Bifidobacterium animalis, particularly the subspecies B. animalis subsp. lactis, has been investigated for its potential to support or treat colitis, especially in the context of ulcerative colitis and inflammatory bowel disease (IBD). Several clinical and preclinical studies have explored its effects on gut inflammation and mucosal health. Research indicates that B. animalis may help modulate the immune response, reduce inflammatory cytokines, and restore the balance of gut microbiota disrupted in colitis. For example, randomized controlled trials and animal studies have shown that supplementation with B. animalis can reduce colonic inflammation and improve histological markers of disease, though results are variable and sometimes strain-specific. Some multi-strain probiotic formulations that include B. animalis have demonstrated benefit in maintaining remission in ulcerative colitis patients.

However, while there is scientific evidence supporting its use, the overall strength of evidence is moderate, with some limitations. Many studies have small sample sizes, short durations, or combine B. animalis with other probiotics, making it difficult to isolate its specific effects. Additionally, while animal model data are promising, translation to human clinical outcomes remains an area of active research. Systematic reviews and meta-analyses suggest a potential benefit, but call for larger, high-quality human trials to confirm efficacy and optimal dosing. Thus, B. animalis is used with some scientific support, but is not considered a standalone therapy for colitis.