|M.Sc Student||Adi Seifert|
|Subject||Vehicles for Targeted Delivery to Probiotics in the Human|
|Department||Department of Biotechnology and Food Engineering||Supervisor||Professor Livney Yoav|
|Full Thesis text|
The human gut microbiome is known for its importance to human health. Depending on dietary intake, gut microbiome produces either advantageous compounds providing protection against host disease, or adverse compounds associated with human disease. Therefore, maintaining a healthy proportion of probiotic bacteria (known to confer benefits to the host) in our colon is imperative to our health. An effective way to achieve that is by providing the probiotic bacteria with selective support and supplemental fermentation substrates. Proteins are an important source for amino acids, which are scarce (<0.01mM) in the colon, and needed by probiotic bacteria, as most protein digestion products are absorbed in the small intestine. No existing prebiotic product for gut microbiome modulation contains protein. Herein we developed a novel vehicle for selective targeted oral delivery of growth factors to the probiotic bacteria in the human colon, for enhancing their competitive advantage over undesired microorganisms. The vehicle is composed of Maillard-reaction conjugates of galacto-oligosaccharides (GOS) and lactoferrin, pre-digested by pepsin (LFH). LFH-GOS Maillard conjugates were prepared, comprising 76±1% LFH and 25±4% GOS, and formed self-assembled microparticles of 200-1500 nm. An in vitro simulated digestion experiment showed that a significant portion of the protein in the Maillard conjugates survived both gastric and intestinal digestion, and is therefore expected to reach the colon, and be used by the probiotics. Furthermore, we showed that a probiotic bacterium (B. longum) can utilize the GOS-LFH conjugates as sole carbohydrate and amino acid source. Growth rate on the conjugates was double that on the unconjugated components (0.082 and 0.041 hr-1, respectively). This study introduces the next-generation of prebiotics: peptide containing prebiotics.