Metatranscriptomic analysis to define the Secrebiome, and 16S rRNA profiling of the gut microbiome in obesity and metabolic syndrome of Mexican children

Abstract

Background: In the last decade, increasing evidence has shown that changes in human gut microbiota are associated with diseases, such as obesity. The excreted/secreted proteins (secretome) of the gut microbiota affect the microbial composition, altering its colonization and persistence. Furthermore, it influences microbiota-host interactions by triggering inflammatory reactions and modulating the host's immune response. The metatranscriptome is essential to elucidate which genes are expressed under diseases. In this regard, little is known about the expressed secretome in the microbiome. Here, we use a metatranscriptomic approach to delineate the secretome of the gut microbiome of Mexican children with normal weight (NW) obesity (O) and obesity with metabolic syndrome (OMS). Additionally, we performed the 16S rRNA profiling of the gut microbiota. Results: Out of the 115,712 metatranscriptome genes that codified for proteins, 30,024 (26%) were predicted to be secreted, constituting the Secrebiome of the gut microbiome. The 16S profiling confirmed an increased abundance in Firmicutes and decreased in Bacteroidetes in the obesity groups, and a significantly higher richness and diversity than the normal weight group. We found novel biomarkers for obesity with metabolic syndrome such as increased Coriobacteraceae, Collinsela, and Collinsella aerofaciens; Erysipelotrichaceae, Catenibacterium and Catenibacterium sp., and decreased Parabacteroides distasonis, which correlated with clinical and anthropometric parameters associated to obesity and metabolic syndrome. Related to the Secrebiome, 16 genes, homologous to F. prausniitzi, were overexpressed for the obese and 15 genes homologous to Bacteroides, were overexpressed in the obesity with metabolic syndrome. Furthermore, a significant enrichment of CAZy enzymes was found in the Secrebiome. Additionally, significant differences in the antigenic density of the Secrebiome were found between normal weight and obesity groups. Conclusions: These findings show, for the first time, the role of the Secrebiome in the functional human-microbiota interaction. Our results highlight the importance of metatranscriptomics to provide novel information about the

Gut Phageome Analysis Reveals Disease-Specific Hallmarks in Childhood Obesity

“…This observation is in agreement with the proposed that virome diversity correlates with intestinal bacterial diversity 32 . We also found distinct phageome and bacterial 18 structure among OMS and O groups. Hence, considering their microbiomes, is very important that obesity and obesity with metabolic syndrome are studied as separate conditions to better understand the interplay between bacteria and phages and their role in these pathologies.…”

“…Additionally, we followed similar sequence thresholds recently proposed for accurate estimation of viral community composition and diversity 53 Our research group previously reported 18 for the same set of samples that OMS and O groups had a significantly higher bacterial richness and diversity than NW group 18 .…”

“…These processes, among others, are considered as the link between gut microbiota, obesity and metabolic syndrome 17 . Our group recently demonstrated that 16S profiling and metatranscriptomic analyses showed distinct microbiota alterations among obesity and obesity with metabolic syndrome profiles 18 .…”

Endocrine Disruptors in Food: Impact on Gut Microbiota and Metabolic Diseases

“…When fed with a similar diet, the comparison of the gut microbiota of genetically obese (ob/ob) mice with that of lean mice showed a greater abundance of Firmicutes and lower relative abundance of Bacteriodetes (50%) in obese mice [15]. These changes in the microbiota have also been found in different human studies [16,17]. Moreover, low relative amounts of Bifidobacterium vulgatus and high abundances of Lactobacillus spp.…”

Characterization of the Duodenal Mucosal Microbiome in Obese Adult Subjects by 16S rRNA Sequencing

“…Further, the microbial Firmicutes/Bacteroidetes ratio is reported to be increased in obesity, but it is usually calculated in stool samples, whose microbiome is mostly representative of colon [47]. The latter microbiome is largely different from those present in other intestinal tracts such as duodenum or jejunum, which host lower than colon abundance of Bacteroidetes, probably related to a limited availability of mucin as carbon source for Bacteroidetes [18,21].…”