Moringa oleifera (MO) is a multipurpose plant with a high polyphenol content, which is being increasingly consumed to lessen the risk of chronic metabolic diseases such as Type 2 diabetes; however, scientific evidence from clinical trials is scarce. A double-blind, randomized, placebo-controlled, parallel group intervention study with MO leaves as a food supplement was conducted in subjects with prediabetes. They consumed six daily capsules of MO dry leaf powder (2400 mg/day) (MO, n = 31) or placebo (PLC, n = 34) over 12 weeks. Glycemia, appetite-controlling hormones and gut microbiota composition were studied. ANCOVA with the fixed factor “treatment” and the basal value as covariate was used to compare the change score between the groups. The results showed significant differences between groups in the rate of change of fasting blood glucose (FBG) and glycated hemoglobin (HbA1c), which showed opposite directions during the intervention, decreasing in MO and increasing in PLC. No different change scores were found between the groups in microbiota, hepatic and renal function markers or the appetite-controlling hormones measured. In conclusion, MO supplementation resulted in favorable changes in glycaemia markers compared to placebo in the subjects with prediabetes studied, suggesting that MO might act as a natural antihyperglycemic agent.

Background and objectives: The gut microbiota performs many functions in the host organism, and metabolites derived from its activity, such as short-chain fatty acids (SCFA), are involved in immunometabolism. Alterations in gut microbial composition play an essential role in diseases such as heart failure, kidney disease, obesity, and diabetes mellitus. The current work aimed to analyze the associations of serum and fecal inflammatory biomarkers with the microbiota and SCFA in prediabetic subjects. Methods: 65 prediabetic patients, diagnosed according to the American Diabetes Association criteria, who participated in a randomized controlled intervention study with Moringa oleifera Lam. (2.4 g/day), were included. Inflammatory markers (Serum C reactive protein [CRP] and fecal calprotectin and sIgA), gut microbiota (qPCR), and short-chain fatty acids (SCFA; GC-FID) were studied before (V0) and after a 12-week intervention (V12). Relationships were explored using principal component analysis (PCA). Lineal regression models were performed to determine the predictive variables of inflammatory markers by including SCFA and gut microbiota groups as one block of independent variables. Fat mass percentage (BIA) and treatment group were used to adjust the models. Analyses were performed for V0 and V12 separately. Results: Only for calprotectin were significant models found at V0 (p = 0.044) and V12 (p = 0.010). Lactobacillus (standardized beta, β= 0.292; p = 0.047) and Bacteroides (β = 0.430; p = 0.009) groups were significant predictors at V0 and Lactobacillus (β = 0.339; p = 0.015) and the SCFA valeric acid (β = −0.533; p = 0.014) were predictors of calprotectin in V12. For CRP, a trend was found at V12 regression (p = 0.079), with significant contributions for the Blautia coccoides–Eubacterium rectale group (β = 0.585; p = 0.016) and the categorical binomial variable “Above normal fat mass percentage” (“yes”, “no”) (β = 0.478; p < 0.001). No significant influence of the treatment group was observed. Discussion: Calprotectin levels seem to be dependent on microbiota and SCFA levels. Calprotectin showed a positive and consistent relationship with Lactobacillus spp.; however, its relationships with the Bacteroides group and valeric acid were not consistent and deserve further exploration. CRP and sIgA do not seem to be explained to a significant level by the microbiota and SCFA concentrations in this prediabetic population.