[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: 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.