July 22 (Reuters) - U.S. pipeline operator Kinder Morgan KMI.N beat Wall Street expectations for second-quarter profit on Wednesday, helped by higher volumes of natural gas transported through its pipelines.

The Houston, Texas-based firm posted an adjusted profit of 37 cents per share for the three months ended June 30, compared with analysts' estimate of 32 cents per share, according to data compiled by LSEG.