## 3 Results
### Effects of Prebiotics on the Intestinal Microbiome, Obesity and Metabolic Syndrome  
In a 12-week randomized controlled trial, the aim was to evaluate the influence of prebiotic consumption on metabolic endotoxin and systemic inflammation in overweight and obese adults. Thirty-seven participants were randomly separated into two groups. One group of 20 subjects consumed 7 g of oligofructose three times a day, and the second group of 17 subjects received an isocaloric maltodextrin placebo. Plasma LPS was reduced by 40% in the oligofructose group while in the placebo group it increased by 48%. Higher levels of LPS and PAI-1 may contribute to the complications of obesity. For this reason prebiotics can help to avoid obesity-related comorbidities [37]. Another triple-blind randomized controlled trial investigated the effects of inulin on inflammatory markers and metabolic endotoxemia in patients with type 2 diabetes. The participants were 49 diabetic women randomly divided into two groups. An intervention group of 24 subjects and a control group of 25 subjects consumed 10 g/d inulin or maltodextrin for 8 weeks, respectively. In the inulin group only, there was a remarkable reduction in body weight and BMI. In the intervention group, in contrast with the control group, energy intake and total fat were significantly decreased. Additionally, in the intervention group there was an important reduction in fasting glucose, HbA1c, fasting insulin and an important reduction in CRP, TNF-a and LPS. These results led to the conclusion that inulin supplementation may ameliorate glycemic status and modulate inflammation and metabolic endotoxemia in women with type 2 diabetes [38]. The aim of another randomized, placebo-controlled, double-blind, 6-week crossover trial was to evaluate the prebiotic effect of inulin-type fructans on SCFAs and gut microbiota in patients with type 2 diabetes. Participants had a BMI \(\leq\) 40 kg/m\({}^{2}\), HbA1c \(<\) 10.0% (86 mmol/mol), and were not treated with insulin or glucagon-like peptide-1 (GLP-1) analogues. For two periods of 6 weeks separated by a 4-week wash-out, the subjects received 16 g per day of inulin-type fructans (a 50/50 mixture of oligofructose and inulin and placebo (maltodextrin 16 g per day) in addition to their usual diet and in a randomized order. The supplements were powdered, were very much alike in colour and taste, and were given in identical and non-transparent portion packages of 8 g. During the first week, the participants were required to consume only 8 g and for the remaining 5 weeks, switched to 16 g per day. Subjects added the supplements to food or drinks and ate them whenever they preferred. Unused packages were returned to measure compliance. Importantly, higher faecal concentrations of bifidobacteria and total SCFA, acetic acid and propionic acid were observed after prebiotic consumption in comparison to placebo. The prebiotic fiber had no effects on the concentration of butyric acid or on the variability of gut microflora. Bifidobacteria are not able to produce butyric acid themselves; however, through cross-feeding, various species metabolize non-digestible carbohydrates through various steps. The bifidobacteria help with their capacity to degrade fructan chains and in this mode prepare for other species to complete the fermentation. Bifidobacteria may also help to prevent endotoxemia and ameliorate regulation of blood glucose. Increased faucal concentrations of SCFA were found, indicating alterations of the microbial metabolic activity in the gut. Total SCFA, acetic acid and propionic acid increased. The results of this study indicate the modest potential of inulin-type fructans to ameliorate gut microbiota composition and increase microbial fermentation in type 2 diabetes [39].