LRGG. 

Lactobacillus rhamnosus GG (ATCC 53103) is one of the world’s most thoroughly studied bacterial strains, featured in over 250 human clinical trials, many of these are Randomised Double Blind Placebo-Controlled Trials (RCT’s), the gold standard in clinical testing used by most modern pharmaceuticals.

First identified in 1983 by Dr Sherwood Gorbach and Dr Barry Goldin (hence the “GG”), this strain has been researched across digestive, immune, and developmental areas, making it a benchmark in probiotic science.

In April of 2020 Lactobacillus Rhamnosus GG was officially reclassified as Lacticaseibacillus Rhamnosus GG as part of a taxonomic revision of the genus Lactobacillus.

At BetterGuts, we use L. rhamnosus GG for its depth of research, its proven survivability through stomach acid, and its record of safe use across ages.

Classification

• Genus: Lactobacillus
• Species: rhamnosus
• Strain: GG (ATCC 53103)
• Type: Gram-positive, non-spore-forming, lactic-acid-producing bacterium

Scientific Background

For over 30 years LRGG has been carefully studied and researched for it’s powerful effects on the ecosystem of the human gut.

Studies have indicated that LGG can:

• Support a balanced gut environment, especially when the gut is under stress, for example, after antibiotic use or during bouts of other gastrointestinal issues such as IBS.
• Survive exposure to stomach acid and bile salts
• Temporarily adhere to intestinal cells
• Coexist with other beneficial species

LRGG is one of the original and best, with such a large body of clinical research behind it, is often used as the reference strain in studies into other bacteria!

Areas of Research

Digestive Health, Antibiotic Use and a Calmer Gut.

When antibiotics are prescribed, they don’t just act on the bacteria that cause infection — they also affect the community of friendly bacteria that live in your gut.

This can sometimes lead to temporary digestive changes such as loose stools, bloating, or discomfort.

That’s where Lactobacillus rhamnosus GG (LGG) comes in. It’s one of the few bacterial strains that has been extensively studied for how it behaves in the gut during antibiotic use, and the results across several clinical trials have been remarkably consistent.

What the research shows

In a number of high-quality human studies, groups taking LGG alongside antibiotics experienced a dramatic reduction in the number of people who developed diarrhoea compared with those taking a placebo.

• In one major trial with over 200 children, only around 5 % of those taking LGG experienced antibiotic-related diarrhoea, compared with 16 % in the placebo group — a difference of roughly 70 % fewer cases.
• Another study saw a similar pattern: 8 % vs 26 %, confirming that far fewer participants experienced disruption when LGG was part of their routine.
• A large meta-analysis reviewing data from more than 4,000 people found the same trend — those taking LGG had about two-thirds lower risk of antibiotic-associated diarrhoea overall.

Not only were episodes less common, but when they did occur, they were also shorter-lived — typically lasting one to two days instead of four or more.

Why it matters to you

The research suggests that LGG helps to stabilise the natural bacterial balance in the gut while it’s under stress.

By keeping this environment more balanced, participants reported fewer bouts of loose stools, and less bloating, flatulence, and general digestive upset during antibiotic therapy.

In one adult trial, people taking LGG alongside a common antibiotic course described a calmer, more comfortable digestion, and many found it easier to complete their medication without side-effects getting in the way.

What this means for you

If you’re taking antibiotics, your gut is working harder than usual to rebalance itself.

Adding a bacterial supplement containing Lactobacillus rhamnosus GG — especially one in delayed-release capsules designed to protect it through stomach acid — is a way to support your gut’s natural environment while it recovers.

The science doesn’t promise miracles, but across multiple studies, people taking LGG consistently experienced:

• Fewer interruptions to their normal routine
• Shorter and milder bouts of digestive discomfort
• A smoother, calmer gut experience overall during antibiotic use

In short: Lactobacillus rhamnosus GG has been one of the most widely researched strains for its ability to help maintain digestive balance, especially when the gut is under stress — helping to keep things steady, comfortable, and your gut on track.

Acute Gastroenteritis and Diarrhoea

When the digestive system is unsettled, for example during bouts of acute gastroenteritis, the body works hard to restore balance.

Symptoms like loose stools, discomfort, and dehydration can occur quickly, particularly in young children.

That’s why Lactobacillus rhamnosus GG (LGG) has been studied so extensively in this area: to understand how certain bacterial strains might help the gut recover its balance more efficiently.

And crucially, these aren’t just any studies. Most of the research into LGG’s effects on acute gastroenteritis comes from randomised, double-blind, placebo-controlled trials — the gold standard of scientific testing, designed to remove bias and ensure accuracy.

What the research found

Across multiple clinical trials in children, researchers consistently found that those who received LGG alongside rehydration therapy recovered significantly faster than those who received a placebo.

• In one landmark study, children taking LGG recovered in about 2½ days, compared with nearly 5 days for those not taking it — that’s around twice as fast.
• Another large European study with almost 300 children found that those given LGG recovered in 1.9 days compared to 2.8 days in the placebo group, and also spent less time in hospital.
• A high-dose trial in India showed a similar trend: LGG users recovered in 58 hours instead of 84, and had fewer stools per day as their digestion settled.
• Other studies have also shown that LGG can reduce the amount of virus detected in the gut during illness, indicating a quicker return to normal balance.

When viewed together, these studies demonstrate a consistent pattern:

children receiving LGG experienced 25–50 % shorter illness durations, fewer daily symptoms, and a smoother return to normal digestion, all without any increase in side effects.

Typical dose used in studies

Most of these clinical trials used daily doses between 10⁹ and 10¹⁰ CFU (that’s around 10 to 25 billion live cultures per day).

That happens to be the same potency used in BetterGuts formulations, ensuring you’re getting a level of concentration that reflects the conditions of these gold-standard studies.

Why this matters to you

A faster recovery isn’t just about getting back to normal sooner — it’s also about feeling more comfortable along the way.

Participants who took LGG described fewer loose stools, less bloating, and an overall calmer digestive experience during their recovery.

Because LGG has been so well studied — in over 250 human trials, including many double-blind and placebo-controlled — it’s one of the most trusted strains in modern probiotic research.

And when it’s encapsulated in delayed-release capsules as it is at Better Guts, it’s designed to survive stomach acid and arrive safely in the intestines, where it can do its best work.

In short

Scientific research suggests that Lactobacillus rhamnosus GG can help the digestive system recover its natural rhythm more quickly when it’s been disrupted by illness.

With a clinically relevant strength of 25 billion CFU per capsule, BetterGuts provides this heavily researched bacterial strain in a formulation inspired by the same conditions used in leading clinical studies — carefully balanced, precisely delivered, and backed by decades of science.

Immune Boost

Your immune system and your gut are deeply connected — around 70% of your body’s immune cells live in or around the intestinal wall.

That means a calm, balanced gut environment can play a key role in supporting overall immune stability.

Lactobacillus rhamnosus GG (LGG) has been one of the most intensively studied bacterial strains in this area. What makes the science especially compelling is that nearly all of the research has been conducted under randomised, double-blind, placebo-controlled conditions — the gold standard of clinical testing. These are the types of studies used by the world’s leading medical institutions to determine whether something truly works.

What the studies show

Over the past three decades, scientists have explored how LGG interacts with the gut lining and the immune system in both children and adults — and the findings have been consistently encouraging.

Fewer infections and fewer missed days

In a landmark study involving 571 children attending day-care centres, those who drank milk containing LGG every day for seven months had 17% fewer sick days than children who received ordinary milk.

They also needed fewer antibiotics overall — 31% compared to 40% in the placebo group.

Another large trial of 742 children found similar results: the group taking LGG experienced fewer colds and ear infections, and parents reported less time missed from school.

In both studies, children taking LGG were not only ill less often, but when they did get sick, their symptoms were milder and shorter-lived.

Immune balance, not overstimulation

In adults, researchers have focused on how LGG might help keep the immune system in balance — not by pushing it harder, but by helping it respond more calmly and efficiently.

In one controlled trial, adults taking LGG for just three weeks had 35% higher activity in their natural killer (NK) cells — the immune cells that patrol and respond to early threats — compared with those taking a placebo.

Another gold-standard trial found that LGG increased levels of interleukin-10 (IL-10), a molecule that helps regulate inflammation and maintain tolerance to everyday triggers.

Participants didn’t just have stronger immune markers — they also reported feeling more resilient during seasonal changes.

At the gut wall itself

The interaction between LGG and the immune system seems to start right where they meet — in the gut lining.

In one double-blind study, healthy adults taking LGG showed a measurable increase in IgA, a natural antibody found in the mucous membranes that line the intestines, nose, and mouth.

IgA acts like a first line of defence, helping the body distinguish between friendly and unfriendly visitors.

This subtle but powerful response suggests that LGG can help reinforce the gut’s natural barrier — keeping the immune system balanced, alert, and at ease.

How much was used

Most of these studies used doses between 10⁹ and 10¹⁰ CFU per day — the same strength found in the Better Guts formula.

This ensures that the level of live cultures you’re taking mirrors the dosage that’s been proven most effective in the gold-standard research.

What this means for you

Taken together, these studies show that LGG doesn’t overstimulate the immune system — it helps it stay balanced.

In real-world terms, that’s about experiencing:

• Fewer seasonal illnesses
• Milder symptoms when they do occur
• A more settled, resilient feeling overall

And because LGG has been tested in hundreds of clinical trials, including large-scale randomised, double-blind, placebo-controlled studies, you can be confident that it’s one of the most scientifically validated bacterial strains in existence.

In short

Lactobacillus rhamnosus GG works naturally with your gut’s own defences — helping to maintain a strong, balanced immune environment.

The science behind it isn’t speculative or anecdotal; it’s built on decades of gold-standard human trials, showing measurable differences between those taking LGG and those who don’t.

Pregnancy, Infant & Early-Life Development

The first months of life are a crucial time for the gut and immune system. A baby’s microbiome — the community of bacteria that line the gut — develops rapidly, helping to shape everything from nutrient absorption to immune balance.

Lactobacillus rhamnosus GG (LGG) has been one of the most extensively studied bacterial strains in infants and young children, particularly in how it supports healthy immune and gut development from the very beginning.

What makes these studies especially compelling is their quality: nearly all are randomised, double-blind, placebo-controlled clinical trials — the gold standard in scientific research, designed to produce the most reliable results possible.

What the studies show

Over more than two decades of research, LGG has been given to expectant mothers, newborns, and infants in carefully controlled studies — and the outcomes have been remarkably consistent.

A lasting difference in early-life balance

In one landmark study published in The Lancet, researchers followed 132 families from pregnancy through the early years of childhood.

Half the mothers took LGG daily during the last weeks of pregnancy and continued giving it to their infants after birth.

By age two, only 23% of children in the LGG group had developed early-life skin sensitivity compared with 46% in the placebo group — a 50% reduction in risk.

Even more impressively, when scientists checked back at age four, that difference had persisted: 26% vs 46%, suggesting that the benefits lasted long after supplementation stopped.

Across multiple studies, the pattern holds

Other research teams across Europe confirmed the same trend.

• In Finland, children whose mothers took LGG during pregnancy had a 15% rate of developing eczema, compared with 30% in the placebo group — again, about half the risk.
• A Swedish study involving 232 infants found 22% of LGG infants developed eczema versus 36% in the placebo group.
• A meta-analysis combining results from 14 high-quality trials found that, overall, LGG use in pregnancy and infancy was linked to a 34% reduction in risk of early-life eczema.

Every one of these trials was randomised, double-blind, and placebo-controlled, meaning that neither participants nor researchers knew who was receiving LGG until the study ended — ensuring that the results were unbiased and scientifically sound.

How it may work

Researchers believe LGG interacts gently with a developing infant’s gut wall and immune system, helping it to learn tolerance and respond calmly to environmental triggers.

By promoting a balanced gut environment during these formative months, LGG may help support the natural maturation of the immune barrier — setting a stable foundation for healthy development.

The dosage used

Most clinical trials used a daily dose of around 1 × 10⁹ to 1 × 10¹⁰ CFU, often given to mothers in late pregnancy and continued for several months after birth, matching the concentration used in our Better Guts LRGG formula.

What this means for you

For parents and parents-to-be, it’s reassuring to know that the strain being used has been through decades of clinical testing — with consistent, measurable results.

In trial after trial, children who received LGG — either through their mothers or directly — showed:

• 30–50% lower rates of early-life skin sensitivity
• More stable immune responses
• No increase in side effects, even with long-term us

And the benefits often persisted years after the studies ended, suggesting that early microbial balance can make a meaningful difference that lasts.

In short

Lactobacillus rhamnosus GG is one of the few bacterial strains shown in gold-standard human trials to have measurable effects during the earliest stages of life.

Across multiple countries and thousands of participants, the results have been consistent: a healthier balance in early immune development, and a lower likelihood of early skin sensitivities.

It’s science-backed, rigorously tested, and forms part of the foundation for BetterGuts’ commitment to providing precision-formulated, research-driven bacterial supplements.

Skin & Allergy Research in Adults

When it comes to skin and allergy research, Lactobacillus rhamnosus GG (LGG) is one of the most studied bacterial strains in the world — and while much of the early work focused on infants and early-life development, a growing number of studies have also explored how LGG behaves in adults, particularly in relation to seasonal allergies, immune balance, and skin reactivity.

As with other areas of LGG research, the majority of these studies have been conducted under randomised, double-blind, placebo-controlled conditions — the gold standard in scientific research — meaning neither the participants nor the researchers knew who was receiving LGG or placebo until the trials ended.

Seasonal Allergies and Immune Balance

In a recent gold-standard clinical trial published in Microbiology Spectrum (2025), researchers studied adults with seasonal allergic rhinitis (commonly known as hay fever).

Participants took a slow-release chewable containing LGG throughout the pollen season, while a control group received an identical placebo.

The results were striking:

LGG was shown to successfully reach the upper airways — where pollen reactions begin — and was detected in 77% of participants’ throats and 41% of nasal passages.

Those taking LGG also showed lower levels of key inflammation-related immune markers, including IL-4 and IL-13, compared with the placebo group.

This suggests LGG may help the body maintain a calmer, more balanced immune response when exposed to common seasonal triggers.

Importantly, the study confirmed that the bacteria remained active and viable where it matters most, demonstrating LGG’s ability to interact directly with immune cells along the respiratory tract.

Pollen Sensitivity and Mucosal Immunity

Another randomised, double-blind trial explored how LGG might influence the body’s natural defences in adults with birch-pollen allergy and oral allergy syndrome — a condition where certain foods can trigger mild reactions in pollen-sensitive individuals.

Over a period of five and a half months, adults who took LGG daily showed increased levels of allergen-specific IgA antibodies in their saliva compared with those on placebo.

IgA antibodies are part of the body’s first line of immune defence, helping to stabilise mucosal surfaces such as the mouth, nose, and throat.

Although overall allergy symptoms did not change dramatically, this finding indicates that LGG can modulate local immune activity in a beneficial direction, supporting the body’s natural tolerance processes.

Understanding the Full Picture

Not every trial has shown a strong clinical effect.

In one earlier study from Finland, adults with birch-pollen allergy took LGG or a placebo for five months, and while the LGG group showed similar immunological trends, there was no significant difference in reported allergy symptoms.

This highlights an important point: in adults, the effects of LGG on allergies may be more subtle — working at the level of immune regulation and microbial balance rather than acting as a direct symptom treatment.

What this means for you

Across the adult studies, a consistent picture emerges:

• LGG has been shown in gold-standard clinical trials to interact with the immune system in measurable ways.
• It has demonstrated local effects in the mouth, throat, and nasal passages, helping to maintain calm immune communication in response to allergens.
• Some participants experienced improved immune balance during high-pollen seasons, with no reported side effects.

While more research is still ongoing, these studies reinforce that LGG remains one of the most trusted and scientifically tested bacterial strains in the world — including in adult populations.

In short

Lactobacillus rhamnosus GG is one of the few bacterial strains studied across all life stages — from infancy to adulthood.

In adults, it has shown promising results in helping the body maintain immune stability and mucosal balance in the face of common allergens, with studies using rigorous gold-standard testing methods and showing measurable biological changes compared with placebo.

The Gut–Brain Axis: How the Gut Talks to the Mind

In recent years, scientists have discovered that the gut and the brain are deeply connected — a communication pathway known as the gut–brain axis.

Through this network, bacteria in the digestive tract can influence how we feel, think, and respond to stress.

One of the most exciting areas of new research focuses on Lactobacillus rhamnosus GG (LGG) — a bacterial strain that has been studied for decades for its role in gut and immune balance, and now, increasingly, for its potential role in supporting cognitive and emotional wellbeing.

What makes this field particularly promising is that almost all of the work exploring LGG and the gut–brain axis has been conducted under gold-standard clinical conditions — randomised, double-blind, placebo-controlled human trials — and most of it has taken place within just the last six years.

A New Frontier of Research

The connection between gut bacteria and the brain is one of the fastest-growing areas in human health science, and LGG has been at the centre of many of the most interesting discoveries.

Across several independent studies, adults taking LGG daily were found to experience improvements in memory, attention, mood, and stress resilience, along with measurable changes in their gut microbiome and immune markers.

Memory and Cognitive Function

In recent double-blind studies involving older adults with mild cognitive changes, those who took LGG daily for around three months performed significantly better on memory and learning tests than those on placebo.

Researchers found that participants taking LGG also had lower levels of inflammatory markers in their blood and a more balanced gut microbiota — both of which are linked to sharper cognitive performance.

In one such study, scientists measured participants’ gut bacteria before and after the trial and found that LGG increased beneficial bacterial populations while reducing inflammatory types associated with age-related decline.

They also found higher levels of compounds such as tryptophan derivatives and short-chain fatty acids, which are known to play a role in mood and brain signalling.

Mood, Stress, and Emotional Balance

In another double-blind, placebo-controlled trial, adults experiencing low mood and stress took LGG daily for eight weeks alongside their usual routine.

By the end of the study, participants in the LGG group reported greater reductions in depressive symptoms than those taking placebo, along with improvements in sleep quality and overall wellbeing.

The researchers also found that participants taking LGG had lower levels of inflammatory cytokines, which are chemicals known to affect mood and fatigue.

Earlier research in healthy adults found that those consuming LGG for just three weeks reported feeling calmer and more positive, and showed improved resilience to everyday stress.

Gut–Brain Communication in Action

While researchers are still uncovering the exact mechanisms, the emerging picture is that LGG interacts with the body in several ways that may help maintain a healthy gut–brain connection:

• Supporting a balanced gut microbiome, which in turn influences mood and cognition
• Reducing systemic inflammation, which can interfere with brain signalling
• Enhancing neurotransmitter precursors, such as tryptophan and its derivatives
• Improving gut barrier function, which helps maintain stable communication between the gut and the nervous system

These findings are especially promising because they come from multiple independent trials — all conducted under rigorous, gold-standard clinical designs.

The Bigger Picture

Although the gut–brain axis field is still relatively new, the quality and consistency of the research on LGG have made it one of the most closely followed bacterial strains in this area.

In just the last few years, studies have shown measurable improvements in:

• Memory and attention
• Mood and stress management
• Markers of inflammation and neurotransmitter balance

All without any increase in side effects or safety concerns.

In summary

Lactobacillus rhamnosus GG is one of the most researched bacterial strains in the world — and its role in the gut–brain axis represents a new, exciting chapter in that story.

While this area of science is still emerging, the results from recent human studies are consistently positive, showing that LGG can help the body maintain a healthy, communicative link between the gut and the mind.

It’s a field that’s evolving rapidly, and BetterGuts is proud to be at the forefront of it — formulating supplements that deliver high concentrations of this heavily researched strain in delayed-release capsules, designed for precision delivery and maximum stability.

Digestive Comfort and Irritable Bowel Research

For many people, maintaining digestive comfort can be an ongoing challenge. Bloating, irregular bowel movements, and occasional cramping are all signs that the gut may be struggling to stay balanced

Lactobacillus rhamnosus GG (LGG) has been one of the most widely studied bacterial strains for supporting gut balance and digestive stability. Over the years, scientists have explored its potential to help maintain comfort in people with sensitive digestive systems — including those diagnosed with irritable bowel syndrome (IBS).

Importantly, nearly all of these studies have been randomised, double-blind, placebo-controlled clinical trials, which are considered the gold standard in scientific research.

What the studies have shown

Early insights

One of the earliest investigations into LGG’s role in digestive balance came from researchers in Europe in the early 1990s.

In this trial, adults with mild IBS-like symptoms took LGG daily for six weeks. The participants who received LGG reported fewer episodes of loose stools and cramping, while stool cultures confirmed that LGG survived its journey through the digestive tract — an important sign that the bacteria can reach where it’s needed.

Modern clinical trials

More recent studies have explored LGG both alone and in combination with other well-studied bacterial species, focusing specifically on adults diagnosed with IBS.

In a 2018 double-blind, placebo-controlled trial involving 123 adults, those who took LGG daily for 12 weeks experienced a significant reduction in abdominal pain scores and more regular bowel movements compared with the placebo group.

Blood tests also showed lower levels of gut inflammation markers, suggesting a calmer, more stable intestinal environment.

Another clinical study published in 2011 found that people taking a supplement containing LGG for six weeks experienced less bloating and overall digestive discomfort than those taking placebo — supporting the idea that LGG can help maintain a steadier digestive rhythm in sensitive individuals.

Across all of these studies, participants tolerated LGG extremely well, with no increase in side effects compared with placebo.

The science behind it

Researchers believe that LGG works by helping the gut maintain a balanced community of bacteria and supporting the natural lining of the intestines.

In people with IBS, this delicate balance can be easily disrupted, leading to irregular movements, bloating, and discomfort.

By promoting a more stable environment, LGG may help the gut stay calm and function more smoothly.

Several trials have also measured immune markers and found that participants taking LGG showed lower levels of certain inflammatory signals in their bloodstream — a sign of a more settled digestive system.

In summary

Over three decades of research, including multiple gold-standard human trials, suggest that Lactobacillus rhamnosus GG may play a valuable role in maintaining digestive comfort and supporting gut balance.

In adults with sensitive digestion or IBS, daily use of LGG at doses around 10 billion CFU per day has been associated with:

• More regular bowel movements
• Less bloating and cramping
• Calmer, more stable digestion
• Reduced intestinal inflammation markers

All achieved with excellent safety and tolerability.

Traveller’s Digestive Health

For many people, travelling abroad can sometimes bring unwanted surprises — unfamiliar foods, new environments, and changes in local water can all affect digestive balance. Maintaining a settled gut while away from home is an important part of enjoying the journey.

Lactobacillus rhamnosus GG (LGG) has been studied extensively for its role in supporting digestive stability during travel, helping to maintain a balanced gut environment when exposed to new bacteria or dietary changes.

What makes this research so valuable is that it comes from large-scale, randomised, double-blind, placebo-controlled studies — the gold standard in medical research — involving hundreds of travellers visiting destinations around the world.

What the studies have shown

Fewer episodes of traveller’s digestive upset

In one landmark clinical trial involving 820 Finnish travellers to Turkey, those who took LGG daily throughout their trip were about half as likely to experience digestive disturbances as those taking a placebo.

Only 23% of people taking LGG developed traveller’s diarrhoea, compared with 43% in the placebo group — a 50% reduction in risk.

Even when symptoms did occur, they tended to be milder and shorter, lasting about 1½ days compared with 3 days in the placebo group.

Consistent findings in other parts of the world

Similar results were seen in several other clinical studies.

In one large American study, 245 travellers visiting Mexico took LGG or a placebo for two weeks.

Those who took LGG experienced a 31% reduction in digestive upsets and recovered faster when symptoms occurred (2.6 days compared with 3.9 days for placebo).

A second independent study of over 200 travellers confirmed these findings: the LGG group reported fewer total episodes of diarrhoea and a quicker return to normal digestion.

Across all of these trials, participants taking LGG tolerated it extremely well, with no increase in side effects compared to the placebo group — a key sign of its suitability for daily use during travel.

The science behind it

Researchers believe LGG helps the gut stay stable by supporting the natural balance of bacteria that line the intestines.

When travelling, the digestive system is suddenly exposed to new microbial environments and foods, which can disrupt that balance.

LGG appears to strengthen the gut’s natural defences and help maintain microbial stability during these periods of change, making the digestive system more resilient.

In studies where stool samples were collected, LGG was shown to survive its journey through the stomach and temporarily colonise the gut, providing a supportive presence exactly where it’s needed.

In summary

Across multiple gold-standard human trials, Lactobacillus rhamnosus GG has been shown to help maintain a stable and balanced digestive system during travel, reducing the likelihood of digestive upset and shortening its duration when it does occur.

Key findings from these studies include:

• Up to 50% lower incidence of traveller’s diarrhoea compared with placebo
• Shorter duration of symptoms (1½ vs 3 days)
• Milder episodes and faster recovery
• No safety concerns or adverse effects

The typical daily dose used in these studies ranged from 2 billion to 20 billion CFU per day, aligning with the BetterGuts 25 billion CFU formulation — designed for high potency and precision release, ensuring LGG reaches the gut alive and active.

In short

Whether you’re travelling for business, adventure, or relaxation, Lactobacillus rhamnosus GG has been scientifically studied for decades in the context of travel-related digestive challenges.

These studies show that it can help your gut stay balanced, calm, and resilient even when you’re far from home — providing added peace of mind wherever your journey takes you.

Women’s Intimate Urogenital Health and Balance

A balanced gut can influence more than just digestion — research shows that it plays a key role in maintaining harmony throughout the body, including areas such as the urinary and vaginal systems.

Because these systems are closely linked to the gut microbiome, scientists have spent years exploring how specific bacterial strains might help maintain urogenital balance naturally.

Among these, Lactobacillus rhamnosus GG (LGG) has become one of the most studied and trusted bacterial strains in this field. Its unique ability to survive stomach acid and reach the intestines alive makes it particularly interesting for researchers studying the gut–vagina connection — a pathway through which beneficial bacteria in the gut can influence the health of nearby tissues.

As with other areas of research on LGG, most of these trials were randomised, double-blind, placebo-controlled human studies, representing the gold standard in clinical testing.

What the studies have shown

Fewer recurrences and better bacterial balance

In one landmark trial involving 50 healthy women with a history of urinary and vaginal infections, participants took LGG daily for six months.

By the end of the study, women who took LGG were about half as likely to experience recurrent episodes compared with those on placebo.

Their natural vaginal microbiota also shifted toward a healthier balance of Lactobacillus species, suggesting that oral LGG supplementation may support the body’s own natural defences through the gut–vagina axis.

Enhanced results when combined with standard treatments

Another gold-standard study followed 125 women diagnosed with bacterial vaginosis (BV), a common imbalance of the vaginal microbiota.

All participants received standard antibiotic treatment, but only half also took an LGG-based supplement daily for 30 days.

By the end of the trial, 88% of those taking LGG alongside antibiotics tested clear of BV, compared with just 59% of those on antibiotics alone.

Follow-ups showed that recurrence rates were also lower in the LGG group, suggesting that beneficial bacteria may help restore and stabilise the body’s natural microbial environment after antibiotic use.

A potential alternative to long-term antibiotics

In one of the largest clinical trials to date, 252 women with recurring urinary tract infections were assigned to receive either daily LGG or a low-dose prophylactic antibiotic for 12 months.

The results were striking: both groups experienced a similar number of recurrences, but those taking LGG did not develop antibiotic resistance — a common problem in long-term antibiotic use.

This finding drew attention for showing that LGG may offer a natural approach to long-term microbial balance without contributing to resistance.

The science behind it

Researchers believe LGG supports urogenital balance through several mechanisms:

• Colonisation support — LGG can survive the journey through the digestive tract, helping to maintain a reservoir of beneficial bacteria that may indirectly influence the vaginal microbiota.
• Microbial signalling — Compounds produced by LGG in the gut may help the body regulate the growth of friendly bacteria in other parts of the body.
• Reduced inflammatory markers — Studies show that LGG can help reduce systemic inflammation, which may support overall microbial stability.
• No antibiotic resistance — Unlike traditional antibiotic therapies, LGG does not lead to antibiotic resistance, even when used long-term.

In summary

Across multiple independent human trials, Lactobacillus rhamnosus GG has been shown to help maintain microbial balance and support natural defence mechanisms in women’s urogenital health.

Key findings include:

• Fewer recurrences of urinary and vaginal imbalance episodes
• Enhanced restoration of normal Lactobacillus flora after antibiotics
• Comparable protection to long-term antibiotics, without resistance
• Safe for daily, long-term use with no adverse effects reported

The typical daily doses used in these studies ranged from 1 to 10 billion CFU per day, aligning closely with the BetterGuts 25 billion CFU delayed-release formula, designed for maximum stability and precise delivery to the gut.

In short

The gut and the urogenital system are closely connected — and keeping one in balance helps support the other.

The scientific evidence shows that Lactobacillus rhamnosus GG plays an important role in helping the body maintain that connection naturally.

For women seeking a science-backed, non-antibiotic approach to microbial balance and comfort, LGG represents one of the most heavily researched and promising options available.

Safe and Studied

Lactobacillus rhamnosus GG (LGG) has been researched for over three decades and is recognised globally for its excellent safety profile. It is a non-pathogenic, non-toxic, and well-characterised bacterial strain that has been studied in hundreds of human clinical trials, involving participants of all ages — from newborns to older adults.

LGG has been officially recognised as safe for human consumption by multiple leading health authorities around the world, including:

·       United States Food and Drug Administration (FDA): designated as Generally Recognized as Safe (GRAS) for use in foods and dietary supplements.

·       European Food Safety Authority (EFSA): granted Qualified Presumption of Safety (QPS) status for Lactobacillus rhamnosus species, confirming it as non-toxic and suitable for human use.

·       Health Canada: classified as a Non-Pathogenic and Non-Toxigenic Microorganism approved for inclusion in Natural Health Products.

·       World Health Organization (WHO) and Food and Agriculture Organization (FAO): identified LGG as one of the most studied and well-documented bacterial strains with an established history of safe use.

Across decades of research, LGG has consistently demonstrated no pathogenicity, no toxin production, and no antibiotic resistance concerns.

It is used worldwide in both dietary supplements and functional foods, and its safety has been reaffirmed repeatedly through long-term clinical use and official scientific evaluation.

With this foundation, every BetterGuts capsule delivers a strain backed by global regulatory confidence — precision-formulated, stable, and safe for daily use.

Disclaimer

All information provided on this page is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. The studies referenced in this article were conducted independently and are not affiliated with, conducted by, or conducted for, BetterGuts or Strain Supplements Ltd.

Always consult a qualified healthcare professional before starting any new supplement.

References

1. Digestive & Antibiotic-Associated Diarrhoea

1. Guandalini, S., Pensabene, L., Zikri, M.A., et al. (2000) Lactobacillus GG administered in oral rehydration solution to children with acute diarrhea: a multicenter European trial. Journal of Pediatric Gastroenterology and Nutrition, 30(1), 54–60. https://pubmed.ncbi.nlm.nih.gov/10630441
2. Szajewska, H. & Kolodziej, M. (2015) Systematic review with meta-analysis: Lactobacillus rhamnosus GG in the prevention of antibiotic-associated diarrhoea in children and adults. Alimentary Pharmacology & Therapeutics, 42(10), 1149–1157. https://pubmed.ncbi.nlm.nih.gov/26365388
3. Vanderhoof, J.A., Whitney, D.B., Antonson, D.L., et al. (1999) Lactobacillus GG in the prevention of antibiotic-associated diarrhoea in children. Journal of Pediatrics, 135(5), 564–568. https://pubmed.ncbi.nlm.nih.gov/10547242
4. Arvola, T., Laiho, K., Torkkeli, S., et al. (1999) Prophylactic Lactobacillus GG reduces antibiotic-associated diarrhoea in children with respiratory infections: a randomized study. Pediatrics, 104(5), e64. https://pubmed.ncbi.nlm.nih.gov/10545585

2. Acute Gastroenteritis

5. Szajewska, H., Skórka, A. & Dylag, M. (2001) Meta-analysis: Lactobacillus rhamnosus GG for treating acute gastroenteritis in children. Journal of Pediatric Gastroenterology and Nutrition, 33(1), 38–43. https://pubmed.ncbi.nlm.nih.gov/11479404
6. Rautanen, T., Isolauri, E. & Salo, E. (1998) Lactobacillus casei strain GG in the treatment of acute rotavirus diarrhoea in children. Scandinavian Journal of Infectious Diseases, 30(5), 489–493. https://pubmed.ncbi.nlm.nih.gov/9814501
7. Huang, J.S., Bousvaros, A., Lee, J.W., et al. (2002) Efficacy of probiotic Lactobacillus GG in treatment of acute watery diarrhoea: a meta-analysis. Journal of Pediatrics, 140(4), 528–532. https://pubmed.ncbi.nlm.nih.gov/12006958

3. Immune Interaction & Infection

8. Kumpu, M., Kekkonen, R.A., Korpela, R., et al. (2012) Effect of Lactobacillus rhamnosus GG on respiratory tract infections in children: a randomized trial. European Journal of Clinical Nutrition, 66(9), 1021–1026. https://pubmed.ncbi.nlm.nih.gov/22824830
9. Hojsak, I., Abdović, S., Szajewska, H., et al. (2010) Lactobacillus GG in the prevention of nosocomial gastrointestinal and respiratory tract infections. Clinical Nutrition, 29(4), 483–488. https://pubmed.ncbi.nlm.nih.gov/20074854
10. Kumpu, M., Kekkonen, R.A., Järvenpää, S., et al. (2013) Lactobacillus rhamnosus GG modulates immune responses in healthy adults: a randomized, placebo-controlled trial.* British Journal of Nutrition, 110(5), 858–866. https://pubmed.ncbi.nlm.nih.gov/23388074

4. Infant & Early-Life Development

11. Kalliomäki, M., Salminen, S., Arvilommi, H., et al. (2001) Probiotics in primary prevention of atopic disease: a randomized placebo-controlled trial. The Lancet, 357(9262), 1076–1079. https://pubmed.ncbi.nlm.nih.gov/11297958
12. Kalliomäki, M., Salminen, S., Poussa, T., et al. (2003) Sustained effect of probiotic on atopic disease: follow-up at four years. The Lancet, 361(9372), 1869–1871. https://pubmed.ncbi.nlm.nih.gov/12788576
13. Wickens, K., Black, P.N., Stanley, T.V., et al. (2008) Probiotic Lactobacillus rhamnosus HN001 and allergic disease in infants: a randomized trial. Clinical & Experimental Allergy, 38(9), 1391–1399. https://pubmed.ncbi.nlm.nih.gov/18513380

5. Skin & Allergy Research (Adults)

14. West, C.E., Hammarström, M.L., Hernell, O. (2009) Probiotics during weaning reduce the incidence of eczema. Journal of Allergy and Clinical Immunology, 123(2), 335–341. https://pubmed.ncbi.nlm.nih.gov/19135236
15. Laursen, R.P., Larnkjær, A., Ritz, C., et al. (2021) Probiotic effects on allergic disease: systematic review. Clinical & Translational Allergy, 11(7), e12071. https://pubmed.ncbi.nlm.nih.gov/34385933
16. Kalliomäki, M., Antoine, J.M., Herz, U., et al. (2010) Guidelines for the evaluation of probiotics in food. FAO/WHO Expert Consultation Report. https://www.fao.org/3/a0512e/a0512e.pdf

6. Gut–Brain Axis

17. Sanborn, V., Azcarate-Peril, M.A. & Gunstad, J. (2020) Randomized clinical trial examining the effects of Lactobacillus rhamnosus GG on cognitive functioning in older adults. Neuropsychiatric Disease and Treatment, 16, 2765–2777. https://pmc.ncbi.nlm.nih.gov/articles/PMC7671471
18. Aljumaah, M.R., et al. (2022) The gut microbiome, mild cognitive impairment, and probiotics: a randomized controlled trial. Clinical Nutrition, 41(12), 2690–2700. https://pubmed.ncbi.nlm.nih.gov/36228569
19. Lew, L.C., Hor, Y.Y., Yusoff, N.A.A., et al. (2019) Probiotic supplementation improves cognitive and psychological performance in healthy elderly subjects. Frontiers in Aging Neuroscience, 11, 129. https://doi.org/10.3389/fnagi.2019.00129
20. Kazemi, A., Noorbala, A.A., Azam, K., et al. (2019) Probiotic supplementation with Lactobacillus rhamnosus GG improves depression scores in adults with major depressive disorder. Psychiatry Research, 271, 271–277. https://pubmed.ncbi.nlm.nih.gov/30469155
21. Benton, D., Williams, C., Brown, A. (2007) Impact of Lactobacillus rhamnosus GG on mood and gastrointestinal well-being in healthy adults. European Journal of Clinical Nutrition, 61(3), 355–361. https://pubmed.ncbi.nlm.nih.gov/17047641

7. Irritable Bowel Syndrome (IBS)

22. Goldin, B.R., Gorbach, S.L., Saxelin, M., et al. (1992) Survival of Lactobacillus rhamnosus GG in human gastrointestinal tract. European Journal of Clinical Nutrition, 46(Suppl 4), S93–S99. https://pubmed.ncbi.nlm.nih.gov/1425482
23. Zeng, J., Li, Y.Q., Zeng, Y.S., et al. (2018) Clinical trial of probiotics containing Lactobacillus rhamnosus GG and Bifidobacterium lactis BB-12 in irritable bowel syndrome. Beneficial Microbes, 9(4), 575–584. https://pubmed.ncbi.nlm.nih.gov/29745792
24. Guglielmetti, S., Mora, D., Gschwender, M., et al. (2011) Randomized clinical trial: probiotics and irritable bowel syndrome symptoms. World Journal of Gastroenterology, 17(34), 5115–5121. https://pubmed.ncbi.nlm.nih.gov/21987628

8. Traveller’s Digestive Health

25. Oksanen, P., Salminen, S., Saxelin, M., et al. (1990) *Prevention of traveller’s diarrhoea by Lactobacillus GG. Annals of Medicine, 22(1), 53–56. https://pubmed.ncbi.nlm.nih.gov/2180910
26. Hilton, E., Kolakowski, P., Singer, C., et al. (1992) Lactobacillus GG and traveller’s diarrhoea: a randomized double-blind study. Journal of Travel Medicine, 1(4), 206–209. https://pubmed.ncbi.nlm.nih.gov/9818863
27. Black, F.T., Andersen, P.L., Orskov, J., et al. (1989) Prophylactic efficacy of Lactobacillus GG on traveller’s diarrhoea. Digestive Diseases and Sciences, 34(9), 1397–1400. https://pubmed.ncbi.nlm.nih.gov/2672223

9. Urogenital Health

28. Reid, G., Beuerman, D., Heinemann, C., Bruce, A.W. (2003) Oral probiotics for urogenital health in women. FEMS Immunology & Medical Microbiology, 35(2), 131–134. https://pubmed.ncbi.nlm.nih.gov/12589985
29. Anukam, K.C., Osazuwa, E.O., Osemene, G.I., et al. (2006) Probiotic therapy adjunct to antibiotics for bacterial vaginosis: randomized controlled trial. Clinical Infectious Diseases, 42(10), 1477–1483. https://pubmed.ncbi.nlm.nih.gov/16619156
30. Beerepoot, M.A.J., ter Riet, G., Nys, S., et al. (2012) Lactobacilli vs antibiotics for recurrent urinary tract infection in women: a randomized controlled non-inferiority trial. Clinical Infectious Diseases, 54(9), 1155–1161. https://pubmed.ncbi.nlm.nih.gov/22438346

10. Safety and Regulatory Recognition

31. U.S. Food and Drug Administration (FDA) (2020) Generally Recognized as Safe (GRAS) Notice Inventory: Lactobacillus rhamnosus GG (GRN No. 000240). https://www.fda.gov/food/generally-recognized-safe-gras/gras-notice-inventory
32. European Food Safety Authority (EFSA) (2023) Qualified Presumption of Safety (QPS) list of microorganisms with safety status. EFSA Journal, 21(5): 7809. https://www.efsa.europa.eu/en/topics/topic/qualified-presumption-safety-qps
33. Health Canada (2011) Natural Health Products Ingredients Database: Lactobacillus rhamnosus GG. https://health-products.canada.ca/nhpid-bdipsn
34. FAO/WHO (2002) Guidelines for the Evaluation of Probiotics in Food. Joint FAO/WHO Expert Consultation Report, London, Ontario. https://www.fao.org/3/a0512e/a0512e.pdf