Development of the food supplement Nyaditum resae as a new tool to reduce the risk of tuberculosis development.

Nyaditum resae (NR) is a galenic preparation of heat-killed Mycobacterium manresensis (hkMn). This is a new species that belongs to the Mycobacterium fortuitum complex, and it is present in drinking water-thus, regulatorily speaking, it is considered a food supplement. Preclinical studies in the murine model of active tuberculosis (TB) in the C3HeB/FeJ strain have demonstrated that daily administration of NR containing 103-106hkMn for 14days was able to stop the progression toward active TB [1]. The mechanism of action was linked to the induction of low dose tolerance and was related to the increase of Tuberculin Purified Protein Derivative (PPD) memory-specific Tregs (CD4+CD25+CD39+ cells) after ex vivo incubation of splenocytes for 7days. This increase of Tregs was related to the increase of interleukin (IL)-10 in the spleen and in the reduction of IL-17 in the lungs, where there was also a reduction in bacillary load and the pathology caused by a reduction of neutrophiles' infiltration [2]. Two randomized, double-blind placebo-controlled clinical trials (CTs) have been conducted in humans. The NYADATREG study (Clinicaltrials.gov identifier NCT02076139; 2013-2014) was aimed to evaluate the safety and the immunogenicity of two concentrations of NR (containing 104hkMn and 105hkMn) versus placebo (all administered orally everyday for 14days) in tuberculin-positive and tuberculin-negative volunteers (total n=51). The results demonstrated an excellent safety record, with no differences between groups in terms of adverse effects. A significant increase in PPD-specific memory regulatory T cells was also detected in both NR groups [3]. The NYADAPETRICS study (Clinicaltrials.gov identifier NCT02581579) is evaluating the safety and immunogenicity of NR 105hkMn (capsule format, orally) in the pediatric population. Currently, an efficacy study (randomized, double-blinded, placebo-controlled CT) is being conducted in Georgia. This NYADAGEORG trial includes close contacts of active TB cases with positive sputum not tributaries of chemoprophylaxis (<5-year-old children and HIV-positive individuals), which will receive NR (containing 105hkMn) or placebo (orally, every day for 14days). A total of 3300 participants will be recruited in four medical centers around Tbilissi. The participants are monitored by telephone for up to 2years to evaluate the incidence of active TB. The hypothesis is that the NR group will exhibit a 40% reduction in expected TB incidence. Thus, the anticipated TB incidence will be 3% in the NR group versus 5% in the placebo group. The CT is projected to end by 2021 (Clinicaltrials.gov identifier NCT02897180). The administration of the food supplement NR appears to be a new, easy, safe, and reliable method for reducing the risk of developing active TB, and new CTs must be encouraged to discern the particular efficacy power according to different population characteristics.

RCT Entities:   Population Interventions Outcomes