Fecal virome transfer improves proliferation of commensal gut Akkermansia muciniphila and unexpectedly enhances the fertility rate in laboratory mice.

Probiotics are intended to improve gastrointestinal health when consumed. However, the probiotics marketed today only colonize the densely populated gut to a limited extent. Bacteriophages comprise the majority of viruses in the human gut virome and there are strong indications that they play important roles in shaping the gut microbiome. Here, we investigate the use of fecal virome transplantation (FVT, sterile filtrated feces) as a mean to alter the gut microbiome composition to lead the way for persistent colonization of two types of probiotics: Lacticaseibacillus rhamnosus GG (LGG) representing a well-established probiotic and Akkermansia muciniphila (AKM) representing a putative next-generation probiotic. Male and female C57BL/6NTac mice were cohoused in pairs from 4 weeks of age and received the following treatment by oral gavage at week 5 and 6: AKM+FVT, LGG+FVT, probiotic sham (Pro-sham)+FVT, LGG+Saline, AKM+Saline, and control (Pro-sham+Saline). The FVT donor material originated from mice with high relative abundance of A. muciniphila. All animals were terminated at age 9 weeks. The FVT treatment did not increase the relative abundance of the administered LGG or AKM in the recipient mice. Instead FVT significantly (p < 0.05) increased the abundance of naturally occurring A. muciniphila compared to the control. This highlights the potential of propagating the existing commensal "probiotics" that have already permanently colonized the gut. Being co-housed male and female, a fraction of the female mice became pregnant. Unexpectedly, the FVT treated mice were found to have a significantly (p < 0.05) higher fertility rate independent of probiotic administration. These preliminary observations urge for follow-up studies investigating interactions between the gut microbiome and fertility.

Characterization of the Vaginal DNA Virome in Health and Dysbiosis.

Bacterial vaginosis (BV) is characterized by a reduction in Lactobacillus (L.) spp. abundance and increased abundance of facultative anaerobes, such as Gardnerella spp. BV aetiology is not fully understood; however, bacteriophages could play a pivotal role in the perturbation of the vaginal bacterial community. We investigated the vaginal viral community, including bacteriophages and the association to the bacterial community and BV-status. Vaginal samples from 48 patients undergoing IVF treatment for non-female factor infertility were subjected to metagenomic sequencing of purified virus-like particles. The vaginal viral community was characterized and correlated with the BV-status by Nugent score, bacterial community, structure, and the presence of key vaginal bacterial species. The majority of identified vaginal viruses belonged to the class of double-stranded DNA bacteriophages, with eukaryotic viruses constituting 4% of the total reads. Clear links between the viral community composition and BV (q = 0.006, R = 0.26) as well as the presence of L. crispatus (q = 0.001, R = 0.43), L. iners, Gardnerella spp., and Atopobium vaginae were found (q < 0.002, R > 0.15). The eukaryotic viral community also correlated with BV-status (q = 0.018, R = 0.20). In conclusion, the vaginal virome was clearly linked with bacterial community structure and BV-status.

Faecal virome transplantation decreases symptoms of type 2 diabetes and obesity in a murine model.

OBJECTIVE: Development of obesity and type 2 diabetes (T2D) are associated with gut microbiota (GM) changes. The gut viral community is predominated by bacteriophages (phages), which are viruses that attack bacteria in a host-specific manner. The antagonistic behaviour of phages has the potential to alter the GM. As a proof-of-concept, we demonstrate the efficacy of faecal virome transplantation (FVT) from lean donors for shifting the phenotype of obese mice into closer resemblance of lean mice. DESIGN: The FVT consisted of viromes with distinct profiles extracted from the caecal content of mice from different vendors that were fed a low-fat (LF) diet for 14 weeks. Male C57BL/6NTac mice were divided into five groups: LF (as diet control), high-fat (HF) diet, HF+ampicillin (Amp), HF+Amp+FVT and HF+FVT. At weeks 6 and 7 of the study, the HF+FVT and HF+Amp+FVT mice were treated with FVT by oral gavage. The Amp groups were treated with Amp 24 hours prior to first FVT treatment. RESULTS: Six weeks after first FVT, the HF+FVT mice showed a significant decrease in weight gain compared with the HF group. Further, glucose tolerance was comparable between the LF and HF+FVT mice, while the other HF groups all had impaired glucose tolerance. These observations were supported by significant shifts in GM composition, blood plasma metabolome and expression levels of genes associated with obesity and T2D development. CONCLUSIONS: Transfer of caecal viral communities from mice with a lean phenotype into mice with an obese phenotype led to reduced weight gain and normalised blood glucose parameters relative to lean mice. We hypothesise that this effect is mediated via FVT-induced GM changes.

Draft Genome Sequence of Streptococcus anginosus Strain CALM001, Isolated from the Gut of an Elderly Dane.

Here, we present a 1.89-Mbp draft genome sequence of Streptococcus anginosus strain CALM001, a Gram-positive bacterium that was isolated from a fecal sample donated by a 70-year-old Dane enrolled in the Counteracting Age-Related Loss of Skeletal Muscle Mass (CALM) intervention study.

Kombucha Beverage from Green, Black and Rooibos Teas: A Comparative Study Looking at Microbiology, Chemistry and Antioxidant Activity.

Kombucha is usually obtained from the fermentation of black or green tea by a consortium of acetic acid bacteria and yeasts. In this study, kombucha was prepared from the same starter consortium using green and black teas as well as, for the first time, an infusion of rooibos leaves (Aspalathus linearis). Microbial diversity was analysed during fermentation both in the biofilm and in the corresponding kombuchas, using culture-dependent and -independent methods. Polyphenols, flavonoids, ethanol, and acids were quantified and anti-oxidant activities were monitored. All of the Kombuchas showed similarity in bacterial composition, with the dominance of Komagataeibacter spp. Beta diversity showed that the yeast community was significantly different among all tea substrates, between 7 and 14 days of fermentation and between biofilm and kombucha, indicating the influence of the substrate on the fermenting microbiota. Kombucha from rooibos has a low ethanol concentration (1.1 mg/mL), and a glucuronic acid amount that was comparable to black tea. Although antioxidant activity was higher in black and green kombucha compared to rooibos, the latter showed an important effect on the recovery of oxidative damage on fibroblast cell lines against oxidative stress. These results make rooibos leaves interesting for the preparation of a fermented beverage with health benefits.

Counteracting Age-related Loss of Skeletal Muscle Mass: a clinical and ethnological trial on the role of protein supplementation and training load (CALM Intervention Study): study protocol for a randomized controlled trial.

BACKGROUND: Aging is associated with decreased muscle mass and functional capacity, which in turn decrease quality of life. The number of citizens over the age of 65 years in the Western world will increase by 50 % over the next four decades, and this demographic shift brings forth new challenges at both societal and individual levels. Only a few longitudinal studies have been reported, but whey protein supplementation seems to improve muscle mass and function, and its combination with heavy strength training appears even more effective. However, heavy resistance training may reduce adherence to training, thereby attenuating the overall benefits of training. We hypothesize that light load resistance training is more efficient when both adherence and physical improvement are considered longitudinally. We launched the interdisciplinary project on Counteracting Age-related Loss of Skeletal Muscle Mass (CALM) to investigate the impact of lifestyle changes on physical and functional outcomes as well as everyday practices and habits in a qualitative context. METHODS: We will randomize 205 participants older than 65 years to be given 1 year of two daily nutrient supplements with 10 g of sucrose and 20 g of either collagen protein, carbohydrates, or whey. Further, two groups will perform either heavy progressive resistance training or light load training on top of the whey supplement. DISCUSSION: The primary outcome of the CALM Intervention Study is the change in thigh cross-sectional area. Moreover, we will evaluate changes in physical performance, muscle fiber type and acute anabolic response to whey protein ingestion, sensory adaptation, gut microbiome, and a range of other measures, combined with questionnaires on life quality and qualitative interviews with selected subjects. The CALM Intervention Study will generate scientific evidence and recommendations to counteract age-related loss of skeletal muscle mass in elderly individuals. TRIAL REGISTRATION: ClinicalTrials.gov NCT02034760 . Registered on 10 January 2014. ClinicalTrials.gov NCT02115698 . Registered on 14 April 2014. Danish regional committee of the Capital Region H-4-2013-070. Registered on 4 July 2013. Danish Data Protection Agency 2012-58-0004 - BBH-2015-001 I-Suite 03432. Registered on 9 January 2015.

Host-Specific and pH-Dependent Microbiomes of Copepods in an Extensive Rearing System.

Copepods are to an increasing extent cultivated as feed for mariculture fish larvae with variable production success. In the temperate climate zone, this production faces seasonal limitation due to changing abiotic factors, in particular temperature and light. Furthermore, the production of copepods may be influenced by biotic factors of the culture systems, such as competing microorganisms, harmful algae, or other eukaryotes and prokaryotes that may be non-beneficial for the copepods. In this study, the composition of bacteria associated with copepods was investigated in an extensive outdoor copepod production system. Light microscopy and scanning electron microscopy revealed that bacteria were primarily found attached to the exoskeleton of copepods although a few bacteria were also found in the gut as well as internally in skeletal muscle tissue. Through 16S rRNA gene-targeted denaturing gradient gel electrophoresis (DGGE) analysis, a clear difference was found between the microbiomes of the two copepod species, Acartia tonsa and Centropages hamatus, present in the system. This pattern was corroborated through 454/FLX-based 16S rRNA gene amplicon sequencing of copepod microbiomes, which furthermore showed that the abiotic parameters pH and oxygen concentration in rearing tank water were the key factors influencing composition of copepod microbiomes.

Initial adhesion of Listeria monocytogenes to fine polished stainless steel under flow conditions is determined by prior growth conditions.

Listeria monocytogenes is a food-borne pathogen known to persist in food production environments, where it is able to attach and form biofilms, potentially contaminating food products ready for consumption. In this study the first step in the establishment of L. monocytogenes in a food-processing environment was examined, namely the initial adhesion to stainless steel under specific dynamic flow conditions. It was found that the intrinsic ability of L. monocytogenes to adhere to solid surfaces under flow conditions is dependent on nutrient availability. The addition of L-leucine to the growth medium altered the fatty acid composition of the L. monocytogenes cells and increased adhesion. The growth conditions resulting in the highest adhesion (growth medium with added glucose) had cells with the highest electron donating and lowest electron accepting properties, whereas growth conditions resulting in lowest adhesion (growth medium with added mannose) had cells with the lowest electron donating properties and highest electron accepting properties. The highest and lowest adhesion conditions correlated with differences in expression of cell surface protein of L. monocytogenes and among these the autolysin amidase (Ami). This study implies that food composition influences the adhesion of L. monocytogenes to solid surfaces during dynamic flow conditions.