What is a common antibiotic used in ARE and its rationale?

• A. Tylosin or metronidazole; they modulate gut flora and inflammation and are given for 2–4 weeks to assess response.
• B. Acyclovir for antiviral effect.
• C. Ceftriaxone for kidney infection.
• D. Penicillin G for immediate neutropenia.

Answer: (A)

In ARE, a chronic enteropathy is defined by improvement in GI signs when an antibiotic is tried, reflecting a bacterial or inflammatory driver that responds to gut-targeted therapy. A common choice is tylosin or metronidazole, given for about 2–4 weeks to see if there is a clinical response. Tylosin, a macrolide, helps by modulating the gut microbiota and exerting anti-inflammatory effects in the intestinal tract. Metronidazole helps reduce anaerobic bacteria and also has anti-inflammatory properties, which can be beneficial in this context. If there’s a positive response, it supports the diagnosis of antibiotic-responsive enteropathy and guides ongoing management. The other options don’t fit this scenario: acyclovir is an antiviral not used for ARE; ceftriaxone is an IV antibiotic aimed at systemic infections like kidney infections; Penicillin G is not used for neutropenia-related GI issues.