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Bombin, A.

Publications and source records attributed to Bombin, A..

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Obesity influences composition of salivary and fecal microbiota and impacts the interactions between bacterial taxa

Obesity is an increasing global health concern and is associated with a broad range of morbidities. The gut microbiota are increasingly recognized as important contributors to obesity and cardiometabolic health. This study aimed to characterize oral and gut microbial communities, and evaluate host:microbiota interactions between clinical obesity classifications. We performed 16S rDNA sequencing on fecal and salivary samples, global metabolomics profiling on plasma and stool samples, and dietary profiling in 135 healthy individuals. We grouped individuals by obesity status, based on body mass index (BMI), including lean (BMI 18-24.9), overweight (BMI 25-29.9), or obese (BMI [≥]30). We analyzed differences in microbiome composition, community inter-relationships, and predicted microbial function by obesity status. We found that salivary bacterial communities of lean and obese individuals were compositionally and phylogenetically distinct. An increase in obesity status was positively associated with strong correlations between bacterial taxa, particularly with bacterial groups implicated in metabolic disorders including Fretibacterium, and Tannerella. Consumption of sweeteners, especially xylitol, significantly influenced compositional and phylogenetic diversities of salivary and fecal bacterial communities. In addition, obesity groups exhibited differences in predicted bacterial metabolic activity, which was correlated with hosts metabolite concentrations. Overall, obesity was associated with distinct changes in bacterial community dynamics, particularly in saliva. Consideration of microbiome community structure, and inclusion of salivary samples may improve our ability to understand pathways linking microbiota to obesity and cardiometabolic disease. IMPORTANCEObesity is a worldwide epidemic that is associated with a wide range of health issues. Microbiota were shown to influence metabolism and obesity development. Our study aimed to evaluate the interactions between obesity, salivary and fecal microbiota, and metabolite concentrations in healthy individuals. The oral bacterial community was more impacted by the obesity status of the host than fecal microbiota. Consistently for oral and fecal microbiota, the number of strong interactions between bacteria increased with the increase in the obesity status. Several predicted microbial metabolic pathways that were shown to be associated with metabolic health were uniquely enriched between obesity groups. In addition, these metabolic pathways were correlated with plasma and stool metabolites. Our results suggest that oral microbiota might better reflect the obesity status of the host than fecal microbiota, and that correlations between microbial taxa are altered during obesity.

microbiology

Symbiotic bacterial community of Drosophila melanogaster changes with nutritional modifications of the diet but can alleviate negative effects on larval phenotypes

Obesity is an increasing pandemic and is caused by multiple factors including genotype, psychological stress, and gut microbiota. Our project investigated the effects produced by high fat and high sugar dietary modifications on microbiota and metabolic phenotype of Drosophila melanogaster. Larvae raised on the high fat and high sugar diets exhibited bacterial communities that were compositionally and phylogenetically different from bacterial communities of the larvae raised on normal diets, especially if parental microbiota were removed. Several of the dominant bacteria taxa that are commonly associated with high fat and high sugar diets across model organisms and even human populations showed similar pattern in our results. Corynebacteriaceae and Erysipelotrichaceae were connected with high fat food, while Enterobacteriaceae and Lactobacillaceae were associated with high sugar diets. In addition, we observed that presence of symbiotic microbiota often mitigated the effect that harmful dietary modifications produced on larvae, including elevated triglyceride concentrations and was crucial for Drosophila survival, especially on high sugar peach diets.

microbiology

Influence of the lab adopted natural diet, environmental, and parental microbiota on life history and metabolic phenotype of Drosophila melanogaster larvae.

Obesity is an increasing worldwide epidemic and contributes to physical and mental health losses. The development of obesity is caused by multiple factors including genotype, hormonal misregulation, psychological stress, and gut microbiota. Our project investigated the effects produced by microbiota community, acquired from the environment and horizontal transfer, on traits related to obesity. The study applied a novel approach of raising Drosophila melanogaster from ten, wild-derived genetic lines (DGRP) on naturally fermented peaches, thereby preserving genuine microbial conditions. Our results indicated that larvae raised on the natural and standard lab diets were significantly different from each other in every tested phenotype. In addition, sterilized larvae raised on the autoclaved peach diet, therefore exposed to natural nutritional stress but lacking natural microbiota community, were associated with adverse phenotypes such as low survival rate, longer developmental time, smaller weight, and elevated triglyceride and glucose levels. Our findings suggested that frozen peach food provided nutritional conditions similar to the natural ones and preserved key microbial taxa necessary for survival and development of Drosophila larvae. The presence of parental microbiota did not produce a significant effect on any of the tested phenotypes when larvae were raised on the lab diet. Contrarily, on the peach diet, the presence of parental microbiota increased the weight and development rate, even if the original peach microbiota were still present. In addition, we found that larvae raised on the peach diet formed a microbial community distinctive from larvae raised on the lab or peach autoclaved diets. The effect that individual microbial taxa produced on the host varied significantly with changing environmental and genetic conditions, occasionally to the degree of opposite correlations.

microbiology