Probiotic treatment of inflammatory bowel disease: Its extent and intensity

Abstract

Free radicals (reactive oxygen species, superoxides and hydroxyl radicals) lead to the development of oxidative stress because of imbalance in the amount of antioxidants. Continued development of oxidative stress leads to chronic diseases in humans. The instability in the antioxidant activities and accumulation of oxidative stress due to free radicals may occur in diseases like inflammatory bowel disease (IBD). Antioxidants are substances that inhibit or delay the mechanism of oxidation of molecules mediated by free radicals and also transform into lesser-active derivatives. Probiotics are defined as live microorganisms that show beneficial effects on inflamed intestine and balance the inflammatory immune responses in the gut. Probiotic strains have been reported to scavenge hydroxyl radicals and superoxide anions that are abundantly produced during oxidative stress. The most widely studied probiotic strains are Streptococcus, Bifidobacterium and Lactobacillus. Probiotics cultured in broth have shown some amount of antioxidant activities. Fermented milk and soy milk, which possess starter microorganisms (probiotics), tends to increase the antioxidant activities many-fold. This review aims to discuss the in vivo and in vitro antioxidant activities of specific probiotics with various assays with respect to IBD.

Keywords: Oxidative stress, Inflammatory bowel disease, Probiotics, Therapy, Anti-oxidative activity

Core tip: Inflammatory bowel diseases (IBDs) are degenerative diseases that cause chronic inflammation in the intestine. The most prevalent therapy for IBD is conventional antibiotic therapy. Keeping the adverse effects of antibiotics in mind, researchers have shown that Streptococcus, Lactobacillus and Bifidobacterium are some of the most efficient antioxidative agents with respect to in vitro and in vivo activities. Probiotics individually or in combination play an important role in regulating superoxide dismutase activity, which is always dysregulated due to oxidative stress caused in IBD. The mechanism of antioxidation of probiotics using NRf2-antioxidative response element pathway, nuclear factor-B and protein kinase C pathway may be activated to contribute to the reduction of oxidative-stress-induced IBD. The review focuses on the antioxidative activities of the specific bacterial strains as therapeutic molecules in IBD. Multiple combinations of probiotic strains have still not been adequately studied. We are currently researching the antioxidative effect of Streptococcus thermophilus, Lactobacillus acidophilus and Bifidobacterium bifidumin combination.