The 71-year-old actor, who entered the small screen with the show in 2000, began shooting yesterday for the eighth season.
"The new season of KBC starts and the first day has been shot and canned... the crew and the atmosphere familiar, but never too familiar to destroy the work on hand," he wrote in his blog.
"It may be 14 years since our association with it... but each moment needs the kind of concentration and effort that shall make it endurable and loved," he added.
The theme of 'KBC 8' is community bonding and respect, with the promos sending message of peace, harmony and religious tolerance and the tagline of the show saying 'Yahan Sirf Paise Nahi, Dil Bhi Jeete Jaate Hain' (You not only win money here, but win hearts too).
Bachchan said the stories of the contestants touched his heart. "First day of KBC recording and it attracts you from word 'go' !! Lovely contestants, moving stories, and the joy of meeting them," he wrote on his Twitter page.
Bachchan is currently seen on television in his maiden fiction show, 'Yudh'.