Background: Obesity has become a common health problem all over the world. Benefiting from a national representative sample, the present study aimed to estimate the prevalence of overweight/obesity and the distribution of Body Mass Index (BMI) levels in the Iranian adult population, by sex, age, and geographical distribution. Methods: This was a large-scale national cross-sectional study of Non-communicable Diseases risk factor surveillance in Iran. Through a systematic random sampling cluster, 31,050 Iranian adult participants aged 18 years and over were enrolled in the study. The main research tools were used to assess three different levels of data, namely: (1) demographic, epidemiologic, and risk-related behavioral data, (2) physical measurements, and (3) lab measurements. Anthropometric measurements were taken using standard protocols and calibrated instruments.

Objective The increasing prevalence of obesity over the past few decades constitutes a global health challenge. Pharmacological therapy is recommended to accompany life-style modification for obesity management. Here, we perform a clinical trial to investigate the effects of metformin on anthropometric indices and gut microbiota composition in non-diabetic, treatment-naive obese women with a low-calorie diet (LCD). Design Randomized double-blind parallel-group clinical trial Methods Forty-six obese women were randomly assigned to the metformin (500 mg/tab) or placebo groups using computer-generated random numbers. Subjects in both groups took two tablets per day for 2 months. Anthropometric measurements and collection of blood and fecal samples were done at the baseline and at the end of the trial. Gut microbiota composition was assessed using 16S rRNA amplicon sequencing. Results Twenty-four and twenty-two subjects were included in the metformin + LCD and placebo + LCD groups, respectively; at the end of trial, 20 and 16 subjects were analyzed. The metformin + LCD and placebo + LCD caused a 4.5 and 2.6% decrease in BMI from the baseline values, respectively (P < 0.01). Insulin concentration decreased in the metformin + LCD group (P = 0.046). The overall fecal microbiota composition and diversity were unaffected in the metformin + LCD group. However, a significant specific increase in Escherichia/Shigella abundance was observed after metformin + LCD intervention (P = 0.026). Fecal acetate concentration, but not producers, was significantly higher in the placebo + LCD group, adjusted for baseline values and BMI (P = 0.002). Conclusions Despite the weight reduction after metformin intake, the overall fecal microbiota composition remained largely unchanged in obese women, with exception of changes in specific proteobacterial groups.

Gut Microbiota as a Target in the Pathogenesis of Metabolic Disorders: A New Approach to Novel Therapeutic Agentsing and its metagenomic applications allowed the study of the microbiota composition in metabolic disorders without cultivation [8]. Results of the human microbiome studies, which are part of the human genome projects could have possible clinical applications like personalized medicine in the future [8]. It is noteworthy that despite the inter-individual variations in gut microbiota, serial stool collections have shown that core gut microbiota composition of an individual remains stable over time. Therefore, susceptibility to the development of specific diseases was different among subjects. The composition of the gut microbiota is modulated by prenatal events, delivery methods, infant feeding, duration of lactation, complementary foods, geographical location, and environmental factors such as life style, antibiotic use, and dietary pattern [9]. It seems that these factors, effective in altering gut microbiota composition, can be used for therapeutic purposes. In this review, the mechanisms by which the gut microbiota may affect host metabolism are considered, and the methods of gut microbiota modulation as novel therapeutic strategies in metabolic disorders including obesity, diabetes, and osteoporosis are provided, as well. Introduction ▼The prevalence of metabolic disorders is increasing worldwide, leading to recognize them as public health concerns. The most prevalent metabolic disorders are diabetes mellitus, obesity, and osteoporosis. The involvement of both genetic and environmental factors makes the pathophysiologies of these disorders complicated. Gut microbiota is suggested as a potential contributor to the development of metabolic disorders in recent years [1,2]. Gut microbiota is defined as the microbial community inhabiting the intestine; and gut microbiome are its genomic contents, which are 100-to 150-fold more numerous than the human genome [3]. These microbes, as an endocrine organ, play important roles in human health and their imbalances are related to numerous diseases such as inflammatory bowel disease, cardiovascular diseases, allergies, and metabolic disorders. Recent evidence in mice and humans has shown that gut microbiota is linked with the development of metabolic disorders [1,[4][5][6] Abstract ▼As the prevalence of metabolic disorders increases dramatically, the importance of identifying environmental factors affecting metabolism control becomes greater accordingly. Gut microbiota, a complex ecosystem inhabiting the human gastrointestinal tract, is one of these potential factors. Recently, the evidence has shown the associations between alteration in gut micro biota composition and obesity, diabetes, and osteoporosis. However, the causality of gut microbiota on metabolic health has yet to be explored in intervention studies and the underlying mechanisms need to be investigated more in depth. Gut microbiota plays critical roles in the control of immunity, food intake, lipi...

Metabolomics methods have been widely used in the field of biomarker discovery in TC and attempts are still in progress to use these methods to find a reliable biomarker panel besides current diagnostic tools.