TABLE 3.

Proposed strengths and limitations of MET as HDT for TB therapy.

Strengths	Limitations
Suitable for Phase II clinical trials	Lack of biological plausibility
Known toxicity profile and cheap	Limited knowledge on cellular interactions in the presence of anti-TB therapy
Potential to shorten the standard anti-TB regimen	Limited knowledge on the interaction with resistant TB strains
Decreased risk of TB in patients with diabetes mellitus
Potential to limit TB mortality
Increased probability of 2 months sputum culture conversion
Enhancing macrophage effector mechanisms
Decreasing inflammation and/or averting lung damage

HDT, host-directed therapy; MET, metformin; TB, tuberculosis.