People with metabolic dysfunction-associated steatohepatitis (MASH), a severe form of fatty liver disease, have limited treatment options beyond diet and exercise. Despite how common the condition is, there’s only one FDA-approved medication available right now.

A growing body of evidence suggests that bariatric surgery can be an effective MASH treatment tool. In a 15-year study published in Nature Medicine, researchers found that bariatric surgery can significantly reduce the risk of severe liver problems for some people with MASH.

These findings provide support for bariatric surgery as a safe and effective way to manage MASH for people with obesity and severe liver scarring (cirrhosis). As cirrhosis progresses, it can lead to liver failure, liver cancer, or the need for a liver transplant.

The new study found that only 20.9% of people who received bariatric surgery experienced severe liver outcomes, compared to 46.4% of those who used medical therapies.

“Bariatric surgery is one of the treatments that’s so incredibly effective. In fact, I would probably argue that as a single therapy, it is the most effective treatment of fatty liver disease, or MASH, just because the response rates are incredible,” said Sujit Janardhan, MD, PhD, a hepatologist at Rush University Medical Center and a diplomate of the American Board of Obesity Medicine.

Bariatric Surgery Aids Sustained Weight Loss

Considered the gold standard for obesity treatment, bariatric surgery can reduce stomach size or help lower the absorption of calories from food, which contributes to sustained weight loss.

After 15 years, the participants who received the surgery lost an average of 26.6% of their body weight, while the non-surgical group lost 9.8%, according to the new study.

Overweight and MASH often go hand-in-hand. A 2015 study found that people with MASH who lost 10% or more of their body weight experienced better outcomes and had significant improvements in liver scar tissue.

Many MASH treatment plans currently focus on weight management through lifestyle changes. However, due to genetics and environmental factors, lifestyle modifications won’t work for everyone.

“Lifestyle changes leading to weight loss is always the goal, but it’s not achievable in everyone, which is why bariatric surgical procedures such as gastric sleeve or Roux-en-Y gastric bypass are such important options,” Janardhan said.

Weight Loss Medications Show Promise, Too

Weight-management medications have also been considered for MASH treatment. An ongoing study has shown some improvements in liver scarring for MASH patients who take semaglutide—the active ingredient in Ozempic and Mounjaro—compared to those given a placebo.

“Certainly weight loss medications will help. However, you have to be on it forever,” Christine J. Ren-Fielding, MD, chief of bariatric surgery at NYU Langone Health, told Verywell.

People may stop these medications for a variety of reasons and, as a result, often regain some of the weight they lost.

“It’s the sustained weight loss that is what really impacts MASH progression or non-progression, and therefore, surgery really is the much better, more effective option for MASH management,” she added.

What Are the Risks of Bariatric Surgery?

Like any medical procedure, bariatric surgery comes with risks. Possible side effects include nausea, malnutrition, vomiting, infection, or acid reflux. The surgery may also be ineffective for some people. It is important to discuss your unique concerns and risk factors with a trusted healthcare provider.

To lower the risk of liver injury during bariatric surgery, people with MASH often have to follow a liver-shrinking diet mainly consisting of protein shakes. An enlarged liver can accidentally get injured during the operation, Ren-Fielding explained.

If left untreated, MASH can lead to decompensated cirrhosis or liver failure. Once someone has decompensated liver disease, they may need a liver transplant.

“People with MASH are all excellent candidates for bariatric surgery,” Ren-Fielding said. “It won’t always reverse it, but it will certainly drastically slow down the progression to cirrhosis, or decompensated cirrhosis.”