Fermented pickles improve gut microbiota and immune profile in women in a community trial in rural Pakistan

A gut microbiome-targeted diet can potentially mitigate chronic diseases, including malnutrition. In a prospective 12-week intervention trial, we evaluated the effects of six different plant-based fermented pickles (~ 50 g/day) on clinical, inflammatory, and gut microbiota parameters in a cohort of women (n = 230) in a rural setting with a high prevalence of undernutrition. Blood was collected at two, whereas stool was collected at three timepoints. Among fecal biomarkers, myeloperoxidase (MPO), Lipocalin-2 (LCN2), and 16S rRNA gene sequencing were measured at baseline, 8^th, and 12^th weeks. Overall, the compliance rate was > 70%. Among radish group, WBCs (p = 0.002, two-tailed paired T-test) decreased, whereas neutrophils and platelets decreased among both radish (p = 0.016, p = 0.017, two-tailed paired T-test) and carrot (p = 0.005, p = 0.006, two-tailed paired T-test) groups after intervention. Similarly, in lemon-chilli group, platelets decreased while mean corpuscular hemoglobin (MCH) increased (p < 0.001, p = 0.022, two-tailed paired T-test). In onion and lemon-chilli groups, α- (р =0.001 and p = 0.0005, Kruskal-Wallis Test, respectively) and β-diversity indices (p = 9e-04 and p = 0.022, pairwise PERMANOVA, respectively) were significantly increased, post-intervention. Linear discriminant analysis (LDA) of lemon-chilli group identified 25 bacterial taxa markers in 8^th and 12^th week, which included Eggerthellaceae and Oscillospiraceae, Erysipelatoclostridiaceae and Subdoligranulum. Correlation analysis revealed six taxa negatively associated with inflammatory markers such as C-reactive protein (CRP), LCN2, and platelets. Our study provides preliminary evidence that the consumption of traditional fermented pickles leads to beneficial changes in women's hematological and gut microbiota profiles.