Colon-targeted delivery of live bacterial cell biotherapeutics including microencapsulated live bacterial cells

The Effect of Encapsulating a Prebiotic-Based Biopolymer Delivery System for Enhanced Probiotic Survival

Orally delivered probiotics must survive transit through harsh environments during gastrointestinal (GI) digestion and be delivered and released into the target site. The aim of this work was to evaluate the survivability and delivery of gel-encapsulated Lactobacillus rhamnosus GG (LGG) to the colon. New hybrid symbiotic beads alginate/prebiotic pullulan/probiotic LGG were obtained by the extrusion method. The average size of the developed beads was 3401 µm (wet), 921 µm (dry) and the bacterial titer was 109 CFU/g. The morphology of the beads was studied by a scanning electron microscope, demonstrating the structure of the bacterial cellulose shell and loading with probiotics. For the first time, we propose adding an enzymatic extract of feces to an artificial colon fluid, which mimics the total hydrolytic activity of the intestinal microbiota. The beads can be digested by fecalase with cellulase activity, indicating intestinal release. The encapsulation of LGG significantly enhanced their viability under simulated GI conditions. However, the beads, in combination with the prebiotic, provided greater protection of bacteria, enhancing their survival and even increasing cell numbers in the capsules. These data suggest the promising prospects of coencapsulation as an innovative delivery method based on the inclusion of probiotic bacteria in a symbiotic matrix.

Potential Use of Biotherapeutic Bacteria to Target Colorectal Cancer-Associated Taxa

The role of the gut microbiome in human health and disease is the focus of much attention. It has been widely agreed upon that our gut bacteria play a role in host immunity, nutrient absorption, digestion, metabolism, and other key drivers of health. Furthermore, certain microbial signatures and specific taxa have also been associated with the development of diseases, such as obesity; inflammatory bowel disease; and, indeed, colorectal cancer (CRC), which is the focus of this review. By extension, such taxa represent potential therapeutic targets. In particular, the emerging human pathogen Fusobacterium nucleatum represents an important agent in CRC development and its control within the gastrointestinal tract is desirable. This paper reviews the principal bacterial pathogens that have been associated with CRC to date and discusses the in vitro and human studies that have shown the potential use of biotherapeutic strains as a means of targeting CRC-associated bacteria.

Polymeric carriers for enhanced delivery of probiotics

Probiotics are live microorganisms (usually bacteria), which are defined by their ability to confer health benefits to the host, if administered adequately. Probiotics are not only used as health supplements but have also been applied in various attempts to prevent and treat gastrointestinal (GI) and non-gastrointestinal diseases such as diarrhea, colon cancer, obesity, diabetes, and inflammation. One of the challenges in the use of probiotics is putative loss of viability by the time of administration. It can be due to procedures that the probiotic products go through during fabrication, storage, or administration. Biocompatible and biodegradable polymers with specific moieties or pH/enzyme sensitivity have shown great potential as carriers of the bacteria for 1) better viability, 2) longer storage times, 3) preservation from the aggressive environment in the stomach and 4) topographically targeted delivery of probiotics. In this review, we focus on polymeric carriers and the procedures applied for encapsulation of the probiotics into them. At the end, some novel methods for specific probiotic delivery, possibilities to improve the targeted delivery of probiotics and some challenges are discussed.

Anti-atherosclerotic effect of traditional fermented cheese whey in atherosclerotic rabbits and identification of probiotics

Background

Traditional fermented cheese whey (TFCW), containing probiotics, has been used both as a dairy food with ethnic flavor and a medicine for cardiovascular disease, especially regulating blood lipid among Kazakh. We therefore investigated anti-atherosclerotic effects of TFCW in atherosclerotic rabbits and identified lactic acid bacteria (LAB) and yeasts in TFCW.

Methods

Atherosclerotic rabbits were induced by administration of atherosclerotic diet for 12 weeks and divided randomly into three groups and treated for 4 weeks with Simvastatin (20 mg/kg) or TFCW (25 mg/kg) and (50 mg/kg). In addition, a normal control group and an atherosclerotic group were used for comparison. All drugs were intragastrical administered once daily 10 mL/kg for 4 weeks. Body weight (BW), lipid profiles, C-reactive protein (CRP), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) were tested and theromatous plaques and the number of foam cells and infiltrating fibroblast cells in the thoracic aorta endothelium was evaluated by hematoxylin and eosin stainin. LAB and yeasts were isolated and purified by conventional techniques and identified using morphological and biochemical properties as well as gene sequences analysis.

Results

After 4 weeks of treatment, high and low dose TFCW decreased serum TC, TG, LDLC, CRP, VCAM-1 and ICAM-1 (P < 0.05) compared to atherosclerotic group, and increased HDL-C (P < 0.05) compared to normal controls. Histological analysis showed TFCW reduced VCAM-1 expression and formation of atheromatous plaques on the aortic endothelium of atherosclerotic rabbits.

Conclusion

Seven classes of LBA from two different genera including Lactobacillus brevis, Lactobacillus kefianofaciens, Lactobacillus helveticus, Lactobacillus Casei, Lactobacillus plantarum, Lactobacillus kefiri and Lactococcus lactic as well as 2 classes of yeasts from two different genera including Saccharomyces unisporus and Issatchenkia orientalis were isolated and identified from TFCW. In summary, TFCW, containing 7 classes of LBA and 2 classes of yeasts, has significant anti-atherosclerotic potential in atherosclerotic rabbits and may modulate lipid metabolism and protect aorta in the atherosclerotic condition, which might be related to various probiotics acting through reducing the CRP, VCAM-1 and ICAM-1 levels and protecting the aortic endothelium.