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Diet as an Optional Treatment in Adults With Inflammatory Bowel Disease: A Systematic Review of the Literature.
Jaramillo, AP, Abaza, A, Sid Idris, F, Anis, H, Vahora, I, Moparthi, KP, Al Rushaidi, MT, Muddam, M, Obajeun, OA
Cureus. 2023;15(7):e42057
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Crohn's disease (CD) and ulcerative colitis (UC) are linked with significant morbidity and higher healthcare costs. The current model of CD pathogenesis implies that environmental variables and the gut microbiota interact in those who are genetically predisposed to the condition. The aim of this study was to investigate a treatment based on the diet of IBD patients. This study was a systematic review of nine studies. Results showed that following a diet that reduces inflammation may prevent its recurrence in UC patients in clinical remission. In fact, there were significant systemic changes in the intestinal microbiota of anti-inflammatory diet patients. Authors concluded that a four-week FODMAP diet combined with professional counseling and regular follow-up will be helpful in the therapy of persistent gastrointestinal symptoms in quiescent IBD, although care should be used in the long run.
Expert Review
Conflicts of interest:
None
Take Home Message:
Whilst concise, this limited review highlights the current lack of evidence supporting stand alone dietary strategies in preventing relapse for IBD patients. At the very least an anti-inflammatory diet should ideally be implemented alongside specific medical care and counselling to minimise risk of disease relapses.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This systematic review evaluated the efficacy of diet as a preventative therapeutic treatment for Inflammatory Bowel Disease (IBD).
Methods
A total of 9 studies (published in the last 5 years) were chosen. The articles included 6 randomised controlled trials (RCT), one systematic literature review (SLR) and two SLR and meta-analysis. The authors used the Assessment Systematic Reviews (AMSTAR) approach and an unspecified Cochrane Risk of Bias assessment tool.
Results
(The following refers to the original RCT articles as the review article data was sparse).
- A 6-month, open-label, randomised, placebo-controlled trial of 53 adult Ulcerative Colitis (UC) patients compared response to an Anti-inflammatory Diet (AID) with Canada’s Food Guide (CFG). The outcome showed that the faecal calprotectin value (<150 µg/g at the endpoint) was significantly higher in the AID group (69.2 vs. 37.0%, p = 0.02) (Keshteli et al., 2022).
- The Specific Carbohydrate Diet (SCD) was not superior to the Mediterranean Diet (MD) in terms of achieved symptomatic remission at 6 weeks (SCD 46.5%, MD 43.5%; p = .77) (Lewis et al., 2022).
- A single-blind, 4-week trial concluded significant relief from gut symptoms was achieved when comparing a low FODMAP diet (14/27, 52% of positive patient feedback) to a control diet (4/25, 16%, p=.007) (Cox et al., 2020).
- A 7-day trial of 28 volunteers compared individualised food-based diet (CD-TREAT), with similar composition to Exclusive Enteral Nutrition (EEN) and found a change in relative abundance in faecal microbiome genera of 58 (49.3%) and 38 (32.3%) following both feeding practices respectively (Svolos et al., 2019).
- Substantial reduction in red and processed meat was not significant in reducing time to symptomatic relapse in Crohn’s Disease (CD) patients when comparing 115 high red meat consumers with 87 low red meat CD patients (p = 0.61 any relapse and p = 0.50 for moderate to severe relapse) (Aldenberg et al., 2019).
Conclusion
An anti-inflammatory diet may prolong clinical remission for UC patients. CD patients, with mild to severe symptoms, may tolerate both the MD and SCD equally well. The authors advise a low FODMAP diet for a 4-week period combined with professional counselling and regular follow-up sessions to delay flare-up episodes. However the findings were based on a very limited number of scientific material that requires extensive further assessment prior to deriving any firm conclusions.
Clinical practice applications:
- In order to delay relapse in IBD it is imperative that foods that support anti-inflammatory mechanisms are incorporated and maintained
- Whilst limited, the papers reviewed highlight potential for an initial low FODMAP diet followed by a longer term MD or SCD combined with constant monitoring
- From one study, red meat consumption did not appear to exacerbate symptoms.
Considerations for future research:
- Future studies need to include larger cohorts to ascertain the efficacy of dietary interventions as a stand alone treatment option for IBD
- Longer periods of intervention are needed to confirm dietary intervention efficacy and safety in this population.
Abstract
While the exact cause of IBD is unknown, there are a number of factors that are thought to contribute to its development, including environmental and genetic factors. While exclusive enteral nutrition (EEN) is a promising therapy for Crohn's disease (CD), it is not yet considered a first-line treatment. Additionally, the efficacy of EEN compared to corticosteroid treatment is still being investigated. EEN is suggested as a first-line therapy by which guidelines and in which age groups, as it may differ in pediatric and adult recommendations. Another finding was that dietary changes involving an increase in anti-inflammatory foods and decreased intake of foods high in inflammatory compounds are linked to a beneficial outcome both metabolically and microbiologically in patients with ulcerative colitis (UC) in remission. For relevant medical literature, we examined PubMed/Medline, the Cochrane Library, and Google Scholar as examples of medical databases. The articles were identified, evaluated, and eligibility applied, and nine publications were found. The finished articles investigated the role of several diet alternatives for patients with IBD. Some others have shown that following a normal low-fat diet may be effective in reducing the occurrence of subclinical colitis. The EEN and partial enteral nutrition (PEN) indicated no significant differences between both regimens, but both had good outcomes during active IBD. Other strict diets, such as the specific carbohydrate diet (SCD) versus the Mediterranean diet (MD), demonstrate excellent outcomes in patients with IBD. Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) dietary counseling improves gastrointestinal symptoms and quality of life in IBD patients. Based on the above, we concluded that more studies determining which component of the diet is not clear (proteins, carbs balanced) or diet types are required to establish a particular diet employed as a treatment intervention in these individuals.
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Early life gut microbiota profiles linked to synbiotic formula effects: a randomized clinical trial in European infants.
Lagkouvardos, I, Intze, E, Schaubeck, M, Rooney, JP, Hecht, C, Piloquet, H, Clavel, T
The American journal of clinical nutrition. 2023;117(2):326-339
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Microbial colonisation of the intestine after birth is a central event that influences infant health with life-long consequences. Although improvement of hygienic conditions reduces infant mortality due to infections, environments with low microbial biomass counteract natural colonisation by commensal microbes. The aim of this study was to assess the effects of a synbiotic intervention formula (IF) on faecal microbiota. This study was a multicentre, randomised, controlled, double-blind intervention trial which enrolled 540 infants. Infants whose parents had chosen not to breastfeed or were not able to breastfeed prior to study inclusion were allocated randomly to 1 of 2 formula groups (n = 230 control formula, n = 230 IF). The infants in the breastfed reference group (n = 80) were mainly fed human milk. Results showed that synbiotic intervention influenced the gut microbiota and milieu parameters during early life to resemble some major characteristics found in breastfed infants (higher relative abundances of bifidobacteria, lower richness, lower faecal pH and butyrate concentrations), and effects depended on the ecosystem profile of the infants. Authors conclude that specific randomised, controlled studies that focus on infants born by Caesarean section and how early nutrition can support the beneficial development of their microbiota are needed.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Infant gut colonisation differs in vaginal versus cesarean section deliveries and between breastfed and infant formula practices.
- Both enriched strain-specific probiotic and standard infant formula were shown to have a marked effect on microbiota colonisation in infants at age 4 months.
- By the age of 2 years, however, there is no significant difference between breastfed and formula fed infants.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This randomised controlled intervention study compared gut health parameters with the use of a synbiotic pre- and probiotic strain enriched infant formula with human milk and standard formula at three intervals over a period of 2 years.
Methods
This was a double-blinded controlled study of 540 infants from France and Belgium. Participants were randomly allocated to 2 formula groups (n = 230 Control Formula (CF), n = 230 Intervention Formula (IF)) and the breastfed reference group (n = 80) as well as delivery mode (Cesarean and vaginal delivery). The synbiotic IF was a standard infant formula enriched with prebiotic GOS (0.02 g/g) and the probiotic strain L. fermentum CECT5716 (at least 1.0 × 106 cfu/g).
Stool analysis was conducted at three time intervals, 4, 12, and 24 months (infant age). Biomarkers included short chain fatty acids, pH, secretory IgA, calprotectin, and various bacterial phyla via microbiota analysis.
Results
- At 4 months, the IF group tested higher for Bifidobacterium spp., and Lactobacillaceae and lower occurrence of Blautia spp., as well as Ruminoccocus gnavus and relatives compared to CF. They also had lower fecal pH and butyrate levels
- Both the formula cohorts had lower SigA and more basic pH values than the human milk cohort, as well as higher prevalence of anaerobes belonging to the bacterial genera Akkermansia, Collinsella, and Faecalibacterium.
- By age 24 months, the IF cohort exhibited increased levels of Akkermansia, Escherichia-Shigella, and R.gnavus. However there were no significant differences between the formula fed and human milk cohort at this time interval.
- The differences observed at 4 months disappeared over time, except for a significantly higher relative abundance of bifidobacteria and Faecalibacterium spp. in IF infants at 12 months compared with CF infants.
Conclusion:
Although prominent differences between the cohorts were observed at 4 months, it appears that by the age of 2 years, there is little observable difference. This is most likely due to gut ecosystem maturation. The paper draws attention to the fact that changes to microbiota following treatment were more pronounced in infants who tested lower in occurrences of Bacteroides spp at age 4 months. Of note is the prevalence of cesarean birth deliveries in this cohort thereby indicating potential improved alternative feeding options when breastfeeding is not possible for these infants.
Clinical practice applications:
- Probiotic L.fermentum and prebiotic galacto-oligosaccharide enriched infant formula appears to the improve infant microbiome, when compared to that of breastfed infants.
- The most receptive infants were those born via cesarean section.
Limitations to consider:
- The sample groups were from France and Belgium, with no indication as to culture, socio-economic, or sex distribution.
- The two infant formula groups were n=230 each with only 80 infants in the breastfed reference group.
- There was no indication of maternal diet practices pre-, during, and post- pregnancy.
- Stool samples were not collected from the infants at baseline visit prior to formula intervention.
Considerations for future research:
- Future studies need to include more diverse cultural and socio-economic cohorts to ascertain the potential influence of parental diet in baseline infant microbiome.
- It is imperative to establish what role solid food choices, generally introduced at 6 months, might have on gut ecosystem maturation.
- It would be useful to have a larger cesarean section birth cohort to compare to vaginal deliveries for more definitive results.
Abstract
BACKGROUND Microbial colonization of the gastrointestinal tract after birth is an essential event that influences infant health with life-long consequences. Therefore, it is important to investigate strategies to positively modulate colonization in early life. OBJECTIVES This randomized, controlled intervention study included 540 infants to investigate the effects of a synbiotic intervention formula (IF) containing Limosilactobacillus fermentum CECT5716 and galacto-oligosaccharides on the fecal microbiome. METHODS The fecal microbiota from infants was analyzed by 16S rRNA amplicon sequencing at 4, 12, and 24 months of age. Metabolites (e.g., short-chain fatty acids) and other milieu parameters (e.g., pH, humidity, and IgA) were also measured in stool samples. RESULTS Microbiota profiles changed with age, with major differences in diversity and composition. Significant effects of the synbiotic IF compared with control formula (CF) were visible at month 4, including higher occurrence of Bifidobacterium spp. and Lactobacillaceae and lower occurrence of Blautia spp., as well as Ruminoccocus gnavus and relatives. This was accompanied by lower fecal pH and concentrations of butyrate. After de novo clustering at 4 months of age, overall phylogenetic profiles of the infants receiving IF were closer to reference profiles of those fed with human milk than infants fed CF. The changes owing to IF were associated with fecal microbiota states characterized by lower occurrence of Bacteroides compared with higher levels of Firmicutes (valid name Bacillota), Proteobacteria (valid name Pseudomonadota), and Bifidobacterium at 4 months of age. These microbiota states were linked to higher prevalence of infants born by Cesarean section. CONCLUSIONS The synbiotic intervention influenced fecal microbiota and milieu parameters at an early age depending on the overall microbiota profiles of the infants, sharing a few similarities with breastfed infants. This trial was registered at clinicaltrials.gov as NCT02221687.
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The role of gut microbiome in inflammatory skin disorders: A systematic review.
Widhiati, S, Purnomosari, D, Wibawa, T, Soebono, H
Dermatology reports. 2022;14(1):9188
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Gut-skin axis refers to the complex cross-talk between gut bacteria and skin. Although the exact mechanism underlying chronic inflammatory skin conditions is unknown, imbalances in the composition of gut microbes are believed to play a role. Twenty-three studies were included in this systematic review to assess whether gut microbial imbalance may contribute to inflammatory skin conditions such as Psoriasis, Acne Vulgaris, Atopic Dermatitis, and Urticaria. According to this systematic review, immune stimulation, inflammation, and disruption of bacterial composition are common mechanisms in all these skin disorders. A western diet and environmental exposures are found to be contributing to the disruption of bacteria and the pathology of these skin disorders. It has been observed that friendly gut bacteria such as Bifidobacterium are reduced in people with inflammatory skin conditions, whereas elevated levels of pathogenic bacteria such as E. coli and Proteobacteria are present in the gut of patients with inflammatory skin conditions. The abundance of anti-inflammatory bacteria such as Akkermansia muciniphila, Faecalibacterium prausnitzii, Clostridium leptum, Lactobacillus, and Bifidobacterium may protect against inflammatory skin conditions. Further robust studies are required to evaluate the pathogenesis behind inflammatory skin conditions as well as the involvement of gut bacteria in the development and progression of the disease. Healthcare professionals can gain a deeper understanding of gut bacteria that contribute to the pathology of inflammatory diseases as well as how clinically using anti-inflammatory bacterial species may improve the condition of individuals suffering from inflammatory skin conditions.
Abstract
The close relationship between the intestine and the skin has been widely stated, seen from gastrointestinal (GI) disorders often accompanied by skin manifestations. Exactly how the gut microbiome is related to skin inflammation and influences the pathophysiology mechanism of skin disorders are still unclear. Many studies have shown a two-way relationship between gut and skin associated with GI health and skin homeostasis and allostasis. This systematic review aimed to explore the associations between the gut microbiome with inflammatory skin disorders, such as acne, psoriasis, atopic dermatitis, and urticaria, and to discover the advanced concept of this relationship. The literature search was limited to any articles published up to December 2020 using PubMed and EBSCOHost. The review followed the PRISMA guidelines for conducting a systematic review. Of the 319 articles screened based on title and abstract, 111 articles underwent full-text screening. Of these, 23 articles met our inclusion criteria, comprising 13 atopic dermatitis (AD), three psoriasis, four acne vulgaris, and four chronic urticaria articles. Acne vulgaris, atopic dermatitis, psoriasis, and chronic urticaria are inflammation skin disorders that were studied recently to ascertain the relationship of these disorders with dysbiosis of the GI microbiome. All acne vulgaris, psoriasis, and chronic urticaria studies stated the association of gut microbiome with skin manifestations. However, the results in atopic dermatitis are still conflicting. Most of the articles agree that Bifidobacterium plays an essential role as anti-inflammation bacteria, and Proteobacteria and Enterobacteria impact inflammation in inflammatory skin disorders.
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Dynamics of gut microbiota during pregnancy in women with TPOAb-positive subclinical hypothyroidism: a prospective cohort study.
Wu, M, Chi, C, Yang, Y, Guo, S, Li, T, Gu, M, Zhang, T, Gao, H, Liu, R, Yin, C
BMC pregnancy and childbirth. 2022;22(1):592
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Subclinical hypothyroidism (SCH) in pregnancy refers to the elevation of thyroid stimulating hormone level with normal free T4 level. One third of women with SCH have been reported to test positive for anti-thyroid peroxidase antibody (TPOAb+). The aim of this study was to evaluate whether gut microbiota can be potential therapeutic targets for managing TPOAb+ SCH. This study was a nested, prospective observational cohort study. A total of 64 and 68 pregnant women with TPOAb+ and TPOAb negative SCH, respectively, were included in this study. Results showed that women who were diagnosed with TPOAb+ SCH in trimester (T)1 show distinct dynamics of gut microbiota from T2 to T3. Furthermore, changes in the abundances of three types of bacterial species were abnormal in the presence of levothyroxine treatment. Authors conclude that gut microbiota can serve as potential therapeutic targets for TPOAb+ SCH during pregnancy.
Abstract
BACKGROUND Anti-thyroid peroxidase antibody (TPOAb) positivity can contribute to inhibit thyroxine synthesis. Gut microbiota can interact with metabolic or immune diseases. However, dynamics of gut microbiota from the second (T2) to the third trimester (T3) in women with TPOAb-positive/negative subclinical hypothyroidism (TPOAb+/TPOAb- SCH) have not been reported. Therefore, we aimed to evaluate whether gut microbiota can be potential therapeutic targets for managing TPOAb+ SCH. METHODS In this single-center prospective cohort study, we observed gut microbiota dynamics by sequencing 16S rRNA from fecal samples collected in T2 (20-23+ 6 weeks) and T3 (28-33+ 6 weeks). TPOAb+/TPOAb- SCH were stratified depending on whether or not they used levothyroxine (LT4) during the pregnancy (LT4+/LT4-). Microbiome bioinformatics analyses were performed using QIIME2. The linear discriminant analysis effect size (LEfSe) was used for the quantitative analysis of biomarkers. Functional profiling was performed with PICRUSt2. RESULTS Distinct gut microbiota dynamics from T2 to T3 were noted in the TPOAb- (n = 68) and TPOAb+ (n = 64) SCH groups. The TPOAb+ LT4- group was characterized by enriched bacterial amplicon sequence variants (ASVs) of Prevotella in T2 and Bacteria, Lachnospirales, Lachnospiraceae, Blautia, and Agathobacter in T3 and by depleted ASVs of Gammaproteobacteria, Enterobacterales, and Enterobacteriaceae in T2 and Actinobacteriota, Coriobacteriia, Actinobacteria, Coriobacteriales, Bifidobacteriales, Bifidobacteriaceae, Bifidobacterium, Dorea formicigenerans, and Bifidobacterium longum in T3. The TPOAb+ LT4+ group was characterized by enriched bacterial ASVs of Blautia, Streptococcus salivarius, and Bifidobacterium longum in T3 and by depleted ASVs of Bacteroidota, Bacteroidia, Bacteroidales, and Prevotella in T2 and Agathobacter in T3. Moreover, we identified 53 kinds of metabolic functions that were mainly involved in sugar, lipid, and amino acid metabolism. CONCLUSIONS Our results indicated that low dynamics of gut microbiota composition and high dynamics of its metabolic function from T2 to T3 were associated with TPOAb+ SCH. We concluded that gut microbiota could be new targets for treatment of TPOAb+ SCH during pregnancy. TRIAL REGISTRATION This study was retrospectively registered at the Chinese Clinical Trial Registry (registration number ChiCTR2100047175 ) on June 10, 2021.
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Gut Microbiota-Derived Metabolites and Cardiovascular Disease Risk: A Systematic Review of Prospective Cohort Studies.
Sanchez-Gimenez, R, Ahmed-Khodja, W, Molina, Y, Peiró, OM, Bonet, G, Carrasquer, A, Fragkiadakis, GA, Bulló, M, Bardaji, A, Papandreou, C
Nutrients. 2022;14(13)
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Cardiovascular disease (CVD) remains a major public health issue. Identification of circulating biomarkers with prognostic value may help to both identify pathophysiological processes relevant to CVD development and improve preventive cardiovascular risk reduction efforts. The aim of this study was to identify the association of circulating levels of microbial metabolites with CVD incidence. This study is a systematic review of twenty-one studies of which 19 were prospective cohort studies, one study included one nested case-control study and one study included two nested case–control studies. Results show that: - associations of trimethylamine N-oxide (TMAO) [molecular metabolite derived from the gut flora] and subsequent risk of CV outcomes were supported by some but not all prospective studies. - inconsistent results were also obtained for secondary bile acids in relation to CVD and related outcomes, and CVD/all-cause mortality. - with regards to branched-chain amino acids (BCAAs), their associations with CV outcomes were robust amongst most of the studies. Authors conclude that their findings show inconsistent results for TMAO and bile acids but robust ones for the relationships between BCAAs and CVD. Thus, further studies are needed to investigate whether circulating microbial metabolites could be an intervention target for CVD.
Abstract
Gut microbiota-derived metabolites have recently attracted considerable attention due to their role in host-microbial crosstalk and their link with cardiovascular health. The MEDLINE-PubMed and Elsevier's Scopus databases were searched up to June 2022 for studies evaluating the association of baseline circulating levels of trimethylamine N-oxide (TMAO), secondary bile acids, short-chain fatty acids (SCFAs), branched-chain amino acids (BCAAs), tryptophan and indole derivatives, with risk of cardiovascular disease (CVD). A total of twenty-one studies were included in the systematic review after evaluating 1210 non-duplicate records. There were nineteen of the twenty-one studies that were cohort studies and two studies had a nested case-control design. All of the included studies were of high quality according to the "Newcastle-Ottawa Scale". TMAO was positively associated with adverse cardiovascular events and CVD/all-cause mortality in some, but not all of the included studies. Bile acids were associated with atrial fibrillation and CVD/all-cause mortality, but not with CVD. Positive associations were found between BCAAs and CVD, and between indole derivatives and major adverse cardiovascular events, while a negative association was reported between tryptophan and all-cause mortality. No studies examining the relationship between SCFAs and CVD risk were identified. Evidence from prospective studies included in the systematic review supports a role of microbial metabolites in CVD.
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The Role of Lung and Gut Microbiota in the Pathology of Asthma.
Barcik, W, Boutin, RCT, Sokolowska, M, Finlay, BB
Immunity. 2020;52(2):241-255
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Over 300 million people suffer with asthma worldwide and it has emerged that microbiome analysis of the lung and gut bacteria, fungi, viruses, and archaea may help with disease management. This microbiome plays an important role in immune response. Disturbances to these microbes, known as dysbiosis, may influence onset of disease and the body’s ability to respond naturally, and/or to pharmaceutical treatments. Asthma is not a singular disease and there are great variations in symptom severity and underlying immune mechanisms. Patients are typically classified as type 2 or non-type 2. Type 2 patients tend to be allergic to common air-born allergens which can trigger an attack. Treatment usually consists of glucocorticosteroids or novel biologicals. Non type-2 asthma is associated with obesity-related asthma and typically responds poorly to steroid treatment. For a long time, researchers believed the human lungs to be sterile, so they were initially not included in the 2007 Human Microbiome Project. It has since been shown that, like the gut, the lungs and respiratory tract also host various microbes, and this healthy-airway microbiota influence innate and adaptive immune processes. The Gut-Lung axis also confers additional microbial benefits from the intestines. In asthma patients, there is often an over-dominance of pathogenic bacteria. Fungal dysbiosis is associated with high-risk asthma phenotypes in childhood. Viral infections have been shown as a primary cause of asthmatic episodes. Future diagnosis and treatment of patients with asthma should be assisted by analysis of the composition and metabolic activity of an individual’s microbiome.
Abstract
Asthma is a common chronic respiratory disease affecting more than 300 million people worldwide. Clinical features of asthma and its immunological and molecular etiology vary significantly among patients. An understanding of the complexities of asthma has evolved to the point where precision medicine approaches, including microbiome analysis, are being increasingly recognized as an important part of disease management. Lung and gut microbiota play several important roles in the development, regulation, and maintenance of healthy immune responses. Dysbiosis and subsequent dysregulation of microbiota-related immunological processes affect the onset of the disease, its clinical characteristics, and responses to treatment. Bacteria and viruses are the most extensively studied microorganisms relating to asthma pathogenesis, but other microbes, including fungi and even archaea, can potently influence airway inflammation. This review focuses on recently discovered connections between lung and gut microbiota, including bacteria, fungi, viruses, and archaea, and their influence on asthma.
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Serological investigation of IgG and IgE antibodies against food antigens in patients with inflammatory bowel disease.
Wang, HY, Li, Y, Li, JJ, Jiao, CH, Zhao, XJ, Li, XT, Lu, MJ, Mao, XQ, Zhang, HJ
World journal of clinical cases. 2019;7(16):2189-2203
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Crohn's disease and ulcerative colitis are relapsing gut inflammatory diseases that are usually referred to as Inflammatory Bowel Disease (IBD). It may be triggered by an imbalance in immune response in response to environmental factors such as diet. The aim of this retrospective study was to evaluate the presence of IgG and IgE mediated antibodies to food antigens in IBD patients. There were one hundred and thirty-seven IBD patients participating in this study, including forty Ulcerative colitis patients and ninety-seven Crohn's disease patients against fifty healthy controls to test serum IgG antibodies to fourteen specific food antigens and serum IgE antibodies to fourteen specific food antigens. There were significantly higher IgG antibodies in response to food antigens in Crohn's disease patients than in Ulcerative colitis patients and healthy controls. Food antigens such as tomato, corn, egg, rice, and soybean exhibited varying levels of IgG antibody responses in Crohn's disease patients and ulcerative colitis patients. Smokers were more likely to develop IgG reactions. Further robust research is needed to examine more IgG-specific food antigens to help manage IBD with an elimination rotation diet. The results of this study can help healthcare professionals understand the importance of diagnosing food intolerances when treating IBD.
Abstract
BACKGROUND Food antigens have been shown to participate in the etiopathogenesis of inflammatory bowel disease (IBD), but their clinical value in IBD is still unclear. AIM: To analyze the levels of specific immunoglobulin G (IgG) and E (IgE) antibodies against food antigens in IBD patients and to determine their clinical value in the pathogenesis of IBD. METHODS We performed a retrospective study based on patients who visited the First Affiliated Hospital of Nanjing Medical University between August 2016 and January 2018. A total of 137 IBD patients, including 40 patients with ulcerative colitis (UC) and 97 patients with Crohn's disease (CD), and 50 healthy controls (HCs), were recruited. Serum food-specific IgG antibodies were detected by semi-quantitative enzyme-linked immunosorbent assay, and serum food-specific IgE antibodies were measured by Western blot. The value of food-specific IgG antibodies was compared among different groups, and potent factors related to these antibodies were explored by binary logistic regression. RESULTS Food-specific IgG antibodies were detected in 57.5% of UC patients, in 90.72% of CD patients and in 42% of HCs. A significantly high prevalence and titer of food-specific IgG antibodies were observed in CD patients compared to UC patients and HCs. The number of IgG-positive foods was greater in CD and UC patients than in HCs (CD vs HCs, P = 0.000; UC vs HCs, P = 0.029). The top five food antigens that caused positive specific IgG antibodies in CD patients were tomato (80.68%), corn (69.32%), egg (63.64%), rice (61.36%), and soybean (46.59%). The foods that caused positive specific IgG antibodies in UC patients were egg (60.87%), corn (47.83%), tomato (47.83%), rice (26.09%), and soybean (21.74%). Significantly higher levels of total food-specific IgG were detected in IBD patients treated with anti-TNFα therapy compared to patients receiving steroids and immunosuppressants (anti-TNFα vs steroids, P = 0.000; anti-TNFα vs immunosuppressants, P = 0.000; anti-TNFα vs steroids + immunosuppressants, P = 0.003). A decrease in food-specific IgG levels was detected in IBD patients after receiving anti-TNFα therapy (P = 0.007). Patients who smoked and CD patients were prone to developing serum food-specific IgG antibodies [Smoke: OR (95%CI): 17.6 (1.91-162.26), P = 0.011; CD patients: OR (95%CI): 12.48 (3.45-45.09), P = 0.000]. There was no difference in the prevalence of food-specific IgE antibodies among CD patients (57.1%), UC patients (65.2%) and HCs (60%) (P = 0.831). CONCLUSION CD patients have a higher prevalence of food-specific IgG antibodies than UC patients and HCs. IBD patients are prone to rice, corn, tomato and soybean intolerance. Smoking may be a risk factor in the occurrence of food-specific IgG antibodies. Food-specific IgG antibodies may be a potential method in the diagnosis and management of food intolerance in IBD.
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The microbiome and autoimmunity: a paradigm from the gut-liver axis.
Li, B, Selmi, C, Tang, R, Gershwin, ME, Ma, X
Cellular & molecular immunology. 2018;15(6):595-609
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The incidence of autoimmune and inflammatory diseases has been increasing worldwide. Changes in environmental factors, such as modern lifestyle, diet, antibiotics and hygiene are thought to play a critical role in the development of various autoimmune diseases. It is the mucosal microbial flora that is shaped by our environment and communicates with the innate and adaptive immune systems, and when disrupted, can lead to the loss of immune tolerance and dysregulated immune cells. This review paper provides an overview of the interactions between the intestinal microbiome and the immune system. It explains how these interactions affect host autoimmunity locally and systemically and sheds light on the molecular mechanisms, utilised by microbes that may contribute to systemic autoimmunity in genetically susceptible individuals. The links between the gut microbiome and various autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes and multiple sclerosis, as well as the gut-liver axis, involving intestinal microbiome and autoimmune liver diseases, are discussed in more detail.
Abstract
Microbial cells significantly outnumber human cells in the body, and the microbial flora at mucosal sites are shaped by environmental factors and, less intuitively, act on host immune responses, as demonstrated by experimental data in germ-free and gnotobiotic studies. Our understanding of this link stems from the established connection between infectious bacteria and immune tolerance breakdown, as observed in rheumatic fever triggered by Streptococci via molecular mimicry, epitope spread and bystander effects. The availability of high-throughput techniques has significantly advanced our capacity to sequence the microbiome and demonstrated variable degrees of dysbiosis in numerous autoimmune diseases, including rheumatoid arthritis, type 1 diabetes, multiple sclerosis and autoimmune liver disease. It remains unknown whether the observed differences are related to the disease pathogenesis or follow the therapeutic and inflammatory changes and are thus mere epiphenomena. In fact, there are only limited data on the molecular mechanisms linking the microbiota to autoimmunity, and microbial therapeutics is being investigated to prevent or halt autoimmune diseases. As a putative mechanism, it is of particular interest that the apoptosis of intestinal epithelial cells in response to microbial stimuli enables the presentation of self-antigens, giving rise to the differentiation of autoreactive Th17 cells and other T helper cells. This comprehensive review will illustrate the data demonstrating the crosstalk between intestinal microbiome and host innate and adaptive immunity, with an emphasis on how dysbiosis may influence systemic autoimmunity. In particular, a gut-liver axis involving the intestinal microbiome and hepatic autoimmunity is elucidated as a paradigm, considering its anatomic and physiological connections.
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Functional interactions between the gut microbiota and host metabolism.
Tremaroli, V, Bäckhed, F
Nature. 2012;489(7415):242-9
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This literature review aims to discuss evidence for the role of the gut microbiota in metabolism and possible links to obesity. Obesity and caloric intake can influence the microbiota, but whether the reverse is true in humans remains unclear. Much of the mechanisms have been determined in rodents, determining similar pathways in humans is difficult. The interplay of diet, host and gut microbiota may cause increased gut permeability (leaky gut) that could lead to an increase in inflammation that may cause obesity, fatty liver disease and insulin resistance. It is increasingly accepted that gut microbiota can contribute to diseases such as obesity, diabetes and cardiovascular disease, but exactly how and by how much remains unclear. Evidence for treating the microbiota to help with these metabolic diseases, either by pre- or probiotic supplementation, is building. However, double-blind, placebo-controlled studies are required to determine effects. The influence of the gut microbiota is a promising area, but one that needs further research.
Abstract
The link between the microbes in the human gut and the development of obesity, cardiovascular disease and metabolic syndromes, such as type 2 diabetes, is becoming clearer. However, because of the complexity of the microbial community, the functional connections are less well understood. Studies in both mice and humans are helping to show what effect the gut microbiota has on host metabolism by improving energy yield from food and modulating dietary or the host-derived compounds that alter host metabolic pathways. Through increased knowledge of the mechanisms involved in the interactions between the microbiota and its host, we will be in a better position to develop treatments for metabolic disease.