The modulation of the gut microbiome during a multispecies probiotic intervention in compensated cirrhosis

Liver cirrhosis is accompanied by significant changes of the intestinal microbiome including the regression of beneficial and autochthonous taxa. Probiotics are said to modulate the microbiome and have been shown to be beneficial in cirrhosis patients. However, their effect on the microbiome in cirrhosis has not been comprehensively studied yet. Therefore, the aim of this study was to test the effects of a multispecies probiotic on gut microbiome composition in compensated cirrhosis. Gut microbiome composition of 58 patients with Child's A cirrhosis who received a daily dose (1.5*10 10 CFU) of a multispecies probiotic or placebo for six months was analysed by 16S rRNA gene sequencing. Gut barrier function was assessed with faecal zonulin measurements. Microbiome composition of patients was enriched with probiotic strains Lactobacillus salivarius , Lactobacillus brevis and Lactococcus lactis . Furthermore, the abundance of Faecalibacterium prausnitzii , Syntrophococcus sucromutans, Bacteroides vulgatus, Alistipes shahii and a Prevotella species was increased in the probiotic group compared to the placebo group. Patients with modulated microbiome compositions also showed a significant decrease in faecal zonulin levels after intervention which was not observed in patients with unchanged microbiome compositions [-18.8 (IQR = 23.4) vs. +4.7 (IQR = 37.0)ng/mg, p = 0.012]. Changes in several different strains of the species Bacteriodes vulgatus could be observed in both groups. In conclusion, a six months intervention with a multispecies probiotic enriched the microbiome of cirrhotic patients with probiotic bacteria and beneficially modulated the gut microbiome and gut barrier function. Changes in the abundance of Bacteriodes vulgatus , a starch-utilizing bacterium, might be a reaction to the product matrix that was also used as placebo, and should be observed in the future development of probiotic formulations.