Probiotics have been reported to ameliorate symptoms of type 2 diabetes mellitus (T2DM) in animal models and human studies. We previously demonstrated that oral administration of Lactobacillus reuteri ADR-3 reduced insulin resistance in high-fructose-fed (HFD) rats. In the present study, we first identified another L. reuteri strain, ADR-1, which displayed anti-diabetes activity that reduced the levels of serum HbA1c and cholesterol and that increased antioxidant proteins in HFD rats. We further performed a randomized, double-blinded, placebo-controlled trial with a total of 68 T2DM patients to examine the beneficial effects of oral consumption of L. reuteri strains ADR-1 and ADR-3 and to investigate the associated changes in intestinal flora using a quantitative PCR method to analyze 16 S rRNA in fecal specimens. Significant reductions in HbA1c and serum cholesterol were observed in participants in the live ADR-1 consumption group (n = 22) after 3 months of intake when compared with those in the placebo group (n = 22). Although there was no significant difference in the HbA1c serum level among participants who consumed heat-killed ADR-3 (n = 24), the systolic blood pressure and mean blood pressure were significantly decreased after 6 months of intake. There was no obvious change in serum inflammatory cytokines or antioxidant proteins in participants after intaking ADR-1 or ADR-3, except for a reduction in IL-1β in the ADR-3 consumption group after 6 months of intake. With the analysis of fecal microflora, we found that L. reuteri or Bifidobacterium spp. were significantly increased in the ADR-1 and ADR-3 consumption groups, respectively, after 6 months of intake. Interestingly, a significant reduction in HbA1c was observed in the ADR-1 and ADR-3 consumption participants who displayed at least an 8-fold increase in fecal L. reuteri. We also observed that there was a significantly positive correlation between Bifidobacterium spp. and Lactobacillus spp. in participants with increased levels of fecal L. reuteri. In the ADR-1 intake group, the fecal Lactobacillus spp. level displayed a positive correlation with Bifidobacterium spp. but was negatively correlated with Bacteroidetes. The total level of fecal L. reuteri in participants in the ADR-3 consumption group was positively correlated with Firmicutes. In conclusion, L. reuteri strains ADR-1 and ADR-3 have beneficial effects on T2DM patients, and the consumption of different strains of L. reuteri may influence changes in intestinal flora, which may lead to different outcomes after probiotic intake.

SUMMARY Staphylococcus aureus encodes the specialized ESAT-6 Secretion System (ESS). EsxA and EsxB are secreted by the ESS pathway, and share sequence features of ESAT-6 and CFP-10 of the Type VII Secretion System (T7SS) of Mycobacterium tuberculosis. Unlike ESAT-6 and CFP-10, EsxA and EsxB do not interact. Instead, EsxB associates with a novel substrate, EsxD, and EsxA dimerizes with itself or EsxC (EsaC). Unlike EsxA and EsxB, EsxC and EsxD do not share obvious sequence features of WXG100 proteins nor PE/PPE and Esp families of proteins, all of which belong to the pfam EsxAB clan of mycobacterial T7SS. EsxD carries the C terminal motif YxxxD/E that has been proposed to target T7 substrates for secretion in mycobacteria. Here, we find that deletion, but not amino acid substitutions, in this motif prevent secretion of EsxA and EsxC but not EsxB or EsxD. This is unlike the genetic inactivation of esxA, esxB, esxC or esxD that leads to loss of secretion of all four substrates. Thus, substrate secretion can be uncoupled by deleting the last six amino acids of EsxD. The physical association of EsxC and EsxD with canonical WXG100 proteins suggests that these proteins belong to the EsxAB clan.

In SLE patients, the use of HCQ is associated with reduced risk of incident diabetes mellitus in a dose-dependent manner. High-dose glucocorticoids increase the risk of diabetes, which can be decreased by concomitant HCQ use.