The Effect of Sargassum angustifolium Brown Seaweed Extracts on Gut Microbiota in Induced Obese Male Rats

Marine organisms, especially brown algae are good dietary complements with probiotic and anti-obesity activities. The objective of this study was to find the effects of Persian Gulf marine algae Sargassum angustifolium (SA) on the intestinal microbiota of animals exposed to a high-fat diet (HFD). Rats were fed with hot water (HW) and ethanolic (E) extracts of Sargassum angustifolium for two months. At the end of the experimental period, serum indices, food intake, and weight loss were measured. We also analyzed the intestinal microorganisms through 16SrRNA sequencing in all groups. The distribution ratio of intestinal microorganisms showed that Bacteroides and Firmicutes as dominant phyla in the intestinal rats, and obesity-associated bacteria were decreased and leanness-associated genera were increased in all treatment groups compared with the control obese group. Clostridium and Lactobacillus were the dominant genera in all groups with pathogenic potentials, and lactic acid genera, respectively. In addition, all the extracts could decrease the level of cholesterol, inflammatory factors including IL1 and TNF-α, and liver enzymes, and also led to reduction of the food intake and weight loss due to high fibers. Our results indicate that consumption of Sargassum angustifolium seaweeds can balance intestinal microbiota as well as decrease serum indices.