A Novel Stable Isotope Approach for Determining the Impact of Thickening Agents on Water Absorption

Research on the bioavailability of water from thickened fluids has recently been published and it concluded that the addition of certain thickening agents (namely, modified maize starch, guar gum, and xanthan gum) does not significantly alter the absorption of water from the healthy, mature human gut. Using xanthan gum as an example, our “proof of concept” study describes a simple, accurate, and noninvasive alternative to the methodology used in that first study, and involves the measurement and comparison of the dilution space ratios of the isotopes 2H and 18O and subsequent calculation of total body water. Our method involves the ingestion of a thickening agent labeled with 2H 1 day after ingestion of 18O. Analyses are based on the isotopic enrichment of urine samples collected prior to the administration of each isotope, and daily urine samples collected for 15 days postdosing. We urge that further research is needed to evaluate the impact of various thickening agents on the bioavailability of water from the developing gut and in cases of gut pathology and recommend our methodology

'Walking Along Beside the Researcher': How Canadian REBs/IRBs ar eResponding to the Needs of Community-Based Participatory Research

research ethics boards and institutional review boards (REBs/IRBs) have been criticized for relying on conceptions of research that privilege biomedical, clinical, and experimental designs, and for penalizing research that deviates from this model. Studies that use a community-based participatory research (CBPR) design have been identified as particularly challenging to navigate through existing ethics review frameworks. However, the voices of REB/IRB members and staff have been largely absent in this debate. The objective of this article is to explore the perspectives of members of Canadian university-based REBs/IRBs regarding their capacity to review CBPR protocols. We present findings from interviews with 24 Canadian REB/IRB members, staff, and other key informants. Participants were asked to describe and contrast their experiences reviewing studies using CBPR and mainstream approaches. Contrary to the perception that REBs/IRBs are inflexible and unresponsive, participants described their attempts to dialogue and negotiate with researchers and to provide guidance. Overall, these Canadian REBs/IRBs demonstrated a more complex understanding of CBPR than is typically characterized in the literature. Finally, we situate our findings within literature on relational ethics and explore the possibility of researchers and REBs/IRBs working collaboratively to find solutions to unique ethical tensions in CBP