Several double-blind trials have evaluated the efficacy of fructo-oligosaccharides (FOS) or inulin (a related compound) for lowering blood cholesterol and triglyceride levels. These trials have shown that in individuals with elevated total cholesterol or triglyceride levels, including people with type 2 diabetes, FOS or inulin (in amounts ranging from 8 to 20 grams daily) produced significant reductions in triglyceride levels; however, the effect on cholesterol levels was inconsistent.^5,6,7,8 In people with normal or low cholesterol or triglyceride levels, FOS or inulin produced little effect.^9,10,11

 

In a double-blind trial, the addition of a mixture of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides to infant formula prevented the development of eczema in infants who were at high risk of developing eczema. The incidence of eczema in the first six months of life was 9.8% in the group receiving oligosaccharides, compared with 23.1% in the placebo group, a statistically significant difference. The product used in this study was designed to mimic the oligosaccharide content of human milk, and was added at a concentration of 0.8 grams per 100 ml.¹²

The gut microbiome is now recognized as an important target for anti-diabetes therapies, with its ability to impact carbohydrate and fat metabolism and regulate inflammatory activity in the body.¹³ Prebiotic fibers like fructo-oligosaccharides promote the growth of gut bacterial colonies associated with healthy metabolic function. A review of 27 clinical trials investigating the effects of prebiotics in people with type 2 diabetes reported the majority (74%) of studies found beneficial results on metabolic and/or inflammatory markers, including blood glucose and lipid levels. The best evidence was for fructo-oligosaccharides, with fewer trials performed using other prebiotics.¹⁴ A meta-analysis that included six randomized controlled trials using prebiotics in people with type 2 diabetes found there was a significant positive effect on fasting blood glucose levels, HbA1c, and lipid profiles. Prebiotic supplements used in the research provided 10–20 grams of fructo-oligosaccharides per day.¹⁵

In a double-blind trial, supplementation with 5 grams of fructo-oligosaccharides per day for six weeks was significantly more effective than a placebo at relieving symptoms of dyspepsia such as such as abdominal discomfort, fullness, constipation, urgency, and diarrhea. The average symptom severity decreased by 44% in the group receiving fructo-oligosaccharides.¹⁶

 

One preliminary study found iron levels to be reduced after both minor and major surgeries, and iron supplementation prior to surgery was not able to prevent this reduction.¹⁷ A controlled trial found that intravenous iron was more effective than oral iron for restoring normal iron levels after spinal surgery in children.¹⁸ One animal study reported that supplementation with fructo-oligosaccharides (FOS) improved the absorption of iron and prevented anemia after surgery,¹⁹ but no human trials have been done to confirm this finding. Some researchers speculate that iron deficiency after a trauma such as surgery is an important mechanism for avoiding infection, and they suggest that iron supplements should not be given after surgery.²⁰