRGD.