Tension on Guinea and Sierra Leone border

Guinean troops have fired shots in the disputed town of Yenga, which is on the border with Sierra Leone. What's behind this unprecedented development? Also why are farmworkers in Kenya occupying tea plantations owned by multinational companies? And why we should be eating more fermented foods..Presenter: Audrey Brown Technical Producer: Francesca Dunne Producers: Tom Kavanagh in London and Blessing Aderogba in Lagos Senior Journalist: Karnie Sharp Editors: Andre Lombard and Alice Muthengi