Research News

The oral microbiota as a potential source of information in irritable bowel syndrome

Tuesday, 04 October 2016 12:02

Recent research advances have revolutionized our understanding of the oral microbiota and its role in health. Although stool or gastrointestinal (GI) mucosa samples have often been used for microbiota characterization, the oral cavity microbiota in both in GI conditions and non-oral-non-GI conditions is attracting the interest of a growing number of scientists. Perturbations in gut bacterial communities may be reflected in the oral microbiota and this suggests that either acute or subtle alterations in oral bacterial communities could be a useful indicator of disease.

A recent study, led by Dr. Wendy A. Henderson from the National Institute of Nursing Research at National Institutes of Health (NIH) in Bethesda (USA), and co-authored by Research Fellow Dr. Nicolaas Fourie, has found that the oral microbiota could be a useful source of information in patients with irritable bowel syndrome (IBS).

“We were interested in whether or not we could see differences between those with IBS [and healthy controls] by looking at the oral mucosa,” explained Henderson in a phone interview with GMFH editors.

In order to study oral microbial perturbations and their relationship with symptom severity in patients with IBS, 20 participants with IBS and 20 healthy controls were recruited. In the study group were individuals who had suffered from chronic visceral pain and altered bowel habits for more than six months without any organic underlying cause (Rome III criteria). Participants were subtyped as IBS-diarrhoea, IBS-constipation or IBS-mixed.

Henderson says her group used a test solution, formulated by the NIH pharmacy, as a gastrointestinal stressor. The test solution comprised a mixture of absorbable and non-absorbable sugars (sucrose, lactulose, sucralose, and mannitol) that enabled researchers to test for gastrointestinal permeability. The researchers orally administered 100mL of the solution after an overnight fast and asked participants to self-report the induced pain (See here for the protocol).

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The potential of probiotics and diets to reverse asocial behaviours in mice that are seen in autism spectrum disorders

Tuesday, 04 October 2016 11:53

It has been previously suggested that a high-fibre diet can prevent neurodegeneration by increasing gut microbiota derived butyrate in the colon, but how changes in gut bacteria could influence brain development and function is still poorly studied.

A recent study, led by Dr. Mauro Costa-Mattioli from the Baylor College of Medicine in Houston, Texas (USA), has found that the reintroduction of a commensal bacterial strain can reverse asocial behaviours in mice that are seen in autism spectrum disorders (ASDs).

Previous human epidemiological studies that have found that maternal obesity during pregnancy could increase children’s risk of neurodevelopmental disorders, including ASDs. Besides this, recurrent gastrointestinal problems are frequently reported in individuals with ASDs. Based on these observations, the researchers sought to explore the connections between changes in diet, the gut microbiome, and social behaviours.

First of all, female mice were fed either a regular diet (RD, consisting of 13.4% kcal from fat, 30% kcal from protein, and 57% kcal from carbohydrates) or a high-fat diet (HFD, consisting of 60% kcal from fat, 20% kcal from protein, and 20% kcal from carbohydrates) for 8 weeks. Females then were paired with males to produce offspring that all were given RD after weaning. Maternal high-fat diet (MHFD) significantly increased maternal weight. At 7-12 weeks of age behavioural and electrophysiological experiments were performed in order to study social behaviour in maternal regular diet (MRD) and maternal high-fat diet offspring. Maternal high-fat diet offspring displayed impaired sociability and dysbiosis of the gut microbiota.

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Fitness may predict a diverse gut microbiota in healthy people

Tuesday, 04 October 2016 11:47

It has been previously found that exercise may play an important role in the overall health of the host by contributing to the diversity of gut microbiota. However, extreme dietary differences, especially high protein intakes, amongst the elite athletes studied may confound interpretations about the specific role of exercise in determining gut bacterial richness. How physical fitness contributes to intestinal microbial diversity is currently not known.

A recent study, led by Dr. Deanna L. Gibson from the Department of Biology at the University of British Columbia (Canada), has found that cardiorespiratory fitness is correlated with increased microbial diversity and increased production of faecal butyrate in healthy humans.

he researchers used high-throughput sequencing to analyse faecal microbiota of 39 healthy participants with similar age, body mass index, and diet, but with varying cardiorespiratory fitness (CRF) levels, as assessed by the peak oxygen uptake (VO2peak). Faecal short-chain fatty acids (SCFAs) were also analysed using gas chromatography.

Diet was not a confounding factor across fitness groups, as there was a lack of distinct dietary patterns amongst all fitness groups (low fitness, n=14; average fitness, n=12 and high fitness, n=13). It was shown that VO2peak, an indicator of physical fitness, accounted for more than 20% of the variation in taxonomic richness, after accounting for all other factors such as diet. Although VO2peak was not associated with specific bacterial taxa, it was correlated with distinct microbiome functions including chemotaxis, motility, and fatty acid biosynthesis.

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Concordat on Open Research Data developed by a UK multi-stakeholder group

Friday, 30 September 2016 10:55

This concordat will help to ensure research data gathered and generated by members of the UK research community is, wherever possible, made openly available for use by others in a manner consistent with relevant legal, ethical and regulatory frameworks and disciplinary norms, and with due regard to the costs involved.

The benefits from opening up research data for scrutiny and reuse are potentially very significant; including economic growth, increased resource efficiency, securing public support for research funding and increasing public trust in research. However, the concordat recognises that access may need to be managed in order to maintain confidentiality, protect individuals’ privacy, respect consent terms, as well as managing security or other risks.

Openness implies more than disclosure of data. All those engaged with research have a responsibility to ensure the data they gather and generate is properly managed, and made accessible, intelligible, assessable and usable by others unless there are legitimate reasons to the contrary. Access to research data therefore carries implications for cost and there will need to be trade-offs that reflect value for money and use.

Commitment to the principles set out in the concordat will help demonstrate to government, business, international partners, other researchers and the wider public that, where appropriate, they can expect to see research data made open for the benefit of all. Such commitment will also ensure the results of research are properly open to scrutiny, with the data that underlies the concepts and arguments set out in published papers made accessible for testing and validation by other researchers, reinforcing the vital principle of self-correction.

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