High blood sugar changes how a natural immune peptide called LL-37 works in immune cells. In normal cells, more sugar lowers LL-37, while in cells infected with TB, more sugar actually raises LL-37 but also lets the bacteria grow more. This suggests that blood sugar control matters for TB risk in diabetics, and LL-37 might become a marker for disease progression, but it’s not ready for any DIY treatment yet.

Diabetes mellitus (DM)-2 patients have an increased susceptibility to develop pulmonary tuberculosis; this is partly due to the impairment of the innate immunity because of their higher glucose concentrations. In the present study, we determined the effect of the glucose concentrations in the LL-37 expression in infected and non-infected macrophages. Our results showed that the increasing glucose concentrations correlates with the low cathelicidin expression in non-infected cells, however in Mycobacterium tuberculosis infected cells, LL-37 expression was substantially increased in higher glucose concentrations, nevertheless the mycobacterial burden also increased, this phenomena can be associated with the cathelicidin immunomodulatory activity. Further evaluation for LL-37 needs to be done to determine whether this peptide can be used as a biomarker of tuberculosis progression in DM2 patients.