Saraki administered the oath of office at the Senate on Wednesday.
Mr Babba-Kaita who was declared winner of the Katsina North senatorial election by the Independent National Electoral Commission (INEC), with 224,607 votes, replaces late senator Mustapha Bukar, who died on April 4.
Also, Mr Gumau emerged winner of the Bauchi South senatorial election held on August 11. He was declared winner by the returning officer of the election, Ahmed Fadam, who supervised the final collation of the results.
Gumau replaces late senator Ali Wakili, who died on March 17. SHARE THIS STORY USING ANY OF THE BUTTON BELOW ⬇ PLACE YOUR TEXT ADVERT BELOW ⬇⬇⬇