Porto head the group standings with two wins from as many games going into Wednesday's fixture, but the Brazilian does not believe that makes them favourites.
Helton, who is set to make his 40th Champions League appearance against the Ukrainian side, told a press conference: "This idea (of being favourites) is not even mentioned in training or in the dressing room. The idea is humility. Our ethics do not allow this. They need the win just like us.
"Regarding the 40 games, I try to do the best. I am grateful and proud of it."
Helton praised his team-mates ahead of a game which sees the reigning Portuguese champions not having conceded a goal at this stage of the competition.
He said: "This is not just thanks to Helton. I have 10 team-mates who make sure FC Porto have not conceded."
Porto, who are top of the current Primeira Liga standings and won 1-0 away to FC Vizela in the third round of the Portuguese Cup on Saturday with a goal from Danilo, met Dynamo in the group stages of the 2008/09 season when both teams won away from home.
Dynamo's attacking midfielder Andriy Yarmolenko has put his 23rd birthday celebrations on hold as his team bid for victory against Porto.
Instead of celebrating his birthday today the St Petersburg native was in Portugal preparing for tomorrow night's game.
Yarmolenko told the club website: "Last year, we all had a game on my birthday, so I spent it on the field.
"Now we are preparing for an important game with Porto. I will gather most people close to me after returning from Portugal (for a celebration).
"Of course, we would like to have a party, but we need to achieve a positive result in the Champions League.
"That would be the best gift for me from my team-mates. I will play with a special inspiration."
Dynamo coach Oleg Blokhin will be without Brazilian striker Raffael who was injured in the 3-1 defeat to Metalist Kharkiv on Saturday which left them 12 points behind leaders Shakhtar Donetsk in second place in the Ukrainian league.
Dynamo, with one win from two Champions League Group A matches so far, will also be without Brazilian defenders Dudu and Leandro Almeida.
But another Brazilian defender Betao is back in the squad after missing the defeat to Metalist.
