NEW YORK, United States — Vox Media Inc., the owner of news and lifestyle websites like SB Nation and Eater, is laying off about 50 employees, a sign that Facebook Inc.'s recent algorithm changes are forcing publishers to shift strategies.

The cuts were confined mostly to workers who produce social media video for Vox’s Media’s fashion site, Racked; Curbed, which focuses on real estate; and sports-oriented SB Nation, Chief Executive Officer Jim Bankoff said in a memo to staff. He cited “industry changes over the past few months” as a reason for the cuts, which represent a total staff reduction of 5 percent.

In January, Facebook said it was changing how it ranks content in its News Feed, prioritising posts from friends and family over those from publishers. For Vox Media and other companies, that means a smaller audience from the world’s biggest social network to sell to advertisers.

The layoffs at Vox Media are yet another sign of upheaval in digital media. As Facebook and Google capture larger shares of online advertising, some publishers missed their annual revenue goals last year. Many are cutting costs and seeking new ways to make money.

Vox Media is expanding its podcast network and producing shows for television, including an A+E Networks program about prefabricated homes called “Prefabulous.” Vox Media’s audience grew by 20 percent across all its websites over the past year, according to Bankoff.

Vox Media publishes eight websites, including Vox.com and Polygon. In 2015, the company received a $200 million investment from Comcast Corp.’s NBCUniversal and has started jointly selling online and TV advertising with NBC.

By Gerry Smith; editors: Crayton Harrison, Mark Schoifet, Rob Golum.