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Fecal Microbiota Transplantation in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Jamshidi, P, Farsi, Y, Nariman, Z, Hatamnejad, MR, Mohammadzadeh, B, Akbarialiabad, H, Nasiri, MJ, Sechi, LA
International journal of molecular sciences. 2023;24(19)
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Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder the cause of which is not yet fully elucidated. Probiotics, prebiotics and dietary changes have been shown to mitigate IBS symptoms whilst the results from studies of faecal microbiota transplants (FMT) have been inconsistent. The aim of this systematic review and meta-analysis of double-blind, randomised controlled trials (RCT) was to evaluate the efficacy and safety of FMT in IBS. 7 RCTs with a low risk of bias and no publication bias were included in the meta-analysis. Overall, no statistically significant effect was observed. A subgroup analysis by treatment modality showed that benefits were seen with lower GI administration of a single dose of multiple-donor FMT. Abdominal pain, nausea, diarrhoea and bloating were the most common adverse events, with no severe or critical adverse events reported. The authors call for larger and longer clinical trials to fill existing knowledge gaps.
Abstract
Irritable bowel syndrome (IBS) poses a significant challenge due to its poorly understood pathogenesis, substantial morbidity, and often inadequate treatment outcomes. The role of fecal microbiota transplantation (FMT) in managing IBS symptoms remains inconclusive. This systematic review and meta-analysis aimed to ascertain the effectiveness of FMT in relieving symptoms in IBS patients. A thorough search was executed on PubMed/Medline and Embase databases until 14 June 2023, including all studies on FMT use in IBS patients. We examined the efficiency of FMT in reducing patients' symptoms overall and in particular subgroups, classified by placebo preparation, FMT preparation, frequency, and route of administration. Among 1015 identified studies, seven met the inclusion criteria for the meta-analysis. The overall symptomatology of FMT-treated IBS patients did not significantly differ from the control group (Odds Ratio (OR) = 0.99, 95% Confidence Interval (CI) 0.39-2.5). Multiple doses of FMT compared with non-FMT placebo, or single-donor FMT therapy compared with autologous FMT placebo also showed no significant benefit (OR = 0.32, 95%CI (0.07-1.32), p = 0.11, and OR = 1.67, 95%CI (0.59-4.67), p = 0.32, respectively). However, a single dose of multiple-donor FMT administered via colonoscopy (lower gastrointestinal (GI) administration) significantly improved patient symptoms compared with autologous FMT placebo (OR = 2.54, 95%CI (1.20-5.37), p = 0.01, and OR = 2.2, 95%CI (1.20-4.03), p = 0.01, respectively). The studies included in the analysis showed a low risk of bias and no publication bias. In conclusion, lower GI administration of a single dose of multiple-donor FMT significantly alleviates patient complaints compared with the autologous FMT used as a placebo. The underlying mechanisms need to be better understood, and further experimental studies are desired to fill the current gaps.
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Effects of Probiotics in Adults with Gastroenteritis: A Systematic Review and Meta-Analysis of Clinical Trials.
Mitra, AK, Asala, AF, Malone, S, Mridha, MK
Diseases (Basel, Switzerland). 2023;11(4)
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Gastroenteritis is a major cause of morbidity and mortality globally and symptoms can range from mild to life-threatening. Some studies have suggested benefits of probiotics in the treatment of gastroenteritis in children whilst in adults, results are inconsistent. The aim of this systematic review and meta-analysis was to evaluate the effects of probiotics on acute and chronic gastroenteritis in adults. 35 clinical trials were included in the systematic review and 22 in the meta-analysis. Of these, 23 dealt with inflammatory bowel disease, 5 with pouchitis, 3 with antibiotic-induced diarrhoea, 2 with Helicobacter pylori infection and one each with diverticulitis and acute watery diarrhoea. 27 (77%) of studies showed some benefits of probiotic administration. The meta-analysis of 22 studies did not show a statistically significant benefit of probiotics. Although statistical analysis showed the studies to be homogenous, the authors point out that studies differed widely in aetiologies and probiotics used. A subgroup analysis of 8 studies in patients with ulcerative colitis also showed no benefit. In all studies, probiotics were well tolerated and no adverse side effects were reported. The authors concluded that further research is needed to help identify the most appropriate use of probiotics for the different types of gastroenteritis.
Expert Review
Conflicts of interest:
None
Take Home Message:
- For chronic inflammatory gastroenteritis conditions in adults, probiotics were effective in treating and preventing relapse
- In ulcerative colitis, probiotics were not effective and adverse events outweighed the benefits
- No safety concerns were found for probiotic use in any studies
- Aetiologies, disease severity and duration as well as the type of probiotics used were widely diverse.
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
To date, evidence has been mixed for probiotic effectiveness in gastrointestinal syndromes associated with gastroenteritis. The aim of this study was to review current evidence on the effect of probiotics on gastroenteritis in adults.
Methods
This was a systematic review (n=35; total sample size 4577, median 44) and meta-analysis (n=22) of randomised controlled trials. Quality was assessed using CADIMA as per a rating scale (0 to 4) and standards of critical appraisal.
Results
All 35 studies on gastroenteritis included participants with chronic diarrhoea of diverse aetiologies such as IBD, antibiotic-associated, except one which had acute watery diarrhoea.
51% (n=18) of studies assessed the effects of probiotics in the treatment of ulcerative colitis (UC) and Crohn's disease (CD). 60% (n=21) used multiple strains of probiotics while the rest used single strains. Lactobacilli, Bifidobacteria, Escherichia and Streptococcus were the most common and only a few studies administered probiotics with another conventional treatment.
19 studies (55%) rated highly in terms of quality while 15 (43%) scored moderately. The majority (63%) of the 27 studies where probiotics were shown to be effective were of high quality.
Systematic review results:
- 27/53 studies (77%) showed a favourable response after using probiotics (resolution, improvement, remission or no relapse), mostly in patients with IBDs
- 7 studies (20%) found probiotics to be ineffective
- 1 study was inconclusive
- Multiple strain probiotics (VSL #3) was found to be most effective in IBD
- All administered probiotics were well tolerated with no adverse side effects although caution in immunocompromised patients was mentioned in several studies.
The meta-analysis results:
- Overall effectiveness for 22 studies (p=0.37) highlighted there was not enough evidence that the intervention was more protective than controls.
- Probiotics were not effective in UC (p = 0.28), and adverse events caused by probiotics may outweigh the benefits in studies with UC patients.
Conclusion
While benefits of effectiveness were found for probiotic use in gastroenteritis in adults, results from the systematic review and meta-analysis showed a mixed effect.
Clinical practice applications:
- Based on the systematic review, probiotics may be an effective treatment or adjuvant treatment for gastroenteritis but ineffective for around 20% of patients
- It is worth noting that combined therapy with standard treatment showed effective results
- Beneficial effects of probiotics in other key clinical outcomes including disease prevention, relapse, quality of life, morbidity were found
- While the results are interesting it is difficult to apply them in practice as the type of probiotics used were widely different as were the causes, severity and duration of gastroenteritis.
Considerations for future research:
- Further and larger studies would be beneficial to understand the benefits of probiotics in terms of single therapy or in combination with standard treatment particularly for UC, CDs, gastroenteritis not due to viral infection
- Individual-level data instead of aggregated data could give a better idea of effectiveness of probiotics in the future
- In this study aetiologies and the type, dosage, duration of probiotics used were widely diverse therefore systematic reviews and meta-analysis on specific conditions, specific probiotic strains and combinations would be beneficial.
Abstract
Probiotics have been widely used in gastroenteritis due to acute and chronic illnesses. However, evidence supporting the effectiveness of probiotics in different health conditions is inconclusive and conflicting. The aim of this study was to review the existing literature on the effects of probiotics on gastroenteritis among adults. Only original articles on clinical trials that demonstrated the effects of probiotics in adults with gastroenteritis were used for this analysis. Multiple databases, such as PubMed, Google Scholar, MEDLINE and Scopus databases, were searched for the data. The study followed standard procedures for data extraction using a PRISMA flow chart. A quality appraisal of the selected studies was conducted using CADIMA. Finally, a meta-analysis was performed. Thirty-five articles met the selection criteria; of them, probiotics were found effective in the treatment and/or prevention of chronic inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease in 17 (49%), and the treatment of pouchitis in 4 (11.4%), antibiotic-induced diarrhea in 3 (8.6%), Helicobacter pylori infection in 2 (5.7%) and diverticulitis in 1 (2.9%), while the remaining 7 (20%) were ineffective, and 1 study's results were inconclusive. The meta-analysis did not demonstrate any significant protective effects of probiotics. Having a τ2 value of zero and I2 of 6%, the studies were homogeneous and had minimum variances. Further studies are suggested to evaluate the beneficial effects of probiotics in IBDs and other chronic bowel diseases.
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Diabetes mellitus, prediabetes and the risk of Parkinson's disease: a systematic review and meta-analysis of 15 cohort studies with 29.9 million participants and 86,345 cases.
Aune, D, Schlesinger, S, Mahamat-Saleh, Y, Zheng, B, Udeh-Momoh, CT, Middleton, LT
European journal of epidemiology. 2023;38(6):591-604
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Diabetes mellitus and prediabetes may increase an individual’s risk for Parkinson’s disease (PD), however the research completed to date has been controversial. This meta-analysis of 15 observational studies with 86,345 individuals with PD aimed to update the research on PD risk for individuals with diabetes or prediabetes and determine possible reasons for the ambiguity of previous research. The results showed that compared to people without diabetes, those with, were at a 27% increased relative risk of PD and a 4% increase amongst those with prediabetes. Individuals with a history of complications alongside diabetes were at a higher risk than those without. It was concluded that the risk of developing PD is increased amongst individuals with diabetes. This study could be used by healthcare professionals to understand that individuals with diabetes may be at an increased risk for PD and should be monitored. However, as this is based on observational studies, there is a chance that PD increases the risk for diabetes and not the reverse.
Abstract
A diagnosis of diabetes mellitus and prediabetes has been associated with increased risk of Parkinson's disease (PD) in several studies, but results have not been entirely consistent. We conducted a systematic review and meta-analysis of cohort studies on diabetes mellitus, prediabetes and the risk of PD to provide an up-to-date assessment of the evidence. PubMed and Embase databases were searched for relevant studies up to 6th of February 2022. Cohort studies reporting adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for the association between diabetes, prediabetes and Parkinson's disease were included. Summary RRs (95% CIs) were calculated using a random effects model. Fifteen cohort studies (29.9 million participants, 86,345 cases) were included in the meta-analysis. The summary RR (95% CI) of PD for persons with diabetes compared to persons without diabetes was 1.27 (1.20-1.35, I2 = 82%). There was no indication of publication bias, based on Egger's test (p = 0.41), Begg's test (p = 0.99), and inspection of the funnel plot. The association was consistent across geographic regions, by sex, and across several other subgroup and sensitivity analyses. There was some suggestion of a stronger association for diabetes patients reporting diabetes complications than for diabetes patients without complications (RR = 1.54, 1.32-1.80 [n = 3] vs. 1.26, 1.16-1.38 [n = 3]), vs. those without diabetes (pheterogeneity=0.18). The summary RR for prediabetes was 1.04 (95% CI: 1.02-1.07, I2 = 0%, n = 2). Our results suggest that patients with diabetes have a 27% increased relative risk of developing PD compared to persons without diabetes, and persons with prediabetes have a 4% increase in RR compared to persons with normal blood glucose. Further studies are warranted to clarify the specific role age of onset or duration of diabetes, diabetic complications, glycaemic level and its long-term variability and management may play in relation to PD risk.
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The Efficacy of Self-Management Strategies for Females with Endometriosis: a Systematic Review.
Mardon, AK, Leake, HB, Hayles, C, Henry, ML, Neumann, PB, Moseley, GL, Chalmers, KJ
Reproductive sciences (Thousand Oaks, Calif.). 2023;30(2):390-407
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Endometriosis is a gynaecological condition with symptoms of pelvic pain, fatigue, and stress. Decreased quality of life, impaired fertility and hinderances to carry out day to day tasks are all associated with endometriosis. Treatment options involve medications and surgery; however, both are associated with poorer outcomes than the initial disease itself. Self-management strategies that the individual can perform themselves, such as lifestyle changes, meditation, and rest have all been used to improve the quality of life of individuals with endometriosis, however their effectiveness has not been determined. This systematic review and meta-analysis aimed to determine the effectiveness of self-management strategies for the management of endometriosis. The study showed that many self-management strategies were no more effective than placebo or hormonal therapies for the management of endometriosis. It was concluded that many self-management strategies were no more effective than hormonal treatment at reducing endometriosis symptoms and the studies that did show a benefit were insufficient to base recommendations on due to poor design. This study could be used by healthcare professionals to understand that currently the research on self-management strategies of endometriosis is poor and whilst some may be of benefit to individuals who cannot or do not want to take hormone therapy, more research is warranted.
Expert Review
Conflicts of interest:
None
Take Home Message:
It is not possible to generalise the findings of this systematic review for the self-management of endometriosis due to the poor quality of evidence. Further studies of higher quality are needed.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
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
Endometriosis is an inflammatory condition where endometrial-like tissue is found outside of the uterus. Diagnosis of endometriosis is made in around 6-10% of females of reproductive age. Endometriosis can adversely affect fertility, psychological well being and quality of life (QoL). Conventional interventions can have side effects and limited effectiveness. The aim of this systematic review (SR) was to evaluate the efficacy of self-management interventions for pain-related symptoms and QoL.
Methods
Fifteen experimental studies were included in this SR. Ten evaluated dietary supplements, three evaluated dietary modifications, one evaluated over-the-counter (OTC) medication, and one evaluated exercise. Outcome measures were self-reported for dysmenorrhoea, dyspareunia, overall pain, non-menstrual pelvic pain, use of medications and QoL.
Results
- Most dietary supplements were no more effective than placebo or frequently recommended medical interventions, at reducing pain-related outcomes.
- Melatonin (one RCT n=30) performed better than placebo for managing dysmenorrhoea and overall pain but not for non-menstrual pelvic pain. PEA-transploydatin (one RCT n=20) performed better than placebo for dysmenorrhoea and non-menstrual pelvic pain but not better than medical intervention.
- Resveratrol (one RCT n=22 & one intervention study n=12) plus the oral contraceptive pill (OCP) was more effective than the OCP alone for managing dysmenorrhoea.
- In one observational study, 75% of participants (n=295) reported a reduction in ‘high’ intensity pain scores following a 12-month gluten-free diet (p- value =<0.005). Similarly, a full dietary modification (one non randomised controlled trial , n=30) found less participants reporting pain at ‘high intensity’ (18%) compared to linseed and calcium oil supplements (41%) and placebo (62%).
- A metal trace element supplement was more effective than placebo for managing overall pain (one RCT p- value<0.001).
- Naproxen (one cross over trial, n=11) performed better than placebo at managing dysmenorrhoea (83% vs 41%, p- value 0.008).
- Hatha yoga (one RCT n=12) was found to be effective at reducing overall pain and improving QoL compared to no yoga (p-value <0.05).
Conclusion
Due to limited, low-quality evidence, high risk of bias and high levels of heterogeneity between studies, it was not possible to generalise the findings of the studies included in this systematic review. Further research of high-quality is needed in order to make self-management recommendations for females with endometriosis.
Notes: The authors reported no conflicts of interest.
Clinical practice applications:
Evidence-based self-management interventions are considered critical for the management of endometriosis. However, the quality of evidence in this SR was considered of poor quality. Further high-quality research is needed in order to be able to make recommendations. Strategies that showed potential benefits included:
- Dietary modifications and a gluten-free diet may be effective for reducing the intensity of pain associated with endometriosis.
- Hatha yoga may be effective at reducing overall pain and supporting psychological wellbeing and QoL.
Considerations for future research:
High quality studies are needed as well as a ‘gold standard’ definition for self-management criteria. Understanding potential barriers to self-management interventions may also be beneficial.
Abstract
Self-management is critical for the care of endometriosis. Females with endometriosis frequently use self-management strategies to manage associated symptoms; however, the efficacy of such strategies is unknown. The aim of this review was to systematically appraise the evidence concerning efficacy of self-management strategies for endometriosis symptoms. Electronic databases, including Medline, Embase, Emcare, Web of Science Core Collection, Scopus, and the Cochrane Central Register of Controlled Trials, were searched from inception to March 2021. We included peer-reviewed experimental studies published in English evaluating the efficacy of self-management strategies in human females laparoscopically diagnosed with endometriosis. Studies underwent screening, data extraction, and risk of bias appraisal (randomised studies: Risk of Bias 2 tool; non-randomised studies: Risk Of Bias In Non-randomized Studies - of Interventions tool). Of the fifteen studies included, 10 evaluated dietary supplements, three evaluated dietary modifications, one evaluated over-the-counter medication, and one evaluated exercise. Most studies had a high-critical risk of bias. Many self-management strategies were not more effective at reducing endometriosis symptoms compared to placebo or hormonal therapies. Where studies suggest efficacy for self-management strategies, no recommendations can be made due to the poor quality and heterogeneity of evidence. High-quality empirical evidence is required to investigate the efficacy of self-management strategies for females with endometriosis.
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The right bug in the right place: opportunities for bacterial vaginosis treatment.
Wu, S, Hugerth, LW, Schuppe-Koistinen, I, Du, J
NPJ biofilms and microbiomes. 2022;8(1):34
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The vaginal microbiome is generally dominated by Lactobacilli bacteria. However, variations exist, and in some ethnic groups a dominance of non-Lactobacilli species is more common. Lactobacilli produce various antimicrobial substances which keep growth of other bacteria in check. Bacterial vaginosis (BV) is characterized by a disturbance of the vaginal microbe balance and deficiency of Lactobacilli, giving rise to the overgrowth of certain bacteria, such as Gardnerella, Atopobium, Megasphaera, Prevotella, and Sneathia. In some countries, BV can affect over half of the women. This review discusses the advantages and challenges of the current treatment options for BV and postulates directions for future research. The article examines the use of antibiotics, their effectiveness and difficulties in obtaining long-term remission, their negative impact on the existing vaginal microbiome, the risk of antibiotic resistance and the benefits and challenges of local antibiotic applications. Following this, the authors discussed the use of prebiotics and probiotics, possible reasons why clinical trials in the past showed mixed results, and what strains may be of particular importance in vaginal health, with L. crispatus and L. iners being of particular interest here. Considered are also factors that influence and enhance bacterial colonization. Lastly, the article summarizes some current thinking on Vaginal Microbiome Transplantation, which is the transfer of vaginal microbes and fluids from a healthy donor, what benefits they may have, the associated safety risks and legislative challenges. This review is a comprehensive summary of BV treatment options, their current evidence, efficacy and drawbacks, yielding useful information to consider in the clinical management of BV.
Abstract
Bacterial vaginosis (BV) is a condition in which the vaginal microbiome presents an overgrowth of obligate and facultative anaerobes, which disturbs the vaginal microbiome balance. BV is a common and recurring vaginal infection among women of reproductive age and is associated with adverse health outcomes and a decreased quality of life. The current recommended first-line treatment for BV is antibiotics, despite the high recurrence rate. Live biopharmaceutical products/probiotics and vaginal microbiome transplantation (VMT) have also been tested in clinical trials for BV. In this review, we discuss the advantages and challenges of current BV treatments and interventions. Furthermore, we provide our understanding of why current clinical trials with probiotics have had mixed results, which is mainly due to not administering the correct bacteria to the correct body site. Here, we propose a great opportunity for large clinical trials with probiotic strains isolated from the vaginal tract (e.g., Lactobacillus crispatus) and administered directly into the vagina after pretreatment.
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Dietary supplements in neurological diseases and brain aging.
Naureen, Z, Dhuli, K, Medori, MC, Caruso, P, Manganotti, P, Chiurazzi, P, Bertelli, M
Journal of preventive medicine and hygiene. 2022;63(2 Suppl 3):E174-E188
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The rate of neurodegenerative diseases (ND) is increasing at a concerning rate. The condition is characterized by the progressive decline of neuron function in the brain, eventually leading to cognitive impairment and motorneuron disorders. This process appears to be mediated by the complex interplay of factors. The brain is extremely sensitive to oxidative stress, and oxidative stress and inflammation of the nervous tissue appear to be a common denominator in all neurodegenerative diseases. One of the challenges of ND for prevention as well as treatment and treatment development, is that the initial disease progression usually goes unnoticed, with symptoms only becoming apparent in the more advanced stages when irreversible damage has occurred. Diet quality has a significant impact on brain health and hence can also influence ND development. For example, the Mediterranean diet (MedDiet) has demonstrated many valuable attributes that can reduce ND incidences and improve cognitive function. This review looked at dietary components, natural compounds and medicinal plants that have shown to be beneficial for brain health in ND. The authors discussed the MedDiet followed by a brief review of dietary supplements, including N-acetylcysteine (NAC), phospholipids (Phosphatidylserine, Phosphatidylcholine), Gamma-aminobutyric acid, melatonin, omega-3 fatty acids, neurotropic vitamin B (B1, B6 and B12), S-adenosyl methionine (SAMe), the amino acid tryptophan, magnesium and various polyphenols. Several medicinal plants are reviewed that have demonstrated positive effects on preventing or alleviating neurological diseases. This includes Withania somnifera (Ashwagandha), Baccopa monnieri (Brahmi), Acorus calamus (Calamus) and Hypericum perforatum (St. Johns Wort). The review concluded that many bioactive compounds and plant constituents that can be obtained from a qualitative diet, as well as certain medicinal plants and supplements, can help preserve and promote brain health and prevent the onset of ND. Large clinical trials are needed to assess their suitability for their wider use.
Abstract
A healthy diet shapes a healthy mind. Diet quality has a strong association with brain health. Diet influences the onset and consequences of neurological diseases, and dietary factors may influence mental health at individual and population level. The link between unhealthy diet, impaired cognitive function and neurodegenerative diseases indicates that adopting a healthy diet would ultimately afford prevention and management of neurological diseases and brain aging. Neurodegenerative diseases are of multifactorial origin and result in progressive loss of neuronal function in the brain, leading to cognitive impairment and motoneuron disorders. The so-called Mediterranean diet (MedDiet) with its healthy ingredients rich in antioxidant, anti-inflammatory, immune, neuroprotective, antidepressant, antistress and senolytic activity plays an essential role in the prevention and management of neurological diseases and inhibits cognitive decline in neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's diseases. The MedDiet also modulates the gut-brain axis by promoting a diversity of gut microbiota. In view of the importance of diet in neurological diseases management, this review focuses on the dietary components, natural compounds and medicinal plants that have proven beneficial in neurological diseases and for brain health. Among them, polyphenols, omega-3 fatty acids, B vitamins and several ayurvedic herbs have promising beneficial effects.
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Gut and Reproductive Tract Microbiota Adaptation during Pregnancy: New Insights for Pregnancy-Related Complications and Therapy.
Siena, M, Laterza, L, Matteo, MV, Mignini, I, Schepis, T, Rizzatti, G, Ianiro, G, Rinninella, E, Cintoni, M, Gasbarrini, A
Microorganisms. 2021;9(3)
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During pregnancy, several adaptations occur in the female organism. In fact, from fertilization until delivery, the maternal body changes and activates a series of physiological transformations to welcome the new life. The microbiota as a component of human bodies is subject to these modifications. This study is a review that focused on gut and reproductive tract microbiota variations during physiologic pregnancy and in case of pregnancy complications, particularly gestational diabetes mellitus (GDM), pre-eclampsia (PE), and preterm birth (PTB). Results show that: - during pregnancy, major changes have been seen in mothers’ gut microbiota. Between the first and third trimester of pregnancy, to support the foetus growth, there is a shift towards communities of microbes implicated in energy production and storage. - in nonpregnant women, vaginal microbiota could be classified into five major types, representing the community state types. - meconium’s microbes seems to be dominated by the Enterobacteriaceae family, suggesting prenatally stepwise colonization. - gut microbiota may contribute to enhanced insulin resistance in early pregnancy (1st and 2nd trimester). - microbiota imbalances in PE women are related not only with blood pressure levels but also with markers of kidney dysfunction. Thus, it is of key importance to understand the role of microbiota and other factors involved in the etiopathogenesis of PE - dysbiosis is related to PTB (however, further studies are necessary to better understand the correlation between this pregnancy complication and the specific microbiota alteration). Authors conclude that microbiota modulation could be a novel strategy to reduce the morbidity and mortality related to pregnancy complications in the future.
Abstract
Pregnancy is characterized by maternal adaptations that are necessary to create a welcoming and hospitable environment for the fetus. Studies have highlighted how the microbiota modulates several networks in humans through complex molecular interactions and how dysbiosis (defined as quantitative and qualitative alterations of the microbiota communities) is related to human pathologies including gynecological diseases. This review analyzed how maternal uterine, vaginal, and gut microbiomes could impact on fetus health during the gestational period. We evaluated the role of a dysbiotic microbiota in preterm birth, chorioamnionitis, gestational diabetes mellitus and pre-eclampsia. For many years it has been hypothesized that newborns were sterile organisms but in the past few years this paradigm has been questioned through the demonstration of the presence of microbes in the placenta and meconium. In the future, we should go deeper into the concept of in utero colonization to better understand the role of microbiota through the phases of pregnancy. Numerous studies in the literature have already showed interesting results regarding the role of microbiota in pregnancy. This evidence gives us the hope that microbiota modulation could be a novel strategy to reduce the morbidity and mortality related to pregnancy complications in the future.
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Is Premenstrual Syndrome Associated with Inflammation, Oxidative Stress and Antioxidant Status? A Systematic Review of Case-Control and Cross-Sectional Studies.
Granda, D, Szmidt, MK, Kaluza, J
Antioxidants (Basel, Switzerland). 2021;10(4)
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Premenstrual syndrome (PMS) is a set of emotional and physical symptoms, which occurs in the days leading up to a woman’s period. The cause of PMS is unknown; however, it is thought that the occurrence of inflammation in the body, an imbalance in the number of free radicals in the body and a lack of dietary antioxidants may all contribute. This systematic review of observational studies aimed to determine if inflammation and imbalanced free radicals contribute to the development of PMS. The results showed that based on 11 studies, there was a small amount of evidence to suggest that increased inflammation and decreased antioxidants is present in women with PMS. However, there was inconsistent results and insufficient data to determine whether free radical imbalance may contribute. It was concluded that further research is required to make firm conclusions on the role of free radicals and inflammation in the development of PMS. This study could be used by healthcare professionals to understand the possible mechanisms behind the development of PMS.
Abstract
Premenstrual syndrome (PMS) is a cyclically occurring combination of various symptoms, leading to decreased life quality among approximately 30% of women of childbearing age. PMS etiology remains unknown; however, there are some suggestions that inappropriate inflammatory response and oxidative stress are involved. This study aimed to systematically review case-control and cross-sectional studies investigating inflammation markers, oxidative stress, and antioxidant status among women with PMS and controls. The study protocol was registered with PROSPERO (no. CRD42020178545), and the authors followed the guidelines for performing a systemic review recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). By searching PubMed and Scopus databases (up to 8 January 2021), six case-control studies and five cross-sectional studies of medium or high quality were classified to the review. The systematic review included 652 women with PMS and 678 controls, for whom 36 eligible markers were determined. Limited evidence indicates increased levels of inflammatory parameters and suggests decreased antioxidant status in PMS women. Insufficient data with inconsistent results made it impossible to formulate a firm conclusion on the contribution of oxidative stress in PMS occurrence. To acknowledge the role of inflammation, oxidative stress, and antioxidant status in the pathophysiology of PMS, further research with case-control design and large study groups is needed.
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Contribution of Lactobacillus iners to Vaginal Health and Diseases: A Systematic Review.
Zheng, N, Guo, R, Wang, J, Zhou, W, Ling, Z
Frontiers in cellular and infection microbiology. 2021;11:792787
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The vaginal microbiome is an important contributor to vaginal health. Here the dominance of Lactobacilli species, alongside their antimicrobial compounds play a critical role in contributing and protecting the vaginal milieu. Conversely the disruption or absence of Lactobacilli dominance is frequently associated with vaginal disease and infections. One of the Lactobacilli species prevalent in the vaginal microbiome is Lactobacillus iners. It was long overlooked in research due to it being so difficult to culture, and it was first identified in 1999 thanks to DNA sequencing. Researchers since discovered that the relationship between L. iners and vaginal health is far more complicated and ambiguous compared to the other Lactobacilli species. This systematic review explores the current knowledge of the characteristics of L. iners and its role in vaginal health and disease. The article discusses L. iners identification, genetic make up and differences to other Lactobacilli species and how they relate to vaginal health. The article also summarizes L. iners nutrient requirements and its role in diseases like dysbiosis, bacterial vaginosis, sexually transmitted infections and biofilm formation. Furthermore the authors look at the relation between L. iners and premature birthing, fertility and menstrual cycles. A final section in discusses the antimicrobial and immune sytem activating qualities of L. iners. In light of all these findings the authors describe L . iners as a very unique Lactobacilli due to its unusual characteristics. Whether L. iners is beneficial or pathogenic for the host remains controversial, as it can adapt to high and low pH environment and is seen in health and equally dysbiotic states of infection. Hence some describe it as a transitional species that colonizes the vagina after disturbances. It may be a risk factor for infections by contributing to the onset and maintenance of dysbiotic disturbances. Further studies are needed to clarify the role of L. iners and its role on vaginal health and whether it could serve as a biomarker for vaginal inflammation. This article is a useful summary about the characteristics and role of L. iners in vaginal health in disease.
Abstract
Lactobacillus iners, first described in 1999, is a prevalent bacterial species of the vaginal microbiome. As L. iners does not easily grow on de Man-Rogosa-Sharpe agar, but can grow anaerobically on blood agar, it has been initially overlooked by traditional culture methods. It was not until the wide application of molecular biology techniques that the function of L. iners in the vaginal microbiome was carefully explored. L. iners has the smallest genome among known Lactobacilli and it has many probiotic characteristics, but is partly different from other major vaginal Lactobacillus species, such as L. crispatus, in contributing to the maintenance of a healthy vaginal microbiome. It is not only commonly present in the healthy vagina but quite often recovered in high numbers in bacterial vaginosis (BV). Increasing evidence suggests that L. iners is a transitional species that colonizes after the vaginal environment is disturbed and offers overall less protection against vaginal dysbiosis and, subsequently, leads to BV, sexually transmitted infections, and adverse pregnancy outcomes. Accordingly, under certain conditions, L. iners is a genuine vaginal symbiont, but it also seems to be an opportunistic pathogen. Further studies are necessary to identify the exact role of this intriguing species in vaginal health and diseases.
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Implications of the vaginal microbiome and potential restorative strategies on maternal health: a narrative review.
Moumne, O, Hampe, ME, Montoya-Williams, D, Carson, TL, Neu, J, Francois, M, Rhoton-Vlasak, A, Lemas, DJ
Journal of perinatal medicine. 2021;49(4):402-411
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Plain language summary
The vaginal microbiome is a complex community of bacteria that maintains and contributes to vaginal health and works together to protect the host from disease. Lactobacilli are the predominant species in a healthy vaginal microbiome. This review sought to summarize current evidence on how changes in the vaginal microbiome composition before and throughout pregnancy influence and contribute to several health conditions. The authors investigated the role of the vaginal microbiome in fertility and in-vitro fertilization (IVF), where evidence is still conflicting, followed by conditions that can present during pregnancy such as preterm labour, gestational diabetes, and preeclampsia. In preterm labour, lower levels of Lactobacillus and its D-lactic acid secretions have been observed as a common denominator; in gestational diabetes, it remains unclear whether the changes in the vaginal microbiome associated with the condition are causative or rather a result of the condition. Little research has been done regarding preeclampsia, but initial studies indicate there may be a link between the condition and the vaginal microbiome. The authors also reviewed the evidence on methods of restoring vaginal health, including oral and vaginally applied probiotics as well as vaginal microbiome transplants (VMT) - the transfer of vaginal secretions from a healthy donor. The paper discusses the evidence on the use of oral and locally applied probiotics for the aforementioned conditions, and the promising potential of VMTs alongside the risks and regulatory challenges that come with it. This review provides a helpful summary of the current understanding of the role of the vaginal microbiome in fertility and throught pregnancy.
Abstract
The vaginal microbiome undergoes dramatic shifts before and throughout pregnancy. Although the genetic and environmental factors that regulate the vaginal microbiome have yet to be fully elucidated, high-throughput sequencing has provided an unprecedented opportunity to interrogate the vaginal microbiome as a potential source of next-generation therapeutics. Accumulating data demonstrates that vaginal health during pregnancy includes commensal bacteria such as Lactobacillus that serve to reduce pH and prevent pathogenic invasion. Vaginal microbes have been studied as contributors to several conditions occurring before and during pregnancy, and an emerging topic in women's health is finding ways to alter and restore the vaginal microbiome. Among these restorations, perhaps the most significant effect could be preterm labor (PTL) prevention. Since bacterial vaginosis (BV) is known to increase risk of PTL, and vaginal and oral probiotics are effective as supplemental treatments for BV prevention, a potential therapeutic benefit exists for pregnant women at risk of PTL. A new method of restoration, vaginal microbiome transplants (VMTs) involves transfer of one women's cervicovaginal secretions to another. New studies investigating recurrent BV will determine if VMTs can safely establish a healthy Lactobacillus-dominant vaginal microbiome. In most cases, caution must be taken in attributing a disease state and vaginal dysbiosis with a causal relationship, since the underlying reason for dysbiosis is usually unknown. This review focuses on the impact of vaginal microflora on maternal outcomes before and during pregnancy, including PTL, gestational diabetes, preeclampsia, and infertility. It then reviews the clinical evidence focused on vaginal restoration strategies, including VMTs.