What to Know About Lactobacillus Rhamnosus (LGG) Probiotic

Medically Reviewed by Minesh Khatri, MD on February 20, 2024
3 min read

Lactobacillus is a type of bacteria that is naturally found in your gut. It has many benefits for your digestive and immune systems. 

LGG probiotic comes from a specific strain of friendly bacteria called Lactobacillus rhamnosus GG. The letters at the end refer to scientists Sherwood Gorbach and Barry Goldwin, who first isolated the strain in humans. It is the most common strain available in probiotic supplements and foods like yogurt

Your gut is full of "friendly" bacteria that help break down your food and make vitamins like B12 and vitamin K. The collection of bacteria and other organisms like fungi and parasites in your gut are called your microbiome

Everyone’s microbiome is a little different based on their genetics and their mother’s biome at the time of birth, but the Lactobacillus family of bacteria is naturally found in most people’s guts. 

The LGG strain is resistant to bile and acid, so it isn’t easily destroyed, it can grow a healthy population in your gut, and it can stick to your gut lining. It can:

Block bacteria. While probiotics are friendly bacteria, some bacteria can cause disease. The LGG probiotic can block other bacteria from growing by competing for nutrients and attachment sites on your gut lining. If there isn’t enough food, harmful bacteria can’t live inside you. 

Improve gut barrier. Your gut lining acts as a barrier between the food, toxins, and microbes in your intestine, your body cavity, and your bloodstream. The lining is made of cells with shared membranes called tight junctions. 

Damage to the lining makes the tight junctions loosen, which can leak harmful compounds into your bloodstream. LGG, though, can stimulate different reactions in your gut that make these tight junctions work better. 

This bacteria might also help people with inflammatory bowel diseases like ulcerative colitis. Gut-lining damage is a common complication of inflammatory bowel disease. While probiotics don’t cure inflammatory bowel disease, they can help replenish friendly bacteria and increase the tightness of those junctions.   

Regulate your immune response. Bacteria can bind to proteins on your immune cells, which activates your immune system. Once they bind to your cells, this signals your body to release chemicals that influence other immune cells and regulate your immune response. 

Restore your microbiome. If you lose friendly bacteria or have an imbalance caused by a medication, infection, or bowel disease/syndrome, taking Lactobacillus rhamnosus can help build back a healthy microbiome. 

LGG probiotics ease uncomfortable digestive symptoms from bowel conditions like irritable bowel syndrome or antibiotic treatment. These include:

LGG probiotics can also:

  • Restore your microbiome
  • Lower severe diarrhea from acute gastroenteritis, or the stomach flu
  • Ease colic in babies
  • Lower diarrhea from a C. difficile infection
  • Treat periodontal disease, a gum infection that causes tissue damage and bone loss in your teeth
  • Prevent a blood infection called sepsis in premature babies
  • Prevent intestinal inflammation and tissue death in premature babies (necrotizing enterocolitis)
  • Restore the microbiome in ulcerative colitis and help stay in remission

Probiotics are generally safe to take and eat in food, especially if you’re healthy. There are possible side effects, though.

Infections. Probiotics could cause infections if you are unhealthy or you are taking medications that suppress your immune system. Without a strong immune system, you don’t have the ability to manage even friendly bacteria. 

Harmful chemicals. Bacteria help break down your food and make vitamins, but they also release gasses and other compounds that can be potentially harmful. Even though probiotics are described as friendly bacteria, they could make some people sick.

Antibiotic resistance. Probiotic bacteria are generally antibiotic-resistant. In theory, they could pass on their resistant genes to the other bacteria in your gut. If you end up with an infection, this could make it hard to treat a major problem. 

While friendly bacteria are necessary for your gut, it’s best to get your probiotics from fermented foods that contain probiotics, such as yogurt. There are lots of probiotic supplements available to buy, but these aren’t regulated like medications, and studies show mixed results. If you’re sick, talk to your doctor about whether you should take a probiotic.