A: The Jaine religious sect in India believe this, and usually carry a broom to sweep the path before them preventing the accidental death of any bugs. Some wear masks to prevent inhaling any living matter--what they call Jiva--to avoid accruing any negative Karma. Of course they have to eat something, and the vegetable world is apparently OK, even though a living substance too.
The continued existence of living creatures requires the consumption of living things. We don't hold the lioness guilty for bringing down a gazelle to feed her cubs. Our ancestors, not too long ago, took the bounty of the earth, and the balance of nature was hardly upset. Such is not the case today. Animals sent to the slaughter house for food are stock animals born, bred, and fed for this purpose. They owe their lives to us in the first place; taking their lives to feed our growing population does not upset the Karmic equation, at least not in my mind. These are sensitive issues, and the Law of cause and effect is not always clear on the ramifications for soul development.