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Synbiotic as an ameliorating factor in the health-related quality of life in women with polycystic ovary syndrome. A randomized, triple-blind, placebo-controlled trial.
Hariri, Z, Yari, Z, Hoseini, S, Abhari, K, Sohrab, G
BMC women's health. 2024;24(1):19
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Polycystic ovary syndrome (PCOS), as a chronic endocrine disorder, can affect many aspects of young women’s lives. Apart from physical complications, women with polycystic ovary syndrome are more likely to suffer from mental and behavioural disorders. The aim of this study was to examine whether synbiotic supplementation could improve the health quality of life of women with PCOS. This study was a triple-blind, randomised clinical trial which recruited women with polycystic ovary syndrome. Participants were randomly divided into synbiotic or placebo groups for 12 weeks. Results showed that synbiotic supplementation improved the scores of emotional, body hair, weight and infertility domains of PCOSQ-26 compared to placebo group. Authors concluded that 12-week supplementation with synbiotics could noticeably improve the emotional, body hair, weight, infertility and general physical health status of women with polycystic ovary syndrome.
Abstract
BACKGROUND There are complicated mechanisms that link the disruption of the gut microbiome to the symptoms and complications of polycystic ovary syndrome (PCOS). In this study, an attempt was made to assess the effects of synbiotics on the health-related quality of life (HRQoL) in women with PCOS . METHODS Fifty-six women with PCOS were enrolled in a triple-blind controlled trial for 12 weeks. They were randomly assigned to receive a daily 2-gram synbiotic sachets (containing Bacillus coagulans (GBI-30), Lactobacillus rhamnosus, Lactobacillus helveticus, and fructooligosaccharide) (n = 28) or placebo (n = 28). To evaluate the impact on the HRQoL, participants were required to fill 26-Item Polycystic Ovary Syndrome Health-Related Quality of Life Questionnaire (PCOSQ-26), 12-Item Short-Form Health Survey (SF-12) and Perceived Stress Scale (PSS-10) pre and post the intervention. RESULTS Finally, statistical analyses were performed on 52 participants who finished the trial. Synbiotic supplementation improved the scores of emotional (P = 0.044), body hair (P = 0.016), weight (P = 0.033) and infertility domains (P = 0.027) of PCOSQ-26 compared to placebo group. The physical score within SF-12 also had a significant enhancement (P = 0.035). No significant improvement was seen in the PSS-10 score at the end of the trial. CONCLUSION This study illustrated the advantageous effects of synbiotics on the health-related quality of life in women with PCOS. Further studies are required to confirm our findings. TRIAL REGISTRATION http://www.irct.ir : IRCT20211108053007N1; date of registration: 14/02/2023.
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The Influence of Whey Protein on Muscle Strength, Glycemic Control and Functional Tasks in Older Adults with Type 2 Diabetes Mellitus in a Resistance Exercise Program: Randomized and Triple Blind Clinical Trial.
Soares, ALS, Machado-Lima, A, Brech, GC, Greve, JMD, Dos Santos, JR, Inojossa, TR, Rogero, MM, Salles, JEN, Santarem-Sobrinho, JM, Davis, CL, et al
International journal of environmental research and public health. 2023;20(10)
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Type 2 Diabetes Mellitus (T2DM) is a common metabolic disease and the prevalence of T2DM is increasing among older adults. Resistance training is known to be an effective therapeutic strategy as it can positively influence the mechanisms of T2DM pathophysiology. Previous research suggests that whey protein supplementation can positively influence the different mechanisms of T2DM pathophysiology and improve muscle mass and glycaemic control. This triple-blinded, randomised controlled parallel-arm trial included twenty-eight male older adults to assess the effect of whey protein supplementation combined with resistance training for twelve weeks on glycaemic control, functional tasks, muscle strength, and body composition. The control group was supplemented with maltodextrin. All participants followed resistance training and were given nutritional guidance. Twelve weeks of resistance training improved muscle strength significantly. However, 20g whey protein supplementation did not improve performance in functional tasks, glycaemic control, or body composition in the test group of older adults with T2DM. Whey protein supplementation showed no significant synergetic effects when combined with resistance training in the test group. Due to the heterogeneity of the present study, further robust studies are warranted to investigate the effects of whey protein supplementation and resistance training. However, healthcare professionals can use the results of this study to understand the effect of resistance training alone and the safety profile of whey protein supplementation in older adults with T2DM.
Abstract
OBJECTIVES To evaluate the effect of whey protein (WP) supplementation associated with resistance training (RT) on glycemic control, functional tasks, muscle strength, and body composition in older adults living with type 2 diabetes mellitus (T2DM). Secondly, to evaluate the safety of the protocol for renal function. METHODS The population comprised twenty-six older men living with T2DM (68.5 ± 11.5 years old). The participants were randomly assigned to the Protein Group (PG) and the Control Group (CG). The handgrip test and evolution of exercise loads, according to the Omni Resistance Exercise Scale, evaluated muscle strength. Functional tasks were assessed by force platform in three different protocols: Sit-to-Stand, Step/Quick Turn, and Step Up/Over. Body composition was evaluated by bioimpedance and glycemic control and renal function were assessed by biochemical analyses. Both groups performed RT for 12 weeks, twice a week, prioritizing large muscle groups. Protein supplementation was 20 g of whey protein isolate and the CG was supplemented with an isocaloric drink, containing 20 g of maltodextrin. RESULTS There was a significant difference in muscle strength, according to the evolution of the exercise loads, but it was not confirmed in the handgrip test. However, there was no significant difference between the groups, regarding performance in functional tasks, glycemic control, or body composition. Renal function showed no alteration. CONCLUSION The intake of 20 g of WP in older male adults living with T2DM did not increase the effect of RT on muscle strength, functional tasks, and glycemic control. The intervention was proven safe regarding renal function.
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Nicotinamide adenine dinucleotide metabolism and arterial stiffness after long-term nicotinamide mononucleotide supplementation: a randomized, double-blind, placebo-controlled trial.
Katayoshi, T, Uehata, S, Nakashima, N, Nakajo, T, Kitajima, N, Kageyama, M, Tsuji-Naito, K
Scientific reports. 2023;13(1):2786
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Nicotinamide adenine dinucleotide (NAD+) is a coenzyme that plays a crucial role in energy metabolism and different biological processes. Sirtuins (SIRT1) are NAD+-dependent deacetylases, an enzyme that plays a key role in enhancing metabolic efficiency. Nicotinamide mononucleotide (NMN) is a precursor to NAD+. NMN supplementation may help to reduce the risk of developing metabolic diseases and cardiovascular diseases. This randomised, double-blinded, and placebo-controlled, parallel trial investigated the effects of 12 weeks of 125 mg NMN supplementation on metabolic health parameters, including CVD risk factors, blood NAD+ metabolites level, and SIRT1 expression in middle-aged men and women. Serum nicotinamide was significantly higher and arterial stiffness was lower in the NMN test group of middle-aged men and women after 12 weeks of NMN supplementation. The results of the study indicate that the administration of 250mg of nicotinamide mononucleotide (NMN) daily for an extended period is considered safe and well-tolerated. Healthcare professionals can use this finding to understand the significant implications of the use of NMN as a potential therapeutic agent in individuals seeking to improve their metabolic and cardiovascular health. Further robust studies are required to evaluate the effects of NMN supplementation due to the limitations and high baseline variability between the participants of this study.
Expert Review
Conflicts of interest:
None
Take Home Message:
- As we age, NAM levels decline, which could have a negative effect on cardiovascular health.
- Middle-aged adults may like to consider NMN supplementation to improve NAM metabolism and arterial stiffness.
- However, without data on CVD events, it is difficult to determine actual risk reductions.
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
- Nicotinamide adenine dinucleotide (NAD+) is a coenzyme involved in metabolism. When we age, NAD+ levels decline resulting in poorer metabolism and age-related disease such as cardiovascular disease (CVD). Nicotinamide mononucleotide (NMN) is a precursor in the biosynthesis of NAD+.
- This double-blind, randomised control trial aimed to determine the effect of supplementing NMN on NAD+ levels, CVD risk factors and sirtuin 1 (SIRT1) expression, which relies on NAD+ for adequate functioning.
Methods
- 36 healthy male and female individuals aged between 40-65 years of age were assigned to either NMN (125mg/day) or placebo for 12 weeks.
- One capsule was taken twice per day after meals.
- Serum nicotinamide (NAM), NAD+, NMN, advanced glycation end products (AGES), 8-hydroxydeoxyguanosine (8-OHdG) and SIRT1 mRNA expression were measured.
- The condition of blood vessels (arterial stiffness) was also assessed using the ankle brachial index (ABI).
- In a sub-analysis, individuals with hypertension, above average body mass index (BMI), or blood glucose level were also assessed for blood vessel condition using the ABI.
Results
- The results showed that from baseline serum NAM decreased in the placebo group (P=0.014), whereas it increased in the NMN group (P=0.006). This resulted in an increase in the NMN group compared to placebo (P=0.037).
- Interestingly serum NAM was lower in the NMN group compared to placebo at baseline (P=0.001).
- There was no statistically significant difference in ABI with NMN supplementation.
- Amongst those with hypertension there was also no change in ABI. However, those with high BMI or blood glucose, there was an improvement in vascular condition compared to placebo (P=<0.007 and P=0.019 respectively).
- 8-OHdG, SIRT1 mRNA and AGEs remained unchanged by NMN supplementation
Conclusion
- NMN supplementation enhanced NAD+ metabolism in middle-aged adults.
- It also relieved arterial stiffness and reduced CVD risk factors.
Clinical practice applications:
- Apparently healthy middle-aged adults who would like to activate NAD metabolism and decrease their risk for CVD, should consider 12-week supplementation with NMN (125mg/day).
- ABI should be monitored to ensure desired effects.
- It is unclear as to the effects of NMN supplementation after 12-weeks.
Considerations for future research:
- Future research should consider longer supplementation duration and/or adding in a follow-up period to determine duration of effect.
- Different supplemental doses should also be researched to determine an optimal dose.
Abstract
Many animal studies have shown that oral administration of the nicotinamide adenine dinucleotide (NAD+) precursor nicotinamide mononucleotide (NMN) prevents the reduction of NAD+ levels in organs and tissues, helping alleviate aging-related diseases. However, there are very few clinical reports of NMN supplementation in humans. Thus, this study aimed to investigate the influence of a 12-week NMN oral supplementation on biochemical and metabolic health parameters. A 12-week randomized, double-blind, placebo-controlled, parallel-group clinical trial was conducted. A total of 36 healthy middle-aged participants received one capsule of either 125 mg NMN or placebo twice a day. Among the NAD+ metabolites, the levels of nicotinamide in the serum were significantly higher in the NMN intake group than in the placebo group. Pulse wave velocity values indicating arterial stiffness tended to decrease in the NMN intake group. However, no significant difference was found between the two groups. Long-term NMN supplementation at 250 mg/day was well tolerated and did not cause adverse events. NMN safely and effectively elevated NAD+ metabolism in healthy middle-aged adults. Additionally, NMN supplementation showed potential in alleviating arterial stiffness.
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A dietary intervention for vasomotor symptoms of menopause: a randomized, controlled trial.
Barnard, ND, Kahleova, H, Holtz, DN, Znayenko-Miller, T, Sutton, M, Holubkov, R, Zhao, X, Galandi, S, Setchell, KDR
Menopause (New York, N.Y.). 2023;30(1):80-87
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Postmenopausal vasomotor symptoms cause recurrent discomfort, disrupt sleep, and reduce quality of life. A role for nutritional factors in vasomotor symptoms was suggested by their low prevalence in areas where traditional dietary staples included grains, legumes, vegetables, and other plant-derived foods. The aim of this study was to investigate the effects of a dietary intervention on vasomotor symptoms and menopause-related quality of life. This study is a randomised controlled study. Eighty-four participants were randomly assigned, in two cohorts; the intervention or control group. Results show that the dietary intervention led to clinically important reductions in menopausal symptoms. In fact, there was an 88% reduction in moderate-to-severe vasomotor events among participants in the intervention-group, accompanied by weight loss and improvements in physical, psychosocial, and sexual domains. Authors conclude that a dietary intervention, combining a reduced-fat vegan diet and daily soybeans, was associated with a marked reduction in postmenopausal vasomotor events, significant weight loss, and reductions in physical and sexual symptoms.
Abstract
OBJECTIVE Postmenopausal vasomotor symptoms disrupt quality of life. This study tested the effects of a dietary intervention on vasomotor symptoms and menopause-related quality of life. METHODS Postmenopausal women (n = 84) reporting at least two moderate-to-severe hot flashes daily were randomly assigned, in two successive cohorts, to an intervention including a low-fat, vegan diet and cooked soybeans (½ cup [86 g] daily) or to a control group making no dietary changes. During a 12-week period, a mobile application was used to record hot flashes (frequency and severity), and vasomotor, psychosocial, physical, and sexual symptoms were assessed with the Menopause-Specific Quality of Life questionnaire. Between-group differences were assessed for continuous ( t tests) and binary ( χ2 /McNemar tests) outcomes. In a study subsample, urinary equol was measured after the consumption of ½ cup (86 g) of cooked whole soybeans twice daily for 3 days. RESULTS In the intervention group, moderate-to-severe hot flashes decreased by 88% ( P < 0.001) compared with 34% for the control group ( P < 0.001; between-group P < 0.001). At 12 weeks, 50% of completers in the intervention group reported no moderate-to-severe hot flashes at all. Among controls, there was no change in this variable from baseline ( χ2 test, P < 0.001). Neither seasonality nor equol production status was associated with the degree of improvement. The intervention group reported greater reductions in the Menopause-Specific Quality of Life questionnaire vasomotor ( P = 0.004), physical ( P = 0.01), and sexual ( P = 0.03) domains. CONCLUSIONS A dietary intervention consisting of a plant-based diet, minimizing oils, and daily soybeans significantly reduced the frequency and severity of postmenopausal hot flashes and associated symptoms.
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Effectiveness of a minimally processed food-based nutritional counselling intervention on weight gain in overweight pregnant women: a randomized controlled trial.
Sartorelli, DS, Crivellenti, LC, Baroni, NF, de Andrade Miranda, DEG, da Silva Santos, I, Carvalho, MR, de Lima, MC, Carreira, NP, Chaves, AVL, Manochio-Pina, MG, et al
European journal of nutrition. 2023;62(1):443-454
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Excessive gestational weight gain exposes the woman and the child to a higher risk of harmful health outcomes in the short and long term. Dietary patterns based on the substitution of meals made with unprocessed or minimally processed foods for the consumption of ultra-processed items can be partly blamed for the exponential global growth in the incidence of obesity. The main aim of this study was to evaluate the effectiveness of a nutritional intervention based on encouraging the consumption of unprocessed and minimally processed foods rather than ultra-processed products. This study is a two-armed parallel randomised controlled trial conducted among overweight, pregnant women receiving prenatal care in seven primary health units. Participants (n=350) were randomly allocated into the intervention group (IG) or control group (CG). The women allocated into the IG, in addition to the usual prenatal care, were invited to participate in three individualised nutritional counselling sessions conducted by trained nutritionists. Results show that even though there were more women in the IG who had increased their daily intake of minimally processed foods and vegetables at lunch time when compared to the CG, this was not statistically significant. Additionally, there weren’t any differences between the groups in relation to physical activity. Authors conclude that their study was unprecedented in demonstrating that a nutritional counselling intervention based on the NOVA food classification system, together with the practice of physical activity, is effective in preventing excessive gestational weight gain in overweight pregnant women.
Abstract
PURPOSE This study aimed at evaluating the effectiveness of a nutritional counselling intervention based on encouraging the consumption of unprocessed and minimally processed foods, rather than ultra-processed products, and the practice of physical activities to prevent excessive gestational weight gain in overweight pregnant women. METHODS This was a two-armed, parallel, randomized controlled trial conducted in primary health units of a Brazilian municipality from 2018 to 2021. Overweight, adult pregnant women (n = 350) were randomly assigned to control (CG) or intervention groups (IG). The intervention consisted of three individualized nutritional counselling sessions based on encouraging the consumption of unprocessed and minimally processed foods rather than ultra-processed products, following the NOVA food classification system, and the practice of physical activities. The primary outcome was the proportion of women whose weekly gestational weight gain (GWG) exceeded the Institute of Medicine guidelines. Adjusted logistic regression models were employed. RESULTS Complete data on weight gain were available for 121 women of the IG and 139 of the CG. In modified intention-to-treat analysis, there was a lower chance of the IG women having excessive GWG [OR 0.56 (95% CI 0.32, 0.98), p = .04], when compared to the CG. No between-group differences were observed for the other maternal outcomes investigated. CONCLUSION The present study was unprecedented in demonstrating that nutritional counselling based on the NOVA food classification system, together with encouraging the practice of physical activity, is effective in preventing excessive weight gain in overweight pregnant women. TRIAL REGISTRATION Registered on July 30th 2018 at Brazilian Registry of Clinical Trials (RBR-2w9bhc).
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Docosahexaenoic acid (DHA) intake estimated from a 7-question survey identifies pregnancies most likely to benefit from high-dose DHA supplementation.
Christifano, DN, Crawford, SA, Lee, G, Brown, AR, Camargo, JT, Kerling, EH, Gajewski, BJ, Valentine, CJ, Gustafson, KM, DeFranco, EA, et al
Clinical nutrition ESPEN. 2023;53:93-99
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Preterm birth (PTB) is the primary cause of infant mortality worldwide; and infants who survive have a higher risk of child disability. A recent Cochrane Review concluded that there is strong evidence that omega-3 fatty acids, especially docosahexaenoic acid (DHA), reduce early PTB (EPTB, <34 weeks gestation) and PTB (<37 weeks gestation) by 42% and 11%, respectively. The aim of this study was to investigate whether DHA intake at baseline alone could identify pregnancies for which high dose DHA supplementation lowered risk of EPTB and PTB. This study used the results from two randomised clinical trials of DHA supplementation during pregnancy in which participants completed the DHA-Food Frequency Questionnaire (FFQ) before randomisation to 200mg/day or high dose DHA, i.e., 800mg/day or 1000mg/day. A total of 1400 participants were enrolled in the two trials. Results show that the DHA-FFQ predicted participants whose risk of EPTB and PTB was reduced by consuming a DHA supplement of 800mg/day or 1000mg/day compared to 200mg/day. In fact, participants who started the study with an average daily DHA intake of <150mg had a 64% lower rate of EPTB and a 24% lower rate of PTB if they were assigned to 800mg/day or 1000mg/day compared to 200mg/day DHA. Authors conclude that the DHA-FFQ identifies women who could benefit from high dose DHA supplementation at least as effectively as a blood measure of DHA but with far fewer barriers for clinical implementation.
Abstract
BACKGROUND Two randomized trials found women with low blood docosahexaenoic acid (DHA; an omega 3 fatty acid) had fewer early preterm births (<34 weeks gestation) if they were assigned to high dose DHA supplementation, however, there is currently no capacity for clinicians who care for pregnancies to obtain a blood assessment of DHA. Determining a way to identify women with low DHA intake whose risk could be lowered by high dose DHA supplementation is desired. OBJECTIVE To determine if assessing DHA intake can identify pregnancies that benefit from high dose DHA supplementation. STUDY DESIGN This secondary analysis used birth data from 1310 pregnant women who completed a 7-question food frequency questionnaire (DHA-FFQ) at 16.8 ± 2.5 weeks gestation that is validated to assess DHA status. They were then randomly assigned to a standard (200 mg/day) or high dose (800 or 1000 mg/day) DHA supplement for the remainder of pregnancy. Bayesian logistic regressions were fitted for early preterm birth and preterm birth as a function of DHA intake and assigned DHA dose. RESULTS Participants who consumed less than 150 mg/day DHA prior to 20 weeks' gestation (n = 810/1310, 58.1%) had a lower Bayesian posterior probability (pp) of early preterm birth if they were assigned to high dose DHA supplementation (1.4% vs 3.9%, pp = 0.99). The effect on preterm birth (<37 weeks) was also significant (11.3% vs 14.8%, pp = 0.97). CONCLUSION The DHA-FFQ can identify pregnancies that will benefit most from high dose DHA supplementation and reduce the risk of preterm birth. The DHA-FFQ is low burden to providers and patients and could be easily implemented in obstetrical practice.
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High-fiber diet ameliorates gut microbiota, serum metabolism and emotional mood in type 2 diabetes patients.
Chen, L, Liu, B, Ren, L, Du, H, Fei, C, Qian, C, Li, B, Zhang, R, Liu, H, Li, Z, et al
Frontiers in cellular and infection microbiology. 2023;13:1069954
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Accumulating studies have demonstrated that there are strong correlations between type 2 diabetes mellitus (T2DM) and gut microbiota. A nutritious diet composed of an adequate level of dietary fibres could provide enough carbohydrates for the gut microbiota to ferment, and the microbial metabolites could provide energy supply and regulate the immune function of the host. The aim of this study was to analyse the changes in gut microbiota, serum metabolism and emotional mood of patients with T2DM after consumption of a high-fibre diet. This study was a randomised, open-label, parallel-group clinical trial in T2DM patients with a 4-week treatment period. Seventeen patients clinically diagnosed with T2DM enrolled in the clinical trial and were randomly assigned into two groups: the control group (n = 8) or the intervention group (n = 9). Results showed that the high-fibre diet (compared to the control group): - improved glucose homeostasis and lipid metabolism of participants with T2DM; - decreased serum levels of inflammatory chemokines in participants with T2DM; - alleviated depression and anxiety symptoms, particularly by the uptake of more diverse carbohydrates in the diet in participants with T2DM; - enhanced the diversity of gut microbiota in the treatment group. Authors conclude that the dietary source of fibre demonstrated protective impacts on the gut ecosystem, and the alteration of the gut microbiota composition improved the glucose homeostasis in patients with T2DM.
Abstract
Previous studies have demonstrated that patients with type 2 diabetes mellitus (T2DM) often had the problems of fecal microbiota dysbiosis, and were usually accompanied with psychiatric comorbidities (such as depression and anxiety). Here, we conducted a randomized clinical study to analyze the changes in gut microbiota, serum metabolism and emotional mood of patients with T2DM after consumption of a high-fiber diet. The glucose homeostasis of participants with T2DM was improved by the high-fiber diet, and the serum metabolome, systemic inflammation and psychiatric comorbidities were also altered. The increased abundances of Lactobacillus, Bifidobacterium and Akkermansias revealed that the proportions of beneficial gut microbes were enriched by the high-fiber diet, while the abundances of Desulfovibrio, Klebsiella and other opportunistic pathogens were decreased. Therefore, the current study demonstrated that the intestinal microbiota alterations which were influenced by the high-fiber diet could improve the serum metabolism and emotional mood of patients with T2DM.
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Gut microbiome modulates the effects of a personalised postprandial-targeting (PPT) diet on cardiometabolic markers: a diet intervention in pre-diabetes.
Ben-Yacov, O, Godneva, A, Rein, M, Shilo, S, Lotan-Pompan, M, Weinberger, A, Segal, E
Gut. 2023;72(8):1486-1496
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Diet is a major contributor to cardiometabolic health and plays a fundamental role in the prevention, management and even reversal of many chronic diseases. The gut microbiota has a central role in human health and disease. Specifically, its role in cardiometabolic health has been studied extensively in recent years. The aim of this study was to evaluate the interplay between dietary modifications, microbiome composition and cardiometabolic health outcomes. This study was a randomised controlled trial of a 6-month dietary intervention comparing a personalised postprandial-targeting (PPT) diet versus Mediterranean (MED) diet in 200 adults with pre-diabetes. Results showed that: - PPT intervention induced greater changes in multiple dietary features compared with MED intervention. - PPT intervention increased microbiome diversity and richness and exerted specific microbiome species changes that associate with clinical outcomes. - Changes in specific gut microbiome species partially mediated the effects of dietary modifications on clinical outcomes. Authors conclude that the PPT diet prompted greater changes in gut microbiota composition, consistent with overall greater dietary modifications, as compared with the MED intervention.
Abstract
OBJECTIVE To explore the interplay between dietary modifications, microbiome composition and host metabolic responses in a dietary intervention setting of a personalised postprandial-targeting (PPT) diet versus a Mediterranean (MED) diet in pre-diabetes. DESIGN In a 6-month dietary intervention, adults with pre-diabetes were randomly assigned to follow an MED or PPT diet (based on a machine-learning algorithm for predicting postprandial glucose responses). Data collected at baseline and 6 months from 200 participants who completed the intervention included: dietary data from self-recorded logging using a smartphone application, gut microbiome data from shotgun metagenomics sequencing of faecal samples, and clinical data from continuous glucose monitoring, blood biomarkers and anthropometrics. RESULTS PPT diet induced more prominent changes to the gut microbiome composition, compared with MED diet, consistent with overall greater dietary modifications observed. Particularly, microbiome alpha-diversity increased significantly in PPT (p=0.007) but not in MED arm (p=0.18). Post hoc analysis of changes in multiple dietary features, including food-categories, nutrients and PPT-adherence score across the cohort, demonstrated significant associations between specific dietary changes and species-level changes in microbiome composition. Furthermore, using causal mediation analysis we detect nine microbial species that partially mediate the association between specific dietary changes and clinical outcomes, including three species (from Bacteroidales, Lachnospiraceae, Oscillospirales orders) that mediate the association between PPT-adherence score and clinical outcomes of hemoglobin A1c (HbA1c), high-density lipoprotein cholesterol (HDL-C) and triglycerides. Finally, using machine-learning models trained on dietary changes and baseline clinical data, we predict personalised metabolic responses to dietary modifications and assess features importance for clinical improvement in cardiometabolic markers of blood lipids, glycaemic control and body weight. CONCLUSIONS Our findings support the role of gut microbiome in modulating the effects of dietary modifications on cardiometabolic outcomes, and advance the concept of precision nutrition strategies for reducing comorbidities in pre-diabetes. TRIAL REGISTRATION NUMBER NCT03222791.
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A dietary intervention for postmenopausal hot flashes: A potential role of gut microbiome. An exploratory analysis.
Kahleova, H, Holtz, DN, Strom, N, La Reau, A, Kolipaka, S, Schmidt, N, Hata, E, Znayenko-Miller, T, Holubkov, R, Barnard, ND
Complementary therapies in medicine. 2023;79:103002
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Postmenopausal vasomotor symptoms not only lead to discomfort and reduced quality of life but also signal an increased risk of cardiovascular disease and diabetes. Nutrition is an important modifying factor and may be helpful in alleviating vasomotor symptoms. The aim of this study was to test the effects of a low-fat plant-based diet, including daily consumption of soybeans, on the gut microbiome composition, particularly the equol-producing gut bacteria, and their association with changes in postmenopausal vasomotor symptoms. This study was a secondary exploratory analysis of a randomised controlled trial were participants were randomly assigned to the intervention or control group. Results showed that the dietary intervention led to a 95 % reduction in total hot flashes, and a 96 % decrease in moderate-to-severe hot flashes. Daytime and night-time hot flashes were reduced by 96 % and 94 %, respectively. Even though in the intervention group there were significant changes in gut microbiome after 12 weeks, changes in the equol-producing bacteria were not significant. Authors conclude that their findings revealed potential associations between changes in vasomotor symptoms in response to a diet change and changes in the gut microbiome.
Abstract
OBJECTIVE This study examined the role of gut microbiome changes in mediating the effects of a dietary intervention on the frequency and severity of postmenopausal vasomotor symptoms METHODS Postmenopausal women (n = 84) reporting ≥2 moderate-to-severe hot flashes daily were randomly assigned, in 2 successive cohorts, to an intervention including a low-fat, vegan diet and cooked soybeans (½ cup [86 g] daily) or to stay on their usual diet. Over a 12-week period, frequency and severity of hot flashes were recorded with a mobile application. In a subset of 11 women, gut microbiome was analyzed at baseline and after 12 weeks of the dietary intervention (low-fat vegan diet with soybeans), using deep shotgun metagenomic sequencing. Differences in the microbiome between baseline and 12 weeks were assessed by comparing alpha diversity with Wilcoxon signed rank tests, beta diversity with permanovaFL, and taxon abundance with Wilcoxon signed rank tests. Pearson correlations were used to assess the association between changes in hot flashes and gut bacteria. RESULTS In the subset for which microbiome testing was done, total hot flashes decreased by 95 % during the dietary intervention (p = 0.007); severe hot flashes disappeared (from 0.6 to 0.0/day; p = 0.06); and moderate-to-severe hot flashes decreased by 96 % (p = 0.01). Daytime and nighttime hot flashes were reduced by 96 % (p = 0.01) and 94 % (p = 0.004), respectively. Alpha and beta diversity did not significantly differ in the intervention group between baseline and 12 weeks. Two families (Enterobacteriaceae and Veillonellaceae), 5 genera (Erysipelatoclostridium, Fusicatenibacter, Holdemanella, Intestinimonas, and Porphyromonas), and 6 species (Clostridium asparagiforme, Clostridium innocuum, Bacteroides thetaiotaomicron, Fusicatenibacter saccharivorans, Intestinimonas butyriciproducens, Prevotella corporis, and Streptococcus sp.) were differentially abundant, but after correction for multiple comparisons, these differences were no longer significant. Changes in the relative abundance of Porphyromonas and Prevotella corporis were associated with the reduction in severe day hot flashes both unadjusted (r = 0.61; p = 0.047; and r = 0.69; p = 0.02), respectively), and after adjustment for changes in body mass index (r = 0.63; p = 0.049; and r = 0.73; p = 0.02), respectively). Changes in relative abundance of Clostridium asparagiforme were associated with the reduction in total severe hot flashes (r = 0.69; p = 0.019) and severe night hot flashes (r = 0.82; p = 0.002) and the latter association remained significant after adjustment for changes in body mass index (r = 0.75; p = 0.01). CONCLUSIONS This exploratory analysis revealed potential associations between changes in vasomotor symptoms in response to a diet change and changes in the gut microbiome. Larger randomized clinical trials are needed to investigate these findings.
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Differential Responders to a Mixed Meal Tolerance Test Associated with Type 2 Diabetes Risk Factors and Gut Microbiota-Data from the MEDGI-Carb Randomized Controlled Trial.
Skantze, V, Hjorth, T, Wallman, M, Brunius, C, Dicksved, J, Pelve, EA, Esberg, A, Vitale, M, Giacco, R, Costabile, G, et al
Nutrients. 2023;15(20)
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Type 2 diabetes (T2D) is a growing worldwide health problem. Increased blood sugars and a corresponding increase in the production of the hormone insulin, which functions to lower blood sugar are risk factors for T2D development. However, it has been shown that everyone has an individual response to the food and the production of differing levels of blood sugar and insulin when eating the same meals has been shown. This secondary analysis of a 12-week randomised control trial of 155 individuals aimed to determine relationships between gut microbiota composition and the glucose response to high and low glycaemic index Mediterranean diets. The results identified two distinct types of response amongst the participants. Cluster A individuals had a lower but more rapid glucose response following food and were deemed to have a better glucose control than cluster B individuals. The clusters also differed in the gut microbiota composition. Cluster A had a higher proportion of Clostridium sensu stricto 1 and a lower proportion of Blautia, than cluster B. It was concluded that the glucose response to a standardised meal can differ between individuals and are associated with differing gut microbiota and risk for T2D. This study could be used by healthcare professionals to understand that diet recommendations are not one size fits all and that the recommendation of certain diets may have differing success. Understanding and differentiating individuals and tailor making recommendations may be of benefit, however further understanding is required on different glucose responses following a meal.
Abstract
The global prevalence of type 2 diabetes mellitus (T2DM) has surged in recent decades, and the identification of differential glycemic responders can aid tailored treatment for the prevention of prediabetes and T2DM. A mixed meal tolerance test (MMTT) based on regular foods offers the potential to uncover differential responders in dynamical postprandial events. We aimed to fit a simple mathematical model on dynamic postprandial glucose data from repeated MMTTs among participants with elevated T2DM risk to identify response clusters and investigate their association with T2DM risk factors and gut microbiota. Data were used from a 12-week multi-center dietary intervention trial involving high-risk T2DM adults, comparing high- versus low-glycemic index foods within a Mediterranean diet context (MEDGICarb). Model-based analysis of MMTTs from 155 participants (81 females and 74 males) revealed two distinct plasma glucose response clusters that were associated with baseline gut microbiota. Cluster A, inversely associated with HbA1c and waist circumference and directly with insulin sensitivity, exhibited a contrasting profile to cluster B. Findings imply that a standardized breakfast MMTT using regular foods could effectively distinguish non-diabetic individuals at varying risk levels for T2DM using a simple mechanistic model.