Background and Objective
Functional gastrointestinal disorders (FGIDs) are among the most common and chronically persistent disorders affecting the digestive system. IBS is an apt example of chronic FGID that is associated with abdominal pain and discomfort which may be present along with other gastrointestinal symptoms such as bloating, fullness, belching, constipation, diarrhoea etc. Although the etiology of IBS may not be understood clearly, it mainly depends on the pathophysiology of the host and its interaction with the environment. Among the environmental factors, the role of the diet must be studied exclusively as most of the IBS patients have reported that their symptoms become worse after the consumption of certain foods. Thus, there was need to carry out Narrative Review to study the role of food items, probiotics and fiber consumption and impact of available dietary guidelines on the health of IBS patients.
Methods
A systematic literature search was conducted following PRISMA guidelines at three databases that is PubMed, Embase and Google Scholar. Articles that were published in past 10 years were included. Mainly observational studies, randomized controlled trials, systematic reviews and meta-analysis that were available in English language were included in this review. The automation tool was helpful in screening the articles. After reading the title and abstract, selected articles were further screened in detail to be included or excluded.
Key content and Findings
The main goal of IBS treatment is to provide relief from symptoms rather than cure. The factors that exacerbate IBS symptoms need to be identified and conditions that are favourable to control these factors should be implemented. The diet may directly affect the gut microflora and therefore by modifying the dietary factors, improvement can be observed among IBS patients. Low FODMAP diet is highly recommended for IBS patients but in developing countries, these guidelines may not be economically feasible and may also cause nutritional deficiency in long run. Also, there is a huge difference in the diet followed in the Asian countries and the Western world, thereby responsible for the vast variation that can be seen in the prevalence rates, gender differences and manifestation of symptoms Hence, there is a need to formulate individualized diet for the patients based on their dietary history, socio-economic status, willingness to change, environmental factors, socio-cultural believes and associated psychological comorbidities. This can only be achieved by a team of well-trained dieticians working in collaboration with doctors, nurses and other health care professionals from clinical nutrition, gastroenterology, psychiatry and associated departments.
Conclusions
The Narrative Review concludes that there is need to adopt individualized approach for treating IBS patients. Although the benefits of low FODMAP diet are known, universalization may not be the best approach. Proper hydration and regular sleep are beneficial for all the IBS patients around the world. A team of specialists from the department of gastroenterology and dietetics should take the initiative of formulating individualized diet which will decrease the number of patient’s visits thereby reducing the economic burden on the individual and health care system in long run.
Diet; Fiber; Irritable Bowel Syndrome; Probiotics
Functional gastrointestinal disorders (FGIDs) are among the most common and chronically persistent disorders affecting the digestive system [1]. Functional constipation, dyspepsia and Irritable Bowel Syndrome (IBS) are the most reoccurring gastrointestinal disorders affecting the quality of life [1,2] IBS is an apt example of chronic FGID that is associated with abdominal pain and discomfort which may be present along with other gastrointestinal symptoms such as bloating, fullness, belching, constipation, diarrhoea etc. [3].The prevalence of IBS is 10-20% in developed countries [4] but the availability of data about developing countries is sparce. IBS patients are more likely to be on medical leave which affects their work productivity and also causes economic burden [5]. This affects their quality of life, along with degradation in family and social life [6]. Thus, IBS is a multisymptomatic condition that affects patients physically, mentally, socially and economically [7].
IBS is a disorder of gut-brain interaction in which psychological factors play a significant role [8]. 30% - 50% of FGID patients suffer from psychological comorbidities such as anxiety and depression [9]. A systematic review and meta-analysis have reported that patients suffering from IBS have significantly high levels of anxiety and depression than healthy controls [10] (Figure 1).
Figure 1: Shows commonly reported clinical manifestations and psychiatric associations in irritable bowel syndrome patients.
Note: The fig. is drawn using Canva, the graphic design tool.
Diagnosis
IBS can be diagnosed by following the latest ROME IV criteria according to which: IBS is a functional bowel disorder with recurrent abdominal pain that is associated with defecation or a change in bowel habits. Disordered bowel habits are typically present (i.e., constipation, diarrhea or a mix of constipation and diarrhea), as are symptoms of abdominal bloating/distension. Symptom onset should occur at least 6 months prior to diagnosis and symptoms should be present during the last 3 months. Recurrent abdominal pain atleast 1 day/week in the last 3 months associated with two or more of the following: a) Related to defecation, b) Associated with a change in frequency of stool, c) Associated with a change in the form (appearance) of stool [11].
Rome IV criteria have replaced the formerly used Rome III criteria, according to which the term ‘discomfort’ is replaced by ‘pain’. Also, the frequency of pain from 3 times in month (Rome III) have been specified to at least one day per week (Rome IV). The updated criteria has resulted in a decrease in the prevalence of IBS patients [12].
Classification
According to stool pattern, IBS is classified as: a) IBS with constipation (IBS-C):
IBS is further classified as 1) sporadic or non-specific and 2) post-infection. In the sporadic type, the IBS symptoms occur without any history of gastrointestinal infection whereas in post-infection cases, IBS may be observed in patients with a history of infection mainly affecting the digestive system. Post-infection IBS covers 6% to 17% of IBS patients [13]. IBS patients visit the physician more often than the patients of hypertension and diabetes mellitus. 12 to 14% of primary care visits and 28% of referral to the gastroenterology department are due to IBS [13].
Significance of the study
Although the etiology of IBS may not be understood clearly, it mainly depends on the pathophysiology of the host and its interaction with the environment. Among the environmental factors, the role of the diet must be studied exclusively as most of the IBS patients have reported that their symptoms become worse after the consumption of certain foods [14]. Food choices along with psychosocial factors play a significant role in symptom emanation and perpetuation [3,13,15].
The main aim of this Narrative Review is to understand the role of different food choices on the health of IBS patients around the world. Only the latest studies done in the past 10 years are included in this review so that they can be useful in providing the current developments in this field and also present prospects of research in the coming future.
Methodology
A systematic literature search was conducted following PRISMA guidelines at three databases that is PubMed, Embase and Google Scholar to acquire comprehensive and meaningful insights. The following keywords were used, “Diet” OR “Role of diet” AND “irritable bowel syndrome” OR “IBS” AND “fiber” AND “Probiotics” AND “functional gastrointestinal disorder” OR “FGID”. The publication date was customized to past ten years so that the latest developments in the field can be reviewed, then the articles were screened for their eligibility regarding titles and article type. If the title and abstract were not enough for making a decision then full articles were studied in detail to make a decision regarding its inclusion or exclusion.
The quality of papers that were included was checked thoroughly which involved the selection criteria of participants, diagnosis, study designs that were used, methodology followed and presentation of results. Since the preparation of this Narrative Review did not involve any human trial, ethical clearance was not taken.
Inclusion and Exclusion Criteria
The articles that were published in English language, were selected for the study. Studies which included IBS patients ≥18 years were included, any study about paediatric patients (below 18 years) was excluded. Studies in which diagnosis was done by Rome IV, III, II, I or Manning criteria were included. Randomized clinical trials, systematic reviews, observational study, case-control study and meta-analysis were included. Non-human trials were excluded from the study. Articles in any other language except English or other gastrointestinal disorder except IBS or organic diseases were excluded.
Data extraction
The following data was extracted from each included study:
Author’s name, year in which the study was conducted, country/region, sample size, age of participants, study design, type of intervention provided and the main outcome of the study.
Role of diet:
Food is both the trigger as well as treatment for IBS. The dietary habits of people differ in different countries and even places within the countries. Diet is an important factor which can alter the gut microbiota [16,17,14]. In a survey consisting of 1,242 IBS patients, the majority of them had an opinion that modifying diet can improve the severity of symptoms in them [18]. Recent research by the division of gastroenterology in Boston, USA suggested that different subtypes of IBS differ in dietary habits and gut microbial composition and function, indicating potential research in the field of gut-microbiome interactions [19]. One common advice given to all the IBS patients around the world is to avoid certain foods that can worsen IBS symptoms. The IBS patients are advised to eat regular meals in a calm manner and chew it properly [16].
Low FODMAP diet
Recently many studies have indicated the benefits of low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet for IBS patients [3,16]. The short chain carbohydrates are not easily digested and absorbed by the IBS patients. They can cause osmotic flow towards large bowel. These partially digested carbohydrates are easily fermented by the intestinal microbes thus, producing symptoms such as bloating, distension, flatulence etc. To alleviate IBS symptoms low FODMAP diet is advised [20]. A study conducted on 20 IBS-D patients showed that using low FODMAP diet for 90 days was beneficial in reducing IBS symptoms as well as improved their anthropometric profile [17]. Several systematic reviews and meta-analysis have indicated that low FODMAP diet is beneficial in 50% of the IBS patients [6] leaving with a challenge to formulate diet for the remaining patients.
A low FODMAP diet consists of food groups that includes fruits, vegetables, cereals, tubers, dairy products, legumes, sweeteners etc. In Asian countries including India and Korea, onions and garlic are consumed regularly which are high FODMAP foods. In western countries processed meat, dairy products and wheat products such as bread form a major part of their diet which are also high FODMAP foods [20]. The currently available low FODMAP diet is formulated based on studies vastly carried out in western countries. Still detailed data about the dietary practices followed in the developing world including Asian countries such as Korea and India with reference to IBS is sparse. Moreover, high FODMAP wheat products such as chapatti (staple food of North India), dalia, laddu, biscuits are consumed regularly by Indian population. Along with this there is an increase in the consumption of refined wheat flour products such as bread, noodles and other convenient foods by the Asian population including Korea and India. Thus the implementation of a low FODMAP diet come with its own challenges such as availability, vegetarianism, social acceptability, nutritional deficiency in long run and it might be not be an affordable option for chronic disease like IBS [6].
Traditional diet
Both traditional as well as low FODMAP diet is benefial for IBS patients. However, low FODMAP diet has also shown significant improvement in gut microbiota [16]. Some common food items that were reported by IBS patients that may exacerbate their symptoms include coffee, alcohol, spicy and fatty foods but more research need to be done in order to find significant association.
A recent systematic review and meta-analysis reported that coffee drinkers have a reduced likelihood of developing IBS as compared to the non-drinkers. Although they also pointed out that the included studies had major methodological issues and there is a need for more investigations to clearly understand the biological mechanism [21].
Gluten free and lactose free diet
Coeliac disease and lactose intolerance are other common gastrointestinal disorders affecting the population around the globe. Each of these can be present simultaneously with IBS. Some studies have reported that gluten free diet and lactose free diet are beneficial to IBS patients however the evidence are conflicting. More research is required to obtain data regarding which part of wheat or milk may act as a trigger for IBS symptoms.
Current Dietary guidelines
Dietary guidelines given by National Institute for Health and Care Excellence (NICE) and British Dietetic Association includes reduction in fats, caffeine, excessive fiber intake and avoidance of bloating or flatulence causing vegetables like onion, cabbage and beans and carbonated beverages.
The modified NICE (mNICE) diet is another option for IBS patients in which they have to avoid excess alcohol and caffeine, eat small frequent meals and avoid large meals and also avoid specific food triggers which vary from patient to patient. In long term mNICE diet is easy to follow and it won’t cause any issue of malnutrition whereas low FODMAP diet is difficult to follow in long term, may cause deficiencies [22] and are also expensive for patients living in developing countries (Table 1).
Study |
Region |
Diagnosis |
n (Sample) |
Study Design |
Interventional Groups |
Duration |
Result |
[23] |
Australia |
Rome IV criteria |
n=59 IBS patients (18-65 years) |
RCT |
n=29, Mediterranean diet (MD) & n=30, control |
6 weeks |
**IBS-SSS score was low in MD group as compared to control (p<0.001). Reduction in IBS-SSS was correlated with ***MEDAS score (p<0.001). |
[24] |
Italy |
Rome III-IV criteria |
n=42 IBS-D patients (Not mentioned) |
Single blind, parallel group RCT |
n=21, Low Fodmap Diet & n=21, Tritordium based diets |
Jan/2018-Sept/2020, Intervention for 12 weeks |
According to IBS-SSS the two diets equally improved the gastrointestinal symptoms and ****QoL. |
[25] |
Sweden |
Rome IV criteria |
n=103 IBS patients (18-70 years) |
Double blind, placebo controlled, 3-way crossover RCT |
1 week intervention with FODMAP (50g/day), Gluten (17.3g/day) or placebo followed by 1 week washout period |
Sept/2018-June/2019 |
FODMAP group indicated modest improvement in **IBS-SSS whereas placebo and gluten groups showed no difference. |
[26] |
Sweden |
Rome-III criteria |
IBS patients (18-65 years) |
Novel approach: 4-day food diary intregrated into food tree and relation with gut microbiota |
n=149, IBS n=52, healthy controls |
Not mentioned |
Study showed that individuals with severe IBS symptoms had higher intake of poor-quality foods at main meals as compared to patients with mild IBS symptoms and controls. |
[27] |
China |
Rome-III criteria |
n=108, IBS-D patients (31-57 years) |
RCT |
n=54, Low FODMAP n=54, *TDA |
Oct/2017-May/2018 |
Patients taking low FODMAP diet achieved earlier symptom improvement than TDA. Although both the diets reduced IBS-D symptoms. |
[16] |
Sweden |
Rome III criteria |
n = 67 IBS patients (21-63 years) |
RCT |
n = 34, traditional diet n = 33, Low FODMAP |
4 weeks |
Low FODMAP diet was associated with reduced Bifidobacterium and Actinobacteria whereas traditional diet was not significantly associated with change in faecal bacterial profile |
[28] |
Germany |
Rome III criteria |
n = 59 IBS patients (18-75 years) |
RCT |
n = 30, yoga n = 29, low FODMAP |
12-24 weeks |
Significant difference was not observed between the intervention groups with reference IBS-SSS score. |
[29] |
Netherlands |
Rome III criteria |
n=194, IBS patients n=186, healthy controls (18-75 years) |
Case-Control study |
- |
May/2012–April/2015 |
Quality of diet in IBS patients was lower as compared to controls as they consumed high amounts of fats, sugars and processed meat with lower amounts of fiber. |
[30] |
London, U.K. |
Rome-III criteria |
n = 104, IBS-patients (18-65 years) |
RCT
|
n = 27, Sham diet + placebo n = 26, sham diet + probiotic, n = 24, low FODMAP + placebo n = 27, low FODMAP + probiotic |
4 weeks |
Total mean IBS-Severity Scoring System score was significantly lower for patients on the low FODMAP diet as compared to sham diet (p = 0.001). |
Table 1: Research showing role of diet in irritable bowel syndrome, chronologically arranged studies of past ten years.
TDA: Traditional dietary advice, IBS-SSS: IBS symptom severity score, MEDAS: Mediterranean Diet Adherence Screener, Quality of Life
There are mainly two kinds of fibers found in foods, water-soluble dietary fiber and water-insoluble dietary fiber [1]. These fibers play a very significant role in maintaining gut health. Both the fibers play different roles in the digestive system, the coarse or insoluble fiber such as bran improves gut motility by stimulating the secretion of mucous and water [1]. It also increases bulk or volume of food and keeps full for longer duration. On the other hand the soluble fibers have high water holding capacity as they form gels, thus keeping the stools moist and soft, which is essential for easy passage or excretion (eg: psyllium husk) [1]. Recent studies have indicated cautious use of fiber in IBS patients as they may exacerbate IBS symptoms [31].
In a randomized controlled trial (RCT) consisting of 3 groups of IBS patients, in which the first group was given soluble fiber (ispaghula, psyllium), the second group was given bran and the third group was given placebo (rice flour) [32]. The result indicated that there was no significant difference between bran and placebo control group, but soluble fiber significantly reduced the abdominal pain and distension in IBS patients [32]. Low fiber diet may increase the number of IBS-C patients [33]. A systematic review and meta-analysis consisting of 14 RCT’s involving 906 patients reported the significant benefits of soluble fiber whereas no useful or harmful effect of bran was indicated [31].
In a crossover RCT, IBS – C patients in one group were given inulin, choline and silymarin (Stoptoxin) along with diet for 28 days and the other group was only advised diet. There was significant decrease (p=0.004) in abdominal pain as well as abdominal bloating (p=0.04) when IBS-C patients were advised diet with Stoptoxin. Thus, these studies have concluded that fiber supplementation may be effective in improving global IBS symptoms [34]. Another research published in 2023, studied the effect of guar gum (a low viscosity soluble fiber) on IBS patients. They reported that IBS patients with normal baseline microbiota showed positive response to guar gum and those with low microbiota diversity did not show significant improvement, concluding that baseline microbiota play a significant role in influencing the response towards fiber intervention [35].
Dietary fiber guidelines
The recommended dietary allowance (RDA) of fiber for Indians is 40g/2000 kcal consumed. It is considered as a safe limit [36]. NICE (National Institute for Care and Excellence) recommends fiber modification i.e., not a mere increase or decrease in the amount of fiber rather adding variety of fiber as IBS patients may be intolerant to certain specific fibers such as wheat bran. The adequate intake (AI) of fiber recommended by Australian dietary guidelines suggests 30g of fiber for adult males and 25g for adult females whereas to reduce chronic gastrointestinal diseases the suggested dietary target (SDT) is 38g/day for adult males and 28g/day for adult females [37]. The modified NICE guidelines also recommend the use of psyllium husk as a source of fiber for IBS patients along with proper hydration [22] (Table 2).
Study |
Region |
Diagnosis |
n (Sample) |
Study Design |
Interventional Groups |
Duration |
Result |
[35] |
Australia |
Rome IV Criteria |
n=40 IBS Patients (18-80 years) |
Prospective Study |
n=14, normal gut microbiota diversity & n=26, low gut microbiota diversity were given *PHGG (10g/day) in 300ml of water |
Intervention: 1-30 & 31-90 days Follow up: 91-120 days |
The IBS patients with nomal gut microbiota showed positive response to *PHGG intervention and also reported decreased **IBS-SSS score whereas IBS patients with low gut microbiota diversity did not show significant reduction compared to baseline. |
[38] |
Romania |
Rome IV Criteria |
n = 51 IBS – C Patients (22-77 years) |
Crossover RCT
|
n = 24, diet n = 23, diet + Stoptoxin (inulin, choline and silymarin) n = 4, lost patients |
4-8 weeks |
Abdominal pain severity and abdominal bloating improved significantly in diet + Stoptoxin group. |
[39]
|
London |
Rome III criteria |
n = 40 IBS-C Patients (18-70 years) |
Pilot RCT |
n = 14, 2 tablespoons of linseed n = 13, ground linseed n = 13, control (no linseed) |
4 weeks |
No significant changes in stool frequency in any group |
[32] |
Netherlands |
Rome II criteria |
n = 275 IBS patients (18-65 years) |
RCT
|
n = 85 psyllium, n = 97 bran, n = 10 placebo |
3 months |
Psyllium group shows significant improvement in IBS patients |
[40] |
England |
Rome criteria (Not specified) |
n = 28 IBS-C Patients (18-70 years) |
RCT |
n = 14 coarse wheat bran, n = 14 low fiber placebo |
8-12 weeks |
Interventional group was interviewed and reported improvement |
Table 2: Research showing role of fiber in irritable bowel syndrome, chronologically arranged studies of past ten years.
PHGG: Partially hydrolyzed guar gum (low viscosity soluble fiber),
IBS-SSS: IBS symptom severity score
Role of Probiotics
The term “Probiotics” was first coined by WHO/FAO, they are live organisms which when consumed in adequate amounts are beneficial to the health of people [41]. In case of IBS patients when probiotics are given in proper amount and composition then they may be beneficial in producing the desired effects [22]. In order to obtain the benefits, the probiotics should be able to survive the effect of acid in stomach and bile and pancreatic juice in the small intestine [41]. Many studies have indicated that the microbiota of IBS patients is affected by several factors resulting in symptoms such a bloating, belching, flatulence and distention. Many IBS patients show a decrease in Lactobacillus and Bifidobacterium sp. which are usually important component of probiotics [4]. In a study, mucosal analysis demonstrated lower biodiversity of luminal microbiota in 16 IBS-D patients in comparison to 12 healthy controls [42]. Studies have indicated that in IBS patients, the diversity of intestinal microbiota is reduced as compared to healthy individuals [14,43]. Therefore, probiotics are given with an aim to manipulate the intestinal microbiota thereby improving IBS symptoms.
Several systematic reviews and meta-analysis have encouraged the use of probiotics for improvement of IBS symptoms as compared to placebo, however the limitations of the methodology followed to proceed towards such conclusions cannot be ignored [43]. 4th Triennial Yale/Harvard Workshop recommended the use of Bifidobacterium infantis, Bifidobacterium animalis and Lactobacillus plantarum 299V for IBS patients [44].
In a recent RCT, the IBS-C and IBS-D patients were supplemented with probiotic for 8 weeks and wash out period of 2 weeks which was compared with placebo given to 17 IBS patients from both groups. There was no significant effect of administering probiotic on the symptoms of IBS patients which was estimated by Francis Severity Score (FSS: validated questionnaire for IBS patients). Also, the gastrointestinal microbiota which was analysed by qPCR did not manifest any significant changes, as the number of target microbes may be below the detection limit [43].
A recent systematic review and meta-analysis published in Aug, 2023 indicated that there was moderate certainty of benefit from Escherichia strains, low certainty of benefit from Lactobacillus strains and Lactobacillus plantarum 299V and very low certainty of benefit from Bacillus strains for global symptoms [45]. For abdominal pain, there was low certainty of benefit from Saccharomyces cerevisiae I-3856 and Bifidobacterium strains and very low certainty of benefit from combination probiotics, Lactobacillus, Saccharomyces and Bacillus strains [45] (Table 3).
Study |
Region |
Diagnosis |
n (Sample) |
Study Design |
Interventional Groups |
Duration |
Result |
[43] |
Cape Town, South Africa |
Screeningby gastro-enterologist (Criteria not specified) |
n = 52 where n = 24, IBS-C and n = 28, IBS-D (24-75 years) |
RCT |
n = 19, IBS-D and n = 16, IBS-C received Probiotic (Lactobacillus plantarum 299V) n = 17, Placebo |
12 weeks |
Lactobacillus profile was significantly different in IBS-C and IBS-D at run-in phase (2 weeks). After probiotic supplementation (8 weeks) and washout period (2 weeks), no statistically significant difference was reported. |
[30] |
London, U.K. |
Rome-III criteria |
n = 104, IBS-patients (18-65 years) |
Randomized placebo-controlled study |
n = 27, Sham diet + placebo n = 26, sham diet + probiotic, n = 24, low FODMAP + placebo n = 27, low FODMAP + probiotic |
4 weeks |
Abundance of Bifidobacterium sp. was more in faecal samples of patients taking probiotic as compared to those taking placebo (p = 0.019). |
[46] |
Italy |
Rome-III criteria |
n=157, IBS-C patients (18-65 years) |
Randomized double blind placebo-controlled study |
n=50, *F_1 n=50, **F_2 n=50, placebo 7 discontinued interventions |
90 days |
Multispecies probiotic supplements are beneficial in IBS-C patients. |
Table 3: Research studying the effect of probiotic in irritable bowel syndrome patients, chronologically arranged studies of past ten years.
F_1: 5 × 109 CFU L. acidophilus (30 mg as lyophilized), 5 × 109 CFU L. reuteri (30 mg as lyophilized), 330 mg inulin, 5 mg silica, and 5 mg talc.
F_2: 5 × 109 CFU L. plantarum (12 mg as lyophilized), 5 × 109 CFU L. rhamnosus (20 mg as lyophilized), 5 × 109 CFU B. animalis subsp. lactis (60 mg as lyophilized), 298 mg inulin, 5 mg silica, and 5 mg talc
Role of physical activity
In a randomized clinical trial, comparing yoga and low FODMAP diet indicated no statistically significant difference between the interventional groups. However, both the interventions showed statistically significant benefits (p<0.001) in IBS patients when measured after 12 and 24 weeks respectively [28]. Thus, moderate physical activity and proper hydration is also essential part of IBS treatment [22]. In another prospective study conducted on 19,885 IBS patients reported that both light and vigorous activity can mitigate the risk of IBS [47]. Another study reported that running particularly of moderate intensity may be beneficial for improving the symptoms such as bloating, flatulence and constipation in IBS patient [48]. Cochrane database of systematic reviews also reported that physical activity may improve IBS symptoms but there is little to no improvement on the quality of life and abdominal pain [49].
Role of sleep
The pineal gland secretes melatonin in response to darkness which is responsible for maintaining the 24-hour rhythm of human body. It affects the sleep-wake cycle, body temperature, melanin secretion, metabolism and even the defence mechanism. In females it also maintains the menstrual cycle. On an average 7 hours or more of sleep is recommended for adults between 18-60 years of age to maintain optimum health [50]. Numerous studies have reported the effect of sleep in IBS patients, usually the IBS symptoms exacerbate after a night of poor sleeping pattern [51].
In a double-blind placebo controlled RCT, the effect of melatonin on IBS patients with and without sleeping disorder was studied. It was concluded that there was significant improvement in IBS score and gastrointestinal symptoms in both the groups [52]. A prospective analysis conducted for 8.45 years by Peking University, Bejing reported 19,885 IBS patients from a sample size of 345,348 participants. They concluded that unhealthy sleeping behaviour was positively associated with worsening IBS symptoms [47].
New approach for population of Asia and other developing countries
The main goal of IBS treatment is to provide relief from symptoms rather than cure. The factors that exacerbate IBS symptoms need to be identified and conditions that are favourable to control these factors should be implemented [20]. The diet may directly affect the gut microflora and therefore by modifying the dietary factors, improvement can be observed among IBS patients. Low FODMAP diet is highly recommended for IBS patients but in developing countries, these guidelines may not be economically feasible and may also cause nutritional deficiency in long run. Also, there is a huge difference in the diet followed in the Asian countries and the Western world, thereby responsible for the vast variation that can be seen in the prevalence rates, gender differences and manifestation of symptoms [13]. Another important challenge in developing countries with major population having lower socio-economic status may be lack of awareness about IBS and hesitation to visit the health care provider for symptoms which they consider “minor” [53]. Moreover there is need to further improve the diagnostic criteria of IBS in order to make accurate diagnosis and provide benefit to patients who may improve with an approach of extended treatment [11].
A current prospective observational study (Sample Size: 204 IBS patients and 400 healthy subjects) conducted in India reported that food intolerance among the individuals vary widely [54]. Hence, there is a need to formulate individualized diet for the patients based on their dietary history, socio-economic status, willingness to change, environmental factors, socio-cultural believes and associated psychological comorbidities. This can only be achieved by a team of well-trained dieticians working in collaboration with doctors, nurses and other health care professionals from clinical nutrition, gastroenterology, psychiatry and associated departments.
Although drinking water is the best option but body can be kept hydrated in many ways, some of which are: drinking lime water solution with little amount of salt, consumption of vegetable soup, drinking coconut water etc.
This systematic review focuses on three major points of interest i.e, effect of consuming fiber, probiotic and role of diet in irritable bowel syndrome rather than all the outcomes of different studies. Here, the included studies were mainly assessed for their effect on gastrointestinal tract whereas other significant treatments such as psychotherapy, use of medications, cognitive behavioural therapy (CBT) etc. were not analysed. Moreover, this Narrative Review was limited to adult patients and does not include results related to animal trials or studies carried out on children.
As different countries have different dietary pattern so the dietary guidelines for the IBS patients should be formulated according to the environment, food habits and the resources that are readily available in that region. There must be separate guidelines for western and Asian countries as their dietary habits are completely different according to the environmental factors and cultural differences. There is need to carry out multicentric RCT’s and meta-analysis for in-depth understanding of the role of diet on symptoms and gut microflora of IBS patients.
Also, the wide variety of differences in the diet consumed by population in different geographical regions are affected by the economic differences, climatic conditions, food insecurity issues etc. These points should be kept in mind while formulating dietary guidelines. Thus, a greater number of prospective observational study should be done. which will give a clear picture about dietary pattern which can further be used to carry out studies regarding the impact of consuming various food items and response of IBS patients.
The Narrative Review concludes that there is need to adopt individualized approach for managing food intolerances and IBS symptoms. Although the benefits of low FODMAP diet are known, universalization may not be the best approach. Considering the wide variety of differences in food intolerance among the IBS patients there is a need to carry out more studies. The study emphasis more specific patient-centred approach rather than following generalized dietary guidelines such as low FODMAP diet. Moreover, the effect of diet, probiotics and fiber on the microbiota of IBS patients require research with better experimental designs and results as some of the results are contradictory.
Proper hydration and regular sleep are beneficial for all the IBS patients around the world. A team of specialists from the department of gastroenterology and dietetics should take the initiative of formulating individualized diet which will decrease the number of patient’s visits thereby reducing the economic burden on the individual and health care system in long run.
The authors thank the department of gastroenterology for constant support and cooperation during the research. The authors also thank Dr. Amar Deep Sir, Dept. of Gastroenterology for his valuable suggestions and guidance.
UGC (University Grants Commission)
None
Citation: Saroj S, Gupta K, Rungta S, Kumar N, Bharti D, (2025) Unravelling the Digestive Dilemma: Investigating Dietary Influence on Irritable Bowel Syndrome through Narrative Review. HSOA J Gastroenterol Hepatology Res 9: 055
Copyright: © 2025 Shraddha Saroj, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.