Investigation on synbiotic interactions between catechin and probiotic bacteria: Aggregation, adhesion, and anti-cancer analyses

Catechin, which has strong antioxidant, antibacterial, and anticancer potential, is one of the most abundant phenolic compounds in nature and in human diet. Probiotic bacteria are defined as microorganisms that confer a health benefit on the host, when administered in adequate amounts. The synbiotic relationship of phenolics and probiotics that are found together in the gastrointestinal tract (GIT) and the effects of synbiotic interaction are not fully understood. This study aimed to investigate the effects of catechin on well-known probiotic bacteria Lactobacillus acidophilus LA-5 (LA-5) and Lacticaseibacillus rhamnosus GG (LGG), and in vitro cytotoxic effects of the combination on colon cancer cells Caco-2. Effects of catechin on bacterial growth, auto-aggregation, co-aggregation, adhesion, antioxidant and anticancer were examined. Results indicated that catechin contributed to the bacterial growth of LA-5. In addition, it enhanced the adhesion property of LA-5 and LGG, auto-aggregation of LA-5, co-aggregation of LA-5 with S. aureus, antioxidant property of LGG. Moreover, LA-5 grown in the presence of catechin led to higher cell death of Caco-2 when compared to control while it did not influence the genotoxicity property of LA-5. However, catechin did not promote the cytotoxicity and genotoxicity properties of LGG. In conclusion, catechin improved many physiological properties of probiotic bacteria and thus, synbiotic relationship of catechin and probiotics may have the potential to formulate new nutraceuticals.