Insights into the role of gut microbiota in obesity: pathogenesis, mechanisms, and therapeutic perspectives

摘要

Concern about health risks associated with rising obesityhas become nearly universal, with the mean body massindex (BMI) and the prevalence of obese and overweightindividuals increasing substantially worldwide during theprevious three decades. Unfortunately, prevention andtreatment of obesity and related complications have provencomplex, and successful strategies to tackle this pathologyremain limited. Epidemiological studies have highlightedpotential environmental exposures, including diet, energyexpenditure, early life influences, sleep deprivation, endocrinedisruptors, chronic inflammation, and microbiome status,contributing to higher risk of obesity (Franks andMcCarthy, 2016). Among these, the microbiome hasreceived extensive attention during the previous decade.Variation in gut microorganisms might play an importantrole in the pathogenesis of obesity. Although the compositionof intestinal microbiota is highly diverse in healthy individuals,those exhibiting overall adiposity, insulin resistance anddyslipidemia are characterized by low bacterial richness (LeChatelier et al., 2013). Moreover, composition of gut microbiotain obesity individuals differs from that in lean individuals,although inconsistent changes have been reported.Bacteroidetes prevalence is lower in obese people, with thisproportion increasing along with weight loss based on a lowcaloriediet (Ley et al., 2006a). Lactobacillus and Clostridiumspecies are associated with insulin resistance, with Lactobacilluspositively correlated with fasting glucose and HbA1clevels, whereas Clostridium showed a negative correlationwith these parameters (Karlsson et al., 2013). These datasuggest that specific bacterial phyla, class, or species orbacterial metabolic activities could be beneficial ordetrimental to the onset of obesity. Therefore, the gutmicrobiome has been suggested as a driving force in thepathogenesis of obesity.