A Utah mother-of-six who doled out parenting advice on a popular YouTube channel has been sentenced to prison for abusing her children, holding two of them in conditions prosecutors likened to concentration camps.

Ruby Franke, 42, pleaded guilty in December to four counts of aggravated child abuse and was sentenced on Tuesday to one-to-15 years in prison on each charge.

Franke's business partner Jodi Hildebrandt, 54, whom she described as her "mentor," received the same sentence.

Beginning in 2015, Franke ran a since-deleted YouTube channel called "8 Passengers" which provided parenting advice. She would later feature on a YouTube channel run by Hildebrandt after separating from her husband.

Utah prosecutor Eric Clarke said Franke and Hildebrandt held two of the children, then aged nine and 11, in a "concentration camp-like setting."

"The children were regularly denied food, water, beds to sleep in, and virtually all forms of entertainment," Clarke said. "They were isolated from others, and were hidden when people came to visit the house.

"They were also forced to do manual labor outdoors in the extreme summer heat, at times without shoes or socks," the prosecutor said. "Both children had extensive physical injuries from the abuse that required hospitalization."

Clarke also said the children were emotionally abused, "to the extent that each believed, to some degree, that they deserved what was being done to them.

Eventually, the older one "had the courage" to run away and ask a neighbor to call the police, Clarke said, adding "Heaven knows how much longer they could have survived in that situation."

Franke apologized for her actions at her sentencing hearing before Judge John Walton.

"I was led to believe that this world was an evil place filled with cops who control, hospitals that injure, government agencies that brainwash, church leaders who lie and lust, husbands who refuse to protect and children who need abuse," she said.

She said her paranoia "culminated into criminal activity for which I stand before you today ready to take accountability."

Franke and Hildebrandt will serve a minimum of four years in prison but their exact prison terms will be decided by the Utah Board of Pardons and Parole.