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Comparison of gut microbiota profile in celiac disease, non-celiac gluten sensitivity and irritable bowel syndrome: A systematic review.
Transeth, EL, Dale, HF, Lied, GA
The Turkish journal of gastroenterology : the official journal of Turkish Society of Gastroenterology. 2020;31(11):735-745
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Dysbiosis refers to a disturbance in the quantity and composition of the gut microbiota, and this shift in the microbiota profile is associated with a variety of GI disorders including celiac disease (CD), irritable bowel syndrome (IBS) and non-celiac gluten sensitivity (NCGS). There is no current clinical distinction between IBS and NCGS although it is hypothesised the characteristics of gut microbiota of these clinical presentations may overlap. The aim of this review is to analyse the gut microbiota profile in these three diagnoses. Thirteen trials were included in this review and show the bacterial composition of the gut microbiota of patients with CD and IBS shared many similarities when compared to healthy controls, including an overall reduction in microbial abundance. There were fewer similarities between IBS and NCGS, in part due to the lack of existing literature. Based on these findings, the authors suggest the bacterial profiles of patients CD and IBS share certain disease-specific trends. While the current data is limited, the authors hope these suggested trends influence further research to examine the overlap between NCGS and IBS and distinguish differential diagnostic and treatment plans.
Abstract
Gut microbiota is vital for human health. Shifts in the microbial diversity can affect bacterial function, and dysbiosis is associated with a variety of gastrointestinal disorders, including celiac disease (CD) and irritable bowel syndrome (IBS). The distinction between IBS and non-celiac gluten sensitivity (NCGS) is unclear, and it is conceivable that the gut microbiota profile of these patients may overlap. To our knowledge, no existing literature has evaluated the microbial characteristics in CD, IBS, and NCGS. Hence, this systematic review aims to compare the gut microbiota profile in these three diagnoses. A literature search was conducted in PubMed (Medline) until April 2019. Studies investigating bacterial diversity in the gut of patients with CD, IBS, and NCGS were eligible. Inclusion criteria were observational studies and randomized controlled trials reporting bacterial profile at baseline. Ninety-one articles were identified, of which 13 trials were eligible for inclusion. Overall, the bacterial composition of the gut microbiota of patients with CD and those with IBS shared the many similarities. The microbial richness was correspondingly reduced in these patient-groups compared with healthy controls, but this was not reported for NCGS. Our findings suggest that the bacterial profiles of patients with IBS and CD share certain disease-specific trends. Fewer similarities were observed between the bacterial profiles of patients with IBS and NCGS. Notably, the data are limited; thus, no solid conclusions can be made on the basis of these findings alone. The suggested trends can be a valuable basis for further research.
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Substituting whole grains for refined grains in a 6-wk randomized trial has a modest effect on gut microbiota and immune and inflammatory markers of healthy adults.
Vanegas, SM, Meydani, M, Barnett, JB, Goldin, B, Kane, A, Rasmussen, H, Brown, C, Vangay, P, Knights, D, Jonnalagadda, S, et al
The American journal of clinical nutrition. 2017;105(3):635-650
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Increased whole grain consumption has been associated with reduced levels of inflammation. This randomised, controlled trial aimed to assess the effects of a whole grain diet in comparison with a refined grain diet on the immune system, levels of inflammation and gut bacteria. 81 men and women aged between 40 and 60 were randomly assigned to either a whole grain or a refined grain diet for a period of 6 weeks. All other dietary components were kept the same and calorie levels were controlled to maintain weight levels. The study findings showed a positive effect on stool frequency and stool weight with the whole grain diet in comparison to the refined grain diet. The whole grain diet also showed modest positive effects on gut bacteria profiles and aspects of immunity. The whole grain diet showed no effects on markers of inflammation.
Abstract
Background: Observational studies suggest an inverse association between whole-grain (WG) consumption and inflammation. However, evidence from interventional studies is limited, and few studies have included measurements of cell-mediated immunity.Objective: We assessed the effects of diets rich in WGs compared with refined grains (RGs) on immune and inflammatory responses, gut microbiota, and microbial products in healthy adults while maintaining subject body weights.Design: After a 2-wk provided-food run-in period of consuming a Western-style diet, 49 men and 32 postmenopausal women [age range: 40-65 y, body mass index (in kg/m2) <35] were assigned to consume 1 of 2 provided-food weight-maintenance diets for 6 wk.Results: Compared with the RG group, the WG group had increased plasma total alkyresorcinols (a measure of WG intake) (P < 0.0001), stool weight (P < 0.0001), stool frequency (P = 0.02), and short-chain fatty acid (SCFA) producer Lachnospira [false-discovery rate (FDR)-corrected P = 0.25] but decreased pro-inflammatory Enterobacteriaceae (FDR-corrected P = 0.25). Changes in stool acetate (P = 0.02) and total SCFAs (P = 0.05) were higher in the WG group than in the RG group. A positive association was shown between Lachnospira and acetate (FDR-corrected P = 0.002) or butyrate (FDR-corrected P = 0.005). We also showed that there was a higher percentage of terminal effector memory T cells (P = 0.03) and LPS-stimulated ex vivo production of tumor necrosis factor-α (P = 0.04) in the WG group than in the RG group, which were positively associated with plasma alkylresorcinol concentrations.Conclusion: The short-term consumption of WGs in a weight-maintenance diet increases stool weight and frequency and has modest positive effects on gut microbiota, SCFAs, effector memory T cells, and the acute innate immune response and no effect on other markers of cell-mediated immunity or systemic and gut inflammation. This trial was registered at clinicaltrials.gov as NCT01902394.
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Comparison of Oropharyngeal Microbiota from Children with Asthma and Cystic Fibrosis.
Boutin, S, Depner, M, Stahl, M, Graeber, SY, Dittrich, SA, Legatzki, A, von Mutius, E, Mall, M, Dalpke, AH
Mediators of inflammation. 2017;2017:5047403
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The lungs are under constant exposure to microorganisms contained in inhaled air and the upper respiratory tract. In healthy subjects, the lower airways are colonized by bacteria. Changes in the microbiome are found in several lung diseases associated with chronic airway inflammation including chronic obstructive pulmonary disease, asthma and cystic fibrosis. The aim of the study was to find out whether the throat microbiota of children with asthma and cystic fibrosis differ from healthy children. Another aim was to find out whether the throat microbiota of children with asthma differ from those with cystic fibrosis. The study compared the throat microbiota of healthy school-aged children with that of age-matched children with asthma and cystic fibrosis. Results indicate that the microbiota of cystic fibrosis, asthmatic, and healthy children show high levels of similarities with a strong core microbiota. The cystic fibrosis group show a decrease in both diversity and total bacterial load in the throat in comparison to asthmatic and control children. The cystic fibrosis group also showed a significant increase in typical pathogens in the throat. Based on the results, the authors conclude that the three patient groups had a core microbiome and a host regulation that favours the growth of commensals.
Abstract
A genuine microbiota resides in the lungs which emanates from the colonization by the oropharyngeal microbiota. Changes in the oropharyngeal microbiota might be the source of dysbiosis observed in the lower airways in patients suffering from asthma or cystic fibrosis (CF). To examine this hypothesis, we compared the throat microbiota from healthy children (n = 62) and that from children with asthma (n = 27) and CF (n = 57) aged 6 to 12 years using 16S rRNA amplicon sequencing. Our results show high levels of similarities between healthy controls and children with asthma and CF revealing the existence of a core microbiome represented by Prevotella, Streptococcus, Neisseria, Veillonella, and Haemophilus. However, in CF, the global diversity, the bacterial load, and abundances of 53 OTUs were significantly reduced, whereas abundances of 6 OTUs representing opportunistic pathogens such as Pseudomonas, Staphylococcus, and Streptococcus were increased compared to those in healthy controls controls and asthmatics. Our data reveal a core microbiome in the throat of healthy children that persists in asthma and CF indicating shared host regulation favoring growth of commensals. Furthermore, we provide evidence for dysbiosis with a decrease in diversity and biomass associated with the presence of known pathogens consistent with impaired host defense in children with CF.
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Integrated Evaluation of the Potential Health Benefits of Einkorn-Based Breads.
Antognoni, F, Mandrioli, R, Bordoni, A, Di Nunzio, M, Viadel, B, Gallego, E, Villalba, MP, Tomás-Cobos, L, Taneyo Saa, DL, Gianotti, A
Nutrients. 2017;9(11)
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While health benefits of whole grains has been long established, recent findings suggest ancient grains may provide additional cardiovascular and anti-inflammatory benefits. Einkorn is an ancient crop that has a favourable biochemical makeup however very little research exists on its properties. The aim of this study was to evaluate the nutritional characteristics and health benefits of eikorn-based bread compared to wheat-based breads. Both types of grains were subject to either conventional fermentation with baker’s yeast or sourdough fermentation with lactic acid. Breads were digested in-vitro using the Dynamic Gastrointestinal Digestor, a controlled system that simulates the in vivo digestion process. Bread content was characterised before and after digestion, and the product of their digestion was used to evaluate anti-inflammatory effects. The primary finding of this study was a significantly higher carotenoid level in einkorn compared to modern wheat. Additionally, the use of sourdough fermentation aided to preserve these carotenoids, thus improving the availability and accessibility of nutrient absorption in the final product. Based on this study, the authors conclude einkorn is a good candidate to produce bakery products with enhanced nutritional properties.
Abstract
Nowadays the high nutritional value of whole grains is recognized, and there is an increasing interest in the ancient varieties for producing wholegrain food products with enhanced nutritional characteristics. Among ancient crops, einkorn could represent a valid alternative. In this work, einkorn flours were analyzed for their content in carotenoids and in free and bound phenolic acids, and compared to wheat flours. The most promising flours were used to produce conventional and sourdough fermented breads. Breads were in vitro digested, and characterized before and after digestion. The four breads having the best characteristics were selected, and the product of their digestion was used to evaluate their anti-inflammatory effect using Caco-2 cells. Our results confirm the higher carotenoid levels in einkorn than in modern wheats, and the effectiveness of sourdough fermentation in maintaining these levels, despite the longer exposure to atmospheric oxygen. Moreover, in cultured cells einkorn bread evidenced an anti-inflammatory effect, although masked by the effect of digestive fluid. This study represents the first integrated evaluation of the potential health benefit of einkorn-based bakery products compared to wheat-based ones, and contributes to our knowledge of ancient grains.
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Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows' milk.
Jianqin, S, Leiming, X, Lu, X, Yelland, GW, Ni, J, Clarke, AJ
Nutrition journal. 2016;15:35
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Cows’ milk contains two types of beta-casein, A1 and A2, and the A1 type is thought to cause the adverse gastrointestinal side effects related to lactose intolerance. The aim of this crossover study was to compare the effects of milk consumption with differing beta-casein types in subjects with self-reported lactose intolerance. Forty-five participants were randomised to receive milk containing either both types of casein or only the A2 type, and inflammatory markers, symptoms of digestive discomfort and cognitive processing were assessed. This study demonstrated that consumption of milk containing A1 beta-casein was associated with increased inflammation, worsening of digestive discomfort, delayed transit and decreased cognitive functioning. The findings of this study suggest that some symptoms of lactose intolerance may be attenuated by consuming milk containing only the A2 type of beta-casein.
Abstract
BACKGROUND Cows' milk generally contains two types of β-casein, A1 and A2 types. Digestion of A1 type can yield the peptide β-casomorphin-7, which is implicated in adverse gastrointestinal effects of milk consumption, some of which resemble those in lactose intolerance. This study aimed to compare the effects of milk containing A1 β-casein with those of milk containing only A2 β-casein on inflammation, symptoms of post-dairy digestive discomfort (PD3), and cognitive processing in subjects with self-reported lactose intolerance. METHODS Forty-five Han Chinese subjects participated in this double-blind, randomized, 2 × 2 crossover trial and consumed milk containing both β-casein types or milk containing only A2 β-casein. Each treatment period was 14 days with a 14-day washout period at baseline and between treatment periods. Outcomes included PD3, gastrointestinal function (measured by smart pill), Subtle Cognitive Impairment Test (SCIT), serum/fecal laboratory biomarkers, and adverse events. RESULTS Compared with milk containing only A2 β-casein, the consumption of milk containing both β-casein types was associated with significantly greater PD3 symptoms; higher concentrations of inflammation-related biomarkers and β-casomorphin-7; longer gastrointestinal transit times and lower levels of short-chain fatty acids; and increased response time and error rate on the SCIT. Consumption of milk containing both β-casein types was associated with worsening of PD3 symptoms relative to baseline in lactose tolerant and lactose intolerant subjects. Consumption of milk containing only A2 β-casein did not aggravate PD3 symptoms relative to baseline (i.e., after washout of dairy products) in lactose tolerant and intolerant subjects. CONCLUSIONS Consumption of milk containing A1 β-casein was associated with increased gastrointestinal inflammation, worsening of PD3 symptoms, delayed transit, and decreased cognitive processing speed and accuracy. Because elimination of A1 β-casein attenuated these effects, some symptoms of lactose intolerance may stem from inflammation it triggers, and can be avoided by consuming milk containing only the A2 type of beta casein. TRIAL REGISTRATION ClinicalTrials.gov/NCT02406469.
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Synbiotic therapy decreases microbial translocation and inflammation and improves immunological status in HIV-infected patients: a double-blind randomized controlled pilot trial.
González-Hernández, LA, Jave-Suarez, LF, Fafutis-Morris, M, Montes-Salcedo, KE, Valle-Gutierrez, LG, Campos-Loza, AE, Enciso-Gómez, LF, Andrade-Villanueva, JF
Nutrition journal. 2012;11:90
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HIV causes gastrointestinal dysfunction and microbial translocation that can provoke local and systemic inflammation that may lead to disease progression. Inflammation and intestinal permeability increase and the reduction in immune defences creates the opportunity for microbial overgrowth and raised lipopolysaccharides levels, which may lead to disease progression. HIV-infected patients also tend to have low levels of beneficial bacteria. Probiotics have the potential to stimulate the immune system through IgA secretion and reduce inflammation. Prebiotics selectively stimulate the growth of some bacteria, altering the composition and metabolic activity of gut microbiota. This randomized, prospective, double-blind controlled pilot study evaluates use of probiotics and prebiotic to expand beneficial microbiota that help decrease bacterial translocation and pro-inflammatory cytokine production, thereby improving immune functions in HIV-infected subjects. 20 HIV-infected adult patients were divided into four groups (n=5 per group) to receive probiotics, synbiotic, a prebiotic, or placebo once daily for 16 weeks. Probiotics used were Lactobacillus rhamnosus plus Bifidobacterium lactis. From baseline to week 16, the synbiotic group showed a reduction in bacterial DNA concentrations in plasma. The probiotic and synbiotic groups demonstrated a decrease in total bacterial load in feces. The probiotic group showed a significant increase in beneficial bacteria load (such as Bifidobacterium and a decrease in harmful bacteria load (such as Clostridium). The synbiotic group had greater increases in CD4+ T-cell count and cytokine levels (IL-6) decreased significantly. Serious adverse effects previously reported with the use of probiotics in immunocompromised patients were not reported in this study. The authors found no decrease in HIV-1 plasma viral load so the use of a synbiotic for maintaining an undetectable viral load as part of the primary prevention of HIV transmission is not justified.
Abstract
BACKGROUND HIV-infection results in damage and dysfunction of the gastrointestinal system. HIV enteropathy includes pronounced CD4+ T-cell loss, increased intestinal permeability, and microbial translocation that promotes systemic immune activation, which is implicated in disease progression. A synbiotic is the combination of probiotics and prebiotics that could improve gut barrier function. Our study goal was to determine whether the use of a synbiotic, probiotics or a prebiotic can recover immunological parameters in HIV-infected subjects through of a reduction of microbial translocation and pro-inflammatory cytokine production. METHODS A randomized, double-blind controlled study was performed; twenty Antiretroviral treatment-naïve HIV-infected subjects were subgrouped and assigned to receive a synbiotic, probiotics, a prebiotic, or a placebo throughout 16 weeks. RESULTS We had no reports of serious adverse-events. From baseline to week 16, the synbiotic group showed a reduction in bacterial DNA concentrations in plasma (p = 0.048). Moreover, the probiotic and synbiotic groups demonstrated a decrease in total bacterial load in feces (p = 0.05). The probiotic group exhibited a significant increment of beneficial bacteria load (such as Bifidobacterium; p = 0.05) and a decrease in harmful bacteria load (such as Clostridium; p = 0.063). In the synbiotic group, the CD4+ T-cells count increased (median: +102 cells/μL; p = 0.05) and the level of Interleukin 6 cytokine decreased significantly (p = 0.016). CONCLUSIONS Our study showed a significant increase in CD4+ T lymphocyte levels in the synbiotic group, which could delay the initiation of antiretroviral therapy and decrease costs in countries with limited resources.