Publications by authors named "Ciara O'Donovan"

Restricted sugar and ketogenic diets can alter energy balance/metabolism, but decreased energy intake may be compensated by reduced expenditure. In healthy adults, randomization to restricting free sugars or overall carbohydrates (ketogenic diet) for 12 weeks reduces fat mass without changing energy expenditure versus control. Free-sugar restriction minimally affects metabolism or gut microbiome but decreases low-density lipoprotein cholesterol (LDL-C).

View Article and Find Full Text PDF

Nisin is a broad spectrum bacteriocin used extensively as a food preservative that was identified in Lactococcus lactis nearly a century ago. We show that orally-ingested nisin survives transit through the porcine gastrointestinal tract intact (as evidenced by activity and molecular weight determination) where it impacts both the composition and functioning of the microbiota. Specifically, nisin treatment caused a reversible decrease in Gram positive bacteria, resulting in a reshaping of the Firmicutes and a corresponding relative increase in Gram negative Proteobacteria.

View Article and Find Full Text PDF

Artisanal fermented products (foods and beverages) are produced in an artisanal way in many countries around the world. The main purpose of fermentation is to preserve the food, improve its safety, increase the nutritional and health-promoting value and add specific flavours. In South America, there is a great variety of fermented food produced in an artisanal way.

View Article and Find Full Text PDF

Macroevolution posed difficulties for Darwin and later theorists because species' phenotypes frequently change abruptly, or experience long periods of stasis, both counter to the theory of incremental change or gradualism. We introduce a statistical model that accommodates this uneven evolutionary landscape by estimating two kinds of historical change: directional changes that shift the mean phenotype along the branches of a phylogenetic tree, and evolvability changes that alter a clade's ability to explore its trait-space. In mammals, we find that both processes make substantial independent contributions to explaining macroevolution, and are rarely linked.

View Article and Find Full Text PDF

As with much of science, the female athlete is under researched, particularly in the area of gastrointestinal (GI) physiology. Gut function is of pivotal importance to athletes in that it supports digestion and absorption of nutrients, as well as providing a barrier between the external environment and the circulation. While sex-derived differences in GI structure and function have been well characterised at rest, there remains a paucity of data examining this during exercise.

View Article and Find Full Text PDF

Background: Changes and stresses experienced during travel have the potential to impact the gut microbiome, with travel implicated in the spread of antibiotic resistance genes across continents. The possibility of gut microbiome-mediated negative impacts arising from travel, and consequences for peak performance, would be of particular concern for elite athletes.

Methods: Faecal samples were collected from male (N = 14) and female (N = 7) cricket players during the build-up to the 2016 Cricket World Cup.

View Article and Find Full Text PDF

Objectives: The gut microbiome has begun to be characterised in athlete groups, albeit, to date, only across a subset of sports. This study aimed to determine if the gut microbiome and metabolome differed across sports classification groups (SCGs) among elite Irish athletes, many of whom were participating in the 2016 Summer Olympics.

Methods: Faecal and urine samples were collected from 37 international level athletes.

View Article and Find Full Text PDF

Dinosaurs dominated terrestrial ecosystems across the globe for over 100 million years and provide a classic example of an evolutionary radiation. However, little is known about how these animals radiated geographically to become globally distributed. Here, we use a biogeographical model to reconstruct the dinosaurs' ancestral locations, revealing the spatial mechanisms that underpinned this 170-million-year-long radiation.

View Article and Find Full Text PDF

A prototype respirometric biochip dedicated to monitoring oxygen consumption of preimplantation embryos has been developed. The biochip comprises a linear array of eight flow-through microchambers profiled on silicon substrate, and functions together with a phosphorescent oxygen sensitive probe and fluorescence plate reader detection. A high level of sensitivity to changes in dissolved oxygen was achieved through miniaturisation and optimization of biochip geometry, and incorporation of appropriate sealing and humidification systems.

View Article and Find Full Text PDF

We present a new methodology for testing physiological responses of small organisms (size 70-500 microm) via changes in their oxygen respiration monitored by quenched-phosphorescence oxygen sensing on a scale of a single organism. The method is demonstrated using three different formats of respirometric assays, Artemia salina and mouse embryos as model animals, and various effectors including compounds that induce and prevent superoxide-mediated and heavy metal ion toxicity. These assays, which employ soluble oxygen probes, standard fluorescent readers, and accessorytools, provide sensitive, noninvasive, real-time monitoring of animal respiration, and rapid assessment of EC50, sublethal effects, and metabolic alterations.

View Article and Find Full Text PDF