GUT MICROBIOME
BY ACTIVATED PROBIOTICS January 28, 2025
The brain, gut, and microbiota are connected in ways which affect sleep physiology, the stress response, and what goes on in the gut. If you have found yourself in this cycle, you may wonder which one came first? Was it the chronic stress which disrupted the sleep which worsened the gut symptoms?
Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder characterised by changes in stool form and frequency accompanied by abdominal pain, with tendencies for diarrhoea, constipation, or alternating bowel habits, depending on the individual case (1). IBS can have multiple contributing and exacerbating factors, many of which are unique to the individual. One factor which is associated with IBS is disrupted sleep, so let us explore the connection between IBS and sleep.
Sleep issues are known to be associated with presence of digestive symptoms such as abdominal pain, reflux, gas, and bloating (2). For cases of IBS in particular, people tend to have a hard time falling asleep and have more fragmented sleep (3). A meta-analysis comparing data from 36 studies found that the global prevalence of sleep disorders in IBS was 38% (4), which suggests that for those living with IBS, supporting sleep quality is an important priority.
So, how does having IBS affect a person’s sleep, and how does a person’s sleep impact their experience of IBS? The answer lies in how our gut health connects to our sleep and nervous system physiology. You can gain a deeper understanding on the importance of sleep, sleep physiology, and how sleep impacts the gut microbiome in this article, but for now, let us explore the connection between gut health and the nervous system and how this influences sleep.
Our sleep is regulated by many intersecting processes in the body, including interactions between messengers such as stress hormones and neurotransmitters, and these communications happen within the brain as well as nerves connecting our brain to the gut and other tissues all around the body. For example, the vagus nerve is the longest nerve in the body which serves as a central connection between the brain and the gut (5). The vagus nerve serves many functions, with one of its main actions being stimulation of our “rest and digest” response - required for healthy digestion and a good night's sleep. In opposition to this, stress can activate other nerves which trigger our “fight-flight-freeze” response . These two responses work in tandem depending on what our body needs at the time- that is, do we need to be alert, or are we able to relax? People with IBS have been shown to have reduced “rest and digest” activation and overactivation of the stress response, suggesting that stress and nervous system dysregulation could be an underlying contributor to both their IBS and their sleep issues in some IBS patients (3).
The significant impact of stress on the body more generally is well documented, but did you know that there is a connection between irritable bowel syndrome and stress? Acute stress activates the ‘fight-flight-freeze’ response to keep us alert and help us deal with the stress (whether it is real or perceived). Activation of these stress pathways in the body impair gut function because they reduce activation of our ‘rest and digest’ mode. As people with IBS have a more reactive stress response and reduced ‘rest and digest’ activity, this results in both impaired gut function and hypersensitivity within the gut- meaning that physical symptoms such as pain in the gut are heightened (6). This increased sensitivity and experience of more severe gut symptoms can stress us out even more, which can further exacerbate gut symptoms and sleep issues- and significantly compromise one’s quality of life in the process.
Did you know the organisms living in our gut (the gut microbiota) can also play a role in sleep, stress, and IBS? The gut-brain axis describes the multidirectional pathways which link sleep, stress, and gut symptoms. While nervous system function is altered by our stress levels, which has an effect on our sleep and also impacts our gut function, the health of our gut and its microbiota can also contribute to IBS symptoms, stress and affect our sleep quality - everything is connected!
Looking at the gut microbiota specifically in the gut-brain axis, research shows that the composition of our gut microbiota can influence our ability to sleep. For example, it has been shown that increased diversity of the gut microbiota is associated with better sleep efficiency, and this could be due to higher amounts of certain groups of bacteria which have been shown to produce calming neurotransmitters such as gamma-aminobutyric acid (GABA) and serotonin in the gut (7). Gut microorganisms which produce serotonin can also help to regulate gut function, as serotonin plays an important role in stimulating normal bowel movements as well as modifying sensations of pain. It should come as no surprise then that abnormalities in the gut microbiota composition have both been observed in those with IBS.
The effects of the gut microbiota on serotonin balance may help to explain why some probiotic strains can offer symptom relief in instances of digestive upset. For example, Lactobacillus rhamnosus GG is a specific probiotic strain that has demonstrated an ability to relieve abdominal pain and promote regular bowel movements in people with IBS. In-vitro studies have shown that these benefits may be, at least partly, due to the effects of this probiotic strain on gut serotonin balance and signalling (3, 6).
By exploring how the brain, gut, and microbiota are connected in ways which affect sleep physiology, the stress response, and what goes on in the gut, hopefully this has helped to paint a picture in your mind about how sleep, stress, and IBS all influence each other. But you may be wondering, what came first? Was it the chronic stress which disrupted the sleep which worsened the perception of gut symptoms? Or was it the nights of poor quality sleep which resulted in a dysregulated stress response which made IBS symptoms worse? This is a chicken or egg situation, in that it could be any or all of the above! In many cases of IBS, the most likely scenario is that while each person may have their own unique underlying causes which contribute to their symptoms, their stress tolerance, sleep quality, and gut microbiome composition all play a significant role in their experience with IBS.
We have explored the connection between stress, sleep, the gut microbiota, and IBS, but what does the effect of lack of sleep actually have on people living with IBS and how does it affect their quality of life? Firstly, it has been shown that poor sleep is associated with worsening IBS symptoms, where symptoms such as abdominal pain, fatigue, and anxiety are predictably higher the day after a night of suboptimal sleep (8). Despite IBS patients tending to sleep more hours per night, their increased episodes of wakefulness predictably increases sensations of abdominal pain and gastrointestinal distress while reducing their overall quality of life (9). This makes it a priority to explore what can be done for IBS sufferers who need support with their symptoms, as well as their sleep.
Addressing the underlying causes of IBS symptoms, whether that could be microbiota imbalances, poor sleep, poor stress tolerance, or all of the above, is crucial as part of a plan to manage IBS in a sustainable way. While each case of IBS is unique to the individual, requiring nuanced approaches to management, anyone can benefit from getting better sleep regardless of whether you experience unpleasant digestive symptoms or not.
Understanding how to reduce stress in our daily lives is key in managing the gut-brain axis communication which affects IBS symptoms. Firstly, when it comes to managing symptoms of irritable bowel syndrome, self care is important, with clinical research showing that incorporating regular relaxation techniques can improve quality of life in those with IBS (10). Activities which help regulate nervous system function in IBS patients include things such as yoga, meditation, diaphragmatic breathing, and others (11). Prioritising time for conscious rest and relaxation is a sure-fire way to bring your nervous system back into a regulated state so that you can adapt to daily stress better, which will also allow for a more easeful transition into a night of restful sleep. This can also help to manage unpleasant digestive symptoms via the gut-brain axis as we have discussed, however it is also important to focus on restoring balance to the gut microbiota, so that we can truly address the gut-derived causes of IBS symptoms.
While there are many lifestyle modifications and other strategies which can help us to manage stress and optimise our sleep quality, we can also positively influence the gut-brain axis to help address unpleasant IBS symptoms which feed into the stress-sleep cycle by using condition-specific probiotics.
Biome IBS™ Probiotic has been specifically formulated to help alleviate the unpleasant symptoms experienced by people with IBS, as it includes two specific probiotic strains, Lactobacillus plantarum 299v(12-14) and Lactobacillus rhamnosus GG (15) which have been shown to significantly improve symptoms of IBS in human clinical trials.
A double-blind, placebo-controlled trial in 214 adults with IBS showed that a 4 week treatment with Lactobacillus plantarum 299v significantly reduced the mean frequency of abdominal pain by 52% and the mean severity of abdominal pain by 45%, with 78% of patients rating the efficacy of treatment as good or excellent compared to 8% in the placebo group (p<0.01). In another study, 6 weeks of treatment with Lactobacillus rhamnosus GG reduced the average IBS symptom severity score (IBS-SSS) by 76% which was statistically significant when compared to control (p < 0.01).
In cases where stress and poor sleep may be the biggest contributor to their IBS symptoms, due to the links we have discussed above, Biome Lift Probiotic may be of benefit. This targeted probiotic includes a clinically-trialled combination of four probiotic strains which have been shown to improve mood balance, enhance sleep quality and reduce fatigue (16).