An omega-3-poor diet is associated with a number of metabolic changes, including lower body weight, higher blood sugar levels, and the build-up of triglycerides in the liver.
According to findings published in Nutrition & Metabolism, inclusion of prebiotic fructooligosaccharides in the diet was found to restore some of these metabolic changes, with increased energy efficiency and promoted body weight gain observed in a study with lab mice.
“A low omega-3 PUFA dietary consumption is associated to metabolic alterations that target the liver, leading to [abnormal retention of fat],” report researchers from the Université catholique de Louvain and the Université Libre de Bruxelles in Belgium.
“This long term nutritional depletion is associated with a decrease in global fermentation and with modifications of gut microbiota, characterized by a huge drop of lactobacilli and, unexpectedly, an increase in bifidobacteria.
“Interestingly, a relatively short treatment with prebiotics can promotes energy harvesting and reverses the decrease in caecal lactobacilli, the higher fasting glycemia and the higher expression of key factors involved in hepatic fatty acid catabolism,” they added.
The Western diet is rich in omega-6-containing vegetable oils and poor in omega-3 intakes. A decrease in the ratio of omega-3 to omega-6 polyunsaturated fatty acids is reportedly linked to increased risk of certain cardiovascular disease and inflammation, report the Belgian scientists.
Furthermore, scientists have reported that obese people typically display low blood levels of omega-3s, and lower omega-3 to omega-6 ratios.
“We have previously observed that mice fed with a diet poor in omega-3 PUFA for two generations exhibit [abnormal fat retention in the liver] together with a decrease in body weight,” explained the researchers, led by Prof Nathalie Delzenne.
Because the gut microbiota can contribute to energy metabolism and regulation, the researchers tested if daily supplementation with prebiotic fructooligosaccharides could redress the detrimental effects of consuming a diet poor in omega-3s.
Lab mice were fed either a control or an omega-3 deficient diet with or without 0.20 grams per day of fructooligosaccharides (Beneo Orafti) for 24 days.
Results showed that FOS-supplemented animals displayed increased numbers of bifidobacteria, and a higher weight of the cecum (the upper part of the large intestine) compared to the non-supplemented animals.
“Interestingly, FOS treatment promoted body weight gain in [omega-3 deficient] mice by increasing energy efficiency,” wrote the researchers.
“We show that FOS may promote lactobacilli and counteract the catabolic status induced by omega-3 PUFA depletion in mice, thereby contributing to restore efficient fat storage.
“The relevance of gut microbiota modulation in the metabolic disorders associated with nutritional unbalance of fatty acids is a novel concept that merits attention in further studies,” they concluded.
Source: Nutrition & Metabolism
2011, 8:44 doi:10.1186/1743-7075-8-44
“Involvement of gut microbial fermentation in the metabolic alterations occurring in n-3 polyunsaturated fatty acids-depleted mice”
Authors: B.D. Pachikian, A.M. Neyrinck, L. Portois, F.C. De Backer, F.M. Sohet, M. Hacquebard, Y.A. Carpentier, P.D. Cani, N.M. Delzenne