Assuming that the topics are created, and messages are being published. One way of consuming the data in SN is using data stream action. This would entail setting up connections and alias and using the correct connection in the rest api to make the call in the flow designer action. The one issue that comes up in that there are no paging options, and you will need to check if all data are consumed before moving to next topic if need for scheduled load. Since it's JSON, messages will have to be parsed and scripted out to create outputs.
