Select Probiotics Exhibit Antioxidative and Anti-Inflammatory Properties for Gut Modulation: In Vitro Analysis

The gut microbiota harbors a complex ecosystem of bacteria that govern host health homeostasis. Alterations to the intestinal environment, known as gut dysbiosis, is associated with several diseases. Targeting the gut with microbiome-engineered therapeutics, such as probiotics, is a promising approach to restore microbial homeostasis and host health. Probiotics can effectively improve the gut environment, although strain-specific mechanisms remain largely unknown. Thus, this study aims to identify beneficial action of select probiotics to modulate the gut environment through antioxidative and anti-inflammatory properties. To this end, we tested the interaction among three probiotic strains – Lactobacillus gasseri A237 (LgA237), Lactobacillus plan-tarum WCFS1 (LpWCFS1) and Lactobacillus fermentum NCIMB 5221 (Lf5221) – and a human intestinal epithelial cell line, HT-29, for adhesion properties, radical scavenging abilities and anti-inflammatory activities. All three probiotics adhere well to HT-29 cells, indicating proper gut colonization. LpWCFS1 demonstrated the greatest adhesion capacity (68.3%), followed by LgA237 (35.5%) and Lf5221 (25.9%). The probiotics also exhibit excellent antioxidant properties via DPPH radical scavenging activity, comparable to quercetin, a known and potent antioxidant. Moreover, LgA237, LpWCFS1 and Lf5221 decrease interleukin-8 expression in lipopolysaccharide (LPS)-damaged HT-29 cells (41.19, 34.53 and 14.80% reduction, respectively), compared to non-treated cells. Further investigation of LpWCFS1 and LgA237 revealed a significant (p<0.0001) reduction in monocyte chemotactic and activating factor (MCAF) protein expression by 63.81 and 60.33%, respectively, in colitis-induced IECs. Overall, our results indicate adhesion, antioxidative and anti-inflammatory therapeutic potential of the tested probiotics through antioxidative and anti-inflammatory activities. These findings may be used to further understand the role of the tested probiotics in treating inflammation that underlies gut-related diseases. Such knowledge is essential for the development and translation of novel, targeted probiotic therapies to beneficially modulate the gut environment and reduce inflammation, improving host health.