What Does LGG Do? Exploring the Benefits of Lactobacillus Rhamnosus GG

December 7, 2025 •

4 min read

LGG, or Lactobacillus rhamnosus GG, is the most scientifically documented probiotic strain in the world, with over 30 years of research and more than 300 human studies. It is a beneficial bacteria found in the intestines that plays a crucial role in supporting both digestive and immune health. By restoring the balance of your gut microbiome, LGG has a wide-ranging impact on overall well-being.

Quick Summary

An in-depth look at Lactobacillus rhamnosus GG, a well-researched probiotic strain. This article covers its key functions, including supporting gut barrier integrity, modulating the immune system, and combating pathogens. It also details the benefits for specific conditions like diarrhea, IBS, allergies, and its role in infant and child health.

Key Points

Supports Digestive Health: LGG strengthens the intestinal barrier by enhancing tight junctions, which helps prevent 'leaky gut' and reduces gut inflammation.
Modulates the Immune System: A majority of immune cells reside in the gut, and LGG's presence helps regulate the immune response, calming an overactive system and aiding in immunity.
Combats Pathogens: Through competition for resources and adherence sites on the gut lining, LGG helps displace harmful bacteria and restores a healthy microbial balance.
Prevents and Treats Diarrhea: LGG is clinically proven to help prevent and reduce the duration of various types of diarrhea, including antibiotic-associated, rotavirus, and traveler's diarrhea.
Alleviates IBS Symptoms: By reducing intestinal inflammation and strengthening the gut barrier, LGG can provide relief for Irritable Bowel Syndrome symptoms like abdominal pain and bloating.
Addresses Allergies and Eczema: Some studies show LGG can help manage certain allergies and reduce the severity of eczema, particularly in infants and children.
Has High Survivability: LGG is resistant to stomach acid and bile, allowing it to survive passage through the digestive tract and colonize the intestines effectively.

LGG's Role in Improving Digestive Health

LGG plays a pivotal role in maintaining and improving digestive wellness through several key mechanisms. This probiotic strain, known for its resilience to stomach acid and bile, effectively colonizes the gut where it can exert its beneficial effects for a longer period. Its ability to adhere strongly to the intestinal walls, thanks to tiny, hair-like structures called pili, is crucial for its persistence and function.

Strengthening the Intestinal Barrier

The gut lining acts as a protective barrier, keeping toxins and harmful microbes from entering the bloodstream. When this barrier is compromised due to stress, illness, or medications like antibiotics, it can lead to health issues. LGG helps to repair and strengthen this intestinal wall by stimulating reactions that improve the function of 'tight junctions'—the connections between the cells lining the gut. This helps maintain the integrity of the gut lining and prevent 'leaky gut syndrome.'

Combatting Pathogens and Restoring Balance

LGG competes with harmful bacteria for nutrients and attachment sites on the gut lining, effectively blocking their growth. This competitive exclusion is a key part of its ability to restore a healthy balance to the gut microbiome, especially after it has been disrupted by infections or antibiotics. LGG also produces protective proteins and other compounds that can inhibit or block a variety of pathogens, including certain Salmonella species.

The Immunomodulatory Effects of LGG

Beyond its digestive benefits, LGG is a potent modulator of the immune system, with the majority of immune cells residing in the gut. Its influence can shape how the body responds to infections, allergens, and other immune challenges.

Regulating Immune Response and Inflammation

LGG interacts with immune cells in the gut, signaling the body to release chemicals that help regulate the immune response. This can help calm an overactive immune system, making it particularly useful in inflammatory conditions and allergies. For example, LGG has been shown to reduce pro-inflammatory chemicals while increasing anti-inflammatory responses.

Supporting T-Helper Cell Responses

Research has shown that LGG can influence the balance of different T-helper (Th) cell responses. In allergic patients, it has been observed to modulate the Th1/Th2 response to specific allergens. This ability to steer the immune system towards a more balanced response is critical for managing allergic reactions and preventing inflammatory disorders.

LGG's Targeted Actions in Specific Conditions

Due to its unique properties and extensive research, LGG is used to address a number of specific health issues. It is not a one-size-fits-all solution, as its efficacy depends on various factors including dosage, formulation, and the individual's genetic background.

Diarrhea: LGG is well-documented for its ability to prevent and treat various forms of diarrhea, including antibiotic-associated diarrhea (AAD), rotavirus diarrhea, and traveler's diarrhea. Its effectiveness is linked to its ability to survive the gastrointestinal tract and inhibit pathogens.
Irritable Bowel Syndrome (IBS): Studies suggest that LGG can relieve common IBS symptoms such as bloating, abdominal pain, and abnormal bowel movements by strengthening the gut barrier and soothing inflammation. It has also been shown to increase serotonin levels in the gut, which can aid in regulating bowel function.
Allergies: For some individuals, particularly children, LGG may help manage food allergies and reduce eczema symptoms. The timing of administration, such as during pregnancy and infancy, has been shown to potentially impact these outcomes.

Comparison of LGG with Other Probiotic Strains

Different probiotic strains have unique mechanisms and target different health outcomes. It is crucial to choose a strain based on specific health needs rather than relying on general probiotic benefits.


Feature	Lactobacillus rhamnosus GG (LGG)	Saccharomyces boulardii (Sb)	Lactobacillus reuteri	Bifidobacterium species	Lactobacillus plantarum DSM 9843 (LP299V)
Microbe Type	Bacteria	Yeast	Bacteria	Bacteria	Bacteria
Antibiotic Resistance	Sensitive to some antibiotics (e.g., penicillin)	Naturally resistant to all antibiotics	Produces its own antimicrobial compounds	Varies by strain	Shown to be resilient
Adhesion Capacity	Superior adherence to intestinal mucus due to pili	Inhibits pathogens by secreting binding proteins	Has aggregative abilities for colonization	Adheres well but not as extensively studied as LGG	Adheres to mucosal membrane
Primary Action	Blocks pathogens, strengthens gut barrier, modulates immunity	Binds and inactivates toxins, modulates immune system	Produces reuterin to inhibit pathogens	Reduces colonic permeability, modulates immunity	Reduces inflammation and Gram-negative bacteria
Best For	Diarrhea, IBS, allergies, general immune support	Preventing antibiotic-associated and other diarrhea	Diarrheal diseases in pediatrics, H. pylori therapy side effects	Varies by strain, often supports general gut balance	Reducing mucosal inflammation

Conclusion

LGG is a remarkably well-researched and versatile probiotic strain with proven benefits for both the digestive and immune systems. Its ability to adhere to the gut wall, compete with pathogens, and modulate the immune response makes it a powerful ally in maintaining overall health. From treating diarrhea and alleviating IBS symptoms to potentially managing allergies and strengthening the gut barrier, LGG demonstrates a broad range of beneficial actions. However, its effects can be dependent on various factors, highlighting the importance of understanding specific strains and consulting a healthcare provider for personalized advice. Ongoing research continues to shed light on its mechanisms of action, further solidifying its reputation as a leading probiotic in human health.

For more detailed scientific information on LGG and its host interactions, you can consult this extensive review article from Microbial Cell Factories: Towards a better understanding of Lactobacillus rhamnosus GG - host interactions.

Frequently Asked Questions

LGG, or Lactobacillus rhamnosus GG, is a specific strain of beneficial bacteria that was originally isolated from the intestines of a healthy human. It is now one of the most widely used and researched probiotic strains available in supplements and food products like yogurt.

LGG helps prevent and treat diarrhea, particularly antibiotic-associated diarrhea (AAD), by competing with harmful bacteria for resources and attachment sites in the gut. Its high survivability allows it to effectively colonize the gut and re-establish a healthy balance disrupted by antibiotics or infections.

Yes, LGG is generally considered safe for infants and children, and has been extensively studied in these populations. It is used to help ease colic, prevent gastrointestinal infections in hospitalized children, and has shown promise in managing specific conditions like eczema and allergies.

Most people tolerate LGG well, but some may experience temporary side effects like mild bloating or gas, especially when first starting a probiotic. In rare cases, individuals with severely compromised immune systems or intestinal barriers should use caution and consult a doctor.

Yes, LGG has been shown in some studies to help relieve common symptoms of IBS, such as abdominal pain and bloating, by reducing gut inflammation and strengthening the intestinal barrier. It is particularly effective for certain subgroups of patients with IBS.

While not a cure, LGG shows potential in managing some food allergies, especially in children. Studies have explored its role in cow's milk allergy and eczema, suggesting it can modulate the immune response and help build tolerance.

The key difference lies in the specific strain and its documented effects. LGG is a highly researched strain known for its superior adherence to the gut and its proven benefits for diarrhea and immunity. Other probiotics, like Saccharomyces boulardii, are yeasts and naturally resistant to antibiotics, while others have different primary actions.