The use of bacteria—specifically, probiotic bacteria—to support or treat enteritis is scientifically validated. Enteritis, an inflammation of the small intestine, can be caused by infections, autoimmune reactions, or other factors. Probiotics, such as Lactobacillus and Bifidobacterium species, have been studied for their role in modulating gut microbiota and enhancing intestinal barrier function. Multiple randomized controlled trials have demonstrated that certain strains of probiotics can reduce the severity and duration of infectious diarrhea, a common symptom of enteritis, particularly in children and in hospital-acquired cases. Meta-analyses support the efficacy of probiotics in reducing the risk of antibiotic-associated diarrhea and Clostridioides difficile infection, both of which can present as enteritis.

The mechanisms underpinning these effects include competitive inhibition of pathogenic bacteria, production of antimicrobial substances, enhancement of mucosal immunity, and restoration of normal gut flora disrupted by infection or antibiotics. Clinical guidelines, such as those from the World Gastroenterology Organisation, recommend specific probiotic strains as adjunctive therapy for various forms of enteritis, especially in pediatric and immunocompetent populations. However, efficacy can be strain-specific, and not all probiotics have demonstrated benefit. While not a primary treatment for severe or complicated cases, the use of probiotic bacteria is well-supported as an adjunct therapy for certain forms of enteritis.