FADiets Study, a human study investigating the effects of consumption of the emulsifier soya lecithin on the composition and metabolic outputs of the gut microbiota.
Emulsifiers are common components of processed foods consumed as part of a Western diet, but some studies have suggested that consumption of certain emulsifiers may cause increased bacterial translocation across the intestinal epithelium. This project was carried out at the Rowett Institute in Aberdeen, Scotland, and was a human study (“FADiets”) to investigate the effect of consumption of the emulsifier soya lecithin on gut and metabolic health. The study design was a randomised crossover dietary intervention trial in overweight or obese (but otherwise healthy) adults comparing a low-calorie, low-emulsifier diet, with a low-calorie, high-emulsifier diet. The dietary intervention consisted of two 14-day diet periods, with either no added emulsifier (“Control”) or 15 g soya lecithin per day (“Lecithin”). Faecal samples were collected at the end of the interventions, with samples also collected at baseline when volunteers were consuming their habitual diet (“Baseline”) and after a 7-day mid-study washout between diets (“Washout”). Various biomarkers were measured including the faecal microbiota composition. For this, amplicon libraries of the V4 hypervariable region of the 16S rRNA gene were generated from all collected faecal samples, and then sequenced using the Illumina MiSeq system.