Gut microbiota in patients with obesity and metabolic disorders — a systematic review

Abstract

Background Previous observational studies have demonstrated inconsistent and inconclusive results of changes in the intestinal microbiota in patients with obesity and metabolic disorders. We performed a systematic review to explore evidence for this association across different geography and populations. Methods We performed a systematic search of MEDLINE (OvidSP) and Embase (OvidSP) of articles published from Sept 1, 2010, to July 10, 2021, for case–control studies comparing intestinal microbiome of individuals with obesity and metabolic disorders with the microbiome of non-obese, metabolically healthy individuals (controls). The primary outcome was bacterial taxonomic changes in patients with obesity and metabolic disorders as compared to controls. Taxa were defined as “lean-associated” if they were depleted in patients with obesity and metabolic disorders or negatively associated with abnormal metabolic parameters. Taxa were defined as “obesity-associated” if they were enriched in patients with obesity and metabolic disorders or positively associated with abnormal metabolic parameters. Results Among 2390 reports screened, we identified 110 full-text articles and 60 studies were included. Proteobacteria was the most consistently reported obesity-associated phylum. Thirteen, nine, and ten studies, respectively, reported Faecalibacterium, Akkermansia, and Alistipes as lean-associated genera. Prevotella and Ruminococcus were obesity-associated genera in studies from the West but lean-associated in the East. Roseburia and Bifidobacterium were lean-associated genera only in the East, whereas Lactobacillus was an obesity-associated genus in the West. Conclusions We identified specific bacteria associated with obesity and metabolic disorders in western and eastern populations. Mechanistic studies are required to determine whether these microbes are a cause or product of obesity and metabolic disorders.

Development of the gut microbiota in healthy twins during the first 2 years of life and associations with body mass index z-score: Results from the Wuhan twin birth cohort study

“…This study analyzed the gut microbiota of 204 twins from 129 families at three age stages and demonstrated that five gut microbiota, genera Akkermansia, Parabacteroides, Clostridium innocuum group, Roseburia , and Anaerostipes , were correlated with BMI_Z. As short-chain fatty acid producers, Akkermansia, Roseburia , and Anaerostipes were previously reported to be associated with obesity in animal models and adults ( Pinart et al, 2021 ; Gao et al, 2022 ; Pai et al, 2022 ; Xu et al, 2022 ; Zou et al, 2022 ). There were only two studies that reported a positive association between Akkermansia and BMI_Z in early childhood in singleton children, which was consistent with our findings ( Houtman et al, 2022 ; Reyna et al, 2022 ).…”

Impact of gut microbiome on dyslipidemia in japanese adults: Assessment of the Shika-machi super preventive health examination results for causal inference

“…Yoshida et al reported that oral administration of Bacteroides in mice prone to atherosclerosis reduced lipopolysaccharide production by intestinal microorganisms and suppressed the formation of atherosclerotic lesions (Yoshida et al, 2018). The genus Bacteroides is also abundant in the intestines of healthy adults (The human microbiome project consortium, 2012 ), and many studies have reported that they have anti-obesity effect (Xu et al, 2022). Yoshida et al (Yoshida et al, 2021).…”

Beneficial Effects of Anti-Inflammatory Diet in Modulating Gut Microbiota and Controlling Obesity

“…The most recent studies comparing the gut microbiome in adults with obesity and control groups have demonstrated that gut microbiota diversity in obese people is significantly decreased, and there are significant differences between the microbiota of these two groups at different levels, from phylum to species. Furthermore, it has been shown that obese people have abnormalities mainly with respect to carbohydrate and lipid metabolism pathways compared to the control group [ 68 , 69 , 70 , 71 ]. Additionally, comparing the structure of the gut microbiota between obese and normal school-age children revealed that the gut microbiota in obese children was less diverse than in the control group.…”