Effect of long-term oral glutathione supplementation on gut microbiome of type 2 diabetic individuals.

The aim of this study was to check the effect of long-term oral glutathione (GSH) supplementation on alteration in gut microbiome of Indian diabetic individuals. Early morning fresh stool sample of diabetic individuals recruited in a randomized clinical trial wherein they were given 500 mg GSH supplementation orally once a day for a period of 6 months was collected and gut microbiome was analysed using high throughput 16S rRNA metagenomic sequencing. Long-term GSH supplementation as reported in our earlier work showed significant increase in body stores of GSH and stabilized decreased glycated haemoglobin (HbA1c). Analysis of gut microbiome revealed that abundance of phylum Proteobacteria significantly decreased (P < 0.05) in individuals with GSH supplementation after 6 months compared to those without it. Beneficial dominant genera such as Megasphaera, Bacteroides, and Megamonas were found to be significantly enriched (P < 0.05), while pathogenic Escherichia/Shigella was found to be depleted (P < 0.05) after supplementation. Data clearly demonstrate that GSH supplementation along with antidiabetic treatment helps restore the gut microbiome by enriching beneficial bacteria of healthy gut and reducing significantly the load of pathogenic bacteria of diabetic gut.