Similar effects have been seen with galacto-oligosaccharide (GOS) prebiotics [20]. Consumption of 5.5 g GOS per day by 45 overweight women for 12 weeks in a placebo controlled crossover study reduced their inflammatory state as determined by faecal calprotectin and plasma CRP. This correlated with increased expression of secretory IgA. By the end of the study, significant decreases were also seen in total cholesterol, HDL-cholesterol, total cholesterol:HDL-cholesterol ratio and triglycerides. Plasma glucose levels were not changed but insulin levels were reduced at the end of the study period relative to the placebo. GOS has a good track record of manipulating the microbiota in human studies [33, 34, 35 and 36] and in this study, an increase in bifidobacteria and decreases in bacteroides and the Clostridium histolyticum group were seen [ 20].