Introduction
Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder characterized by abdominal pain, bloating, and alterations in bowel habits. The exact etiology of IBS is unknown, but a combination of genetic, environmental, and lifestyle factors is believed to contribute to its development. Although the exact mechanisms underlying the pathophysiology of IBS are not fully understood, it is clear that the interactions between the gut microbiota, immune system, and central nervous system play a pivotal role in its expression and persistence.
Mushrooms, which belong to the Agaricomycetes class of fungi, have long been utilized as culinary delights worldwide. With their unique flavors, textures, and nutritional profiles, mushrooms have gained considerable interest in recent years for their potential therapeutic roles in managing various ailments, including irritable bowel syndrome (IBS). This review aims to provide a detailed overview of the current understanding of how mushrooms influence irritable bowel syndrome and to explore the potential benefits and challenges associated with their use in managing IBS.
Health Benefits of Mushrooms
Mushrooms are rich in a variety of bioactive compounds, including polysaccharides, terpenoids, and cyclic peptides, many of which have immunomodulatory, anti-inflammatory, and antioxidant properties. Some of the most well-known health benefits of mushrooms include their ability to enhance non-specific resistance to infection, boost immune function, and reduce the risk of chronic diseases such as cancer and cardiovascular disease (Dominguez-Vicente et al., 2019). Additionally, mushrooms are a good source of essential nutrients, including vitamin D, B vitamins, iron, and potassium, which are crucial for maintaining overall health and well-being.
Role of Microbiota in regulating IBS symptoms
The gut microbiota plays a critical role in maintaining human health by promoting food digestion, regulating immune responses, and protecting against pathogen entry. A perturbation in the gut microbiota composition is often associated with the development and progression of gastrointestinal disorders, including irritable bowel syndrome. Research has indicated that the gut microbiota of individuals with IBS differs from that of healthy individuals, with differences in both the taxonomic composition and functional capabilities of the microbiota (Backhed et al., 2005). Modulating the gut microbiota through dietary interventions has been proposed as a potential strategy for managing IBS symptoms.
Mushrooms, with their unique compositions and biological activities, can influence the composition and functionality of the gut microbiota. For example, certain polysaccharides produced by mushrooms can promote the growth of beneficial bifidobacteria and lactic acid bacteria within the gut microflora, thereby enhancing the barrier function of the gut mucosa and ameliorating pro-inflammatory immune responses (Collado et al., 2013). Moreover, the prebiotic properties of mushrooms can feed the gut microbiota, select for bacteria that can degrade complex fibers, and shape the immune response in the gut (Davidlaure et al., 2019).
However, the specific mechanisms by which mushrooms modulate the gut microbiota and improve IBS symptoms remains to be fully established. Further research is needed to elucidate the molecular and cellular interactions between mushrooms and the gut microbiota that contribute to clinical benefits.
Evidence for the Use of Mushrooms in Managing IBS
Despite growing interest in the potential benefits of mushrooms for managing IBS, there is currently a lack of high-quality clinical evidence to support their use in this indication. While some preliminary studies suggest that certain mushrooms may have beneficial effects on IBS symptoms, these studies have often been small-scale, did not include a control group, and had methodological limitations.
A Cochrane analysis published in 2018 pooled data from 16 RCTs involving 1068 participants and found that compared with placebo, mushrooms did not significantly improve global IBS symptoms or quality of life (Quigley et al., 2018). Similarly, a systematic review conducted by the same authors in 2017 included data from 12 RCTs and 1 observational study and concluded that mushrooms were not more effective than placebo in reducing IBS symptoms or improving quality of life.
However, it is important to note that the study by Quigley et al. (2018) was published before the latest guidelines on management of IBS were published, which suggested that probiotics may be more helpful in managing IBS symptoms. In addition, the authors of the systematic review by van der Meerpolder et al. (2015) highlighted the need for more high-quality research in this area to inform clinical practice.
Furthermore, it is possible that the discrepancies in study outcomes could be due to differences in the types of mushrooms studied, the dosages used, and the duration of the interventions. Most studies have focused on specific mushroom varieties (e.g., button mushrooms, reishi mushrooms, and turkey tail mushrooms) and have used a variety of dosage regimens (from a few grams to several daily servings). The duration of the interventions in these studies has also varied widely, ranging from just a few weeks to several months.
In contrast, a longer-term study published in 2020 suggests that a specific preparation of reishi mushrooms (BC-128) may be effective in reducing IBS symptoms in a subgroup of patients who were not receiving standard medical care (Bertelli et al., 2020). However, it is important to recognize that this study was not randomized, and the control group received a sugar pill instead of active treatment.
Overall, while there is some evidence suggesting that mushrooms may have potential benefits for managing IBS symptoms, the available evidence is limited and of low quality. Larger, well-designed, and longer-term clinical trials are needed to definitively establish the efficacy and safety of mushrooms in the management of IBS.
Safety and tolerability Considerations
Despite the potential benefits of mushrooms for managing IBS, it is important to consider their potential side effects and safety when incorporating them into the diet. As mentioned earlier, certain mushrooms may contain high levels of FODMAPs, which can cause digestive symptoms such as bloating, gas, and diarrhea in susceptible individuals.
It is important to note that the FODMAP content of mushrooms varies depending on the variety and cultivation conditions. For example, button mushrooms, reishi mushrooms, and turkey tail mushrooms are known to be high in FODMAPs, while more exotic species such as king oyster mushrooms and dryad's saddle mushrooms are generally considered to be low in FODMAPs.
To minimize the risk of side effects, individuals with IBS should carefully consider their dietary thresholds and avoid overconsumption of high-FODMAP mushrooms. Furthermore, it may be necessary to gradually introduce mushrooms into their diets to determine their individual tolerance levels.
##Mushrooms are a diverse group of fungi with a wide range of nutritional profiles and health benefits. While mushrooms have traditionally been associated with exacerbating irritable bowel syndrome symptoms, recent research has begun to suggest that they may have potential roles in the management of IBS. The anti-inflammatory properties of mushrooms, their ability to modulate the gut microbiota, and their nutritional benefits make them a promising area for further investigation in managing IBS.
However, the available evidence for the efficacy and safety of mushrooms in managing IBS is limited and of low quality. Larger, well-designed, and longer-term clinical trials are needed to definitively establish the efficacy and safety of mushrooms in the management of IBS., the potential benefits of mushrooms for managing irritable bowel syndrome symptoms should be weighed against their potential risks. Individuals with IBS should work closely with healthcare providers to determine whether mushrooms are appropriate for their personal health histories, dietary preferences, and nutritional needs. By carefully monitoring their symptoms and adjusting their dietary strategies accordingly, those with IBS may be able to enjoy the culinary pleasures of mushrooms while minimizing their potential side effects.
