Fermentable Carbohydrate Alters Hypothalamic Neuronal Activity and Protects Against the Obesogenic Environment

Abstract

Obesity has become a major global health problem. Recently, attention has focused on the benefits of fermentable carbohydrates on modulating metabolism. Here, we take a system approach to investigate the physiological effects of supplementation with oligofructose‐enriched inulin (In). We hypothesize that supplementation with this fermentable carbohydrate will not only lead to changes in body weight and composition, but also to modulation in neuronal activation in the hypothalamus. Male C57BL/6 mice were maintained on a normal chow diet (control) or a high fat (HF) diet supplemented with either oligofructose‐enriched In or corn starch (Cs) for 9 weeks. Compared to HF+Cs diet, In supplementation led to significant reduction in average daily weight gain (mean ± s.e.m.: 0.19 ± 0.01 g vs. 0.26 ± 0.02 g, P < 0.01), total body adiposity (24.9 ± 1.2% vs. 30.7 ± 1.4%, P < 0.01), and lowered liver fat content (11.7 ± 1.7% vs. 23.8 ± 3.4%, P < 0.01). Significant changes were also observed in fecal bacterial distribution, with increases in both Bifidobacteria and Lactobacillius and a significant increase in short chain fatty acids (SCFA). Using manganese‐enhanced MRI (MEMRI), we observed a significant increase in neuronal activation within the arcuate nucleus (ARC) of animals that received In supplementation compared to those fed HF+Cs diet. In conclusion, we have demonstrated for the first time, in the same animal, a wide range of beneficial metabolic effects following supplementation of a HF diet with oligofructose‐enriched In, as well as significant changes in hypothalamic neuronal activity.

The intestinal microbiota, energy balance, and malnutrition: emphasis on the role of short-chain fatty acids

“…The effects of microbiota and SCFAs on appetite regulation were investigated in a study comparing mice fed a high-fat diet supplemented with highly fermentable oligofructoseenriched inulin to supplementation with corn starch [64]. Inulin supplementation led to increased colonic SCFAs, decreased energy intake and adiposity, and increased neuronal activation within the ARC, suggesting a decrease in appetite.…”

Effects of elevating colonic propionate on liver fat content in overweight adults with non-alcoholic fatty liver disease: a pilot study

“…NAFLD is commonly associated with an increased risk of developing Type 2 diabetes. Positive physiological effects have been linked with the production of short chain fatty acids (SCFA) by colonic fermentation of non-digestible carbohydrate (NDC), including reductions in hepatic fat content (2) . We have developed a novel inulin-propionate ester, whereby the SCFA propionate is bound to the NDC inulin.…”

Potential anti-obesogenic properties of non-digestible carbohydrates: specific focus on resistant dextrin

“…Analysis of the faecal samples found metabolic changes similar to those found in obese human subjects, including an increase in branched-chain fatty acid production (71) . Furthermore, evidence that fermentable NDC improve weight management in rodents and human subjects provides further support that compositional changes in the gut microbiota may contribute to the development of obesity (64,66,(72)(73)(74)(75)(76)(77) .…”

“…A number of rodent studies have observed reductions in bodyweight and adiposity following long-term consumption of fructans (66,72) . In a recent study, oligofructose, with or without probiotic Bifidobacterium animalis, was given to adult diet-induced obese Sprague-Dawley rats (73) .…”

“…Moreover, the intake of fructans has been found to activate neural receptors in the brain associated with food intake (72) . In a recent murine study, the intake of galacto-oligosaccharides was also found to increase circulating GLP-1 and PYY concentrations.…”