Bournemouth had strong claims for a penalty turned down after Fernandinho appeared to push Tyrone Mings in the area, but Gundogan doubled City's lead in the 79th minute, coolly finishing from David Silva's low cross.
"We had a lack of rhythm in the first half".
"In the first half Raheem was not there but then he makes a slalom and changes the game".
Guardiola has not ruled De Bruyne, who has played just 81 minutes of league football this season due to two knee injuries, out of the weekend visit to Chelsea.
Bournemouth suffered its sixth loss of the season and provisionally holds the ninth spot with 20 points.
"Everybody knows it's hard to get a good result against City, but they have drawn twice this season - maybe we are able to be the first getting a victory".
Manchester United fought back from two goals down to grab a point at Southampton after a 2-2 draw at St Mary's.
"After Lyon [in the Champions League] I didn't know we were going to come back here and doctors say to me Sergio can not play".
After G20 Photo, Saudi Prince Left Stage Quickly, Didn't Greet Leaders
With such a keen focus on the US President's trade policies, Mr Trump started the summit with what he certainly considers a win. However, Russia has suggested United States domestic politics may have been the real reason behind the cancellation.
Leicester recorded their first home win in the league since September with a comfortable 2-0 victory over Watford. It seems clear that Bournemouth have the ability to score goals and will set out to cause City difficulties on Saturday. "Always I tell them, expect the best from the other sides, expect that Liverpool will drop minimum points, so we have to win games".
Michael Obafemi fed Armstrong inside the area and from a tight angle the Scottish global smashed the ball confidently past De Gea for his third goal in two league games. Unfortunately I was out of the Champions League match [against Lyon] that I really wanted to play.
"Hopefully I make the best out of my next chance".
Javi Gracia's team were confident enough to give City a game rather than spend 90 minutes sitting deep on a damage limitation exercise, but ultimately, it wasn't enough against the leaders.
"I think it is too early to see how decisive it is", Guardiola said of City's advantage.
Crystal Palace ended their eight-game winless league run with a 2-0 success against fellow strugglers Burnley.
Newcastle's three-match winning run was halted by a 3-0 home loss to West Ham, with Mexico striker Javier Hernandez scoring twice and Felipe Anderson adding a third in jury time.
Sterling has made a habit of profiting against Bournemouth, and has now scored in each of his six Premier League appearances against them.