Up front, props Brett Wilkinson and Nathan White move to the replacements bench and make way for Rodney Ah You and Ronan Loughney.
Lock Aly Muldowney, who made quite an impression from the bench against the Ospreys, replaces the injured Michael Swift. Muldowney partners Craig Clarke who captains the side this week, with George Naoupu starting at number 8.
In the backs, Tiernan O'Halloran and Fionn Carr are named on the wings while Danie Poolman moves to outside centre to partner Eoin Griffin.
The league's record points scorer Dan Parks starts at out-half and will be joined by Paul O'Donohoe, who makes his first start at scrum half this season.
From the replacements bench, Mata Fifita and Jack Carty are in line to make their first competitive appearances of the season in Italy.
Speaking about the team selection and Friday's round 5 tie, Lam said: "With back-to-back physical games against Ulster and the Ospreys and a short turnaround this week we have made a number of changes.
"Robbie Henshaw is with the IRFU player welfare programme and is unavailable for Treviso. We were also hoping to play James So'oialo but unfortunately his work permit is still yet to come through so we continue to wait.
"We were unfortunate with injuries again this week but that challenge gives our young players, such as Academy out-half Jack Carty, the chance to step up and make their mark.
"Jack has done extremely well in training and playing with the Eagles and he deserves his place in the squad this week.
"We face a tough challenge in playing Treviso and we know the level of physicality we can expect from them.
"For us, this week has been about improving the areas of our game which let us down last time out. It's all about progress and improvement and we need to keep forging ahead."
CONNACHT (v Benetton Treviso): Gavin Duffy; Tiernan O'Halloran, Danie Poolman, Eoin Griffin, Fionn Carr; Dan Parks, Paul O'Donohoe; Rodney Ah You, Sean Henry, Ronan Loughney, Aly Muldowney, Craig Clarke (capt), Andrew Browne, Jake Heenan, George Naoupu
Replacements: James Rael, Brett Wilkinson, Nathan White, John Muldoon, Mata Fifita, Kieran Marmion, Jack Carty, Matt Healy.