Changes in gut microbiota due to supplemented fatty acids in diet-induced obese mice

Abstract

Consumption of a high-fat diet (HFD), which is associated with chronic 'low-grade' systemic inflammation, alters the gut microbiota (GM). The aim of the present study was to investigate the ability of an oleic acid-derived compound (S1) and a combination of n-3 fatty acids (EPA and DHA, S2) to modulate both body weight and the GM in HFD-induced obese mice. A total of eighty mice were fed either a control diet or a HFD, non-supplemented or supplemented with S1 or S2. At week 19, faeces were collected in order to analyse the GM. Groupspecific primers for accurate quantification of several major bacterial groups from faecal samples were assayed using quantitative PCR. The HFD induced an increase in body weight, which was reduced by supplementation with S1. Furthermore, S1 supplementation markedly increased total bacterial density and restored the proportions of bacteria that were increased (i.e. clostridial cluster XIVa and Enterobacteriales) or decreased (i.e. Bifidobacterium spp.) during HFD feeding. S2 supplementation significantly increased the quantities of Firmicutes (especially the Lactobacillus group). Correlation analysis revealed that body weight correlated positively with the phylum Firmicutes and clostridial cluster XIVa, and negatively with the phylum Bacteroidetes. In conclusion, the consumption of a HFD induced changes in the faecal microbiota, which were associated with the appearance of an obese phenotype. Supplementation of the HFD with S1 counteracted HFD-induced gut dysbiosis, together with an improvement in body weight. These data support a role for certain fatty acids as interesting nutrients related to obesity prevention.Key words: Gut microbiota: Fatty acids: Obese mice: Quantitative PCR The worldwide prevalence of overweight and obesity has increased dramatically in the past decades, reaching epidemic levels (1) . It is well known that a high-fat diet (HFD) leads, especially in genetically predisposed individuals, to an accumulation of adipose tissue (2) and to the development of a cluster of metabolic and cardiovascular disorders such as type 2 diabetes, atherosclerosis, hypertension and stroke (3) .The gut microbiota (GM) has an important role in supplying nutrients and vitamins, giving colonisation resistance against pathogenic bacteria and interacting with the host immune system and intestinal epithelium (4) . The possible involvement of the host genotype, particularly as it relates to immunophenotype, has been frequently postulated as a major influence on GM composition and stability. Other variables known to broadly influence the composition of the GM include the type of delivery (vaginal or caesarean), age, the use of antibiotics and other drugs, and 'lifestyle' (such as diet, physical activity and stress) (5 -9) . The significance of the protective role of the GM has been highlighted by the profound impact seen when the GM is absent or disrupted. Germ-free mice have poorly developed mucosal architecture and rudimentary development of the mucosa-associated lymphoid tissue, b...

Impact of high fat diets, prebiotics and probiotics on gut microbiota and immune function, with relevance to elderly populations

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Fibre digestibility, abundance of faecal bacteria and plasma acetate concentrations in overweight adult mares

“…faecal v. intestine lumen v. intestinal mucosa), region of the gastrointestinal tract evaluated, and time point relative to obesity ( 37 , 38 ) . Nevertheless, these phyla continue to be associated with obesity in recent studies ( 39 , 40 ) and have not yet been evaluated relative to obesity in the horse.…”

Age and High-Fat Diet Effects on Glutamine Synthetase Immunoreactivity in Liver and Hippocampus and Recognition Memory in Mice

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