File Name : esi_figure1a.tif

Caption : intestinal data, n = 22


mean compositional data for varying sample types as taken from the systematic literature search. all data are

given as mean relative percentage and associated sem values. the percentage values are also given with the std. dev. and data set range in table 1.


File Name : esi_figure1b.tif

Caption : epithelial data, n = 18

File Name : esi_figure1c.tif

Caption : human intestinal epithelial data, n = 10

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Caption : mean animal lipid data, n = 42

File Name : esi_figure1e.png

Caption : animal git data, n = 14

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Caption : non-intestinal lipid data, n = 53

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Caption : figure 12: a box plot to show the spread of data for each lipid available from the results of the literature search. the whiskers (i.e. the boundary for a data point being an outlier or not) as q3 + w x (q3 - q1) < x > q1 - w x (q3 - q1), where q1 and q3 are the 25th and 75th percentiles. the default value for whiskers are given as 2.7 of the (assumed) normally distributed data.

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Caption : scatter plots showing the spread of the relative percentages of lipid head groups taken from the systematic literature search. mean value (black line), 1 and 1.5 x standard deviation (solid red and dashed red lines respectively) are shown and data points are grouped by their sample: namely, human or non-human.

File Name : esi_figure5.tif

Caption : scatter plot showing the relative percentages of cholesterol and sphingomyelin plotted against one another to see if there are any discernible trends, although none are apparent.