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The efficacy of fermented foods in the treatment and management of diarrhoeal diseases: A systematic review and meta-analysis.
Olayanju, A, Mellor, D, Khatri, Y, Pickles, N
Nutrition and health. 2023;29(1):71-83
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According to World Health Organisation (WHO), diarrhoeal disease is the second leading cause of death among children under the age of 5 in the world. The WHO’s recommendation for the treatment of diarrhoea is oral rehydration solution (ORS), consisting of a solution of clean water, sugar and salt along with a 10-14 day supplemental treatment course of dispersible 20 mg zinc tablets. The aim of this study was to evaluate the available evidence with respect to the efficacy of fermented foods and beverages in comparison with unfermented or heat-treated products, including dairy and cereal products, focussing on the treatment of diarrhoea in infants. This study is a systematic review and meta-analysis of seven randomised controlled trials. Results show that administering fermented foods during an episode of diarrhoea in infants under five years of age, may reduce the duration of the disease in comparison to the control groups. There was no clear effect on daily stool frequency, but duration of hospitalisation was reduced following administration of fermented foods. Authors conclude that fermented foods may be helpful in the treatment of diarrhoea in infants up to the age of five. Thus, more good quality trials are required to investigate the complex matrix of fermented food products, other than dairy foods, in the management, particularly treatment of gastrointestinal diseases such as diarrhoea.
Abstract
Background: Diarrhoeal disease is a major cause of global infant mortality, and compromises the ability of many countries with respect to achieving sustainable development goals. The WHO's recommendation of Oral Rehydration Solution (ORS) and zinc in the management of this disease, may not be readily available. Consideration and assessment of cultural practices in its management has been an area of increased interest over the last decade. Aim: This study aims to systematically evaluate efficacy of the consumption of traditional fermented foods as functional products for the treatment and management of diarrhoea. Methods: Following PRISMA guidelines, a systematic review was conducted of electronic databases (Cochrane Library, Ovid Medline and Pubmed) databases with no restrictions on language and publication date for RCTs that investigated the effect of consumption of fermented foods on the treatment of diarrhoea in children under five years of age. Results: Seven RCTs were included. Meta-analysis showed that compared to control, consumption of fermented foods significantly reduced mean duration of diarrhoea, -0.61 days; (95% CI, -1.04, -0.18); length of hospitalization, -0.35 days (95% CI, -0.69, -0.02); but not mean daily frequency of stool -2.00 (95% CI,-7.03, 3.04). Conclusion: Limited available evidence suggests that consumption of fermented foods may help reduce duration and severity of symptoms as a treatment of diarrhoea. More high quality research needs to be undertaken to investigate the efficacy of fermented food as an effective alternative to ORS as a potential WHO recommendation for management of diarrhoeal disease.
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Effect of Fructooligosaccharides Supplementation on the Gut Microbiota in Human: A Systematic Review and Meta-Analysis.
Dou, Y, Yu, X, Luo, Y, Chen, B, Ma, D, Zhu, J
Nutrients. 2022;14(16)
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Fructooligosaccharide is a prebiotic fibre that undergoes fermentation in the gut, due to which it can cause gas and bloat. Additionally, this prebiotic fibre ferments to produce short-chain fatty acids, which are beneficial for the body. This systematic review and meta-analysis included eight randomised controlled trials investigating the effects of fructooligosaccharide on gut microbial composition. Short-term supplementation with fructooligosaccharide altered the gut’s microbial composition without causing any adverse effects. Bifidobacterium spp. levels were elevated in those who consumed fructooligosaccharide supplements than those who did not. Supplementation with fructooligosaccharide did not significantly change harmful bacteria such as Bacteroides and Enterobacteriaceae levels. In addition, a higher dosage of 7.5–15 g/d of fructooligosaccharide supplementation for a period of more than four weeks was found to be beneficial. Healthcare professionals can use these results to understand better how fructooligosaccharide modulates beneficial gut bacteria such as Bifidobacterium spp. However, there is a need for more robust studies since the number of currently available studies is limited, and the exact health implications of fructooligosaccharide supplementation need to be evaluated further.
Abstract
Background: Numerous studies have investigated the effects of the supplementation of fructooligosaccharides (FOS) on the number of bacteria in the gut that are good for health, but the results have been inconsistent. Additionally, due to its high fermentability, supplementation of FOS may be associated with adverse gastrointestinal symptoms such as bloating and flatulence. Therefore, we assessed the effects of FOS interventions on the composition of gut microbiota and gastrointestinal symptoms in a systematic review and meta-analysis. Design: All randomized controlled trials published before 10 July 2022 that investigated the effects of FOS supplementation on the human gut microbiota composition and gastrointestinal symptoms and met the selection criteria were included in this study. Using fixed or random-effects models, the means and standard deviations of the differences between the two groups before and after the intervention were combined into weighted mean differences using 95% confidence intervals (CIs). Results: Eight studies containing 213 FOS supplements and 175 controls remained in this meta-analysis. Bifidobacterium spp. counts significantly increased during FOS ingestion (0.579, 95% CI: 0.444-0.714) in comparison with that of the control group. Subgroup analysis showed greater variation in Bifidobacterium spp. in adults (0.861, 95% CI: 0.614-1.108) than in infants (0.458, 95% CI: 0.297-0.619). The increase in Bifidobacterium spp. counts were greater in the group with an intervention duration greater than 4 weeks (0.841, 95% CI: 0.436-1.247) than an intervention time less than or equal to four weeks (0.532, 95% CI: 0.370-0.694), and in the group with intervention doses > 5 g (1.116, 95% CI: 0.685-1.546) the counts were higher than those with doses ≤ 5 g (0.521, 95% CI: 0.379-0.663). No differences in effect were found between FOS intervention and comparators in regard to the abundance of other prespecified bacteria or adverse gastrointestinal symptoms. Conclusions: This is the first meta-analysis to explore the effect of FOS on gut microbiota and to evaluate the adverse effects of FOS intake on the gastrointestinal tract. FOS supplementation could increase the number of colonic Bifidobacterium spp. while higher dose (7.5-15 g/d) and longer duration (>4 weeks) showed more distinct effects and was well tolerated.
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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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Disruption of the Gut Ecosystem by Antibiotics.
Yoon, MY, Yoon, SS
Yonsei medical journal. 2018;59(1):4-12
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The gut microbiome is a complex ecosystem of different micro-organisms, such as bacteria, viruses and fungi, living in the human intestines. It’s involved in numerous functions, such as extracting energy and nutrition from food, protecting against disease-causing microorganisms, and supporting the immune system of the host, and therefore affecting human health and disease. This paper is a review of studies on the effects of antibiotics on the gut microbiota. It outlines how different types of antibiotics can alter the intestinal environment and the composition of the microbes, resulting in various physiological changes that can trigger disease. Relevant mechanisms, such as inflammatory response and the use of intestinal nutrients by infectious bacteria are discussed. Finally, it discusses faecal microbiota transplantation (FMT) and probiotics as treatment approaches, aimed at restoring a disturbed intestinal environment.
Abstract
The intestinal microbiota is a complex ecosystem consisting of various microorganisms that expands human genetic repertoire and therefore affects human health and disease. The metabolic processes and signal transduction pathways of the host and intestinal microorganisms are intimately linked, and abnormal progression of each process leads to changes in the intestinal environment. Alterations in microbial communities lead to changes in functional structures based on the metabolites produced in the gut, and these environmental changes result in various bacterial infections and chronic enteric inflammatory diseases. Here, we illustrate how antibiotics are associated with an increased risk of antibiotic-associated diseases by driving intestinal environment changes that favor the proliferation and virulence of pathogens. Understanding the pathogenesis caused by antibiotics would be a crucial key to the treatment of antibiotic-associated diseases by mitigating changes in the intestinal environment and restoring it to its original state.
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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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Mucosal microbiome dysbiosis in gastric carcinogenesis.
Coker, OO, Dai, Z, Nie, Y, Zhao, G, Cao, L, Nakatsu, G, Wu, WK, Wong, SH, Chen, Z, Sung, JJY, et al
Gut. 2018;67(6):1024-1032
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Gastric cancer (GC) is the 4th most common cancer and a leading cause of cancer-related deaths worldwide. Infection with Helicobacter pylori is an important risk factor for GC and other changes in gastric microbial composition are thought to play role in gastric carcinogenesis. This observational study aimed to elucidate the microbial changes that are characteristic for the different stages of gastric tumor development. The authors found significant changes in microbial composition in stomach cancer patients compared to patients with pre-cancerous mucosal changes, with an increase of some and a depletion of other bacteria, in particular an increase in oral bacteria, which is also found in other gastrointestinal cancers. They also found that interactions between the depleted and enriched bacterial species progressively increased with progressing carcinogenesis. Whilst there was no difference in the diversity of bacteria between H. pylori-positive and negative samples, more bacterial interactions were observed in H. pylori-negative samples. The authors conclude that significant gastric dysbiosis can be seen in samples of stomach cancer patients, however, they point out that from their study it is impossible to tell whether the bacteria increased in GC are “drivers” or “passengers” of gastric carcinogenesis. Their call for more research focusses on using this knowledge to develop better diagnostic biomarkers, rather than using this information for prevention or treatment of stomach cancer.
Abstract
OBJECTIVES We aimed to characterise the microbial changes associated with histological stages of gastric tumourigenesis. DESIGN We performed 16S rRNA gene analysis of gastric mucosal samples from 81 cases including superficial gastritis (SG), atrophic gastritis (AG), intestinal metaplasia (IM) and gastric cancer (GC) from Xi'an, China, to determine mucosal microbiome dysbiosis across stages of GC. We validated the results in mucosal samples of 126 cases from Inner Mongolia, China. RESULTS We observed significant mucosa microbial dysbiosis in IM and GC subjects, with significant enrichment of 21 and depletion of 10 bacterial taxa in GC compared with SG (q<0.05). Microbial network analysis showed increasing correlation strengths among them with disease progression (p<0.001). Five GC-enriched bacterial taxa whose species identifications correspond to Peptostreptococcus stomatis, Streptococcus anginosus, Parvimonas micra, Slackia exigua and Dialister pneumosintes had significant centralities in the GC ecological network (p<0.05) and classified GC from SG with an area under the receiver-operating curve (AUC) of 0.82. Moreover, stronger interactions among gastric microbes were observed in Helicobacter pylori-negative samples compared with H. pylori-positive samples in SG and IM. The fold changes of selected bacteria, and strengths of their interactions were successfully validated in the Inner Mongolian cohort, in which the five bacterial markers distinguished GC from SG with an AUC of 0.81. CONCLUSIONS In addition to microbial compositional changes, we identified differences in bacterial interactions across stages of gastric carcinogenesis. The significant enrichments and network centralities suggest potentially important roles of P. stomatis, D. pneumosintes, S. exigua, P. micra and S. anginosus in GC progression.
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Increased richness and diversity of the vaginal microbiota and spontaneous preterm birth.
Freitas, AC, Bocking, A, Hill, JE, Money, DM
Microbiome. 2018;6(1):117
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The bacterial community in the female lower genital tract plays an important role in the health of both mother and baby. Imbalances in the vaginal microbiota have been associated with negative reproductive outcomes, such as premature birth. Bacterial infection is thought to be an important contributor to the onset of premature labour. The objective of this study was to compare the vaginal microbiota of pregnant women who had premature births (<37 weeks) with those of pregnant women who delivered at term. Vaginal swabs were collected from 216 Canadian women at 11-16 weeks of gestational age. Of these, 170 pregnancies went to full term, and 46 women had premature births. The vaginal microbiota of women who experienced premature birth had higher richness and diversity and higher Mollicutes prevalence when compared to those of women who delivered at term. The results confirm previous reports of an association between Mollicutes and premature birth and suggest that a more diverse microbiome may contribute to the microbiome’s role in premature births.
Abstract
BACKGROUND The bacterial community present in the female lower genital tract plays an important role in maternal and neonatal health. Imbalances in this microbiota have been associated with negative reproductive outcomes, such as spontaneous preterm birth (sPTB), but the mechanisms underlying the association between a disturbed microbiota and sPTB remain poorly understood. An intrauterine infection ascending from the vagina is thought to be an important contributor to the onset of preterm labour. Our objective was to characterize the vaginal microbiota of pregnant women who had sPTB (n = 46) and compare to those of pregnant women who delivered at term (n = 170). Vaginal swabs were collected from women at 11-16 weeks of gestational age. Microbiota profiles were created by PCR amplification and pyrosequencing of the cpn60 universal target region. RESULTS Profiles clustered into seven community state types: I (Lactobacillus crispatus dominated), II (Lactobacillus gasseri dominated), III (Lactobacillus iners dominated), IVA (Gardnerella vaginalis subgroup B or mix of species), IVC (G. vaginalis subgroup A dominated), IVD (G. vaginalis subgroup C dominated) and V (Lactobacillus jensenii dominated). The microbiota of women who experienced preterm birth (< 37 weeks gestation) had higher richness and diversity and higher Mollicutes prevalence when compared to those of women who delivered at term. The two groups did not cluster according to CST, likely because CST assignment is driven in most cases by the dominance of one particular species, overwhelming the contributions of more rare taxa. In conclusion, we did not identify a specific microbial community structure that predicts sPTB, but differences in microbiota richness, diversity and Mollicutes prevalence were observed between groups. CONCLUSIONS Although a causal relationship remains to be determined, our results confirm previous reports of an association between Mollicutes and sPTB and further suggest that a more diverse microbiome may be important in the pathogenesis of some cases.
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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.