Use your antibiotics wisely. Consequences to the intestinal microbiome

Ocular Rosacea microBiome Study (ORBS)-sub-microbial versus antibiotic dosing of doxycycline versus placebo in treatment of symptomatic ocular rosacea: study protocol for a parallel-arm randomized clinical trial

BACKGROUND

Ocular rosacea is common and is often managed with long-term antibiotic treatment. Doxycycline is the most commonly selected antibiotic for the treatment of rosacea. As there is no established standard of care treatment dose for rosacea, prescribed doses of doxycycline vary widely. The FDA classifies 40 mg daily dose of doxycycline for ocular rosacea as sub-microbial in comparison to an antibiotic dose of 200 mg daily. However, this "sub-microbial" dose has never been evaluated in patients with ocular rosacea, and even the sub-microbial dose has potential to alter systemic mucosa flora. Here, we present a randomized controlled trial using RNA sequencing to fully characterize the impact of sub-microbial antibiotic dosing of doxycycline on antimicrobial resistance and bacterial composition of the ocular and gut flora.

METHODS

In a triple-masked parallel randomized control trial, patients with ocular rosacea will be randomized to three arms: a 40-mg dose of doxycycline, a 200-mg antibiotic dose of doxycycline, or placebo. Collected rectal and lower eyelid samples will be compared for frequency of antimicrobial resistance genetic determinants and microbiome diversity. A subjective ocular surface disease index survey and objective tear breakup time measurement will be determined.

DISCUSSION

These results will enhance our understanding of the overall systemic impact of long-term systemic sub-microbial antibiotic dosing for the treatment of chronic recurrent ocular inflammatory diseases.

TRIAL REGISTRATION

This trial was registered on ClinicalTrials.org (NCT05296837) on March 22, 2022.

[Infection prevention in neonatal intensive care units]

In diesem Beitrag werden einige Besonderheiten der Infektionsprävention bei intensivmedizinisch behandelten Früh und Neugeborenen dargestellt. Ergänzend finden sich Hinweise zum krankenhaushygienischen Management der SARS-CoV-2(„severe acute respiratory syndrome coronavirus 2“)-Pandemie und zur Antibiotic Stewardship in der neonatologischen Intensivmedizin.

Antibiotics Modulate Intestinal Regeneration

Simple Summary

The impact of the microbial community on host’s biological functions has uncovered the potential outcomes of antibiotics on host physiology, introducing the caveats of the antibiotic usage. Within animals, the digestive function is closely related to the microorganisms that inhabit this organ. The proper maintenance of the digestive system requires constant regeneration. These processes vary from self-renewal of some cells or tissues in some species to the complete regeneration of the organ in others. Whether antibiotics influence digestive organ regeneration remains unknown. We employ the sea cucumber, Holothuria glaberrima, for its capacity to regenerate the whole intestine after ejection from its internal cavity. We explored the antibiotics’ effects on several intestinal regeneration processes. In parallel, we studied the effect of antibiotics on the animals’ survival, toxicity, and gut bacteria growth. Our results show that tested antibiotics perturbed key cellular processes that occur during intestinal regeneration. Moreover, this happens at doses that inhibited bacteria growth but did not alter holothurian’s metabolic activity. We propose that antibiotics can perturb the cellular events of intestinal regeneration via their impact on the microbiota. These results highlight H. glaberrima as a promising model to study the importance of the microbiota during organ regeneration.

Abstract

The increased antibiotics usage in biomedical and agricultural settings has been well documented. Antibiotics have now been shown to exert effects outside their purposive use, including effects on physiological and developmental processes. We explored the effect of various antibiotics on intestinal regeneration in the sea cucumber Holothuria glaberrima. For this, holothurians were eviscerated and left to regenerate for 10 days in seawater with different penicillin/streptomycin-based cocktails (100 µg/mL PS) including: 100 µg/mL kanamycin (KPS), 5 µg/mL vancomycin (VPS), and 4 µg/mL (E4PS) or 20 µg/mL (E20PS) erythromycin. Immunohistological and histochemical analyses were performed to analyze regenerative processes, including rudiment size, extracellular matrix (ECM) remodeling, cell proliferation, and muscle dedifferentiation. A reduction in muscle dedifferentiation was observed in all antibiotic-treated animals. ECM remodeling was decreased by VPS, E4PS, and E20PS treatments. In addition, organisms subjected to E20PS displayed a significant reduction in the size of their regenerating rudiments while VPS exposure altered cell proliferation. MTT assays were used to discard the possibility that the antibiotics directly affect holothurian metabolic activity while bacterial cultures were used to test antibiotic effects on holothurian enteric microbiota. Our results demonstrate a negative effect on intestinal regeneration and strongly suggest that these effects are due to alterations in the microbial community.

Alveolar microbiota profile in patients with human pulmonary tuberculosis and interstitial pneumonia

BACKGROUND

The presence of the human lung microbiota has been demonstrated in patients with different lung diseases, mainly in sputum samples. However, for study of the alveolar microbiota, a bronchoalveolar lavage (BAL) sample represents the lower respiratory tract (LRT) environment. It is currently unknown whether there is a specific alveolar microbiota profile in human lung diseases, such as pulmonary tuberculosis (TB) and interstitial pneumonia (IP).

METHODS

BAL samples from six active TB patients, six IP patients and ten healthy volunteers were used for DNA extraction followed by amplification of the complete bacterial 16S ribosomal RNA gene (16S rDNA). The 16S rDNA was sequenced with a MiSeq Desktop Sequencer, and the data were analysed by QIIME software for taxonomic assignment.

RESULTS

The alveolar microbiota in TB and IP patients and healthy volunteers was characterized by six dominant phyla, Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, Fusobacteria and Cyanobacteria. A significant reduction in the abundance of Firmicutes was observed in IP patients. In TB and IP patients, the diversity of the alveolar microbiota was diminished, characterized by a significant reduction in the abundance of the Streptococcus genus and associated with increased Mycobacterium abundance in TB patients and diminished Acinetobacter abundance in IP patients with respect to their abundances in healthy volunteers. However, an important difference was observed between TB and IP patients: the Fusobacterium abundance was significantly reduced in TB patients. Exclusive genera that were less abundant in patients than in healthy volunteers were characterized for each study group.

CONCLUSIONS

This study shows that the alveolar microbiota profile in BAL samples from TB and IP patients, representing infectious and non-infectious lung diseases, respectively, is characterized by decreased diversity.

Life-long antimicrobial therapy: where is the evidence?

The decision to prescribe long-term or 'life-long' antibiotics in patients requires careful consideration by the treating clinician. While several guidelines exist to help assist in this decision, the long-term consequences are yet to be well studied. In this review, we aim to provide a summary of the available evidence for patient populations where long-term antibiotic therapy is currently recommended in clinical practice. We will also discuss the pitfalls of this approach, including medication adverse effects, economic cost and any possible contribution to the emerging epidemic of microbial resistance.

Gut microbiota composition associated with alterations in cardiorespiratory fitness and psychosocial outcomes among breast cancer survivors

PURPOSE

In this proof-of-concept pilot study, our purpose was to determine correlations between gut microbiota composition and alterations in cardiorespiratory fitness and psychosocial outcomes among post-primary treatment breast cancer survivors (BCS).

METHODS

Composition of the gut microbiota in BCS (n = 12) was assessed at baseline (M0) and at the end of 3 months (M3) using Illumina MiSeq DNA Sequencing of the 16S rRNA gene. Gut microbiota composition was analyzed using the QIIME bioinformatics software and represented through diversity metrics and taxa analyses. Cardiorespiratory fitness, fatigue, anxiety, depression, and sleep dysfunction were assessed at M0 and M3 via the submaximal treadmill test, Fatigue Symptom Inventory, Hospital Anxiety and Depression Scale, and Pittsburgh Sleep Quality Index, respectively.

RESULTS

Increased fatigue interference in BCS was associated with increased mean within-sample Shannon diversity (organism richness and evenness) (p = 0.009). Weighted UniFrac analysis (shifts in taxa relative abundance) revealed significant differences in between-sample (beta) diversity for changes in fatigue interference (p = 0.01) and anxiety (p = 0.022), with a trend observed for fatigue intensity and sleep dysfunction (p < 0.1). Unweighted UniFrac analysis (shifts in taxa types) found significant beta diversity differences for cardiorespiratory fitness (p = 0.026). Prior to false discovery correction (FDR), changes in fitness, fatigue, anxiety, and sleep dysfunction were associated with the frequency of certain gut bacteria genera (e.g., Faecalibacterium, Prevotella, Bacteroides) (p < 0.05).

CONCLUSIONS

Correlations may exist between alterations in gut microbiota composition and longitudinal changes in cardiorespiratory fitness, fatigue, and anxiety in BCS. Further research examining the role of the microbiota-gut-brain axis in exercise-induced effects on psychosocial outcomes in BCS is warranted.