Probiotic Bacteria and Their Encapsulation Evaluated in Advanced Co-culture Models

It is expected that antimicrobial-resistant bacterial infection is becoming the main cause of death by the year 2050. New strategies for infection control are needed including the development of new antibiotics as well as renewed strategies, such as the use of probiotics. However, in order to study the infection-prone, highly complex ecosystem of the human intestine, a well-defined co-culture model is needed. This thesis describes the use of in vitro co-culture infection models based on transwell and microfluidic devices to evaluate probiotic bacteria for infection control and the possible benefits of their encapsulation. We find that probiotic Bifidobacteria protect intestinal epithelial cells from pathogenic E. coli infection with a delayed TEER-maximum time, a higher cell layer surface coverage and a thicker villi height. In addition, we show that probiotics with an alginate hydrogel encapsulation, a better survival rate in simulated gastric fluidics and antibiotic challenge, which would further operate synergistically with tetracycline in killing the tetracycline-resistant E. coli.