Effect of Saccaromyces Boulardii CNCM I-745 Supplementation on the Fecal Resistome of Patients Treated Against Helicobacter Pylori Infection

Antibiotic use is one of the most common therapeutic strategies of modern medicine. Together with the significant beneficial effects of antibiotic use, side effects accompany the use of these drugs, including the increasing appearance of antibiotic-resistant microbes, a global public health problem. Other significant side effects include gastrointestinal-related symptoms such as diarrhea, pain, intestinal discomfort, and flatulence, which can be the consequence of dysbiosis. A common strategy to limit antibiotic-associated side effects is the addition of probiotics, as S. boulardii CNCM I-745 (Sb). The use of bacterial probiotics to reduce antibiotic-associated side effects has several potential limitations, including the destruction of probiotics, development of probiotics strains resistant to antibiotics, and passage of antibiotic-resistant genes to pathogenic bacteria through horizontal gene transfer. Sb is a probiotic yeast whose benefits on intestinal dysbiosis have been associated with establishing a favorable growth environment for the normal intestinal microbiota. Due to the yeast nature of this probiotic, the limitations of bacterial-probiotics cannot be accounted for during Sb use. Consequently, it is crucial to study the molecular mechanism elicited by Sb on intestinal microbiota, including changes in resistome.

In our previous study regarding the supplementation with Sb on the treatment against H. pylori (Hp) infection, patients that received the probiotic had a significantly lower frequency of gastrointestinal symptoms. Additionally, those patients have a higher number of bacterial diversity evenness (P=0.0156), higher abundance of Enterobactereacea, and lower abundance of Bacteroides and Clostridia upon treatment completion and one month later. Bacteroides and Clostridia have been previously implicated as antibiotic multi-resistant pro-inflammatory strains. The objective of the current project is to characterize the resistome of individuals treated with anti-H. pylori therapy in the presence or absence of Sb in fecal samples.

Specific aims To determine the resistome changes before and after Hp eradication treatment in patients that have received or not Sb.

To compare the resistome patterns between patients treated for Hp infection that have received or not SB, at the time of completion of treatment and one month after finishing them.

Based on the shotgun metagenomics, the researchers seek to characterize the microbiome and resistome in fecal samples and understand the microbiome's functional characteristics, including virulence genes, metabolic pathways, and mobile genetic elements.