Intermittent administration of a fasting-mimicking diet reduces intestinal inflammation and promotes repair to ameliorate inflammatory bowel disease in mice

Fat and proteolysis due to methionine, tryptophan, and niacin deficiency leads to alterations in gut microbiota and immune modulation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is one of the intractable diseases. Nutritional components associated with IBD have been identified, and it is known that excessive methionine intake exacerbates inflammation, and that tryptophan metabolism is involved in inflammation. Analysis of the gut microbiota has also progressed, where Lactobacillus regulate immune cells in the intestine and suppress inflammation. However, whether the methionine and tryptophan metabolic pathways affect the growth of intestinal Lactobacillus is unknown. Here we show how transient methionine, tryptophan, and niacin deficiency affects the host and gut microbiota in mouse models of colitis (induced by dextran sodium sulfate) fed a methionine-deficient diet (1K), tryptophan and niacin-deficient diet (2K), or methionine, tryptophan, and niacin-deficient diet (3K). These diets induced body weight decrease and 16S rRNA analysis of mouse feces revealed the alterations in the gut microbiota, leading to a dramatic increase in the proportion of Lactobacillus in mice. Intestinal RNA sequencing data confirmed that the expression of several serine proteases and fat-metabolizing enzymes were elevated in mice fed with methionine, tryptophan, and niacin (MTN) deficient diet. In addition, one-carbon metabolism and peroxisome proliferator-activated receptor (PPAR) pathway activation were also induced with MTN deficiency. Furthermore, changes in the expression of various immune-related cytokines were observed. These results indicate that methionine, tryptophan, and niacin metabolisms are important for the composition of intestinal bacteria and host immunity. Taken together, MTN deficiencies may serve as a Great Reset of gut microbiota and host gene expression to return to good health.

The regulatory effect of intermittent fasting on inflammasome activation in health and disease

Intermittent fasting (IF), one of the most popular diets, can regulate inflammation and promote health; however, the detailed molecular mechanisms are not fully understood. The present review aims to provide an overview of recent preclinical and clinical studies that have examined the effect of IF on inflammasome signaling, and to discuss the translational gap between preclinical and clinical studies. Three databases (PubMed, Web of Science, and Embase) were searched to identify all relevant preclinical and clinical studies up to October 30, 2022. A total of 1544 studies were identified through the database searches, and 29 preclinical and 10 clinical studies were included. Twenty-three of the 29 preclinical studies reported that IF treatment could reduce inflammasome activation in neurological diseases, metabolic and cardiovascular diseases, immune and inflammatory diseases, gastrointestinal diseases, and pulmonary diseases, and 7 of the 10 clinical studies demonstrated reduced inflammasome activation after IF intervention in both healthy and obese participants. Among various IF regimens, time-restricted eating seemed to be the most effective one in terms of inflammasome regulation, and the efficacy of IF might increase over time. This review highlights the regulatory effect of IF on inflammasome activation in health and disease. Future studies using different IF regimens, in various populations, are needed in order to evaluate its potential to be used alone or as an adjunct therapy in humans to improve health and counteract diseases.

Supplementing probiotics during intermittent fasting proves more effective in restoring ileum and colon tissues in aged rats

This study aimed to explore the impact of SCD Probiotics supplementation on biomolecule profiles and histopathology of ileum and colon tissues during a 30-day intermittent fasting (IF) program. Male Sprague-Dawley rats, aged 24 months, underwent 18-h daily fasting and received 3 mL (1 × 108 CFU) of SCD Probiotics. The differences in biomolecule profiles were determined using FTIR Spectroscopy and two machine learning techniques, Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM), which showed significant differences with high accuracy rates. Spectrochemical bands indicating alterations in lipid, protein and nucleic acid profiles in both tissues. The most notable changes were observed in the group subjected to both IF and SCD Probiotics, particularly in the colon. Both interventions, individually and in combination, decreased protein carbonylation levels. SCD Probiotics exerted a more substantial impact on membrane dynamics than IF alone. Additionally, both IF and SCD Probiotics were found to have protective effects on intestinal structure and stability by reducing mast cell density and levels of TNF-α and NF-κB expression in ileum and colon tissues, thus potentially mitigating age-related intestinal damage and inflammation. Furthermore, our results illustrated that while IF and SCD Probiotics individually instigate unique changes in ileum and colon tissues, their combined application yielded more substantial benefits. This study provides evidence for the synergistic potential of IF and SCD Probiotics in combating age-related intestinal alterations.

Living, Heat-Killed Limosilactobacillus mucosae and Its Cell-Free Supernatant Differentially Regulate Colonic Serotonin Receptors and Immune Response in Experimental Colitis

Lactobacillus species have been shown to alleviate gut inflammation and oxidative stress. However, the effect of different lactobacilli components on gut inflammation has not been well studied. This study aims to identify the differences in the effect and mechanisms of different forms and components of Limosilactobacillus mucosae (LM) treatment in the alleviation of gut inflammation using a colitis mouse model that is induced by dextran sodium sulfate (DSS). Seventy-two C57BL/6 mice were divided into six groups: control, DSS, live LM+DSS (LM+DSS), heat-killed LM+DSS (HKLM+DSS), LM cell-free supernatant + DSS (LMCS+DSS), and MRS medium + DSS (MRS+DSS). The mice were treated with different forms and components of LM for two weeks before DSS treatment. After that, the mice were sacrificed for an assessment of their levels of inflammatory cytokines, serotonin (5-HT) receptors (HTRs), and tryptophan metabolites. The results showed that, compared to other treatments, LMCS was more effective (p < 0.05) in the alleviation of DSS-induced body weight loss and led to an increase in the disease activity index score. All three forms and components of LM increased (p < 0.05) the levels of indole-3-acetic acid but reduced (p < 0.05) the levels of 5-HT in the colon. HKLM or LMCS reduced (p < 0.05) the percentages of CD3+CD8+ cytotoxic T cells but increased (p < 0.05) the percentages of CD3+CD4+ T helper cells in the spleen. LM or HKLM increased (p < 0.05) abundances of CD4+Foxp3+ regulatory T cells in the spleen. The LM and LMCS treatments reduced (p < 0.05) the expression of the pro-inflammatory cytokines Il6 and Il17a. The mice in the HKLM+DSS group had higher (p < 0.05) mRNA levels of the anti-inflammatory cytokine Il10, the cell differentiation and proliferation markers Lgr5 and Ki67, the 5-HT degradation enzyme Maoa, and HTRs (Htr1a, Htr2a, and Htr2b) in the colon. All three forms and components of LM reduced the phosphorylation of STAT3. The above findings can help to optimize the functionality of probiotics and develop new dietary strategies that aid in the maintenance of a healthy gut.

Effects of the periodic fasting-mimicking diet on health, lifespan, and multiple diseases: a narrative review and clinical implications

Dietary restriction and fasting have been recognized for their beneficial effects on health and lifespan and their potential application in managing chronic metabolic diseases. However, long-term adherence to strict dietary restrictions and prolonged fasting poses challenges for most individuals and may lead to unhealthy rebound eating habits, negatively affecting overall health. As a result, a periodic fasting-mimicking diet (PFMD), involving cycles of fasting for 2 or more days while ensuring basic nutritional needs are met within a restricted caloric intake, has gained widespread acceptance. Current research indicates that a PFMD can promote stem cell regeneration, suppress inflammation, extend the health span of rodents, and improve metabolic health, among other effects. In various disease populations such as patients with diabetes, cancer, multiple sclerosis, and Alzheimer's disease, a PFMD has shown efficacy in alleviating disease symptoms and improving relevant markers. After conducting an extensive analysis of available research on the PFMD, it is evident that its advantages and potential applications are comparable to other fasting methods. Consequently, it is proposed in this review that a PFMD has the potential to fully replace water-only or very-low-energy fasting regimens and holds promise for application across multiple diseases.

Nutrition and dietary restrictions in cancer prevention

The composition and pattern of dietary intake have emerged as key factors influencing aging, regeneration, and consequently, healthspan and lifespan. Cancer is one of the major diseases more tightly linked with aging, and age-related mortality. Although the role of nutrition in cancer incidence is generally well established, we are far from a consensus on how diet influences tumour development in different tissues. In this review, we will discuss how diet and dietary restrictions affect cancer risk and the molecular mechanisms potentially responsible for their effects. We will cover calorie restriction, intermittent fasting, prolonged fasting, fasting-mimicking diet, time-restricted eating, ketogenic diet, high protein diet, Mediterranean diet, and the vegan and vegetarian diets.

Unlocking the Benefits of Fasting: A Review of its Impact on Various Biological Systems and Human Health

Fasting has gained significant attention in recent years for its potential health benefits in various body systems. This review aims to comprehensively examine the effects of fasting on human health, specifically focusing on its impact on different body's physiological systems. The cardiovascular system plays a vital role in maintaining overall health, and fasting has shown promising effects in improving cardiovascular health markers such as blood pressure, cholesterol levels, and triglyceride levels. Additionally, fasting has been suggested to enhance insulin sensitivity, promote weight loss, and improve metabolic health, thus offering potential benefits to individuals with diabetes and metabolic disorders. Furthermore, fasting can boost immune function, reduce inflammation, enhance autophagy, and support the body's defense against infections, cancer, and autoimmune diseases. Fasting has also demonstrated a positive effect on the brain and nervous system. It has been associated with neuroprotective properties, improving cognitive function, and reducing the risk of neurodegenerative diseases, besides the ability of increasing the lifespan. Hence, understanding the potential advantages of fasting can provide valuable insights for individuals and healthcare professionals alike in promoting health and wellbeing. The data presented here may have significant implications for the development of therapeutic approaches and interventions using fasting as a potential preventive and therapeutic strategy.

Gut microbiota controlling radiation-induced enteritis and intestinal regeneration

Cancer remains the second leading cause of mortality, with nearly 10 million deaths worldwide in 2020. In many cases, radiotherapy is used for its anticancer effects. However, radiation causes healthy tissue toxicity as a side effect. In intra-abdominal and pelvic malignancies, the healthy bowel is inevitably included in the radiation field, causing radiation-induced enteritis and dramatically affecting the gut microbiome. This condition is associated with significant morbidity and mortality that impairs cancer patients' and survivors' quality of life. This Review provides a critical overview of the main drivers in modulating the gut microenvironment in homeostasis, disease, and injury, focusing on gut microbial metabolites and microorganisms that influence epithelial regeneration upon radiation injury.

A review of the role of intermittent fasting in the management of inflammatory bowel disease

Intermittent fasting (IF) may be a weight management strategy for patients with inflammatory bowel disease (IBD). The aim of this short narrative review is to summarize the evidence related to IF in the management of IBD. A literature search of English publications related to IF or time-restricted feeding and IBD, Crohn's disease, or ulcerative colitis was conducted in PubMed and Google Scholar. Four publications on studies of IF in IBD were found: three randomized controlled trials in animal models of colitis and one prospective observational study in patients with IBD. The results from animal studies suggest either moderate or no changes in weight but improvements in colitis with IF. These improvements may be mediated through changes in the gut microbiome, decreased oxidative stress and increased colonic short-chain fatty acids. The study in humans was small and uncontrolled, and it did not assess changes in weight, making it difficult to draw conclusions around the effects of IF on changes in weight or disease course. Given that preclinical evidence suggests intermittent fasting may play a beneficial role in IBD, randomized controlled trials in large patients with active disease are warranted to determine whether intermittent fasting could be an integrated therapy for patients with IBD management, either for weight or for disease management. These studies should also explore the potential mechanisms of action related to intermittent fasting.

A critical review on inflammatory bowel diseases risk factors, dietary nutrients regulation and protective pathways based on gut microbiota during recent 5 years

The treatment of inflammatory bowel diseases (IBDs) has become a worldwide problem. Intestinal flora plays an important role in the development and progression of IBDs. Various risk factors (psychology, living habits, dietary patterns, environment) influence the structure and composition of the gut microbiota and contribute to the susceptibility to IBDs. This review aims to provide a comprehensive overview on risk factors regulating intestinal microenvironment which was contributed to IBDs. Five protective pathways related to intestinal flora were also discussed. We hope to provide systemic and comprehensive insights of IBDs treatment and to offer theoretical guidance for personalized patients with precision nutrition.

A special polysaccharide hydrogel coated on Brasenia schreberi: preventive effects against ulcerative colitis via modulation of gut microbiota

Ulcerative colitis (UC) is a growing health concern in humans, but it can be prevented by using special dietary strategies. Young stems and leaves of Brasenia schreberi (BS) are coated with a special polysaccharide hydrogel (BS mucilage) which can be beneficial for colon health. The aim of this study was to investigate the preventive effects of BS mucilage against UC in a DSS-treated mouse model. Although containing only 0.3% solid content, our research showed that BS mucilage effectively attenuated the disease activity index (DAI) and the spleen index and downregulated IL-1β, IL-18, IL-6 and CAT mRNA levels in DSS-treated mice, which is a promising UC alleviation function. Additionally, BS mucilage also improved the propionate and butyrate levels in mouse feces and alleviated the imbalanced gut microbiota induced by DSS. The abundance of pro-inflammatory and colorectal cancer related bacteria, such as Prevotella, Ruminococcus, Acutalibacter and Christensenella, was decreased by BS mucilage feeding, whereas the abundance of anti-inflammatory and SCFA-producing bacteria including Alistipes and Odoribacter was increased. In conclusion, the current study shows that the daily consumption of BS mucilage could be an effective way to prevent UC in mice, via modulation of gut microbiota.

Time-restricted feeding ameliorates dextran sulfate sodium-induced colitis via reducing intestinal inflammation

Time-restricted feeding (TRF) is an emerging dietary intervention that improves metabolic disorders such as obesity, insulin resistance and dyslipidemia. Inflammatory bowel disease (IBD) is a chronic inflammatory disorder affecting the gastrointestinal tract, where nutrition plays an important role in its pathogenesis. Although numerous strategies of nutritional intervention have been reported, whether TRF can improve IBD has been elusive. In this study, we investigated the effect of two cycles of 7-day TRF intervention in a dextran sulfate sodium-induced IBD mouse model. We found that TRF was able to reduce the disease activity index and ameliorate the IBD-associated symptoms, as well as increase the number of colonic crypts and decrease the histological score in the colon. Furthermore, TRF lowered the percentage of CD4⁺ T cells in the peripheral blood and mesenteric lymph node, and increased the number of CD4⁺CD25⁺ T cells in the mesenteric lymph nodes. Additionally, TRF reduced the infiltration of leukocytes and macrophages around the crypt base in the colon. However, unlike the intermittent caloric restriction with fasting-mimicking diet, TRF was not able to increase the markers of progenitor and cell proliferation in the colon. Collectively, these results demonstrated that TRF is able to improve IBD in mice via reduction in intestinal inflammation.

Intermittent fasting attenuates lipopolysaccharide-induced acute lung injury in mice by modulating macrophage polarization

Acute lung injury (ALI) is a spectrum of acute and life-threatening pulmonary inflammatory conditions. Treatment of ALI remains a clinical challenge. Recently, intermittent fasting (IF) has been shown to improve health and alleviate many diseases. In this study, we tested whether IF attenuated ALI and investigated the mechanism underlying this process. In vivo, the effects of IF on ALI were evaluated in a lipopolysaccharide (LPS)-induced murine ALI model. We found that two times of 24-h fasting in a week before ALI efficiently ameliorated LPS-induced lung injury in mice, characterized by alleviated lung lesions, wet-to-dry weight ratio, myeloperoxidase activity, malondialdehyde content, and lower levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β. In vitro, functional assays were conducted to assess IF on the inflammatory response and macrophage polarization of bone marrow-derived macrophages (BMDMs) treated with LPS or IL-4. And PPARγ antagonist GW9662 and AMPK siRNA were used to test the role of PPARγ and AMPK in the IF-mediated improvement of ALI. The results showed that IF (serum deprivation) suppressed macrophage M1 activation and promoted M2 activation in LPS-treated BMDMs. While, IF also augmented macrophage M2 polarization in IL-4-treated BMDMs. Further mechanistic studies showed that the promotive effect of IF on M2 polarization was related to the activation of the PPARγ and AMPK pathways. In conclusion, this study suggests that IF enhances M2 polarization by activating the AMPK and PPARγ pathways, thus facilitating anti-inflammatory response and ameliorating ALI.

Dietary Patterns and Gut Microbiota Changes in Inflammatory Bowel Disease: Current Insights and Future Challenges

Inflammatory bowel disease (IBD) is a result of a complex interplay between genes, host immune response, gut microbiota, and environmental factors. As one of the crucial environmental factors, diet plays a pivotal role in the modulation of gut microbiota community and the development of IBD. In this review, we present an overview of dietary patterns involved in the pathogenesis and management of IBD, and analyze the associated gut microbial alterations. A Westernized diet rich in protein, fats and refined carbohydrates tends to cause dysbiosis and promote IBD progression. Some dietary patterns have been found effective in obtaining IBD clinical remission, including Crohn's Disease Exclusion Diet (CDED), Mediterranean diet (MD), Anti-Inflammatory Diet (AID), the low-"Fermentable Oligo-, Di-, Mono-saccharides and Polyols" (FODMAP) diet, Specific Carbohydrate Diet (SCD), and plant-based diet, etc. Overall, many researchers have reported the role of diet in regulating gut microbiota and the IBD disease course. However, more prospective studies are required to achieve consistent and solid conclusions in the future. This review provides some recommendations for studies exploring novel and potential dietary strategies that prevent IBD.

A Comparison of the Impact of Restrictive Diets on the Gastrointestinal Tract of Mice

The rate of gut inflammatory diseases is growing in modern society. Previously, we showed that caloric restriction (CR) shapes gut microbiota composition and diminishes the expression of inflammatory factors along the gastrointestinal (GI) tract. The current project aimed to assess whether prominent dietary restrictive approaches, including intermittent fasting (IF), fasting-mimicking diet (FMD), and ketogenic diet (KD) have a similar effect as CR. We sought to verify which of the restrictive dietary approaches is the most potent and if the molecular pathways responsible for the impact of the diets overlap. We characterized the impact of the diets in the context of several dietary restriction-related parameters, including immune status in the GI tract; microbiota and its metabolites; bile acids (BAs); gut morphology; as well as autophagy-, mitochondria-, and energy restriction-related parameters. The effects of the various diets are very similar, particularly between CR, IF, and FMD. The occurrence of a 50 kDa truncated form of occludin, the composition of the microbiota, and BAs distinguished KD from the other diets. Based on the results, we were able to provide a comprehensive picture of the impact of restrictive diets on the gut, indicating that restrictive protocols aimed at improving gut health may be interchangeable.

Intermittent Caloric Restriction Promotes Erythroid Development and Ameliorates Phenylhydrazine-Induced Anemia in Mice

Background

Dietary restriction has a profound effect in altering immune system and promoting metabolic health and aging. However, how dietary restriction impacts erythroid system is largely unknown. We found that a short-term caloric restriction (CR) stimulates expression of KLF1, a master regulator of erythroid development, in the spleen of mouse, and thus explored the potential effect of CR on erythropoiesis.

Methods

We analyzed the effects of intermittent CR and continuous CR for different lengths of time on parameters of peripheral blood and erythroid profiles in the spleen and bone marrow in C57BL/6 mice. We next assessed how different types of CR affect phenylhydrazine-induced anemia in the mice. Colony formation assay was also used to analyze LK + progenitors and BFU-E in the bone marrow.

Results

Intermittent CR for 2 weeks raised the number of reticulocytes in the blood, while continuous CR for 2 weeks elevated red blood cells and hemoglobin level. Intermittent CR for 2 weeks promoted extramedullary hematopoiesis in the spleen, while continuous CR mainly promoted erythropoiesis in the bone marrow. Interestingly, a short-term intermittent CR but not continuous CR was able to ameliorate phenylhydrazine-induced anemia. Intermittent CR reduced early-stage erythroblasts and increased late-stage erythroblasts/mature RBCs in the spleen, indicating an accelerated transition from early-stage to late-stage erythroblasts/mature red blood cells. Furthermore, a short-term intermittent CR elevated LK + progenitors and the committed erythroid progenitor cells BFU-E in the bone marrow.

Conclusion

Our study demonstrated that a short-term intermittent CR, but not continuous CR, has a significant effect to promote hematopoiesis and such activity can ameliorate phenylhydrazine-induced acute anemia in the mouse.

Exercise, Diet and Sleeping as Regenerative Medicine Adjuvants: Obesity and Ageing as Illustrations

Regenerative medicine uses the biological and medical knowledge on how the cells and tissue regenerate and evolve in order to develop novel therapies. Health conditions such as ageing, obesity and cancer lead to an impaired regeneration ability. Exercise, diet choices and sleeping pattern have significant impacts on regeneration biology via diverse pathways including reducing the inflammatory and oxidative components. Thus, exercise, diet and sleeping management can be optimized towards therapeutic applications in regenerative medicine. It could allow to prevent degeneration, optimize the biological regeneration and also provide adjuvants for regenerative medicine.

NLRP3 Inflammasome: Checkpoint Connecting Innate and Adaptive Immunity in Autoimmune Diseases

Autoimmune diseases are a broad spectrum of human diseases that are characterized by the breakdown of immune tolerance and the production of autoantibodies. Recently, dysfunction of innate and adaptive immunity is considered to be a key step in the initiation and maintenance of autoimmune diseases. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is a multimeric protein complex, which can detect exogenous pathogen irritants and endogenous danger signals. The main function of NLRP3 inflammasome is to promote secretion of interleukin (IL)-1β and IL-18, and pyroptosis mediated by caspase-1. Served as a checkpoint in innate and adaptive immunity, aberrant activation and regulation of NLRP3 inflammasome plays an important role in the pathogenesis of autoimmune diseases. This paper reviewed the roles of NLRP3 inflammasome in autoimmune diseases, which shows NLRP3 inflammasome may be a potential target for autoimmune diseases deserved further study.