Worse inflammatory profile in omnivores than in vegetarians associates with the gut microbiota composition

Abstract

AimsTo describe the abundance of major phyla and some genera in the gut microbiota of individuals according to dietary habits and examine their associations with inflammatory markers, insulin resistance, and cardiovascular risk profile.MethodsA total of 268 non-diabetic individuals were stratified into groups of dietary types (strict vegetarians, lacto-ovo-vegetarians, and omnivores). The taxonomic composition and phylogenetic structure of the microbiota were obtained through the analysis of the 16S rRNA gene. Samples were clustered into operational taxonomic units at 97% similarity using GreenGenes 13.5 database. Clinical, biochemical, and circulating inflammatory markers were compared by ANOVA or Kruskal–Wallis test.ResultsThe sample (54.2% women, mean age 49.5 years) was composed of 66 strict vegetarians, 102 lacto-ovo-vegetarians and 100 omnivores. Considering the entire sample, the greatest abundant phyla were Firmicutes (40.7 ± 15.9%) and Bacteroidetes (39.5 ± 19.9%), and no difference in abundances was found between individuals with normal and excess weight. Stratifying by dietary types, the proportion of Firmicutes was lower and of Bacteroidetes was higher in strict vegetarians when compared to lacto-ovo-vegetarians and omnivores. At the genus level, strict vegetarians had a higher Prevotella abundance and Prevotella/Bacteroides ratio than the other groups. They also had a lower proportion of Faecalibacterium than lacto-ovo-vegetarians, and both vegetarian groups had higher proportions than did omnivores. Succinivibrio and Halomonas from the Proteobacteria phylum were overrepresented in omnivores. The omnivorous group showed higher values of anthropometric data, insulin, HOMA-IR, and a worse lipid profile. Inflammatory markers exhibited a gradual and significant increase from the vegetarians and lacto-ovo-vegetarians to the omnivorous group.ConclusionsThere are differences in gut microbiota composition of individuals with distinct dietary habits, who differ according to their inflammatory and metabolic profiles. Based on the findings relative to bacteria abundances and on their recognized actions in the metabolism, we suggest that exposure to animal foods may favor an intestinal environment which could trigger systemic inflammation and insulin resistance-dependent metabolic disorders.

Atrial fibrillation risk factor management with a plant‐based diet: A review

“…Dietary patterns that are rich in unrefined plant foods have been demonstrated to reduce CRP levels in various studies . A study from 2017 found significantly higher CRP levels in omnivores than in vegans (1.1 mg/L vs 0.5 mg/L; P ‐level: 0.007) . Furthermore, a more recent meta‐analysis investigating the association between vegetarian diets and inflammatory biomarkers found that a vegetarian diet might be a useful approach to manage inflammation in the long term …”

Associations of a vegan diet with inflammatory biomarkers

“…These studies showed conflicting results. Whereas Franco-de-Moraes et al 16 observed higher CRP levels in omnivores compared to vegans, Šebeková et al 15 noticed no differences in CRP levels. The latter is in line with our results.…”

“…Indeed, there are no studies, which perform comprehensive analyses to investigate the association of a vegan diet on the inflammatory profile. Accordingly, until now, only two studies provide data on inflammatory biomarkers in vegans (n = 9) 15 or strict vegetarians (animal products less than once a month, n = 66) 16 as small subgroups, while mainly investigating advanced glycation end products 15 or gut microbiota composition 16 in a vegetarian population. These studies showed conflicting results.…”

TAG.ME: Taxonomic Assignment of Genetic Markers for Ecology

“…Gut and root microbiomes. TAG.ME performance was further compared with DADA2 on two real-world scenarios involving gut [21] and roots samples [22]. In these cases, both DADA2+RDP and DADA2+SILVA versions were compared.…”

“…Two published datasets were used to evaluate the performance of sequenced data. The dataset available under the accession PRJEB19103 [21] represents the human gut environment, and accession PRJEB15671 [22] represents the root ecosystem. The amplicon sequence variants (ASVs) were identified using the DADA2 workflow.…”