Polyclonal antibodies and probiotics improve immune dysfunction in a mouse model of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic digestive disorder caused by the overactivity of the mucosal immune system in response to natural intestinal bacteria and environmental factors, affecting genetically susceptible individuals. This research investigates the preventive effect of probiotics (P), specifically Lactobacillus fermentum, Lactobacillus L. reuteri, and polyclonal antibodies (AB), on morphological changes and markers of intestinal inflammation in the IBD mice model. Our study spanned 54 days. For the first 21 days, we observed microbial populations and immunoglobulin levels. Then, we induced chronic inflammation over three 11-day cycles. In each cycle, subjects received 2% dextran sulfate sodium (DSS) for 4 days, followed by 7 days of normal water. 75 C57BL/6 mice have been used in 5 groups: DSS, control, DSS + P, DSS + AB, and a combined treatment group of antibodies and probiotics (DSS + ABP). Throughout the study period, clinical symptoms were monitored, and morphological changes and histological scores were assessed after the course. Levels of IBD biomarkers in serum such as nitrite, malondialdehyde enzyme (MDA), and myeloperoxidase enzyme (MPO), were measured along with alterations in cytokines Tumor Necrosis Factor-alpha (TNF-α), interleukin (IL)-4, IL-6, and IL-22, IgA and IgG in the blood serum. Results showed that All treatment groups, significantly reduced the Disease Activity Index (DAI), total histological score and oxidative stress markers MDA and MPO compared to the DSS group (p < 0.05). Additionally, the oral administration of polyclonal antibodies increased mucosal immunoglobulin levels, helping to prevent the rise in serum immunoglobulin levels and the associated increase in IL-4 (p < 0.05). Meanwhile, treatment with probiotics significantly (p < 0.05) reduced inflammation by modulating cytokine levels (TNF-α and IL-6). In conclusion, the co-administration of probiotics and polyclonal antibodies effectively mitigates IBD progression by synergistically improving histological parameters and regulating systemic immune responses, offering a more potent preventive strategy than individual treatments.