IBS and the gut microbiome

Irritable bowel syndrome (IBS) is diagnosed when all other causes for irregular bowel habits and digestive discomfort are ruled out. The cause of this collection of uncomfortable digestive symptoms is still under investigation, but it is thought to involve a complex combination of many different factors (1).

As the gut microbiota can influence so many different aspects of gastrointestinal function (including hormones, nerve cell function, gut barrier integrity, and inflammation), it is often considered to be one of the most important contributing factors to IBS (1, 2).

For example, research into potential underlying causes of IBS has revealed abnormalities in the composition of the gut microbiome in people with IBS when compared to healthy people. Whilst these differences in gut microbiome composition between healthy people and those with IBS are evident, whether they are a cause, a consequence, or both is undergoing investigation.

What causes IBS?

Generally, research has found that there are reduced numbers of gut bacteria which are associated with maintaining healthy gut functioning and immune responses in patients with IBS, while there are increased numbers of species which contribute to inflammation in the gut (3). These differences in the gut microbiome are thought to also contribute to leaky gut and hormonal and nerve cell dysfunction, which in turn can contribute to IBS symptoms such as alternating bowel habits, bloating and abdominal pain (1).Therefore, abnormalities in the gut microbiota are being considered as an underlying cause of functional gastrointestinal disorders such as IBS.

These changes can be caused by many different factors, including acute gastrointestinal infections (e.g. food poisoning or ‘gastro’), poor diet and lifestyle, or medications such as antibiotics (1). These factors are known to disrupt the gut microbiome, and are also directly linked to IBS symptoms. For example, antibiotic use has been so well-established as a contributor to IBS that researchers have suggested a new category of IBS, ‘post-antibiotic IBS’, be acknowledged by health practitioners (3). Likewise, epidemiological studies have revealed that many patients with IBS report the onset of symptoms after experiencing infectious gastroenteritis (known by many as ‘gastro’); in fact, evidence suggests there is a six to seven-fold increased risk of developing IBS after gastro. Both of these events alter the landscape of the microbial communities in the gut, reducing levels of certain beneficial communities and allowing other potentially more inflammatory groups of microorganisms to take hold and disrupt the gut environment - in many, this results in IBS.

Dietary influences are another factor which affect the gut microbiome, with certain food choices playing a role in worsening or even triggering IBS symptoms. IBS symptoms can be affected by specific foods unique to an individual, meaning one person with IBS might react to spicy food or caffeine, while another may not. Foods rich in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) can often be a trigger of symptoms, which is why low FODMAP eating plans have become popular for people with IBS (5), and may be helpful as a short-term nutritional strategy. FODMAPs are fibres which can be fermented by different gut microorganisms, with the composition of an individual’s gut microbiota affecting how they respond to the intake of FODMAP rich foods- for some, these fibres can increase the microbiota’s production of gas and other metabolites which contribute to uncomfortable symptoms. So whilst there may be common foods that people with IBS are impacted by more than others, one’s digestive health and gut microbiota make dietary influences relatively subjective between individuals with IBS. This illustrates the complexity and individuality of each case of IBS, and often the need for guidance from health professionals to identify dietary triggers for gastrointestinal symptoms.

In addition to what we eat, what we drink can also impact our gut and influence IBS symptoms. It is known that drinking alcohol contributes to a leaky gut barrier, allowing bacteria and their byproducts to induce inflammation within the digestive tract, and alters the microorganisms present in the gut (6). Heavy alcohol consumption is associated with IBS symptoms, while in some people alcohol consumption can actually be a trigger for the onset of IBS symptoms (7).

In addition to what we eat and drink, stress is another factor linked with IBS which is known to influence our gut microbiome. This goes both ways, as the gut microbiota can influence the regulation of our nervous system while stress can contribute to a leaky gut and reduce gut microbiota diversity, thereby influencing the organisms that make up the gut microbiome (8). Managing stress can therefore go a long way as part of an IBS management plan.

L. plantarum 299v is one of the most extensively studied probiotic strains in IBS and has demonstrated a consistently strong ability to relieve symptoms of IBS.

In a double blind, placebo-controlled, randomised clinical trial, people who took 10 billion CFU of L. plantarum 299v demonstrated a significant reduction in the severity of their abdominal pain and bloating within 4 weeks when compared to those who took a placebo (2). After 4 weeks, 78% of people who took the probiotic rated the effect of their treatment as ‘excellent’ or ‘good’, compared to only 8% for those who received the placebo only. Other clinical trials have also demonstrated significant reductions in flatulence, abdominal pain and overall IBS symptoms (3, 4).

Targeting the gut microbiome with specific probiotic strains

Because of the role that the gut microbiome plays in IBS, research has investigated the potential for probiotics (live beneficial bacteria) to reduce the severity of symptoms and resolve IBS. A number of different probiotic strains have been shown to help to restore balance to the gut microbiome, improve the way the digestive system functions, and offer symptom relief (1). However, clinical research performed on probiotic strains in IBS has demonstrated varying levels of effectiveness, depending on the strain used, with some strains clearly offering greater benefits than others. Therefore, when selecting a probiotic for IBS, it is important to select a probiotic with strains that have been shown to be effective in human clinical trials.

Lactobacillus plantarum 299v

Lactobacillus plantarum 299v (which has recently been renamed Lactiplantibacillus plantarum 299v) is one of the most extensively studied probiotic strains in IBS and has demonstrated a consistently strong ability to relieve symptoms of IBS.

In a double blind, placebo-controlled, randomised clinical trial, participants with IBS who took 10 billion CFU of L. plantarum 299v demonstrated a significant 52% reduction in the frequency of their digestive symptoms (including bloating and abdominal pain). In fact, there was a 45% reduction in the severity of their abdominal pain (2). A marked improvement in abdominal pain was also observed in another clinical trial where after 4 weeks, all participants taking the probiotic reported a resolution of their pain while 55% of participants taking a placebo still reported pain (9). 95% of people taking L. plantarum 299v in this trial also showed improvement in overall IBS symptoms, compared to only 15% of people in the placebo group (p < 0.0001). In addition to showing significant improvements in symptoms such as abdominal pain and bloating with administration of L. plantarum 299v, further studies have also shown alleviation of other IBS symptoms. For example, in a clinical trial where the researchers provided L. plantarum 299v in a fruit drink, they observed significant and more rapid reductions in flatulence and the number of days participants experienced abundant gas production compared to placebo (p < 0.05) (10). Lactobacillus rhamnosus GG 299v

As one of the most extensively studied probiotic strains available, Lactobacillus rhamnosus GG (recently renamed Lacticaseibacillus rhamnosus GG) offers many different benefits to the health of the digestive tract and has also demonstrated an ability to improve IBS symptoms.

One particular randomised controlled trial showed a statistically significant reduction in IBS symptoms after 6 weeks when compared to participants in the control group who followed a standard western diet and did not take the probiotic (p < 0.01) (11). The researchers assessed the IBS symptom severity score (IBS-SSS), which measures frequency and severity of symptoms such as abdominal pain, bloating, and impact on bowel habits and quality of life. By the end of the study, the average IBS-SSS was reduced by 76% in the participants taking L. rhamnosus GG compared to those who did not, indicating the probiotic significantly improved IBS symptoms for those taking it.

IBS management with Biome IBS™ Probiotic

It is clear that the gut microbiota plays a significant role in IBS, so this makes it an important target in IBS management, particularly due to its ability to influence many different aspects of digestive health.

Specific probiotics for IBS can therefore provide assistance in the management of IBS by helping to restore balance to the gut microbiome, improving digestive function, and relieving symptoms. Biome IBS™ was formulated to create a targeted probiotic for IBS relief and includes two specific probiotic strains which have been shown to significantly improve symptoms of IBS in human clinical trials: Lactobacillus plantarum 299v (Lactiplantibacillus plantarum 299v) 299v and Lactobacillus rhamnosus GG (Lacticaseibacillus rhamnosus GG).

Always read the label. Follow the directions for use.