In this edition: Celebrity rehab, a UnitedHealth investigation, and “prebiotic” soda.

Rocky road to recovery. The rich and famous who struggle with substance abuse often pay for high-end rehab facilities that tout constant support. But former patients and employees say some luxury providers fall short of their promises. They recount abuses and easy access to drugs and alcohol. Read more.

How healthcare CEOs courted Trump. In the dining room at Mar-a-Lago, the president-elect met with a parade of pharmaceutical, hospital and insurance CEOs, who wrote large checks to attend. Trump has since embraced arguments he heard from them, including calling out pharmacy-benefit managers for high drug prices. Read more.

Department of Justice launches probe of UnitedHealth. The civil fraud investigation is examining the company’s practices for recording diagnoses that trigger extra payments to its Medicare Advantage plans, according to people familiar with the matter. Read more.

First cows, now cats. Bird flu is here to stay. H5N1 is proliferating among cows and there are now two strains in mammals and birds. There are only 68 confirmed cases in people, but officials think it’s likely more widespread. What hasn’t happened yet is sustained human-to-human transmission. Read more.

These sodas claim to be good for the gut. Coca-Cola and PepsiCo are jumping into the prebiotic soft-drink market dominated by upstarts Olipop and Poppi. Unlike probiotic products such as kombucha that introduce new microbes, prebiotics contain dietary fibers that feed bacteria already living in our systems. Read more.

Are you brushing your teeth wrong? Dentists say it takes a full two minutes for adequate plaque removal, but most of us fall short. Toothbrush designers at companies like Colgate and Procter & Gamble have been trying to close that gap by making devices that make brushing feel like less of a chore. Read more.

Heart device safety concerns. Johnson & Johnson is relaunching sales of its Varipulse heart-rhythm device after a safety scare, but with a new warning that could hamper its market potential. A federal database contains several reports of strokes associated with the device, The Wall Street Journal has reported. J&J has been racing to catch up in this fast-growing market. Read more.

This newsletter was compiled by the WSJ’s Health & Science team. Follow us on X @WSJHealth and @WSJScience. Email us by replying to this newsletter.