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The Effects of Black Tea Consumption on Intestinal Microflora-A Randomized Single-Blind Parallel-Group, Placebo-Controlled Study.
Tomioka, R, Tanaka, Y, Suzuki, M, Ebihara, S
Journal of nutritional science and vitaminology. 2023;69(5):326-339
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Tea from the leaves of the tea plant (Camelia sinensis) is consumed around the world. Tea has many health benefits, and in part, this is due to its rich content in compounds classed as polyphenols. Through the fermentation process, black tea is particularly high in polyphenols. Previous studies around respiratory infections indicated that regular consumption of black tea appeared to improve immune defence mechanisms that protect mucous membranes, called mucosal immunity. As this mucosal immunity is closely influenced by gut bacteria, the authors speculated whether the previously seen impact of improved mucosal immunity is related to the ability of black tea to also modulate bacteria in the gut. A previously run randomised single-blinded, placebo-controlled trial with 72 Japanese participants who consumed three cups of black tea (2g) or a placebo of barley tea for 12 weeks provided the data for this study. Data gathered included gut flora analysis, short-chain fatty acids (SCFAs) levels - fats that play a role in maintaining gut health, and saliva IgA (SIgA) concentrations - which are antibodies made in the lymph tissue of the gut. The results showed that black tea consumption led to a significant increase in the abundance of Prevotella bacteria, which mediate SCFA production and are involved in normalising immune function. Furthermore, tea increased butyrate-producing bacteria. Butyrate is associated with improved barrier function of the gut walls but also helps to manage pathogens and immune responses. Black tea consumption also increased salivary SIgA concentration - a type of antibody on the mucous membranes that prevents pathogens from entering the body -, and a decrease in stool acetic acid concentration, which may be due to the increase in butyrate-producing bacteria which use acetic acid to make butyrate. Notably, participants with low salivary SIgA levels at the start had a more pronounced positive change in total bacteria, after consuming black tea compared to the placebo group. The authors concluded that regular consumption of black tea may help to improve mucosal immunity by increasing the abundance of beneficial bacteria in the gut.
Abstract
We previously reported that black tea consumption for 12 wk reduced the risk of acute upper respiratory tract inflammation, and improved secretory capacity in individuals with low salivary SIgA levels (Tanaka Y et al. 2021. Jpn Pharmacol Ther 49: 273-288). These results suggested that habitual black tea consumption improves mucosal immunity. Therefore, in this study we evaluated the effect of black tea intake on gut microbiota, which is known to be involved in mucosal immunity, by analyzing the bacterial flora and the short-chain fatty acids (SCFAs) concentration of feces collected during the above clinical study. The clinical design was a randomized, single-blind, parallel-group, placebo-controlled study with 72 healthy Japanese adult males and females, who consumed three cups of black tea (Black Tea Polymerized Polyphenols 76.2 mg per day) or placebo per day for 12 wk. In all subjects intake of black tea significantly increased abundance of Prevotella and decreased fecal acetic acid concentration. Particularly in the subjects with low salivary SIgA levels, the change over time of total bacteria, Prevotella, and butyrate-producing bacteria, which are involved in normalizing immune function, were higher in the black tea group than in the placebo group. In subjects with low abundance of Flavonifractor plautii a butyrate-producing bacteria, black tea consumption significantly increased salivary SIgA concentration and the absolute number of Flavonifractor plautii. In conclusion, our results suggest that improvement of mucosal immunity via an increase in butyrate-producing bacteria in the gut may partly contribute to the suppressive effect of black tea consumption on acute upper respiratory tract inflammation observed in our previous report.
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Modulating the Gut Microbiome in Multiple Sclerosis Management: A Systematic Review of Current Interventions.
Tsogka, A, Kitsos, DK, Stavrogianni, K, Giannopapas, V, Chasiotis, A, Christouli, N, Tsivgoulis, G, Tzartos, JS, Giannopoulos, S
Journal of clinical medicine. 2023;12(24)
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Multiple sclerosis (MS) is an autoimmune disease caused by the altered immune system mistakenly attacking the central nervous system. While genetics play a leading causative role in the manifestation of this disease, other contributing environmental factors can also exist, such as a disruption in the intestinal microbial composition. Previous research has shown that the bidirectional communication between the brain's and gut's health, also known as the gut-brain axis, may contribute to the prognosis of MS. Modulating gut microbial composition can be a therapeutic strategy in MS patients to manage symptoms and prevent disease progression. This systematic review assessed different protocols for modulating gut microbial composition, including dietary modifications, probiotic use, intermittent fasting, and faecal microbial transplantation. The review included thirteen studies that compared the effects of the above gut microbial modulation intervention protocols in MS patients with healthy participants. While different dietary modification strategies improved MS symptoms, probiotic supplementations and intermittent fasting reduced inflammation, and faecal microbial transplantation showed promising positive effects in a few reports. Due to the methodological limitations of the included studies, further robust studies are required to evaluate the beneficial effects of gut microbial modulation strategies in reducing the symptoms of MS patients. However, healthcare professionals can use the results of this study to understand the benefits of gut microbial modulation in MS patients.
Abstract
This review attempted to explore all recent clinical studies that have investigated the clinical and autoimmune impact of gut microbiota interventions in multiple sclerosis (MS), including dietary protocols, probiotics, fecal microbiota transplantation (FMT), and intermittent fasting (IF). Methods: Thirteen studies were held between 2011 and 2023 this demonstrated interventions in gut microbiome among patients with MS and their impact the clinical parameters of the disease. These included specialized dietary interventions, the supply of probiotic mixtures, FMT, and IF. Results: Dietary interventions positively affected various aspects of MS, including relapse rates, EDSS disability scores, MS-related fatigue, and metabolic features. Probiotic mixtures showed promising results on MS-related fatigue, EDSS parameters, inflammation; meanwhile, FMT-though a limited number of studies was included-indicated some clinical improvement in similar variables. IF showed reductions in EDSS scores and significant improvement in patients' emotional statuses. Conclusions: In dietary protocols, clinical MS parameters, including relapse rate, EDSS, MFIS, FSS, and MSQoL54 scales, were significantly improved through the application of a specific diet each time. Probiotic nutritional mixtures promote a shift in inflammation towards an anti-inflammatory cytokine profile in patients with MS. The administration of such mixtures affected disability, mood levels, and quality of life among patients with MS. FMT protocols possibly demonstrate a therapeutic effect in some case reports. IF protocols were found to ameliorate EDSS and FAMS scores. All interventional means of gut microbiome modulation provided significant conclusions on several clinical aspects of MS and highlight the complexity in the relationship between MS and the gut microbiome.
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Microbiological and clinical effects of probiotics and antibiotics on nonsurgical treatment of chronic periodontitis: a randomized placebo- controlled trial with 9-month follow-up.
Morales, A, Gandolfo, A, Bravo, J, Carvajal, P, Silva, N, Godoy, C, Garcia-Sesnich, J, Hoare, A, Diaz, P, Gamonal, J
Journal of applied oral science : revista FOB. 2018;26:e20170075
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Chronic periodontitis is an inflammatory disease affecting the gums caused by the accumulation of dental bacterial plaque. There has been evidence that certain bacteria, like Tannerella forsythia, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, are related to the development of chronic perdontitis. Research has shown that probiotic species such as Lactobacillus rhamnosus inhibit the growth of bacteria that cause gum disease. This parallel-arm, randomised, double-blinded, placebo-controlled clinical trial investigated the effects of Lactobacillus rhamnosus SP1 or Azithromycin tablets as an addition to non-surgical therapy on clinical and microbiological parameters of chronic periodontitis in healthy subjects. Participants in the intervention group consumed a probiotic sachet containing Lactobacillus rhamnosus SP1 and an antibiotic placebo daily for three months, whereas the placebo group consumed azithromycin 500 mg for five days and a probiotic placebo. At 6 weeks follow-up, both the probiotic group and the antibiotic group demonstrated improvements in clinical and microbiological parameters with a reduction in cultivable microbiota such as Tannerella forsythia, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. The antibiotic group reduced the number of people with chronic periodontitis more effectively than the probiotic group, but there was no significant difference between the two. To identify the most effective probiotic therapy for chronic periodontitis, more robust studies are required. The results of this study can be used by healthcare professionals to learn about the effects of probiotic therapy in patients with chronic periodontitis.
Abstract
The aim of this double-blind, placebo-controlled and parallel- arm randomized clinical trial was to evaluate the effects of Lactobacillus rhamnosus SP1-containing probiotic sachet and azithromycin tablets as an adjunct to nonsurgical therapy in clinical parameters and in presence and levels of Tannerella forsythia, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Forty-seven systemically healthy volunteers with chronic periodontitis were recruited and monitored clinically and microbiologically at baseline for 3, 6 and 9 months after therapy. Subgingival plaque samples were collected from four periodontal sites with clinical attachment level ≥1 mm, probing pocket depth ≥4 mm and bleeding on probing, one site in each quadrant. Samples were cultivated and processed using the PCR technique. Patients received nonsurgical therapy including scaling and root planing (SRP) and were randomly assigned to a probiotic (n=16), antibiotic (n = 16) or placebo (n = 15) group. L. rhamnosus SP1 was taken once a day for 3 months. Azithromycin 500mg was taken once a day for 5 days. All groups showed improvements in clinical and microbiological parameters at all time points evaluated. Probiotic and antibiotic groups showed greater reductions in cultivable microbiota compared with baseline. The placebo group showed greater reduction in number of subjects with P. gingivalis compared with baseline. However, there were no significant differences between groups. The adjunctive use of L. rhamnosus SP1 sachets and azithromycin during initial therapy resulted in similar clinical and microbiological improvements compared with the placebo group.
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Psoriasis and Microbiota: A Systematic Review.
Benhadou, F, Mintoff, D, Schnebert, B, Thio, HB
Diseases (Basel, Switzerland). 2018;6(2)
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Psoriasis is an autoimmune inflammatory skin disease that causes red, itchy, flaky and scaly skin. Skin integrity and function are critically dependent on the microbial population on it. Based on this systematic review, the immune system's interaction with microbes on the skin was examined and its relationship to psoriasis. T-cell mediated inflammation is characteristic of psoriasis where interaction between type IV collagen and α1β1 integrin, a collagen receptor, occurs. In psoriatic skin lesions, Firmicutes were predominant, while Actinobacteria were less prevalent. Psoriasis exacerbations are also associated with an exacerbated number of fungi, Malassezia species, in skin lesions. As therapeutic strategies for psoriasis, this systematic review suggests adhering to a gluten-free diet and incorporating prebiotics and probiotics such as Lactobacillus. However, further research is needed to develop specific therapeutic and skin modulation strategies. Health care professionals can benefit from this systematic review by understanding the pathophysiology behind psoriasis and possible therapeutic strategies to consider.
Abstract
BACKGROUND Recent advances have highlighted the crucial role of microbiota in the pathophysiology of chronic inflammatory diseases as well as its impact on the efficacy of therapeutic agents. Psoriasis is a chronic, multifactorial inflammatory skin disorder, which has a microbiota distinct from healthy, unaffected skin. AIM: Through an extensive review of the literature, we aim to discuss the skin and gut microbiota and redefine their role in the pathogenesis of psoriasis. CONCLUSIONS Unfortunately, the direct link between the skin microbiota and the pathogenesis of psoriasis remains to be clearly established. Apart from improving the course of psoriasis, selective modulation of the microbiota may increase the efficacy of medical treatments as well as attenuate their side effects.
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Crosstalk between the microbiome and epigenome: messages from bugs.
Qin, Y, Wade, PA
Journal of biochemistry. 2018;163(2):105-112
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Trillions of microbes live symbiotically in and on an individual human being, most of them inside the digestive tract and communally known as the gut microbiome. The gut microbiome plays a vital role in the individual host’s health, not only by helping digest food and harvest energy, but also by regulating immune development and influencing gene expression. Diet and factors, such as infections and the use of antibiotics, can alter the balance of the microbiome and lead to various outcomes. This paper reviewed the current understanding of the ways in which the gut microbiome is capable of altering the host’s gene expression through microbial signals, including metabolites, bile acids, inflammation and altered composition. The studies highlighted in the paper show that gut microbes communicate both with local cells in the intestines and with more distant organs, such as the liver and the cardiovascular system. Through this communication, they can regulate the expression of immune cells, cancer cells, enzymes and inflammation-related molecules. The authors concluded that these interactions, or the crosstalk between the microbes and the host, demonstrate a crucial role of the gut microbiome in the host’s response to environmental signals. However, many of the mechanisms are still unclear, so further studies are needed to explain specific microbe-derived signals, affecting host gene expression, and to deepen our understanding of how lifestyle, health status and environmental exposures, such as antibiotics, regulate the microbiome and its influence.
Abstract
Mammals exist in a complicated symbiotic relationship with their gut microbiome, which is postulated to have broad impacts on host health and disease. As omics-based technologies have matured, the potential mechanisms by which the microbiome affects host physiology are being addressed. The gut microbiome, which provides environmental cues, can modify host cell responses to stimuli through alterations in the host epigenome and, ultimately, gene expression. Increasing evidence highlights microbial generation of bioactive compounds that impact the transcriptional machinery in host cells. Here, we review current understanding of the crosstalk between gut microbiota and the host epigenome, including DNA methylation, histone modification and non-coding RNAs. These studies are providing insights into how the host responds to microbial signalling and are predicted to provide information for the application of precision medicine.
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Gut dysbiosis: a potential link between increased cancer risk in ageing and inflammaging.
Biragyn, A, Ferrucci, L
The Lancet. Oncology. 2018;19(6):e295-e304
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This study looks at the important role our gut bacterial and commensal microbes play in supporting immunity and potentially reducing the risk of cancer from aging. Cancer risk increases as we age and is one of the main causes of reduced life expectancy. Our gut microbiome changes continually in response to diet, lifestyle, infection, and activation of immune responses. Gut dysbiosis is characterised by a shift towards proinflammatory commensals and a reduction of beneficial microbes, which can cause impairment and leakiness of the intestinal barrier. This is thought to trigger inflammaging or rather aging in a state of continual inflammation, where the immune system is in a heightened state of activation, and the body essentially creates an environment conducive to cancer. The gut is populated by trillions of species of bacteria which work together with our immune cells. As we age the diversity and density of these beneficial bacteria reduce. Therapies which support the balance of our commensal bacteria may prove effective at reducing rates of cancer in the elderly.
Abstract
Cancer incidence substantially increases with ageing in both men and women, although the reason for this increase is unknown. In this Series paper, we propose that age-associated changes in gut commensal microbes, otherwise known as the microbiota, facilitate cancer development and growth by compromising immune fitness. Ageing is associated with a reduction in the beneficial commensal microbes, which control the expansion of pathogenic commensals and maintain the integrity of the intestinal barrier through the production of mucus and lipid metabolites, such as short-chain fatty acids. Expansion of gut dysbiosis and leakage of microbial products contributes to the chronic proinflammatory state (inflammaging), which negatively affects the immune system and impairs the removal of mutant and senescent cells, thereby enabling tumour outgrowth. Studies in animal models and the importance of commensals in cancer immunotherapy suggest that this status can be reversible. Thus, interventions that alter the composition of the gut microbiota might reduce inflammaging and rejuvenate immune functions to provide anticancer benefits in frail elderly people.
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Postoperative changes of the microbiome: are surgical complications related to the gut flora? A systematic review.
Lederer, AK, Pisarski, P, Kousoulas, L, Fichtner-Feigl, S, Hess, C, Huber, R
BMC surgery. 2017;17(1):125
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Infections following gastrointestinal surgery are common and patients routinely receive antibiotic medications to reduce the risks involved. Recent reviews have suggested that some of these complications might be related to the patient’s gut bacteria profile. This systematic review of 10 studies, including 677 patients, aimed to identify the relationship between post-operative infections and the gut microbiome. All studies reported a post-operative change to the gut flora, with 5 studies showing a reduction in bacteria present. Surgery tended to lead to an increase in disease causing bacteria and a reduction in health giving bacteria. The rate of post-operative complications was lower in the groups treated with pre- and pro-biotics, suggesting that there might be a relationship between gut flora and infections following surgery. There remains uncertainty however, due to the shortcomings of the methodologies employed by the studies.
Abstract
BACKGROUND The purpose of this review was to identify the relationship between the gut microbiome and the development of postoperative complications like anastomotic leakage or a wound infection. Recent reviews focusing on underlying molecular biology suggested that postoperative complications might be influenced by the patients' gut flora. Therefore, a review focusing on the available clinical data is needed. METHODS In January 2017 a systematic search was carried out in Medline and WebOfScience to identify all clinical studies, which investigated postoperative complications after gastrointestinal surgery in relation to the microbiome of the gut. RESULTS Of 337 results 10 studies were included into this analysis after checking for eligibility. In total, the studies comprised 677 patients. All studies reported a postoperative change of the gut flora. In five studies the amount of bacteria decreased to different degrees after surgery, but only one study found a significant reduction. Surgical procedures tended to result in an increase of potentially pathogenic bacteria and a decrease of Lactobacilli and Bifidobacteria. The rate of infectious complications was lower in patients treated with probiotics/symbiotics compared to control groups without a clear relation to the systemic inflammatory response. The treatment with synbiotics/probiotics in addition resulted in faster recovery of bowel movement and a lower rate of postoperative diarrhea and abdominal cramping. CONCLUSIONS There might be a relationship between the gut flora and the development of postoperative complications. Due to methodological shortcomings of the included studies and uncontrolled bias/confounding factors there remains a high level of uncertainty.