Proc Natl Acad Sci U S A. 2011 Sep 20;108(38):16050-5. doi: 10.1073/pnas. 1102999108. Epub 2011 Aug 29. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Bravo JA(1), Forsythe P, Chew MV, Escaravage E, Savignac HM, Dinan TG, ...
I would say there is a definite distinction between the two, in definition and in proper usage. Et cetera, often shortened to etc., means literally 'and the rest'. Et alii, often shortened to et al., means 'and others' and can be thought of as a specific case of et cetera when the 'rest' refers to a list of persons.
Even if you don't speak Latin, you should know the two meanings of et al. Learn what et al. is, how to use it, and what mistakes to avoid.