* More pressure on Garcia government

* Teachers, transportation workers lead protests

* Garcia cabinet changes expected this weekend

* Humala presents himself for 2011 race (Recasts, adds Humala paragraphs 4, 5)

By Dana Ford

LIMA, July 8 (Reuters) - Thousands of Peruvians marched on Wednesday to protest the pro-business policies of President Alan Garcia, who has bowed to pressure to shuffle his Cabinet as an emboldened opposition gears up for the 2011 elections.

Garcia, whose approval rating is 21 percent and is prohibited from running again for the presidency, has been reeling since last month when indigenous protests in the Amazon turned violent.

At least 34 people died after police broke up roadblocks set up by protesters who were demanding repeal of laws that encourage foreign mining and oil companies to invest in the rainforest.

Ollanta Humala, a self-described nationalist who spooked investors when he nearly won the presidency in 2006, told a rally in the capital Lima that he could lead the left to victory in the next elections.