Intestinal microbiota composition of patients with Behçet's disease: differences between eye, mucocutaneous and vascular involvement. The Rheuma-BIOTA study

OBJECTIVES

Changes in microbiota composition affect the aetiology and patho-genesis of chronic diseases, including Behçet's disease (BD). However, no studies have analysed the potential gut microbiota changes among different clinical forms of BD. This study evaluated the intestinal microbiota composition of patients with BD and healthy controls and also compared differences between patients with BD with respect to eye, mucocutaneous, and vascular involvement.

METHODS

In this prospective cohort study, 27 patients diagnosed with BD according to the International Study Group criteria and 10 age- and sex-matched healthy controls were included. Detailed intestinal microbiota analysis was performed.

RESULTS

There were no differences between the BD group and the control group in terms of alpha and beta microbial diversity and abundance indices (p>0.05). Actinomyces, Libanicoccus, Collinsella, Eggerthella, Enetrohabdus, Catenibacterium, and Enterobacter were significantly higher in the BD group than in the control group. In addition, Bacteroides, Cricetibacter, Alistipes, Lachnospira, Dielma, Akkermansia, Sutterella, Anaerofilum, Ruminococcease-UCG007, Acetanaerobacterium, and Copropaacter were lower in the BD group than in the control group. When we compared three different system involvement (eye, mucocutaneous, and vascular), the linear discriminant analysis effective size revealed a difference for the following genera: Lachnospiraceae NK4A136 in the uveitis group; Dialister, Intestinomonas, and Marvinbryantia in the mucocutaneous group; and Gemella in the vascular group.

CONCLUSIONS

The composition of intestinal microbiota was significantly different in patients with BD compared with healthy adults. Ours is the first study to show differences in microbiota composition in isolated mucocutaneous, eye, and vascular involvement. These findings should be evaluated in a larger series.

The Endobiota Study: Comparison of Vaginal, Cervical and Gut Microbiota Between Women with Stage 3/4 Endometriosis and Healthy Controls

Dysbiosis in the genital tract or gut microbiome can be associated with endometriosis. We sampled vaginal, cervical and gut microbiota from 14 women with histology proven stage 3/4 endometriosis and 14 healthy controls. The V3 and V4 regions of the 16S rRNA gene were amplified following the 16S Metagenomic Sequencing Library Preparation. Despite overall similar vaginal, cervical and intestinal microbiota composition between stage 3/4 endometriosis group and controls, we observed differences at genus level. The complete absence of Atopobium in the vaginal and cervical microbiota of the stage 3/4 endometriosis group was noteworthy. In the cervical microbiota, Gardnerella, Streptococcus, Escherichia, Shigella, and Ureoplasma, all of which contain potentially pathogenic species, were increased in stage 3/4 endometriosis. More women in the stage 3/4 endometriosis group had Shigella/Escherichia dominant stool microbiome. Further studies can clarify whether the association is causal, and whether dysbiosis leads to endometriosis or endometriosis leads to dysbiosis.

The microbiome in respiratory medicine: current challenges and future perspectives

The healthy lung has previously been considered to be a sterile organ because standard microbiological culture techniques consistently yield negative results. However, culture-independent techniques report that large numbers of microorganisms coexist in the lung. There are many unknown aspects in the field, but available reports show that the lower respiratory tract microbiota: 1) is similar in healthy subjects to the oropharyngeal microbiota and dominated by members of the Firmicutes, Bacteroidetes and Proteobacteria phyla; 2) shows changes in smokers and well-defined differences in chronic respiratory diseases, although the temporal and spatial kinetics of these changes are only partially known; and 3) shows relatively abundant non-cultivable bacteria in chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis and bronchiectasis, with specific patterns for each disease. In all of these diseases, a loss of diversity, paralleled by an over-representation of Proteobacteria (dysbiosis), has been related to disease severity and exacerbations. However, it is unknown whether dysbiosis is a cause or a consequence of the damage to bronchoalveolar surfaces.Finally, little is known about bacterial functionality and the interactions between viruses, fungi and bacteria. It is expected that future research in bacterial gene expressions, metagenomics longitudinal analysis and host-microbiome animal models will help to move towards targeted microbiome interventions in respiratory diseases.