Lactobacillus gasseri as a Functional Food and Its Role in Obesity

Abstract

Introduction Obesity is a chronic, relapsing, progressive disease. It is identified by abnormal and excessive fat accumulation which is defined as a body mass index (BMI) higher than 25 kg/m 2. 1 The health risks of obesity include a wide range of medical, surgical, gynecological, obstetric, social, and psychological conditions such as hypertension, cerebrovascular incidents, cancers, hyperlipidemia, coronary heart disease, diabetes mellitus, and degenerative arthritis. 2 Therefore, the costs imposed by obesity are considerable. Changes in lifestyle, exercise, diet therapy, drugs with anti-lipase inhibitory effects, or medicinal plants are some ways to overcome obesity, but one critical factor related to obesity and metabolic disorders is the gut microbiota. The gut microbiota is related to obesity, type 2 diabetes, cardiovascular diseases, and non-alcoholic fatty liver disease. 3 The high proportion of intestinal firmicutes and low percentage of Bacteroides are associated with adipose tissue inflammation and obesity. 4 Bacteroides have a lower number of enzyme genes for lipid and carbohydrate metabolism than firmicutes, and they reduce the energy uptake from diets. 5 Probiotics as live healthy microorganisms are a promising approach to altering gut microbiota. 6 Among probiotics, Lactobacillus gasseri is known as the weight loss probiotic. In this review article, the efficiency of L. gasseri in weight loss is discussed. Lactobacillus gasseri Lactobacillus gasseri is an autochthonous human intestinal bacterium which is acid resistant, bile tolerant, and distinguished from L. acidophilus by typical phenotype characteristics. The cell wall composition and electrophoretic mobility of L. gasseri L-LDH is different from that of L. acidophillus. 7 Cardiolipin as a membrane phospholipid of L. gasseri JCM1131 plays a pivotal role in the bile acid resistance of bacteria. 8 Inulin, poly-oligosaccharides, and a broad range of fructo-oligosaccharides are synthesized by L. gasseri. 9 Inulin is synthesized from sucrose using inulosucrase from L. gasseri DSM 20604. 10 Lactobacillus gasseri reduces the number of fecal mutagenic enzymes, adheres to intestinal tissue, and stimulates macrophages in the intestine. It is able to adhere to Caco-2 cells and exhibits antimicrobial activity. It reduced the fecal coliforms, serum total cholesterol, LDL-cholesterol, triglycerides, and bile acids in rats. The levels of acidic steroid increased in feces, but totally neutral steroids were not affected by L. gasseri in hypercholesterolemic rats. 11 Two different mechanisms are proposed for reducing serum cholesterol using probiotic bacteria. L. gasseri is able to enhance the excretion of acidic steroids in feces and suppress the reabsorption of bile acids into the enterohepatic circulation. It is also able to adhere to the surface of the intestine and deconjugate bile acids with weak absorption from the small intestine is associated with high feces excretion by dietary fiber. Deconjucated bile acids are toxic for the growth of coliform or pathogenic bacteria. 12 L. gasseri Abstract Obesity is a chronic, relapsing, progressive disease which is associated with a wide range of fatal diseases in the world. This review article evaluated the efficacy of Lactobacillus gasseri in the management of obesity. The information was extracted from electronic resources (PubMed, Science Direct, Wiley, and Google). The results of the research showed that the efficacy of L. gasseri on weight loss is strain-sensitive. There are two well-known strains, BNR17 and SBT2055, which come from different sources and are used in many animal and clinical studies. More evidence on the efficacy of L. gasseri SBT2055 than on BNR17 is present in the literature. The daily dose of L. gasseri SBT2055 in clinical trials is higher than BNR17 at the dose of 10 11. It seems that the use of a high dose of L. gasseri BNR17 in clinical trials is associated with more pleasant results on weight loss.