Relapse Prevention in Ulcerative Colitis by Plant-Based Diet Through Educational Hospitalization: A Single-Group Trial

Unveiling the dynamics of gut microbial interactions: a review of dietary impact and precision nutrition in gastrointestinal health

The human microbiome, a dynamic ecosystem within the gastrointestinal tract, plays a pivotal role in shaping overall health. This review delves into six interconnected sections, unraveling the intricate relationship between diet, gut microbiota, and their profound impact on human health. The dance of nutrients in the gut orchestrates a complex symphony, influencing digestive processes and susceptibility to gastrointestinal disorders. Emphasizing the bidirectional communication between the gut and the brain, the Brain-Gut Axis section highlights the crucial role of dietary choices in physical, mental, and emotional well-being. Autoimmune diseases, particularly those manifesting in the gastrointestinal tract, reveal the delicate balance disrupted by gut microbiome imbalances. Strategies for reconciling gut microbes through diets, precision nutrition, and clinical indications showcase promising avenues for managing gastrointestinal distress and revolutionizing healthcare. From the Low-FODMAP diet to neuro-gut interventions, these strategies provide a holistic understanding of the gut's dynamic world. Precision nutrition, as a groundbreaking discipline, holds transformative potential by tailoring dietary recommendations to individual gut microbiota compositions, reshaping the landscape of gastrointestinal health. Recent advancements in clinical indications, including exact probiotics, fecal microbiota transplantation, and neuro-gut interventions, signify a new era where the gut microbiome actively participates in therapeutic strategies. As the microbiome takes center stage in healthcare, a paradigm shift toward personalized and effective treatments for gastrointestinal disorders emerges, reflecting the symbiotic relationship between the human body and its microbial companions.

Plant-based Diets for Inflammatory Bowel Disease: What Is the Evidence?

BACKGROUND

Inflammatory bowel disease is a chronic incurable condition that carries a high morbidity burden for patients. Plant-based diets have emerged as a potentially safe and effective treatment strategy for this condition. However, no attempt has been made to summarize the literature in this field. In this review, we aim to define variants of plant-based diets that have been studied, evaluate their findings, and identify knowledge gaps that warrant further investigation.

METHODS

A literature search was conducted on MEDLINE and Embase.

RESULTS

Twenty-three studies with 2304 participants were included in this review. Eleven studies (48%) were case reports and 8 (35%) were single-arm trials. Semivegetarian diets were the most commonly studied plant-based diet (n = 14, 61%). Most studies reported that plant-based diets were safe and effective in managing inflammatory bowel disease. However, significant limitations restrict the quality and interpretability of these findings, including a paucity of controlled data, small sample sizes, and inconsistent reporting of dietary adherence.

CONCLUSIONS

Although initial findings appear promising, it remains unclear whether plant-based diets are an effective adjunct or sole therapy for managing inflammatory bowel disease. Future investigators should aim to conduct methodologically rigorous interventional trials with appropriate control data and consistent and meaningful outcome reporting.

Therapeutic advancement in inflammatory bowel disease by incorporating plant-based diet

Identification and recognition of the ubiquitous environmental factor are prerequisite for treatment and prevention of the disease. The biggest problem with current practice in inflammatory bowel disease (IBD) is the lack of a widely appreciated ubiquitous environmental factor for the disease. The incidence of IBD is associated with dietary transition from a traditional diet to the current (westernized) diet. Prospective cohort studies and case-control studies indicate that the current diet is a risk factor for IBD. The current diet tends to cause gut microbial dysbiosis resulting in a pro-inflammatory state. Therefore, we regard our current diet as this factor. Even nutritionally balanced meals are unable to suppress relapse, particularly in Crohn's disease (CD). Therefore, we developed a plant-based diet (PBD) (lacto-ovo-semi-vegetarian diet) to counter the current diet. By incorporating the PBD into practice, we achieved far better outcomes in both ulcerative colitis (UC) and CD in both the induction and quiescent phases compared to the current standard therapy. All patients were treated on an inpatient basis and provided with a PBD. CD is far more untenable than UC and is destined to follow a disabling course. Therefore, infliximab was indicated in all patients with CD, but only in severe cases with UC. This infliximab and PBD as first-line (IPF) therapy broke the barrier of primary nonresponders to biologics (around 30%): the remission rate was 96% (44/46) in CD and 76% (13/17) in severe UC. A PBD can induce remission without medication in approximately one-third of mild cases of UC. All patients were advised to adhere PBD after discharge. In CD, a relapse-free outcome was achieved in nearly a half of patients (52%) at 10-year follow-up without biologics or immunosuppressants. Cumulative relapse rates for 51 initial episode cases of UC (18 mild, 30 moderate, 3 severe) at 1 and 5 years were 14% and 27%, respectively. We believe our assertion that the current diet is the ubiquitous environmental factor underlying IBD is correct and a PBD is right diet for the disease.

Role of Hydrogen Sulfide in Inflammatory Bowel Disease

Hydrogen sulfide (H2S), originally known as toxic gas, has now attracted attention as one of the gasotransmitters involved in many reactions in the human body. H2S has been assumed to play a role in the pathogenesis of many chronic diseases, of which the exact pathogenesis remains unknown. One of them is inflammatory bowel disease (IBD), a chronic intestinal disease subclassified as Crohn's disease (CD) and ulcerative colitis (UC). Any change in the amount of H2S seems to be linked to inflammation in this illness. These changes can be brought about by alterations in the microbiota, in the endogenous metabolism of H2S and in the diet. As both too little and too much H2S drive inflammation, a balanced level is needed for intestinal health. The aim of this review is to summarize the available literature published until June 2023 in order to provide an overview of the current knowledge of the connection between H2S and IBD.

Dietary Considerations for Inflammatory Bowel Disease Are Useful for Treatment of Checkpoint Inhibitor-Induced Colitis

Checkpoint molecules are cell surface receptors on immune cells that mitigate excessive immune responses, but they have increased expression levels in cancer to facilitate immune escape. Checkpoint blockade therapies (e.g., anti-PD-1, anti-CTLA-4, and anti-LAG-3 therapy, among others) have been developed for multiple cancers. Colitis associated with checkpoint blockade therapy has pathophysiological similarities to inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis. Current therapeutic guidelines for checkpoint blockade-induced colitis include corticosteroids and, if the patient is refractory to steroids, immunomodulating antibodies, such as anti-TNF and anti-integrin agents. Interestingly, immunomodulatory molecules, such as TNFα, are upregulated in both IBD and checkpoint-mediated colitis. The inflammatory colitis toxicity symptoms from checkpoint blockade are similar to clinical symptoms experienced by patients with IBD. The pathophysiologic, dietary, and genetic factors associated with IBD will be reviewed. We will then explain how the principles developed for the treatment of IBD can be applied to patients experiencing inflammatory bowel toxicity secondary to checkpoint blockade.

Onset of Ulcerative Colitis in a Patient with Type 2 Diabetes: Efficacy of a Plant-Based Diet for Both Diseases

No case has been reported in which ulcerative colitis occurred in a patient with type 2 diabetes mellitus and the patient was treated with a plant-based diet. A 56-year-old man with a 3-year history of diabetes noticed bloody stool about 2 months after his worst glycated hemoglobin A1c test. Endoscopy revealed diffuse inflammation in the rectum. He was diagnosed with ulcerative colitis (proctitis, mild severity). He underwent educational hospitalization. A plant-based diet (1400 kcal/day) was provided. The same dosage of metformin was continued, but no medication was prescribed for ulcerative colitis. At the end of hospitalization, fecal occult blood 271 ng/mL became negative. Glycated hemoglobin A1c 6.9% had decreased to 6.6%. Two months after discharge, glycated hemoglobin A1c decreased to normal for the first time in 3.5 years. Ulcerative colitis had been in remission without medication for one and a half years after the educational hospitalization. Thereafter, however, he experienced two flareups. Deterioration in glycated hemoglobin A1c preceded the flareups. We described a scarcely reported case in which ulcerative colitis occurred in a patient with diabetes and the patient was treated with a plant-based diet. The plant-based diet was effective for both diseases. It seemed that the status of diabetes influenced the onset and relapse of ulcerative colitis.

Stepwise Treatment With Plant-Based Diet and Medication for Patient With Mild Ulcerative Colitis

INTRODUCTION

We regard inflammatory bowel disease as a lifestyle disease mainly mediated by a westernized diet. We developed a plant-based diet (PBD) to counter the westernized diet. PBD can induce remission without medication in a subset of mild cases of ulcerative colitis. Medication is provided when induction of remission is not achieved solely with PBD. We describe such a case in this report.

CASE PRESENTATION

A 34-year-old woman visited us in October 2016 with a complaint of loose stool for nearly 5 years. Laboratory examination revealed mild abnormalities including elevation of C-reactive protein (CRP). Ulcerative colitis was diagnosed due to diffuse colonic inflammation and pathological findings consistent with ulcerative colitis. She was admitted for educational hospitalization for 19 days in the middle of November, during which PBD was provided. A few days after admission, her stool became normal. CRP concentration decreased to within the normal range. However, colonoscopy on discharge showed minimum improvement. Thereafter, CRP was abnormal on three successive occasions, and her stool alternated between normal and loose. Sulfasalazine was initiated at the end of March 2017. Thereafter, her stool was normally formed, and CRP decreased to normal. Endoscopic remission was confirmed in August. Her PBD score, which evaluates adherence to PBD, was 8 before admission, and 37 and 16 at 7 and 21 months after discharge, respectively.

CONCLUSION

Medication was administered when restoration of a healthy dietary lifestyle was insufficient to induce remission. Our stepwise treatment makes the shift from one-size-fits-all medication toward medication to the right patient.

REGISTRATION

http://www.umin.ac.jp UMIN000019061.

Predefined Diets in Patients with Inflammatory Bowel Disease: Systematic Review and Meta-Analysis

Inflammatory bowel disease (IBD) is a chronic disease mediated by the immune system and characterized by the importance of diet in pathological development. This study aims to understand how the use of predefined diets can affect the adult population diagnosed with IBD. We conducted a systematic review and meta-analysis. From the different databases (MEDLINE, Scopus, Cochrane, LILACS, CINAHL, and WOS), we found 4195 registers. After a review process, only 31 research studies were selected for qualitative synthesis and 10 were selected for meta-analysis. The variables used were Crohn’s Disease Activity Index (CDAI) for patients with Crohn’s Disease (CD) and fecal calprotectin (FC), C-Reactive Protein (CRP), and albumin (ALB) for patients with IBD. Predefined diets have been shown to have partial efficacy for the treatment of IBD and are compatible with other medical treatments. CDAI improved but with reasonable doubts due to the high heterogeneity of the data, while no differences were observed for ALB, FC, and CRP. More studies that evaluate the influence of predefined diets on IBD patients are needed due to the great variability in diets and the tools used to measure their effects.

Ulcerative colitis in the postpartum period

We describe a scarcely reported case in which ulcerative colitis (UC) occurred in the postpartum period. The aims of this case report are to reinforce the recent assertion that a diet is a ubiquitous environmental factor in inflammatory bowel disease (IBD) and that a plant-based diet (PBD) is recommended for IBD. A 29-year-old woman normally delivered her first child. She first noticed bloody diarrhea 4.5 months after delivery. She was diagnosed with UC (left-sided colitis, moderate severity). Sulfasalazine induced remission. She then experienced and learned about PBD during an educational hospitalization. She resumed breast-feeding and stopped medication. An interview and questionnaire revealed a change in her diet 3 months after delivery, from a sound diet (plant-based diet score: 25) to an unhealthy diet (score: 9). It happened along with a change in residence, from her parent's home where her mother prepared traditional Japanese meals to her home where she prepared meals by herself. A feeling of release from childbirth prompted her to eat sweets and cheese despite being aware that the quality of the meals deteriorated. We described a scarcely reported case in which UC occurred in the postpartum period. It happened along with a change in her diet, from a sound diet to an unhealthy diet due to a feeling of release from childbirth. She replaced an omnivorous diet by PBD and stopped medication. The critical role of diet is largely ignored by healthcare professionals. We believe that greater appreciation of diet will change and improve management of IBD.

Relapse Prevention by Plant-Based Diet Incorporated into Induction Therapy for Ulcerative Colitis: A Single-Group Trial

CONTEXT

No known previous study has focused on plant-based diet (PBD) to prevent relapse of ulcerative colitis (UC) except our previous educational hospitalization study.

OBJECTIVE

To describe the relapse rate in a large case series of UC after incorporation of PBD into induction therapy.

DESIGN

All patients with UC between 2003 and 2017 were admitted for induction therapy. Patients receiving educational hospitalization or treated with infliximab were excluded. A lacto-ovo-semivegetarian diet (PBD) together with medication prescribed according to UC guidelines was provided during hospitalization.

MAIN OUTCOME MEASURES

The primary endpoint was relapse during follow-up. The secondary endpoint was change over time in the plant-based diet score (PBDS), which evaluated adherence to the PBD.

RESULTS

Ninety-two cases were studied, of which 51 were initial episodes and 41 were relapses. Cases varied in severity (31 mild, 48 moderate, 13 severe) and extent (15 proctitis, 22 left-sided colitis, 55 extensive colitis). More severe cases existed among the relapse cases than among the initial episode cases. Cumulative relapse rates at 1- and 5-year follow-up (Kaplan-Meier analysis) were 14% and 27%, respectively, for the initial episode cases, and 36% and 53%, respectively, for relapse cases. At long-term follow-up (6 years 4 months), PBDS was significantly higher than baseline PBDS (p < 0.0001).

CONCLUSION

Relapse rates in UC after induction therapy with PBD were far lower than those previously reported with conventional therapy. Adherence to PBD was significantly higher than baseline even at 6-year follow-up. We conclude PBD is effective for preventing UC relapse.(Study identification no.: UMIN000019061: Registration: www.umin.ac.jp).

High Remission Rate with Infliximab and Plant-Based Diet as First-Line (IPF) Therapy for Severe Ulcerative Colitis: Single-Group Trial

INTRODUCTION

About one-third of patients with severe ulcerative colitis (UC) do not respond to corticosteroid therapy and receive rescue therapy with infliximab or cyclosporine. Up to 20% of such patients fail to respond to rescue therapy and undergo colectomy.

OBJECTIVE

We investigated the outcomes of infliximab and a plant-based diet (PBD) as first-line therapy for severe UC.

METHODS

Patients with severe UC defined by the Truelove and Witts criteria were admitted and given standard induction therapy with infliximab (5.0 mg/kg-7.5 mg/kg) at 0, 2, and 6 weeks. Additionally, they received a PBD. The primary endpoint was remission or colectomy in the induction phase and 1 year after discharge. Secondary endpoints were changes in inflammatory markers in the induction phase and the PBD score at baseline and follow-up. A higher PBD score indicates greater adherence to a PBD.

RESULTS

Infliximab and PBD as first-line therapy was administered in 17 cases. The remission rate was 76% (13/17), and the colectomy rate was 6% (1/17) in the induction phase. C-reactive protein values and the erythrocyte sedimentation rate significantly decreased at week 6 from 9.42 mg/dL to 0.33 mg/dL and from 59 to 17 mm/h, respectively (p < 0.0001). At 1-year follow-up, the cumulative relapse rate was 25%, and there were no additional colectomy cases. Mean PBD scores of 27.7 at 1 year and 23.8 at 4 years were significantly higher than baseline scores of 8.3 and 9.9, respectively (p < 0.0001 and p = 0.0391).

CONCLUSION

This new first-line therapy for severe UC demonstrated a higher remission rate and lower colectomy rate than with the current modality.

Onset of Ulcerative Colitis in a Patient with Nonalcoholic Fatty Liver Disease (NAFLD): Dramatic Effect of Plant-based Diet for NAFLD

Nonalcoholic fatty liver disease (NAFLD) develops in ulcerative colitis (UC) and Crohn's disease. However, there is scarce reporting on the onset of UC in patients with NAFLD. A 44-year-old man was diagnosed with UC and referred to us in 2019. His height was 166.0 cm, and body weight was 86.3 kg. The waist circumference was 93.7 cm (normal range <85) and triglyceride was 751 mg/dL. These findings, in addition to hypertension, resulted in a diagnosis of metabolic syndrome. HbA1c was normal. Ultrasonography disclosed severe fatty liver. Nonalcoholic fatty liver disease was diagnosed. He underwent 12 days of educational hospitalization for UC. A lacto-ovo-semi-vegetarian diet (1400 kcal/day), a kind of plant-based diet (PBD), was provided. He lost 4 kg, which was 4.6% of his base body weight. Triglyceride and total cholesterol decreased to the normal ranges. Transaminases and γ-glutamyl transpeptidase also decreased. His body weight decreased further after discharge. Follow-up ultrasonography indicated an improvement in hepatic enlargement. The shear wave velocity decreased from 1.11 to 0.88 m/s. His soft stool became normal stool by 2 months after discharge. Records of his health checkups revealed the presence of metabolic syndrome and abnormal liver function tests already in 2015. Thus, it was concluded that UC developed in a patient with NAFLD in this case. Plant-based diet has already been shown to be effective in inflammatory bowel disease (IBD). In the present case, NAFLD parameters were dramatically improved by PBD. Whether the improvement was due to weight loss per se or due to weight loss with PBD is to be clarified.

Analysis of the Nutrients and Food Products Intake of Polish Males with Ulcerative Colitis in Remission

In spite of the lack of evidence of diet therapy efficacy to sustain remission of ulcerative colitis (UC), the dietary counseling may be beneficial, as a number of patients restrict intake of some products with no medical consultation. The aim of the present study was to analyze the nutrients and food products intake of Polish males with UC in remission in comparison with a control group. The UC group of 44 male patients with the confirmed remission, as well as the pair-matched group of 44 male controls, matched by their age and concurrent diseases, was recruited for the study. Their dietary intake was assessed based on three-day dietary records (to analyze the nutrients and food products intake) and information about food products excluded from their diet, and compared between respondents. It was observed that the intake of food products did not differ between the compared groups, except for the intake of potatoes and sugar, which was higher (p = 0.0033, p = 0.0092, respectively) in UC patients (median of 209 g and 11 g, respectively) than the control males (median of 100 g and 1 g, respectively). However, it did not influence differences of energy value and nutrients intake between groups, except for the intake of lactose and vitamin B₂ per 1000 kcal, which was lower (p = 0.0425, p = 0.0444, respectively) in UC patients (median of 1.8 g and 0.7 g/1000 kcal) than the control males (median of 3.6 g and 0.8 g/1000 kcal). It was observed that the differences in food products intake between the UC individuals in remission and healthy controls were only minor and did not contribute to any significant differences in their nutrients intake. It was concluded that UC patients should be educated not only about the potential influence of food products on their well-being but also about healthy diet recommendations.

Westernized Diet is the Most Ubiquitous Environmental Factor in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), a collective term for Crohn disease and ulcerative colitis, is a polygenic disease thought to be triggered by environmental factors. A Western or westernized lifestyle may be a major driver of the growing incidence of IBD. IBD may represent dysregulated mucosal inflammation to gut microbiota. Despite many review articles on environmental factors in IBD, no consensus exists regarding which factor contributes most to trigger the onset of IBD. Identification and recognition of major environmental factors are prerequisite for effective disease treatment and prevention. Representative environmental factors such as smoking, breastfeeding, nonsteroidal anti-inflammatory drugs, antibiotic use in childhood, oral contraceptives, and appendectomy do not correlate with disease onset in most patients with IBD. In contrast, diet appears to be important in most cases of IBD. Diets rich in animal protein (risk factor) and deficient in dietary fiber (preventive factor) are characteristic of westernized diets in affluent societies. Recent research shows that westernized diets are associated with a reduced gut microbial diversity (dysbiosis), which may result in increased susceptibility to IBD and other common chronic diseases. Plant-based diets rich in dietary fiber are associated with increased microbial diversity. Recent reports on IBD therapy that replaced westernized diets with plant-based diets achieved far better outcomes than those previously reported in the literature. We believe that westernized diet-associated gut dysbiosis is the most ubiquitous environmental factor in IBD. Adoption of this concept may have the potential to provide a better quality of life for patients with IBD.

Implications of the Westernized Diet in the Onset and Progression of IBD

Inflammatory bowel diseases (IBD) are currently considered multifactorial pathologies in which various combined environmental factors act on a genetic background, giving rise to a chronic inflammation of the gastrointestinal tract. Among the various environmental factors, it now seems clear that the diet plays the major role in IBD onset and progression. Several clinical studies have attempted to understand the impact of diet in the development and progression of these diseases in order to establish useful guidelines for their management. However, the modest and sometimes contradictory results did not lead to the definition of shared dietary suggestions. On the other hand, food fads and recommendations based on anecdotal episodes are often followed by IBD patients to improve their diet. This review provides a critical overview of existing data on the role of diet as a risk factor for IBD. The methodology used was that of analyzing the results of clinical studies conducted on diet and IBD over the last 12 years through PubMed, as well as analyzing the most relevant studies on nutrients and their possible roles in IBD through the knowledge of the mechanisms by which they can modulate the microbiota or the intestinal physiology.

Dietary Factors in Sulfur Metabolism and Pathogenesis of Ulcerative Colitis

The biogeography of inflammation in ulcerative colitis (UC) suggests a proximal to distal concentration gradient of a toxin. Hydrogen sulfide (H₂S) has long been considered one such toxin candidate, and dietary sulfur along with the abundance of sulfate reducing bacteria (SRB) were considered the primary determinants of H₂S production and clinical course of UC. The metabolic milieu in the lumen of the colon, however, is the result of a multitude of factors beyond dietary sulfur intake and SRB abundance. Here we present an updated formulation of the H₂S toxin hypothesis for UC pathogenesis, which strives to incorporate the interdependency of diet composition and the metabolic activity of the entire colon microbial community. Specifically, we suggest that the increasing severity of inflammation along the proximal-to-distal axis in UC is due to the dilution of beneficial factors, concentration of toxic factors, and changing detoxification capacity of the host, all of which are intimately linked to the nutrient flow from the diet.