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Long-read-metagenomic sequencing is the best method for analyzing the sinus microbiome. 16s-rRNA-sequencing (both long and short read) results in PCR amplification bias that significantly distorts the sinus microbiome.
BACKGROUND: The compound 3-nitrooxypropanol (3-NOP), an inhibitor of methyl-coenzyme M reductase (MCR), reduces enteric methane production in both beef and dairy cattle. Although the proposed mechanisms of 3-NOP involve on inhibiting the activity of MCR in vivo, it is unknown how this process could affect rumen microbiome as a whole and if it differs between beef and dairy cattle. This study conducted a comparative analysis of the rumen microbiome and its functional shifts in four different cattle studies (two beef and two dairy cattle studies) that evaluated 3-NOP supplementation using metataxonomics and metagenomics. RESULTS: Comparative analysis of 281 rumen metataxonomic datasets (143 beef and 138 dairy cattle) revealed that dietary supplementation with 3-NOP affected rumen bacteria and methanogens. Further, comparative analysis of 54 metagenomic datasets (24 beef and 30 dairy cattle) revealed that 3-NOP inhibited mcrA, decreased the abundances of Methanobrevibacter gottschalkii and the protozoal species Isotricha prostoma, while increased the abundances of Methanobrevibacter ruminantium and Methanosphaera sp., Prevotella sp. was a significant bacterial taxon in both beef and dairy cattle, contributing to various pathways such as propionate and butyrate production. Its increased abundance after 3-NOP supplementation may also be linked to the decrease in Isotricha prostoma. Hydrogenotrophic methanogenesis decreased after 3-NOP supplementation with the abundance of genes involved in methylenetetrahydromethanopterin dehydrogenase decreased in beef cattle, while that of 4Fe-4S ferredoxin gene decreased in dairy cattle. The abundance of protozoal Polyplastron multivesiculatum increased after long-term 3-NOP supplementation in beef cattle, potentially due to changes in hydrogen (H2) partial pressure. During 3-NOP-mediated methanogenesis reduction, abundance of genes encoding methanogenic hydrogenase and H2 producing hydrogenase were decreased, while those encoding H2 sensory hydrogenase increased. Acyl-CoA dehydrogenase gene involved in propionate and butyrate production pathways increased in both beef and dairy cattle, while nitrite reductase increased specifically in beef cattle, indicating a rise in alternative H2 sinks. Video Abstract CONCLUSION: Our findings revealed broad effects of 3-NOP on rumen microbiome and functions in vivo, with varied effects in beef and dairy cattle, which provide mechanistic insights into the supplementation of 3-NOP in both beef and dairy cattle, supporting its more sustainable and effective use in the future.
This study aimed to evaluate the gut microbiota and mycobiota composition, depending on the Mediterranean diet (MD) adherence, using metataxonomics. Combining metagenomics and metatranscriptomics, we also investigate the gene expression level in the bacterial community. Two groups of healthy subjects greatly differing in adherence were selected. Significant differences in microbiota composition were observed between individuals with high adherence (HAMD; mean 10.5 +/- 0.9 points) and low adherence (LAMD; 5.23 +/- 83 points). Notably, the olive oil, vegetable, and fruit consumption presented an important discriminant power between groups. Saccharomyces, Penicillium, and Candida were the most abundant genera. Mycobiota richness was higher in LAMD than in HAMD. Aspergillus was identified as a biomarker for LAMD, whereas Yarrowia, a potential probiotic, was a biomarker for HAMD. Metatranscriptomics indicated that Bacillota was the most metabolically active phylum in the gut microbiota. The low-abundant genus, Methanobrevibacter, showed high transcriptional activity, contributing to the crucial methanogenesis process. Gene expression analyses further highlighted functional differences. Overall, HAMD microbiota presented increased metabolic activity, protein synthesis, and cellular mobility. Overexpression of flagellin and urease genes may enhance immune response in HAMD. Further metatranscriptomic studies are necessary to deepen our understanding of intestinal microbiota transcriptional programs and their interactions with the diet and human health.
It has been suggested that the human microbiome might be vertically transmitted from mother to offspring and that early colonizers may play a critical role in development of the immune system. Studies have shown limited support for the vertical transmission of the intestinal microbiota but the derivation of the vaginal microbiota remains largely unknown. Although the vaginal microbiota of children and reproductive age women differ in composition, the vaginal microbiota could be vertically transmitted. To determine whether there was any support for this hypothesis, we examined the vaginal microbiota of daughter-mother pairs from the Baltimore metropolitan area (ages 14-27, 32-51; n = 39). We assessed whether the daughter's microbiota was similar in composition to their mother's using metataxonomics. Permutation tests revealed that while some pairs did have similar vaginal microbiota, the degree of similarity did not exceed that expected by chance. Genome-resolved metagenomics was used to identify shared bacterial strains in a subset of the families (n = 22). We found a small number of bacterial strains that were shared between mother-daughter pairs but identified more shared strains between individuals from different families, indicating that vaginal bacteria may display biogeographic patterns. Earlier-in-life studies are needed to demonstrate vertical transmission of the vaginal microbiota.