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An insight into the functional alterations in the gut microbiome of healthy adults in response to a multi-strain probiotic intake: a single arm open label trial.
Rodenes-Gavidia, A, Lamelas, A, Bloor, S, Hobson, A, Treadway, S, Haworth, J, Vijayakumar, V, Naghibi, M, Day, R, Chenoll, E
Frontiers in cellular and infection microbiology. 2023;13:1240267
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The human gut microbiota is a key mediator of host health and is known to affect many physiological processes, such as digestion, metabolism, immune function and inhibition of pathogen colonisation. The gut microbiome can be impacted by many extrinsic factors. The aim of this study was to assess both compositional and functional changes in the microbiome of healthy individuals using shotgun metagenomics following 8-weeks of daily multi-strain probiotic intake. This study was a single-arm open-label study which enrolled a total of 41 healthy adult males and females between 18 to 40 years old. Results showed that alpha- and beta-diversity of the faecal microbiota structure was not significantly altered in response to probiotic intake. However, significant changes were observed when functional genes were assessed. Abundance of certain genes involved in several functional pathways were also significantly altered. Additionally, there were no significant changes in stool frequency or consistency, faecal biochemistry, or breath tests of methane and hydrogen observed. Authors conclude that the findings of their study have the potential to provide insights into the underlying mechanisms of action of the 14-strain probiotic blend in healthy adults.
Abstract
BACKGROUND Probiotic supplements, by definition, provide a benefit to the host, but few studies have investigated the effect of probiotic supplements in healthy adult populations. PURPOSE The present, single arm, open label clinical trial, evaluated compositional and functional changes in the fecal microbiome of healthy adults after supplementation with a 14-strain probiotic. METHODS We analysed the effect of a 14-strain probiotic blend (Bacillus subtilis NCIMB 30223, Bifidobacterium bifidum NCIMB 30179, B. breve NCIMB 30180, B. infantis NCIMB 30181, B. longum NCIMB 30182, Lactobacillus helveticus NCIMB 30184, L. delbrueckii subsp. bulgaricus NCIMB 30186, Lacticaseibacillus paracasei NCIMB 30185, Lactiplantibacillus plantarum NCIMB 30187, Lacticaseibacillus rhamnosus NCIMB 30188, L. helveticus NCIMB 30224, Lactobacillus salivarius NCIMB 30225, Lactococcus lactis subsp. lactis NCIMB 30222, and Streptococcus thermophilus NCIMB 30189), on the faecal microbiota of healthy young adults (n=41) in a single arm study. The adults consumed 4 capsules daily of the 14 strain blend(8 billion colony forming units/day) for 8 weeks. Compositional and functional changes in faecal microbiota before and after supplementation were assessed using shotgun metagenomic sequencing. Fasting breath analysis, faecal biochemistry and bowel habits were also assessed. RESULTS In healthy adult participants, no significant changes to the overall alpha- or beta-diversity was observed after 8 weeks of multi-strain probiotic supplementation. However, in a simplified model that considered only time and individual differences, significant decreases (p < 0.05) in family Odoribacteraceae and Bacteroidaceae abundance and a significant increase (p < 0.05) in genus Megamonas abundance were observed. At a functional level, there were significant changes in functional gene abundance related to several functional pathways, including phenylalanine metabolism, O-antigen nucleotide sugar biosynthesis, bacterial chemotaxis, and flagellar assembly. No significant changes in stool form or frequency, fecal biochemistry, or methane and hydrogen breath tests were observed. CONCLUSION In healthy young adults, overall alpha- and beta-diversity did not change in response to probiotic intake even though modest compositional changes at the family and genus level were observed. However, at functional level, results identified changes in gene abundance for several functional pathways.
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Blueberries Improve Abdominal Symptoms, Well-Being and Functioning in Patients with Functional Gastrointestinal Disorders.
Wilder-Smith, CH, Materna, A, Olesen, SS
Nutrients. 2023;15(10)
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Functional gastrointestinal disorders (FGID) are the most common cause of recurring, chronic digestive upsets. Irritable bowel syndrome (IBS) and functional dyspepsia (FD), or persistent indigestion, are the most prevalent types of those disorders. Typical symptoms include pain or discomfort in the abdomen, changes in stool patterns or bloating and may also manifest in symptoms not directly relating to the digestive tract. It remains uncertain what the exact mechanisms of those disorders are. However, scientists identified various factors involved, including immune system activation, sensitisation of the nervous system, dysregulated permeability of the gut walls, and changes in the microbiota, their composition and metabolic activity. Polyphenols are natural compounds found abundantly in plants and are most known for their antioxidant qualities. One frequently studied and rich-source of phenols is Blueberries (Vaccinium spp). Blueberries have antioxidant, anti-inflammatory, and neuroprotective properties, and are known to reverse the permeability of the gut membrane. Hence their use in the management of FGID appeared promising. This double-blind, randomized, cross-over study assessed the benefit of blueberries in 43 people with IBS or FD, between 18–60 years of age. The candidates were given 30g freeze-dried blueberries, the equivalent of 180g of fresh blueberries, or a sugar-based placebo of similar calorific value for 6-weeks each. When receiving the blueberries, greater symptom relief was observed when compared to the placebo group. Blueberry intake also positively reflected in experienced improvement in quality of life. No notable differences were observed between groups in stool patterns and fructose digestion. Blueberries and their beneficial compounds such as polyphenols and fiber appear to have a wide range of benefits that can help manage some of the FGID-associated symptoms. Further studies are needed to understand why, despite some notable benefits, some of the other GI markers remained unaffected. As blueberries are generally well tolerated, they can be a simple and helpful food intervention to complement other FGID management strategies.
Abstract
Blueberries beneficially modulate physiologic mechanisms relevant to the pathogenesis of functional gastrointestinal disorders (FGID). Forty-three patients with FGID received freeze-dried blueberries (equivalent to 180 g fresh blueberries) or sugar and energy-matched placebo in a double-blind, randomized, cross-over study. After 6 weeks of treatment, the differences in Gastrointestinal Clinical Rating Scale (GSRS) scores and abdominal symptom relief were compared as primary outcome measures. The quality of life and life functioning ratings (OQ45.2 questionnaire), Bristol stool scales, and fructose breath test results constituted secondary outcome measures. Blueberry treatment resulted in more patients with relevant abdominal symptom relief compared to placebo (53% vs. 30%, p = 0.03). Total and pain GSRS scores improved insignificantly (mean treatment differences [95% CI]: -3.4 [-7.4 to 0.6] (p = 0.09) and -1.0 [-2.2 to 0.1] (p = 0.08), respectively). OQ45.2 scores improved during blueberry treatment compared to placebo (treatment difference -3.2 [95% CI: -5.6 to -0], p = 0.01). Treatment effect differences for the further measures did not reach statistical significance. Blueberries relieved abdominal symptoms and improved general markers of well-being, quality of life, and life functioning more than placebo in patients with FGID. Consequently, the polyphenol and fiber components of blueberries exert broad beneficial effects separate from the sugars present in both treatments.
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Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial.
Roager, HM, Vogt, JK, Kristensen, M, Hansen, LBS, Ibrügger, S, Mærkedahl, RB, Bahl, MI, Lind, MV, Nielsen, RL, Frøkiær, H, et al
Gut. 2019;68(1):83-93
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Whole grain consumption has been linked with decreased risk of lifestyle-related diseases. While animal studies have shown the gut microbiome to be a mediator of metabolic health, human studies examining the effect of whole grain intake of the gut remain inconclusive. The aim of this study was to investigate the effects of a whole grain diet on the gut microbiome, gut functionality and biomarkers of metabolic health. In this randomised, controlled, crossover study, 50 participants completed two 8-week dietary intervention periods comprising of a whole grain diet and a refined grain diet with a 6-week washout period. Examinations were done at the beginning and end of each intervention period to assess anthropometry and various plasma and gut markers. This study found that a whole grain diet as compared with a refined grain diet reduced energy intake and body weight as well as circulating markers of inflammation. Contrary to the hypothesis, these benefits were all observed independent of changes in the gut microbiome. Based on these results, the authors conclude higher intake of whole grains should be recommended to those at risk of inflammation-related disease.
Abstract
OBJECTIVE To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. DESIGN 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ≥6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory markers, anthropometry and urine metabolomics were assessed. RESULTS 50 participants completed both periods with a whole grain intake of 179±50 g/day and 13±10 g/day in the whole grain and refined grain period, respectively. Compliance was confirmed by a difference in plasma alkylresorcinols (p<0.0001). Compared with refined grain, whole grain did not significantly alter glucose homeostasis and did not induce major changes in the faecal microbiome. Also, breath hydrogen levels, plasma short-chain fatty acids, intestinal integrity and intestinal transit time were not affected. The whole grain diet did, however, compared with the refined grain diet, decrease body weight (p<0.0001), serum inflammatory markers, interleukin (IL)-6 (p=0.009) and C-reactive protein (p=0.003). The reduction in body weight was consistent with a reduction in energy intake, and IL-6 reduction was associated with the amount of whole grain consumed, in particular with intake of rye. CONCLUSION Compared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic low-grade inflammation. TRIAL REGISTRATION NUMBER NCT01731366; Results.
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Effects of Mediterranean Diet and Physical Activity on Pulmonary Function: A Cross-Sectional Analysis in the ILERVAS Project.
Gutiérrez-Carrasquilla, L, Sánchez, E, Hernández, M, Polanco, D, Salas-Salvadó, J, Betriu, À, Gaeta, AM, Carmona, P, Purroy, F, Pamplona, R, et al
Nutrients. 2019;11(2)
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The Mediterranean diet is characterised by an abundant consumption of extra-virgin olive oil, fruits, vegetables, nuts, and legumes, a moderate consumption of fish and seafood, poultry, fermented dairy products, and red wine with meals, and low intakes of sweetened beverages, red meat and ready meals. The aim of the study was to evaluate the association between adherence to a Mediterranean diet and physical activity on pulmonary function in a large middle-aged population at low-to-moderate cardiovascular risk. The study is an ongoing study that between 2015 and 2017 enrolled a total of 3020 subjects – women aged between 50 to 70 years and men aged between 45 to 65 years – with the presence of at least one cardiovascular risk factor. Results indicate that a low adherence to the Mediterranean diet was linked with impaired breathing patterns and higher prevalence of abnormal lung function when compared to participants with a higher adherence to this dietary pattern. Additionally, vigorous physical activity was accompanied by better results in lung function than that observed in inactive subjects. The study provides initial clinical evidence about the independent and deleterious effect of both low adherence to the Mediterranean diet and low physical activity practice on lung function in participants without known pulmonary disease.
Abstract
A few studies showed that both adherence to Mediterranean diet (MedDiet) and physical activity practice have a positive impact on pulmonary function in subjects with lung disease. These associations are not well studied in subjects free from lung disease. In a cross-sectional study conducted in 3020 middle-aged subjects free of lung disease, adherence to the MedDiet using the Mediterranean Diet Adherence Screener, and physical activity practice using the International Physical Activity Questionnaire short form were recorded. Respiratory function was assessed using forced spirometry and the results were evaluated according to the Global initiative for Chronic Obstructive Lung Disease. Logistic regression models were used to analyze the associations between adherence to the MedDiet and physical activity practice with the presence of ventilatory defects. Participants with a high adherence to MedDiet, in comparison to those with low adherence, had both higher forced vital capacity (FVC; 100 (87⁻109) vs. 94 (82⁻105) % of predicted, p = 0.003) and forced expired volume in the first second (FEV1; 100 (89⁻112) vs. 93 (80⁻107) % of predicted, p < 0.001). According to their degree of physical activity, those subjects with a high adherence also had both higher FVC (100 (88⁻107) vs. 94 (83⁻105) % of predicted, p = 0.027) and FEV1 (100 (89⁻110) vs. 95 (84⁻108) % of predicted, p = 0.047) in comparison with those with low adherence. The multivariable logistic regression models showed a significant and independent association between both low adherence to MedDiet and low physical activity practice, and the presence of altered pulmonary patterns, with differences between men and women. However, no joint effect between adherence to MedDiet and physical activity practice on respiratory function values was observed. Low adherence to MedDiet and low physical activity practice were independently associated with pulmonary impairment. Therefore, the lung mechanics seem to benefit from heart-healthy lifestyle behaviors.
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Brain fogginess, gas and bloating: a link between SIBO, probiotics and metabolic acidosis.
Rao, SSC, Rehman, A, Yu, S, Andino, NM
Clinical and translational gastroenterology. 2018;9(6):162
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D-lactic acid is produced by intestinal bacteria and a rise in levels can lead to D-lactic acidosis, causing neurological changes such as slurred speech and gait disturbances. This is frequently observed in short bowel syndrome. This small, observational study aimed to determine if brain fogginess (mental confusion, impaired judgement, poor short-term memory and difficulty concentrating) and intestinal gas and bloating is associated with D-lactic acidosis and small intestinal bacterial overgrowth (SIBO). 38 patients presenting with gas and bloating in the absence of short bowel syndrome, and with or without brain fog were assessed. All patients with brain fog were consuming probiotics, with a higher proportion of them diagnosed with SIBO and D-lactic acidosis, when compared to the non-brain fog group. The researchers stopped probiotics in all patients and administered antibiotics, observing a significant reduction in brain fog and gastrointestinal symptoms. Whilst this is a small, observational study, nutrition practitioners may wish to assess the likelihood of SIBO and D-lactic acidosis before recommending probiotics, especially in the presence of brain fog.
Abstract
BACKGROUND D-lactic acidosis is characterized by brain fogginess (BF) and elevated D-lactate and occurs in short bowel syndrome. Whether it occurs in patients with an intact gut and unexplained gas and bloating is unknown. We aimed to determine if BF, gas and bloating is associated with D-lactic acidosis and small intestinal bacterial overgrowth (SIBO). METHODS Patients with gas, bloating, BF, intact gut, and negative endoscopic and radiological tests, and those without BF were evaluated. SIBO was assessed with glucose breath test (GBT) and duodenal aspiration/culture. Metabolic assessments included urinary D-lactic acid and blood L-lactic acid, and ammonia levels. Bowel symptoms, and gastrointestinal transit were assessed. RESULTS Thirty patients with BF and 8 without BF were evaluated. Abdominal bloating, pain, distension and gas were the most severe symptoms and their prevalence was similar between groups. In BF group, all consumed probiotics. SIBO was more prevalent in BF than non-BF group (68 vs. 28%, p = 0.05). D-lactic acidosis was more prevalent in BF compared to non-BF group (77 vs. 25%, p = 0.006). BF was reproduced in 20/30 (66%) patients. Gastrointestinal transit was slow in 10/30 (33%) patients with BF and 2/8 (25%) without. Other metabolic tests were unremarkable. After discontinuation of probiotics and a course of antibiotics, BF resolved and gastrointestinal symptoms improved significantly (p = 0.005) in 23/30 (77%). CONCLUSIONS We describe a syndrome of BF, gas and bloating, possibly related to probiotic use, SIBO, and D-lactic acidosis in a cohort without short bowel. Patients with BF exhibited higher prevalence of SIBO and D-lactic acidosis. Symptoms improved with antibiotics and stopping probiotics. Clinicians should recognize and treat this condition.