[Show abstract][Hide abstract] ABSTRACT: Alterations in the human intestinal microbiota are linked to conditions including inflammatory bowel disease, irritable bowel syndrome, and obesity. The microbiota also undergoes substantial changes at the extremes of life, in infants and older people, the ramifications of which are still being explored. We applied pyrosequencing of over 40,000 16S rRNA gene V4 region amplicons per subject to characterize the fecal microbiota in 161 subjects aged 65 y and older and 9 younger control subjects. The microbiota of each individual subject constituted a unique profile that was separable from all others. In 68% of the individuals, the microbiota was dominated by phylum Bacteroides, with an average proportion of 57% across all 161 baseline samples. Phylum Firmicutes had an average proportion of 40%. The proportions of some phyla and genera associated with disease or health also varied dramatically, including Proteobacteria, Actinobacteria, and Faecalibacteria. The core microbiota of elderly subjects was distinct from that previously established for younger adults, with a greater proportion of Bacteroides spp. and distinct abundance patterns of Clostridium groups. Analyses of 26 fecal microbiota datasets from 3-month follow-up samples indicated that in 85% of the subjects, the microbiota composition was more like the corresponding time-0 sample than any other dataset. We conclude that the fecal microbiota of the elderly shows temporal stability over limited time in the majority of subjects but is characterized by unusual phylum proportions and extreme variability.
Proceedings of the National Academy of Sciences 03/2011; 108 Suppl 1:4586-91. · 9.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess the impact of differing degrees of enamel fluorosis on dental aesthetics according to Irish adolescents. The same participants also aesthetically rated other variations in dental appearances including a carious lesion, bleached teeth and a demarcated opacity.
One hundred and fifty adolescents examined seven identical template photographs of an attractive dental smile displaying varying levels of enamel fluorosis (TF1, TF2, TF3), a demarcated opacity, no fluorosis (TF0), anterior caries and very white or bleached teeth. By indicating their level of agreement or disagreement with five statements on a five-point Likert scale, the participants rated the aesthetic acceptability of each of the photographs.
Using paired t-tests with the Bonferroni correction, it was found that the photographs depicting the very white teeth and anterior caries were rated as the most and least aesthetically pleasing images, respectively. There was no significant difference in the ratings of the photographs displaying TF0, TF1 and TF2 levels of fluorosis indicating that these photographs were viewed similarly (P>0.002). The remaining two photographs (TF3 and the demarcated opacity) were rated similarly and significantly worse (P<0.002) than the photographs showing no or low grades of fluorosis (TF0, TF1 and TF2).
TF3 level of fluorosis represented the break point at which enamel fluorosis became aesthetically objectionable to these participants. Low grades of fluorosis (TF1 and TF2) were rated similarly to the photograph depicting no fluorosis (TF0).
Community Dentistry And Oral Epidemiology 01/2011; 39(2):127-36. · 1.80 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives: To compare the intra-oral distribution of dental caries amongst adults aged 35-44 years in the Republic of Ireland (RoI) and in Northern Ireland (NI).
Methods: Water fluoridation started in Cork in RoI in 1966. In Belfast, NI, the water supplies are not fluoridated. Samples of adults aged 35-44 years in equivalent workplaces in Cork (n=245) and in Belfast (n=240) were included in a study to compare the oral health of adults in the two jurisdictions. The 35-44 year-old age group was targeted because residents of Cork city in this age bracket would have been exposed to water fluoridation most of their lives, when the clinical examinations were conducted in 2008. Equivalent workplaces were targeted in order to balance for socio-economic status, an important determinant of dental caries. The clinical examination included measurement of dental caries, both visual and cavitated, by trained and calibrated examiners.
Initial analysis showed that the mean vDMFS in RoI was 25.1 ( 14.1), significantly lower when compared with 31.8 ( 18.1) in NI (p<0.002), the difference likely to be attributable to water fluoridation rather than variation in the services provided in the two jurisdictions.
Results: The mean vDMFS in anterior teeth (incisors and canines) was 2.9 ( 4.9) in RoI compared with 4.0 ( 6.7) in NI (p<0.05). In RoI, the mean vDMFS in smooth surfaces of posterior teeth was 12.1 ( 8.1), that is 48.2% of the total vDMFS found, and significantly lower than the corresponding figure for NI at 16.3 ( 10.1), which represents 51.3% of the total vDMFS found.
Conclusion: Caries in anterior teeth and in smooth surfaces is substantially higher in NI than in RoI.
This research was funded by the Health Research Board, Ireland.
[Show abstract][Hide abstract] ABSTRACT: The aim of this project was to estimate the fluoride intake of formula-fed infants aged 8-16 weeks in the Cork area. The objective: was to investigate feeding practices in infants aged 8-16 weeks to provide a basis for estimating fluoride intake. Methods: Data on age, weight, gender, disadvantage status and dietary practices were sought for a sample of 79 infants. Parents completed four day diet diaries which included details of the nature and volume of liquids and solids consumed. Samples of water and reconstituted infant formula were gathered for each of the four days. The volume of formula and other liquids and food was calculated from the diet diaries. Fluoride levels in both water and formula were measured using an ion specific electrode. The volume of water consumed from formula was calculated by measurement of its moisture content. Results: The mean daily fluoride intake for the group was 0.11mgF/kg body weight and 0.64mgF/day. These values just exceeded the Tolerable Upper Level (0.10mgF/kg body weight) quoted by the Institute of Medicine and the Lowest Observed Adverse Effect Level (0.10mgF/kg body weight) quoted by the Forum on Fluoridation but satisfied the Institute of Medicine's Tolerable Upper Level for mgF/day (0.7mgF/day). Conclusions: Recommendations on fluoride intake among infants vary between different organisations, and require further consideration and research to reach a consensus. Epidemiological data available from cross sectional studies in Ireland do not support the estimated LOAEL levels which are proposed in the current literature and these levels should be reconsidered in accordance with current evidence.
[Show abstract][Hide abstract] ABSTRACT: parental accompaniment of children during dental treatment has always been a contentious issue. One of the factors that should be considered is the preference of the parents. The aim of this paper is to report the preference of parents of eight-year-old schoolchildren in Ireland in relation to accompanying their child during dental procedures and is part of the National Survey of Children's Dental Health in Ireland, which was conducted between October 2001 and June 2002. The survey had a cross sectional design and parents of children (average age 8.4 years) selected for dental examination were asked to complete a questionnaire.
3629 completed questionnaires were obtained from parents of eight-year-old children giving a response rate of 68 per cent. Sixty-seven per cent of parents expressed a preference to accompany their child during dental treatment, while nine per cent expressed a preference not to accompany their child. The sex of the child (p = 0.33) or the fact that the parents were holders of a medical card (surrogate for disadvantage) (p = 0.08) did not affect parents' preference. However, parents of a single child had a higher preference (78 per cent) for accompanying their child than did parents with greater than one child in the family unit (66 per cent) (p = 0.0009).
If given the choice, the majority of parents would prefer to accompany their child when receiving dental treatment.
Journal of the Irish Dental Association 02/2005; 51(1):23-4.