Early-Life Sugar Consumption Affects the Rat Microbiome Independently of Obesity

Abstract

The gut microbiome has been implicated in various metabolic and neurocognitive disorders and is heavily influenced by dietary factors, but there is a paucity of research on the effects of added sugars on the gut microbiome. With the use of a rodent model, our goal was to determine how added-sugar consumption during the juvenile and adolescent phase of development affects the gut microbiome. Forty-two juvenile male Sprague-Dawley rats [postnatal day (PND) 26; 50-70 g] were given access to 1 of 3 different 11%-carbohydrate solutions designed to model a range of monosaccharide ratios commonly consumed in sugar-sweetened beverages: 1) 35% fructose:65% glucose, 2) 50% fructose:50% glucose, 3) 65% fructose:35% glucose, and 4) control (no sugar). After ad libitum access to the respective solutions for the juvenile and adolescent period (PND 26-80), fecal samples were collected for next-generation 16S ribosomal RNA sequencing and multivariate microbial composition analyses. Energy intake, weight change, and adiposity index were analyzed in relation to sugar consumption and the microbiota. Body weight, adiposity index, and total caloric intake did not differ as a result of sugar consumption. However, sugar consumption altered the gut microbiome independently of anthropometric measures and caloric intake. At the genus level, Prevotella [linear discriminant analysis (LDA) score = -4.62; P < 0.001] and Lachnospiraceae incertae sedis (LDA score = -3.01; P = 0.03) were reduced, whereas Bacteroides (LDA score = 4.19; P < 0.001), Alistipes (LDA score = 3.88; P < 0.001), Lactobacillus (LDA score = 3.78; P < 0.001), Clostridium sensu stricto (LDA score = 3.77; P < 0.001), Bifidobacteriaceae (LDA score = 3.59; P = 0.001), and Parasutterella (LDA score = 3.79; P = 0.004) were elevated by sugar consumption. No overall pattern could be attributable to monosaccharide ratio. Early-life sugar consumption affects the gut microbiome in rats independently of caloric intake, body weight, or adiposity index; these effects are robust across a range of fructose-to-glucose ratios.