Early studies in mice suggested that the gut microbiome may play a role in obesity [17] although this has not been fully borne out in human studies [18]. Agreement in studies to date in humans is not strong but there may be a decrease in levels of bifidobacteria, a decrease in Firmicutes and a reduction in Methanobrevibacter [ 19 and 20]. An increase in capacity to produce short chain fatty acids (SCFA) may also be a characteristic of the obese microbiome [ 21] and this has been reversed by a prebiotic approach [ 22]. Prebiotics have been shown to increase levels of bifidobacteria in obese women [ 23] using HitChip and qPCR analyses. This study of 44 obese women showed non-significant reductions in BMI, fat mass, waist:hip ratio and fat mass:lean mass ratio. Whilst it is not clear at the present time that manipulating the bifidobacterial populations in the gut will have an impact on obesity, there is promising evidence suggesting that prebiotics might have an impact on appetite, thus indirectly impacting upon weight gain. Verhoef et al. [ 24] fed the prebiotic oligofructose (OF) to 28 healthy adults for 13 days and studied appetite profiles, energy intake and expression of the gut hormones PYY and GLP-1. They found that although oligofructose consumption did not suppress appetite, energy consumption was reduced by 11% on day 13 when consuming 16 g OF per day. Expression of both gut hormones was increased. The authors suggest that this might be due to production of elevated levels of SCFA by fermentation of OF. In this regard, Frost [ 25] showed that in mice, colonic acetate can cross the blood brain barrier and produce appetite suppression, at the level of the hypothalamus, in the absence of increased levels of PYY and GLP-1. A recent systematic review has been conducted of the effect of OF and inulin on appetite regulation, energy intake and weight loss in children and adults [ 26]. Studies amplifying this have been published by Cani et al. [ 27 and 28] who showed that fructan prebiotics could influence satiety in humans. Similarly, Parnell and Reimer [ 29] demonstrated that the same type of prebiotics could influence hormonal regulation and therefore appetite in overweight humans. The conclusion is that OF and inulin may have a contribution to make to reducing energy intake and weight loss.