Impact of Portulaca oleracea L. extract in patients with irritable bowel syndrome

Kwangwoo Nam; Jung Ho Choi; Yong Sung Kim; Seong Lee; Jee Hun Park; Hyeongjoo Kim; Sangyun Lee; Yerin Lee; Doohyuck Lee; Sunghyeok Ryou; Jeong Eun Shin

doi:10.5217/ir.2025.00200

Articles

Page Path: HOME > Intest Res > Ahead-of print articles > Article

Original Article Impact of Portulaca oleracea L. extract in patients with irritable bowel syndrome: Kwangwoo Nam^1,*, Jung Ho Choi^2,*, Yong Sung Kim^3,4, Seong Lee⁵, Jee Hun Park², Hyeongjoo Kim², Sangyun Lee², Yerin Lee², Doohyuck Lee¹, Sunghyeok Ryou¹, Jeong Eun Shin¹; DOI: https://doi.org/10.5217/ir.2025.00200
Published online: April 20, 2026

¹Department of Gastroenterology, Dankook University Hospital, Dankook University College of Medicine, Cheonan, Korea

²Research Institute R&D Center, Korea Drug Co., Ltd., Seoul, Korea

³Wonkwang Digestive Disease Research Institute, Iksan, Korea

⁴Good Breath Clinic, Gunpo, Korea

⁵Research Institute of Clinical Medicine, Dankook University Hospital, Cheonan, Korea

Correspondence to Jeong Eun Shin, Department of Gastroenterology, Dankook University Hospital, Dankook University College of Medicine, 201 Manghyang-ro, Dongnam-gu, Cheonan 31116, Korea. E-mail: dreun1028@hanmail.net

*These authors contributed equally to this study as first authors.

• Received: August 31, 2025 • Revised: December 17, 2025 • Accepted: December 28, 2025

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

948 Views
24 Download

Full Article

Download PDF

Abstract
Graphical abstract
INTRODUCTION
METHODS
RESULTS
DISCUSSION
NOTES
Supplementary Material
REFERENCES

Abstract

Background/Aims
Portulaca oleracea is known to have anti-inflammatory and immunoregulatory effects, and also showed positive effect on complete spontaneous bowel movement and bowel symptoms in patients with chronic constipation in a previous study. Thus, we aimed to investigate the impact of P. oleracea in patients with irritable bowel syndrome (IBS).
Methods
Patients with IBS defined by ROME IV criteria were enrolled between July 2022 and April 2023. Patients were randomly assigned to P. oleracea or placebo group and took drugs for 8 weeks. Clinical data including gastrointestinal and IBS symptoms, laboratory tests including inflammatory and immunologic laboratory markers, and stool tests including fecal calprotectin and stool microbial analysis were evaluated at the baseline, week 4, and week 8.
Results
A total of 108 patients were initially enrolled and 101 patients were finally included in the analysis. There was significant improvement during 8 weeks in P. oleracea group compared to placebo group in the aspect of gastrointestinal and IBS-related bowel symptoms (Gastrointestinal Symptom Rating Scale total score: from 44.1 to 31.7 vs. from 41.4 to 39.9; IBS-Symptom Severity Score total score: from 232.0 to 120.6 vs. from 202.7 to 178.2), especially in the aspect of abdominal pain. Interleukin-6 (IL-6) was significantly decreased during 8 weeks in P. oleracea group, although there was no significant difference between 2 groups. In addition, increase in IL-6 during study period was significantly associated with dysbiosis in stool microbial analysis. There was no significant adverse event.
Conclusions
P. oleracea has positive impact in patients with IBS showing improvement of immunologic cytokine and stool microbiome.
Keywords: Portulaca; Irritable bowel syndrome; Defecation; Microbiota; Dysbiosis

Graphical abstract

INTRODUCTION

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders characterized by chronic abdominal pain accompanied by bowel habit change. The prevalence of IBS is increasing in Asian countries and IBS becomes a considerable burden on health-related quality of life [1,2]. Recently, IBS has been regarded as a multifactorial disorder of gut-brain interaction. Dietary therapy such as low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet, lifestyle modification such as regular exercise, and medical therapies including laxatives, antidiarrheals, and antispasmodics are main treatment options for IBS [2-5]. However, there are still unmet needs with conventional treatment, thus new medical treatments such as complementary and alternative medicines are gaining attention in the treatment of IBS [6].

Portulaca oleracea or purslane belongs to one of the annual grass and has been used as a traditional remedy for various diseases [7]. P. oleracea is known to have anti-inflammatory and immunoregulatory effects in previous animal studies [8-10], and also has a positive effect on fecal evacuation in an animal model [11]. Recently, our group reported the effect of P. oleracea on functional constipation which showed significant improvement of complete spontaneous bowel movement (CSBM) in P. oleracea group compared with the placebo group during an 8-week study period (P=0.003) [12].

Given these findings, we hypothesized that P. oleracea also could be effective in patients with IBS, which has not yet been evaluated. Therefore, in this study, we aimed to investigate the impact of P. oleracea in patients with IBS, including not only the constipation-predominant type but all subtypes.

METHODS

1. Patients

This study was a double-blinded, randomized controlled trial performed between July 2022 and April 2023 in a tertiary referral center. Eligible patients were adult subjects aged between 20 and 65 years who met ROME IV criteria of IBS and agreed to participate in this study. These include recurrent abdominal pain (on average, experienced for at least 1 day a week in the last 3 months with symptom onset at least 6 months before diagnosis) associated with 2 or more of the following criteria: (1) related to defecation; (2) associated with a change in a frequency of stool; or (3) associated with a change in form (appearance) of stool. Subtypes were based on stool consistency and included 4 subtypes: (1) constipation-predominant type (IBS-C); (2) diarrhea-predominant type (IBS-D); (3) mixed type (IBS-M); or (4) unclassified type (IBS-U). Patients aged 45 years and above were enrolled only if there were no advanced adenomas (high-grade dysplasia, villous adenoma, and size ≥ 1 cm) in a previous colonoscopy within the last 5 years to exclude significant organic colorectal disease [13-15].

Exclusion criteria were as follows: (1) subjects who took antibiotics or probiotics within the 2 weeks before enrollment; (2) subjects who have a history of suggesting organic gastrointestinal disease; (3) subjects who had undergone abdominal surgery (excluding appendectomy); (4) subjects who take medications affecting gastrointestinal motility such as antispasmodics or prokinetics within the 2 weeks before enrollment; (5) subjects with liver cirrhosis, severe congestive heart failure (New York Heart Association grade III or IV), severe renal dysfunction (creatinine clearance <30 mL/min), uncontrolled hypertension, endocrine disorders, metabolic disorders, malignant tumors, or immunodeficiency; (6) subjects who had a history of clinically significant hypersensitivity reactions; (7) subjects who have engaged in abnormal dietary practices within 30 days before the first day of administration; (8) subjects with a history of drug abuse; (9) subjects with excessive alcohol consumption (alcohol >21 units/week; 1 unit=10 mL of pure alcohol); (10) subjects who were pregnant or lactating women; (11) subjects who have taken other investigational food/drugs within 3 months before the first day of administration of the investigational food; and (12) any other reason which is unsuitable for participation in the clinical trial. This study was approved by the Institutional Review Board of Dankook University Hospital (IRB No. DKUH 2021-12-010) and written informed consent was obtained.

Eligible participants were randomly assigned to either the investigation group, which received KDC16-2, a 70% ethanol extract of P. oleracea (480 mg) [8,11], or the control group, which received a placebo consisting of a 1:1 mixture of maltodextrin and mannitol (480 mg). To maintain the blinding during the study period, the investigation and the placebo drug were designed to be indistinguishable in terms of shape, color, flavor, and scent. Random allocations were carried out using a specific program available at http://randomization.com. Patients took 1 tablet of each medication once daily for 8 weeks, and visited the hospital at baseline, week 4, and week 8. Vital signs, physical exam, and gastrointestinal and bowel symptoms were evaluated at baseline, week 4, and week 8. Laboratory tests including inflammatory and immunologic markers, and stool tests including fecal calprotectin and stool microbial analysis were evaluated at baseline and week 8.

2. Stool Microbial Analysis

Microbial genomic DNA was extracted from stool samples using Qiagen’s QIAamp Power Fecal Pro DNA Kit (Qiagen, Hilden, Germany). Subsequently, the 16S ribosomal RNA V3-V4 hypervariable region was amplified by polymerase chain reaction using 341F/805R library, and microbial genomic data were obtained through Illumina MiSeq sequencing (Illumina, San Diego, CA, USA).

3. Outcome Measurement

Patients were requested to report their gastrointestinal symptoms using Gastrointestinal Symptom Rating Scale (GSRS) [16], bowel symptoms using IBS-Severity Scoring System (IBS-SSS) [17], Bristol Stool Form Scale (BSFS), spontaneous bowel movement (SBM), CSBM at each visit (baseline, week 4, and week 8). Laboratory tests including inflammatory and immunologic biomarkers (tumor necrosis factor-α, interferon-γ, interleukin [IL]-1β, IL-6, IL-8, IL-10, immunoglobulin G, immunoglobulin A, high-sensitivity C-reactive protein, erythrocyte sedimentation rate, prostaglandin E2, myeloperoxidase, and leukotriene B4), and stool tests including fecal calprotectin and stool microbial analyses were performed at the baseline and week 8. Primary outcomes were the improvement of gastrointestinal and bowel symptoms after 4 weeks and 8 weeks compared to the baseline. Secondary outcomes were the improvement of inflammatory and immunologic laboratory findings and the change of microbiome after 8 weeks compared to the baseline.

4. Sample Size

Until now, there was no relevant data about the efficacy of P. oleracea on IBS. It was assumed that statistical power was 80%, dropout rate was 20%, effect size was 0.14, correlation coefficient between repeated measurements was 0.5, and two-sided significance was 5%. Using G-power 3.1.9.7. [18], effective sample size was calculated as 90 patients (45 patients for each group), and considering 20% of dropout rate, the final sample size was assumed as 108 patients (54 patients for each group).

5. Statistical Analysis

Categorical variables were presented as the number and percentages, and evaluated by chi-square test or Fisher exact test. Continuous variables were presented as mean±standard deviation, and evaluated by t-test or Wilcoxon signed rank test. Baseline demographics and safety analysis were performed based on intention-to-treat analysis. Gastrointestinal and bowel symptom, stool consistency and frequency, laboratory data and stool microbial analysis were performed based on per-protocol analysis. To evaluate the effect of P. oleracea during the study period, repeated measure analysis of variance and paired t-test were used for continuous variables, and linear mixed effect model and McNemar test were used for categorical variables. Two-sided P-values <0.05 were considered statistically significant. Statistical analyses were conducted using R software (version 4.1.3, R Foundation for Statistical Computing, Vienna, Austria).

RESULTS

A total of 108 patients were initially enrolled and randomized equally to 54 patients for each group. Mean age was 45.1 years and 49 patients (45.4%) were male. There was no significant difference in demographic data between the 2 groups except mean diastolic blood pressure and mean pulse rate in intention-to-treat analysis (P=0.044) (Table 1). During the study period, 7 patients (1 patient in P. oleracea group and 6 patients in placebo group) were dropped out due to withdrawal of consent for this study. Finally, 53 patients in P. oleracea group and 48 patients in placebo group were analyzed based on per-protocol analysis (Supplementary Table 1). Among them, IBS-D was the most common subtype in both groups, followed by IBS-C (Fig. 1).

1. Impact of P. oleracea on Gastrointestinal Symptoms

During the study period, there was significant improvement of total GSRS in P. oleracea group at week 8 compared with placebo group (from 44.1 at baseline to 31.7 at week 8 in P. oleracea group vs. from 41.4 at baseline to 39.9 at week 8 in placebo group; P<0.001), although no significant difference at week 4 (37.6 at week 4 in P. oleracea group vs. 40.2 at week 4 in placebo group; P=0.261). In detail, abdominal pain, indigestion syndrome, and diarrhea syndrome were significantly improved at week 8 in P. oleracea group compared with placebo group (all P<0.05) (Table 2).

2. Impact of P. oleracea on Bowel Symptoms

During the study period, there was a significant improvement of total IBS-SSS score in P. oleracea group at week 8 compared with placebo group (from 232.0 at baseline to 120.6 at week 8 in P. oleracea group vs. from 202.7 at baseline to 178.2 at week 8 in placebo group; P=0.001). In detail, abdominal pain, abdominal bloating, bowel habit satisfaction, and symptom severity were significantly improved at week 8 in P. oleracea group compared with placebo group (all P<0.05) (Table 3). In addition, P. oleracea group exhibited a higher number of patients who experienced significant improvement (≥ 50) in total IBS-SSS scores compared with placebo group (79.3% in P. oleracea group vs. 25.0% in placebo group) (Table 4).

3. Impact of P. oleracea on Stool Consistency and Frequency

At baseline, the number of patients of BSFS type 3–5 in P. oleracea group was relatively lower than that in placebo group (11.3% vs. 31.3%; P=0.047). During 8-week study period, there were significant increase in the number of patients of BSFS type 3–5 at week 4 and week 8 in both groups (all P<0.05), however no significant difference between the 2 groups at week 4 and week 8 (Table 5). There was no significant difference of SBM and CSBM per week at baseline, week 4, and week 8 in each group, however there were significant improvements of CSBM at week 4 and week 8 compared with baseline in P. oleracea group (Table 6).

4. Impact of P. oleracea on Immunologic and Inflammatory Markers

During the study period, there was no significant difference of immunologic markers in placebo group. In contrast, IL-6 significantly decreased (from 1.70 to 1.25; P=0.034) and IL-8 significantly increased (from 12.31 to 13.72; P=0.003) in P. oleracea group (Supplementary Table 2). In addition, there was no significant difference of inflammatory markers including fecal calprotectin in both groups except myeloperoxidase (from 163.12 to 149.37 in P. oleracea group vs. from 189.80 to 216.04 in placebo group) (Supplementary Table 3).

5. Impact of P. oleracea on Stool Microbiota

During the study period, 52 patients in P. oleracea group and 48 patients in placebo group were evaluated for stool microbiome at baseline and week 8. One patient in P. oleracea group was excluded from the final analysis due to poor data quality. Compared to baseline, there were significant improvements of alpha-diversity indices (observed features, Chao1 index, Shannon index, Simpson index, and Pielou evenness) at week 8, indicating an increase in richness during the study period, in both group (P<0.05) (Fig. 2). For beta-diversity, there were no significant differences in Bray-Curtis dissimilarity, however there were significant differences in unweighted UniFrac in both groups by PERMANOVA test (P=0.028 for P. oleracea group, P=0.027 for placebo group) (Fig. 3).

Considering the impact of P. oleracea on the change of IL-6 in this study, we performed additional stool microbial analysis according to the change of IL-6. In the respect of alpha-diversity, there was a significant decrease in IL-6 increase group (P=0.048 for Shannon index, P<0.01 for Simpson index), whereas no significant change in IL-6 decrease group. In addition, diversity (P=0.04 for Simpson index) and evenness (P=0.02 for Pielou evenness) at week 8 were significantly lower in IL-6 increase group compared to IL-6 decrease group (Fig. 4). In terms of beta-diversity, there was a significant difference in Bray-Curtis dissimilarity between IL-6 increase group and IL-6 decrease group (P=0.05; PERMANOVA test) (Fig. 5). In taxonomic analysis, the relative abundance of beneficial genera such as Blautia, Faecalibacterium, and Weissella decreased in the IL-6 increase group. This inverse relationship suggests that a reduction in these strains may be associated with the aggravation of inflammation (increase in IL-6).

6. Safety Issues

During the study period, there was no serious adverse event but 2 moderate adverse events were reported (urinary stone in P. oleracea group and diarrhea in placebo group). Urinary stone was regarded not to be related to investigation drug. Laboratory tests showed no significant difference between the 2 groups. In terms of vital sign and physical examination, mean diastolic blood pressure at baseline and mean pulse rate at baseline and 4 weeks were significantly higher in P. oleracea group than placebo group (P<0.05), however there was no significant differences in other variables.

DISCUSSION

In this study, clinical impact of P. oleracea in patients with IBS was evaluated by prospective randomized placebo-controlled study. The use of P. oleracea in patients with IBS was associated with significant improvement in gastrointestinal and IBS symptoms, especially in the aspect of abdominal pain and CSBM, which are important clinical aspects in IBS. Proinflammatory markers such as IL-6 were significantly decreased in P. oleracea group during the study period, and increase in IL-6 was associated with stool microbial dysbiosis, suggesting the positive effect of P. oleracea in the intestinal microbiota.

Although IBS is not a life-threatening condition, it puts significant health-related and socioeconomic burden in worldwide. The prevalence of IBS varies according to the studied regions, and recent study reported 12.6% as the prevalence of IBS in East Asia, which was higher than that in North America and Europe, and lower than in Latin America [19], although relatively higher prevalence was reported using ROME III criteria compared to ROME IV criteria [6]. Traditionally, IBS was regarded as a functional bowel disorder. However, more recently, researchers have proposed that low-grade intestinal inflammation and immune system activation as well as the brain-gut axis may play a crucial role in its mechanism [20,21]. Thus anti-inflammatory and immunoregulatory agent could be beneficial to control the IBS-related symptoms [22], and we focused on the clinical impact of P. oleracea in patients with all subtypes of IBS.

In previous study, P. oleracea showed the significant improvement in CSBM (2.1/week in P. oleracea group vs. 1.2/week in placebo group) and CTT (–10.8 hours in P. oleracea group vs. +5.2 hours in placebo group) in patients with functional constipation during 8-week study period [12]. P. oleracea had been used as a laxative in traditional medicine, and animal study also showed that P. oleracea increases fecal volume and improves bowel movement. These anti-constipation effects might be associated with both biochemical and fiber component of P. oleracea. In addition, significant improvement of constipation-related symptoms and quality of life were noted in previous study, which suggested the analgesic and anti-inflammatory effect of P. oleracea [12]. Thus, we hypothesized that P. oleracea could be beneficial for the improvement of clinical symptoms in patients with IBS, not only IBS-C with delayed bowel movement but also other subtypes such as IBS-D and IBS-M.

In this study, P. oleracea group showed significant improvement in gastrointestinal symptoms compared with placebo group, especially in the aspect of abdominal pain. Abdominal pain associated with bowel movements is the most characteristic symptoms of IBS. However, it is challenging to control abdominal pain in IBS rather than constipation or diarrhea, and medical treatment for abdominal pain is more difficult compared with those for bowel movement. Usually, medications such as antispasmodics, antidepressants, and anxiolytics are frequently used in daily practice. However, there are concerns about the decreased effect and adverse events with long-term use of these medications [23,24]. The safety profile of P. oleracea is one of the advantages of its long-term use. In addition, P. oleracea was also effective to improve IBS-related bowel symptoms such as bowel habit satisfaction and effect of IBS symptom, and CSBM was significantly increased during the study period, like the laxative effect of P. oleracea in previous study [12]. Although there was no significant difference between the 2 groups, increased number of the patients with BSFS type 3–5 was seen in P. oleracea group during the study period, suggesting the effect of normalizing bowel movement in patients with IBS. Thus P. oleracea could be alternative option to control abdominal pain in patients with IBS without significant adverse event.

Low-grade inflammation is considered as one of the pathogenic factors in IBS [22,25]. Elevation of proinflammatory cytokines (e.g., tumor necrosis factor-α, IL-1β, IL-6, and IL-8) in the blood or stool has been reported, however data was not consistent between the studies [20,21,26]. In P. oleracea group, IL-6 was significantly decreased, whereas IL-8 was significantly increased during the study period. These results may be attributable to low-grade inflammation that does not influence systemic inflammatory response enough to alter serum cytokine levels. Other inflammatory markers and cytokines showed no significant change during the study period. Although it was not statistically significant, fecal calprotectin showed decreasing tendency during the study period. Considering these anti-inflammatory effects, we supposed that P. oleracea is beneficial for the patients with IBS.

Dysbiosis is an emerging important pathogenetic factor and treatment target in the management of IBS. High level of dysbiosis was associated with poor response to low FODMAP diet in patients with IBS [27], and rifaximin is suggested as the treatment option in patients with IBS-D [3]. In this study, increase in IL-6 was significantly related with decrease in diversity, and intake of P. oleracea was significantly associated with increase in diversity, suggesting beneficial effect of P. oleracea on dysbiosis. Decrease of Blautia, Faecalibacterium, and Weissella after P. oleracea intake is only seen in IL-6 increase group, suggesting beneficial effect of P. oleracea in intestinal dysbiosis. Further studies are needed to prove the impact of P. oleracea on the intestinal dysbiosis.

This study has some limitations. First, relatively small number of patients was enrolled and mean patient age was relatively young, which has limitations to generalize our findings. This study was conducted in a single tertiary referral center and mean age of enrolled patients was 45 years; thus, patient population could be different from those in a daily practice and it is difficult to generalize our results in this study. Second, strict diet control was not applied which can influence IBS symptoms [2]. In addition, 8-week study period was relatively short to distinguish the effect of P. oleracea in a usual clinical setting. Third, subgroup analysis for IBS-D and/or IBS-M was not performed due to the lack of relevant information. To evaluate the net effect of P. oleracea in all subtypes of IBS, further studies are needed including large IBS population and long-term study duration.

In conclusion, this study showed that P. oleracea might have positive impact in patients with IBS. This effect was prominent in the aspect of abdominal pain and immunologic cytokine, and improvement of dysbiosis, without significant adverse effect. Further studies are warranted to validate the application of P. oleracea as an alternative option for the patients with IBS.

NOTES

Funding Source

The present research was conducted by a grant from the High-value Food Technology Development Program funded by the Ministry of Agriculture, Food and Rural Affairs through Korea Pharmaceutical Co., Ltd. (Grant No. 821054031SB010).

Conflict of Interest

Choi J, Park JH, Kim H, Lee S, and Lee Y are employees of Korea Drug Co., Ltd. The remaining authors declare no conflicts of interest.

Data Availability Statement

Data analyzed in this study are available from the corresponding author upon reasonable request.

Author Contributions

Conceptualization: Nam K, Choi JH, Shin JE. Data curation: Nam K, Lee D, Ryou S, Shin JE. Formal analysis: Nam K, Choi JH, Kim YS, Lee S, Shin JE. Investigation: Nam K, Choi JH, Kim YS, Lee S, Park JH, Kim H, Lee S, Lee Y, Shin JE. Methodology: Nam K, Choi JH, Lee S, Shin JE. Project administration: Lee S, Shin JE. Supervision: Shin JE. Writing–original draft: Nam K, Choi JH, Shin JE. Writing–review & editing: all authors. Approval of final manuscript: all authors.

Additional Contributions

The authors thank Yongju Ahn of HuNBiome for support with microbiota analysis and interpretation.

Supplementary Material

Supplementary materials are available at the Intestinal Research website (https://www.irjournal.org).

Supplementary Table 1.

Demographic Characteristics of Enrolled Patients (Per-Protocol Analysis)

ir-2025-00200-Supplementary-Table-1.pdf

Supplementary Table 2.

Changes of Immunologic Cytokines during the Study Period

ir-2025-00200-Supplementary-Table-2.pdf

Supplementary Table 3.

Changes of Immunologic Cytokines during the Study Period

ir-2025-00200-Supplementary-Table-3.pdf

Fig. 1.

Study overview. IBS, irritable bowel syndrome; P. oleracea, Portulaca oleracea; IBS-C, constipation-dominant IBS; IBS-D, diarrheadominant IBS; IBS-M, mixed-type IBS; IBS-U, unclassified IBS.

Fig. 2.

Changes in alpha diversity in subjects before and after the intervention. (A) Placebo group and (B) Portulaca oleracea group. ^*P<0.05, ^**P<0.01, ^***P<0.001. NS, not significant.

Fig. 3.

Change in beta diversity in subjects before and after the intervention, Bray-Curtis and unweighted UniFrac dissimilarity. (A) Placebo group and (B) Portulaca oleracea group.

Fig. 4.

Change in alpha diversity in relation to interleukin-6 (IL-6) alteration in subjects before and after the intervention. Change in alpha diversity in subject with decreased IL-6 (A), increased IL-6 (B), IL-6 change (C). ^*P<0.05, ^**P<0.01. NS, not significant.

Fig. 5.

Change in beta diversity in subject with IL-6 change before and after the intervention, Bray-Curtis and unweighted UniFrac dissimilarity.

Table 1.

Demographic Characteristics of Enrolled Patients

Variable	Total (n=108)	P. oleracea group (n=54)	Placebo group (n=54)	P-value
Age (yr), mean ± SD	45.1 ± 11.3	46.2 ± 10.8	44.1 ± 11.7	0.321
Female sex, No. (%)	59 (54.6)	31 (57.4)	28 (51.9)	0.699
Body mass index (kg/m²)	23.9 ± 3.3	23.8 ± 3.0	24.1 ± 3.5	0.686
Chronic illness, No. (%)	8 (7.4)	4 (7.4)	4 (7.4)	1.000
Regular use medicine, No. (%)	5 (4.6)	3 (5.6)	2 (3.7)	1.000
Smoking, No. (%)				0.637
Never	84 (77.8)	44 (81.5)	40 (74.1)
Ex	9 (8.3)	4 (7.4)	5 (9.3)
Current	15 (13.9)	6 (11.1)	9 (16.7)
Alcohol (ex or current), No. (%)	60 (55.6)	30 (55.6)	30 (55.6)	1.000
Systolic blood pressure (mmHg), mean ± SD	126.7 ± 11.5	128.3 ± 11.6	125.1 ± 11.2	0.150
Diastolic blood pressure (mmHg), mean ± SD	80.3 ± 7.7	81.8 ± 7.1	78.8 ± 8.1	0.044
Pulse rate (beats/min), mean ± SD	78.8 ± 9.8	80.7 ± 10.2	76.9 ± 9.1	0.044
Regular exercise, No. (%)	79 (73.1)	41 (75.9)	38 (70.4)	0.664
Regular meal, No. (%)	61 (56.5)	32 (59.3)	29 (53.7)	0.698
Baseline IBS subtypes, No.	101	53	48	0.080
IBS-C	20	12	8
IBS-D	63	36	27
IBS-M	8	1	7
IBS-U	10	4	6

P. oleracea, Portulaca oleracea; SD, standard deviation; IBS, irritable bowel syndrome; IBS-C, constipation-predominant IBS; IBS-D, diarrhea-predominant IBS; IBS-M, mixed-type IBS; IBS-U, unclassified IBS.

Table 2.

Changes of Gastrointestinal Symptoms during the Study Period

Variable	P. oleracea group (n=53)		Placebo group (n=48)		P-value
Variable	Mean ± SD	P-value	Mean ± SD	P-value	P-value
GSRS total
Baseline	44.17 ± 13.55		41.42 ± 11.60		0.274
Week 4	37.55 ± 12.05		40.21 ± 11.63		0.261
Difference (baseline vs. week 4)		<0.001^*		<0.001^*
Week 8	31.66 ± 10.56		39.85 ± 12.38		<0.001^*
Difference (baseline vs. week 8)		<0.001^*		0.069
Abdominal pain
Baseline	1.42 ± 1.17		1.33 ± 1.12		0.720
Week 4	1.06 ± 0.99		1.23 ± 1.15		0.424
Difference (baseline vs. week 4)		0.001^*		0.133
Week 8	0.64 ± 1.02		1.17 ± 1.12		0.016^*
Difference (baseline vs. week 8)		<0.001^*		0.008^*
Reflux syndrome
Baseline	0.91 ± 1.11		0.81 ± 0.91		0.646
Week 4	0.64 ± 0.96		0.65 ± 0.84		0.981
Difference (baseline vs. week 4)		0.002^*		0.073
Week 8	0.36 ± 0.76		0.60 ± 0.76		0.109
Difference (baseline vs. week 8)		<0.001^*		0.032^*
Indigestion syndrome
Baseline	3.98 ± 2.32		3.73 ± 2.04		0.563
Week 4	3.11 ± 2.32		3.48 ± 2.06		0.403
Difference (baseline vs. week 4)		<0.001^*		0.032^*
Week 8	2.11 ± 1.91		3.44 ± 1.84		0.001^*
Difference (baseline vs. week 8)		<0.001^*		0.047^*
Diarrhea syndrome
Baseline	2.49 ± 1.65		2.50 ± 1.68		0.977
Week 4	1.91 ± 1.23		2.17 ± 1.43		0.331
Difference (baseline vs. week 4)		0.002^*		0.010^*
Week 8	1.49 ± 1.20		2.06 ± 1.56		0.044^*
Difference (baseline vs. week 8)		<0.001^*		0.004^*
Constipation syndrome, mean ± SD
Baseline	2.19 ± 1.61		1.96 ± 1.41		0.445
Week 4	1.83 ± 1.48		1.75 ± 1.33		0.775
Difference (baseline vs. week 4)		0.021^*		0.105
Week 8	1.25 ± 1.11		1.54 ± 1.22		0.206
Difference (baseline vs. week 8)		<0.001^*		0.011^*

^* P<0.05 indicates statistical significance.

P. oleracea, Portulaca oleracea; SD, standard deviation; GSRS, Gastrointestinal Symptom Rating Scale.

Table 3.

Changes of Bowel Symptoms during the Study Period

Variable	P. oleracea group (n=53)	Placebo group (n=48)	P-value
IBS-SSS total, mean ± SD			<0.001^*
Baseline	232.0 ± 88.5	202.7 ± 95.0	0.113
Week 4	178.9 ± 81.3	193.3 ± 87.4	0.395
Week 8	120.6 ± 67.0	178.2 ± 88.7	0.001^*
Abdominal pain, No. (%)			0.001^*
Baseline	49 (92.5)	40 (83.3)	0.168
Week 4	43 (81.1)	38 (79.2)	0.807
Week 8	27 (50.9)	35 (72.9)	0.023^*
Abdominal pain score, mean ± SD			<0.001^*
Baseline	42.1 ± 21.1	33.4 ± 24.1	0.057
Week 4	29.0 ± 20.3	31.0 ± 22.7	0.643
Week 8	16.4 ± 18.1	27.7 ± 22.9	0.008^*
Frequency of abdominal pain during recent 10 days, mean ± SD			<0.001^*
Baseline	3.3 ± 2.5	2.5 ± 2.6	0.129
Week 4	2.1 ± 2.0	2.2 ± 2.2	0.895
Week 8	1.1 ± 1.3	2.2 ± 2.5	0.005^*
Abdominal bloating, No. (%)			0.023^*
Baseline	45 (84.9)	38 (79.2)	0.460
Week 4	42 (79.3)	37 (77.1)	0.796
Week 8	30 (56.6)	37 (77.1)	0.028^*
Abdominal bloating score, mean ± SD			<0.001^*
Baseline	42.8 ± 26.5	36.7 ± 27.8	0.262
Week 4	32.5 ± 24.0	36.3 ± 28.0	0.466
Week 8	19.5 ± 20.9	31.2 ± 25.0	0.013^*
Dissatisfaction with bowel habit, mean ± SD			<0.001^*
Baseline	63.0 ± 16.7	59.2 ± 19.5	0.297
Week 4	52.0 ± 19.2	56.7 ± 20.5	0.242
Week 8	39.6 ± 18.9	52.7 ± 22.1	0.002^*
Effect of symptom, mean ± SD			<0.001^*
Baseline	50.9 ± 19.4	47.6 ± 21.4	0.428
Week 4	44.1 ± 17.9	47.3 ± 21.2	0.418
Week 8	34.5 ± 18.7	44.5 ± 20.6	0.013^*

^* P<0.05 indicates statistical significance.

P. oleracea, Portulaca oleracea; IBS-SSS, Irritable Bowel Syndrome-Severity Scoring System; SD, standard deviation.

Table 4.

Changes of Total IBS-SSS Score during the Study Period

Variable	P. oleracea group (n=53)	Placebo group (n=48)	P value
Change of total IBS-SSS score, No. (%)			<0.001^*
<0	2 (3.7)	16 (33.3)
0–50	9 (17.0)	20 (41.7)
>50	42 (79.3)	12 (25.0)

^* P<0.05 indicates statistical significance; baseline vs. week 8.

IBS-SSS, Irritable Bowel Syndrome-Severity Scoring System; P. oleracea, Portulaca oleracea.

Table 5.

Changes of Stool Consistency during the Study Period

Variable	P. oleracea group (n=53)		Placebo group (n=48)		P-value
Variable	No. (%)	P-value	No. (%)	P-value	P-value
Baseline (BSFS)					0.047^*
Type 1–2	12 (22.6)		9 (18.8)
Type 3–5	6 (11.3)		15 (31.3)
Type 6–7	35 (66.0)		24 (50.0)
Week 4 (BSFS)					0.384
Type 1–2	6 (11.3)		2 (4.2)
Type 3–5	43 (81.1)		41 (85.4)
Type 6–7	4 (7.6)		5 (10.4)
Difference (baseline vs. week 4)		<0.001^*		0.012^*
Week 8 (BSFS)					0.153
Type 1–2	5 (9.4)		1 (2.1)
Type 3–5	43 (81.1)		45 (93.8)
Type 6–7	5 (9.4)		2 (4.2)
Difference (baseline vs. week 8)		<0.001^*		0.003^*

^* P<0.05 indicates statistical significance.

P. oleracea, Portulaca oleracea; BSFS, Bristol Stool Form Scale.

Table 6.

Changes of Stool Frequency during the Study Period

Variable	P. oleracea group (n=53)		Placebo group (n=48)		P-value
Variable	Mean ± SD	P-value	Mean ± SD	P-value	P-value
Spontaneous bowel movement (/week)
Baseline	11.04 ± 7.74		9.21 ± 7.59		0.234
Week 4	10.61 ± 6.45		9.51 ± 6.87		0.409
Difference (baseline vs. week 4)		0.514		0.473
Week 8	9.98 ± 6.03		9.61 ± 6.68		0.774
Difference (baseline vs. week 8)		0.111		0.404
Complete spontaneous bowel movement (/week)
Baseline	5.34 ± 3.22		5.06 ± 4.84		0.738
Week 4	7.33 ± 4.35		5.69 ± 3.97		0.050
Difference (baseline vs. week 4)		<0.001^*		0.419
Week 8	7.48 ± 4.47		6.18 ± 4.22		0.134
Difference (baseline vs. week 8)		<0.001^*		0.195

^* P<0.05 indicates statistical significance.

P. oleracea, Portulaca oleracea; SD, standard deviation.

REFERENCES

1. Song KH, Jung HK, Kim HJ, et al. Clinical practice guidelines for irritable bowel syndrome in Korea, 2017 revised edition. J Neurogastroenterol Motil 2018;24:197–215.Article PubMed PMC
2. Choi Y, Youn YH, Kang SJ, et al. 2025 Seoul Consensus on clinical practice guidelines for irritable bowel syndrome. J Neurogastroenterol Motil 2025;31:133–169.Article PubMed PMC
3. Vasant DH, Paine PA, Black CJ, et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut 2021;70:1214–1240.Article PubMed
4. Chang L, Sultan S, Lembo A, Verne GN, Smalley W, Heidelbaugh JJ. AGA clinical practice guideline on the pharmacological management of irritable bowel syndrome with constipation. Gastroenterology 2022;163:118–136.Article PubMed
5. Lembo A, Sultan S, Chang L, Heidelbaugh JJ, Smalley W, Verne GN. AGA clinical practice guideline on the pharmacological management of irritable bowel syndrome with diarrhea. Gastroenterology 2022;163:137–151.Article PubMed
6. Jung KW, Myung SJ. An Asian perspective on irritable bowel syndrome. Intest Res 2023;21:189–195.Article PubMed PDF
7. Iranshahy M, Javadi B, Iranshahi M, et al. A review of traditional uses, phytochemistry and pharmacology of Portulaca oleracea L. J Ethnopharmacol 2017;205:158–172.Article PubMed
8. Kim Y, Lim HJ, Jang HJ, et al. Portulaca oleracea extracts and their active compounds ameliorate inflammatory bowel diseases in vitro and in vivo by modulating TNF-α, IL-6 and IL-1β signalling. Food Res Int 2018;106:335–343.Article PubMed
9. Lee AS, Kim JS, Lee YJ, Kang DG, Lee HS. Anti-TNF-α activity of Portulaca oleracea in vascular endothelial cells. Int J Mol Sci 2012;13:5628–5644.Article PubMed PMC
10. Ghorani V, Saadat S, Khazdair MR, Gholamnezhad Z, El-Seedi H, Boskabady MH. Phytochemical characteristics and anti-inflammatory, immunoregulatory, and antioxidant effects of Portulaca oleracea L.: a comprehensive review. Evid Based Complement Alternat Med 2023;2023:2075444.Article PubMed PMC PDF
11. Hur G, Lee S, Kim YY, et al. Bioactive effects of a herbal formula KDC16-2 consisting Portulaca oleracea L. extracts. Korean J Pharmacogn 2019;50:37–45.
12. Bang KB, Choi JH, Park JH, et al. Effect of Portulaca oleracea L. extract on functional constipation: a randomized, double-blind, placebo-controlled trial. Saudi J Gastroenterol 2022;28:296–303.PubMed PMC
13. Jeong MA, Kang HW. Early-onset colorectal cancer. Korean J Gastroenterol 2019;74:4–10.Article PubMed PDF
14. Kim SY, Kwak MS, Yoon SM, et al. Korean guidelines for postpolypectomy colonoscopic surveillance: 2022 revised edition. Korean J Gastroenterol 2022;80:115–134.Article PubMed PMC
15. Saraiva MR, Rosa I, Claro I. Early-onset colorectal cancer: a review of current knowledge. World J Gastroenterol 2023;29:1289–1303.Article PubMed PMC
16. Kulich KR, Madisch A, Pacini F, et al. Reliability and validity of the Gastrointestinal Symptom Rating Scale (GSRS) and Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire in dyspepsia: a six-country study. Health Qual Life Outcomes 2008;6:12.Article PubMed PMC
17. Francis CY, Morris J, Whorwell PJ. The irritable bowel severity scoring system: a simple method of monitoring irritable bowel syndrome and its progress. Aliment Pharmacol Ther 1997;11:395–402.Article PubMed
18. Faul F, Erdfelder E, Buchner A, Lang AG. Statistical power analyses using G*Power 3.1: tests for correlation and regression analyses. Behav Res Methods 2009;41:1149–1160.Article PubMed PDF
19. Takeoka A, Kimura T, Hara S, Hamaguchi T, Fukudo S, Tayama J. Prevalence of irritable bowel syndrome in Japan, China, and South Korea: an international cross-sectional study. J Neurogastroenterol Motil 2023;29:229–237.Article PubMed PMC
20. Holtmann GJ, Ford AC, Talley NJ. Pathophysiology of irritable bowel syndrome. Lancet Gastroenterol Hepatol 2016;1:133–146.Article PubMed
21. Mitselou A, Grammeniatis V, Varouktsi A, Papadatos SS, Katsanos K, Galani V. Proinflammatory cytokines in irritable bowel syndrome: a comparison with inflammatory bowel disease. Intest Res 2020;18:115–120.Article PubMed PMC PDF
22. Decraecker L, De Looze D, Hirsch DP, et al. Treatment of non-constipated irritable bowel syndrome with the histamine 1 receptor antagonist ebastine: a randomised, double-blind, placebo-controlled trial. Gut 2024;73:459–469.Article PubMed
23. Kim MC, Park Y, Lee HS. Treatment of irritable bowel syndrome with predominant diarrhea. Korean J Gastroenterol 2025;85:105–109.Article PubMed PMC
24. Kim DH, Song HY, Nam K, Korean Society of Neurogastroenterology and Motility. Pharmacologic treatment of irritable bowel syndrome with predominant constipation. Korean J Gastroenterol 2025;85:110–116.Article PubMed PMC
25. Ng QX, Soh AY, Loke W, Lim DY, Yeo WS. The role of inflammation in irritable bowel syndrome (IBS). J Inflamm Res 2018;11:345–349.Article PubMed PMC PDF
26. Clarke G, Quigley EM, Cryan JF, Dinan TG. Irritable bowel syndrome: towards biomarker identification. Trends Mol Med 2009;15:478–489.Article PubMed
27. Bennet SM, Böhn L, Störsrud S, et al. Multivariate modelling of faecal bacterial profiles of patients with IBS predicts responsiveness to a diet low in FODMAPs. Gut 2018;67:872–881.Article PubMed

Figure & Data

REFERENCES

Citations

Citations to this article as recorded by

PubReader
ePub Link

Cite

CITE: export Copy Download Format; Close

Download Citation

Download a citation file in RIS format that can be imported by all major citation management software, including EndNote, ProCite, RefWorks, and Reference Manager.

Format:

RIS — For EndNote, ProCite, RefWorks, and most other reference management software
BibTeX — For JabRef, BibDesk, and other BibTeX-specific software

Include:

Citation for the content below
Citation and abstract for the content below

Impact of Portulaca oleracea L. extract in patients with irritable bowel syndrome

DOI: https://doi.org/10.5217/ir.2025.00200

XML Download

Figure

Impact of Portulaca oleracea L. extract in patients with irritable bowel syndrome

Fig. 1. Study overview. IBS, irritable bowel syndrome; P. oleracea, Portulaca oleracea; IBS-C, constipation-dominant IBS; IBS-D, diarrheadominant IBS; IBS-M, mixed-type IBS; IBS-U, unclassified IBS.

Fig. 2. Changes in alpha diversity in subjects before and after the intervention. (A) Placebo group and (B) Portulaca oleracea group. *P<0.05, **P<0.01, ***P<0.001. NS, not significant.

Fig. 3. Change in beta diversity in subjects before and after the intervention, Bray-Curtis and unweighted UniFrac dissimilarity. (A) Placebo group and (B) Portulaca oleracea group.

Fig. 4. Change in alpha diversity in relation to interleukin-6 (IL-6) alteration in subjects before and after the intervention. Change in alpha diversity in subject with decreased IL-6 (A), increased IL-6 (B), IL-6 change (C). *P<0.05, **P<0.01. NS, not significant.

Fig. 5. Change in beta diversity in subject with IL-6 change before and after the intervention, Bray-Curtis and unweighted UniFrac dissimilarity.

Graphical abstract

Fig. 1.

Fig. 2.

Fig. 3.

Fig. 4.

Fig. 5.

Graphical abstract

Impact of Portulaca oleracea L. extract in patients with irritable bowel syndrome

Variable	Total (n=108)	P. oleracea group (n=54)	Placebo group (n=54)	P-value
Age (yr), mean ± SD	45.1 ± 11.3	46.2 ± 10.8	44.1 ± 11.7	0.321
Female sex, No. (%)	59 (54.6)	31 (57.4)	28 (51.9)	0.699
Body mass index (kg/m²)	23.9 ± 3.3	23.8 ± 3.0	24.1 ± 3.5	0.686
Chronic illness, No. (%)	8 (7.4)	4 (7.4)	4 (7.4)	1.000
Regular use medicine, No. (%)	5 (4.6)	3 (5.6)	2 (3.7)	1.000
Smoking, No. (%)				0.637
Never	84 (77.8)	44 (81.5)	40 (74.1)
Ex	9 (8.3)	4 (7.4)	5 (9.3)
Current	15 (13.9)	6 (11.1)	9 (16.7)
Alcohol (ex or current), No. (%)	60 (55.6)	30 (55.6)	30 (55.6)	1.000
Systolic blood pressure (mmHg), mean ± SD	126.7 ± 11.5	128.3 ± 11.6	125.1 ± 11.2	0.150
Diastolic blood pressure (mmHg), mean ± SD	80.3 ± 7.7	81.8 ± 7.1	78.8 ± 8.1	0.044
Pulse rate (beats/min), mean ± SD	78.8 ± 9.8	80.7 ± 10.2	76.9 ± 9.1	0.044
Regular exercise, No. (%)	79 (73.1)	41 (75.9)	38 (70.4)	0.664
Regular meal, No. (%)	61 (56.5)	32 (59.3)	29 (53.7)	0.698
Baseline IBS subtypes, No.	101	53	48	0.080
IBS-C	20	12	8
IBS-D	63	36	27
IBS-M	8	1	7
IBS-U	10	4	6

Variable	P. oleracea group (n=53)		Placebo group (n=48)		P-value
Variable	Mean ± SD	P-value	Mean ± SD	P-value	P-value
GSRS total
Baseline	44.17 ± 13.55		41.42 ± 11.60		0.274
Week 4	37.55 ± 12.05		40.21 ± 11.63		0.261
Difference (baseline vs. week 4)		<0.001^*		<0.001^*
Week 8	31.66 ± 10.56		39.85 ± 12.38		<0.001^*
Difference (baseline vs. week 8)		<0.001^*		0.069
Abdominal pain
Baseline	1.42 ± 1.17		1.33 ± 1.12		0.720
Week 4	1.06 ± 0.99		1.23 ± 1.15		0.424
Difference (baseline vs. week 4)		0.001^*		0.133
Week 8	0.64 ± 1.02		1.17 ± 1.12		0.016^*
Difference (baseline vs. week 8)		<0.001^*		0.008^*
Reflux syndrome
Baseline	0.91 ± 1.11		0.81 ± 0.91		0.646
Week 4	0.64 ± 0.96		0.65 ± 0.84		0.981
Difference (baseline vs. week 4)		0.002^*		0.073
Week 8	0.36 ± 0.76		0.60 ± 0.76		0.109
Difference (baseline vs. week 8)		<0.001^*		0.032^*
Indigestion syndrome
Baseline	3.98 ± 2.32		3.73 ± 2.04		0.563
Week 4	3.11 ± 2.32		3.48 ± 2.06		0.403
Difference (baseline vs. week 4)		<0.001^*		0.032^*
Week 8	2.11 ± 1.91		3.44 ± 1.84		0.001^*
Difference (baseline vs. week 8)		<0.001^*		0.047^*
Diarrhea syndrome
Baseline	2.49 ± 1.65		2.50 ± 1.68		0.977
Week 4	1.91 ± 1.23		2.17 ± 1.43		0.331
Difference (baseline vs. week 4)		0.002^*		0.010^*
Week 8	1.49 ± 1.20		2.06 ± 1.56		0.044^*
Difference (baseline vs. week 8)		<0.001^*		0.004^*
Constipation syndrome, mean ± SD
Baseline	2.19 ± 1.61		1.96 ± 1.41		0.445
Week 4	1.83 ± 1.48		1.75 ± 1.33		0.775
Difference (baseline vs. week 4)		0.021^*		0.105
Week 8	1.25 ± 1.11		1.54 ± 1.22		0.206
Difference (baseline vs. week 8)		<0.001^*		0.011^*

Variable	P. oleracea group (n=53)	Placebo group (n=48)	P-value
IBS-SSS total, mean ± SD			<0.001^*
Baseline	232.0 ± 88.5	202.7 ± 95.0	0.113
Week 4	178.9 ± 81.3	193.3 ± 87.4	0.395
Week 8	120.6 ± 67.0	178.2 ± 88.7	0.001^*
Abdominal pain, No. (%)			0.001^*
Baseline	49 (92.5)	40 (83.3)	0.168
Week 4	43 (81.1)	38 (79.2)	0.807
Week 8	27 (50.9)	35 (72.9)	0.023^*
Abdominal pain score, mean ± SD			<0.001^*
Baseline	42.1 ± 21.1	33.4 ± 24.1	0.057
Week 4	29.0 ± 20.3	31.0 ± 22.7	0.643
Week 8	16.4 ± 18.1	27.7 ± 22.9	0.008^*
Frequency of abdominal pain during recent 10 days, mean ± SD			<0.001^*
Baseline	3.3 ± 2.5	2.5 ± 2.6	0.129
Week 4	2.1 ± 2.0	2.2 ± 2.2	0.895
Week 8	1.1 ± 1.3	2.2 ± 2.5	0.005^*
Abdominal bloating, No. (%)			0.023^*
Baseline	45 (84.9)	38 (79.2)	0.460
Week 4	42 (79.3)	37 (77.1)	0.796
Week 8	30 (56.6)	37 (77.1)	0.028^*
Abdominal bloating score, mean ± SD			<0.001^*
Baseline	42.8 ± 26.5	36.7 ± 27.8	0.262
Week 4	32.5 ± 24.0	36.3 ± 28.0	0.466
Week 8	19.5 ± 20.9	31.2 ± 25.0	0.013^*
Dissatisfaction with bowel habit, mean ± SD			<0.001^*
Baseline	63.0 ± 16.7	59.2 ± 19.5	0.297
Week 4	52.0 ± 19.2	56.7 ± 20.5	0.242
Week 8	39.6 ± 18.9	52.7 ± 22.1	0.002^*
Effect of symptom, mean ± SD			<0.001^*
Baseline	50.9 ± 19.4	47.6 ± 21.4	0.428
Week 4	44.1 ± 17.9	47.3 ± 21.2	0.418
Week 8	34.5 ± 18.7	44.5 ± 20.6	0.013^*

Variable	P. oleracea group (n=53)	Placebo group (n=48)	P value
Change of total IBS-SSS score, No. (%)			<0.001^*
<0	2 (3.7)	16 (33.3)
0–50	9 (17.0)	20 (41.7)
>50	42 (79.3)	12 (25.0)

Variable	P. oleracea group (n=53)		Placebo group (n=48)		P-value
Variable	No. (%)	P-value	No. (%)	P-value	P-value
Baseline (BSFS)					0.047^*
Type 1–2	12 (22.6)		9 (18.8)
Type 3–5	6 (11.3)		15 (31.3)
Type 6–7	35 (66.0)		24 (50.0)
Week 4 (BSFS)					0.384
Type 1–2	6 (11.3)		2 (4.2)
Type 3–5	43 (81.1)		41 (85.4)
Type 6–7	4 (7.6)		5 (10.4)
Difference (baseline vs. week 4)		<0.001^*		0.012^*
Week 8 (BSFS)					0.153
Type 1–2	5 (9.4)		1 (2.1)
Type 3–5	43 (81.1)		45 (93.8)
Type 6–7	5 (9.4)		2 (4.2)
Difference (baseline vs. week 8)		<0.001^*		0.003^*

Variable	P. oleracea group (n=53)		Placebo group (n=48)		P-value
Variable	Mean ± SD	P-value	Mean ± SD	P-value	P-value
Spontaneous bowel movement (/week)
Baseline	11.04 ± 7.74		9.21 ± 7.59		0.234
Week 4	10.61 ± 6.45		9.51 ± 6.87		0.409
Difference (baseline vs. week 4)		0.514		0.473
Week 8	9.98 ± 6.03		9.61 ± 6.68		0.774
Difference (baseline vs. week 8)		0.111		0.404
Complete spontaneous bowel movement (/week)
Baseline	5.34 ± 3.22		5.06 ± 4.84		0.738
Week 4	7.33 ± 4.35		5.69 ± 3.97		0.050
Difference (baseline vs. week 4)		<0.001^*		0.419
Week 8	7.48 ± 4.47		6.18 ± 4.22		0.134
Difference (baseline vs. week 8)		<0.001^*		0.195

Table 1. Demographic Characteristics of Enrolled Patients

P. oleracea, Portulaca oleracea; SD, standard deviation; IBS, irritable bowel syndrome; IBS-C, constipation-predominant IBS; IBS-D, diarrhea-predominant IBS; IBS-M, mixed-type IBS; IBS-U, unclassified IBS.

Table 2. Changes of Gastrointestinal Symptoms during the Study Period

P<0.05 indicates statistical significance.

P. oleracea, Portulaca oleracea; SD, standard deviation; GSRS, Gastrointestinal Symptom Rating Scale.

Table 3. Changes of Bowel Symptoms during the Study Period

P<0.05 indicates statistical significance.

P. oleracea, Portulaca oleracea; IBS-SSS, Irritable Bowel Syndrome-Severity Scoring System; SD, standard deviation.

Table 4. Changes of Total IBS-SSS Score during the Study Period

P<0.05 indicates statistical significance; baseline vs. week 8.

IBS-SSS, Irritable Bowel Syndrome-Severity Scoring System; P. oleracea, Portulaca oleracea.

Table 5. Changes of Stool Consistency during the Study Period

P<0.05 indicates statistical significance.

P. oleracea, Portulaca oleracea; BSFS, Bristol Stool Form Scale.

Table 6. Changes of Stool Frequency during the Study Period

P<0.05 indicates statistical significance.

P. oleracea, Portulaca oleracea; SD, standard deviation.