[Summary of the 8th Symposium "Feeding the microbiota": prebiotics and probiotics]. / Synthèse du 8e symposium « Feeding the Microbiota ¼ : prébiotiques et probiotiques.

The microbiota represents all the microorganisms including viruses, bacteria, fungi, and parasites, that have a symbiotic relationship with their host and that are present in a particular system (or niche) of the human body such as the skin, the respiratory tract, the urogenital tract or the digestive tract. This paper is a narrative review of all talks given at the 8th edition of the « Feeding the Microbiota ¼ symposium organized at the Geneva University Hospitals. The symposium gathered 346 participants, both onsite and online, from 23 countries all-around the world. The main thematic of this edition focused on the composition of the gut microbiota as affected by prebiotics and postbiotics and their effects on various diseases.

Le microbiote représente l'ensemble des micro-organismes (virus, bactéries, champignons et parasites) qui ont une relation symbiotique avec leur hôte et qui sont présents dans un système particulier du corps humain comme la peau, les voies respiratoires et/ou uro-génitales ou encore le tube digestif. Cet article est une revue narrative des différentes thématiques exposées lors du 8e symposium « Feeding the Microbiota ¼ organisé aux HUG le 9 février 2023. L'événement a réuni 346 participants en présentiel et en ligne venant de 23 pays différents. La thématique de cette édition s'est focalisée sur les effets des prébiotiques et des probiotiques sur la composition du microbiote et dans le contexte de certaines maladies.

[Management of type 2 diabetes on oral nutritional supplement]. / Prise en charge du diabète de type 2 chez le patient dénutri sous supplément nutritif oral.

The management of a patient with type 2 diabetes is well known and is the subject of numerous studies. Protein-calorie malnutrition, on the other hand, is an entity that is still under-diagnosed and under-treated. When artificial nutrition is introduced, glucose homeostasis can be disturbed in case of (pre-)diabetes. To date, few recommendations based on expert opinion exist on the management of diabetes after the introduction of enteral or parenteral nutrition. This article proposes an algorithm for the management of type 2 diabetes when oral nutritional supplements are introduced.

La prise en charge d'un patient diabétique de type 2 est bien connue et fait l'objet de nombreuses études. La dénutrition protéino-calorique quant à elle est une entité encore sous-diagnostiquée et sous-traitée. Lors de la mise en place d'une nutrition artificielle, l'équilibre glycémique peut être perturbé en cas de prédiabète ou de diabète. À ce jour, quelques recommandations basées sur des avis d'experts existent sur la prise en charge du diabète après la mise en place d'une nutrition entérale ou parentérale. Cet article propose un algorithme de prise en charge du diabète de type 2, lors de l'introduction de suppléments nutritifs oraux.

[Is ketogenic diet effective against cancer ?] / Le régime cétogène : efficace contre le cancer ?

The ketogenic diet, which consists of reduced carbohydrate intake and increased fat intake, is a recognized treatment option for children with intractable epilepsy. This diet is now receiving renewed interest from physicians and researchers because of its potential therapeutic effect in other diseases, such as neurodegenerative diseases, metabolic syndrome or cancer. Since cancer is one of the major public health challenges, complementary approaches to improve the efficacy of standard anti-cancer therapies are the subject of much research. This article reviews the place of the ketogenic diet as a complementary therapy in cancer, the scientific evidence and possible practical aspects of such an approach.

Le régime cétogène vise à réduire l'apport nutritionnel d'hydrates de carbone en augmentant les lipides. Ce régime est une option thérapeutique reconnue, en particulier chez les enfants souffrant d'épilepsie réfractaire. Il fait aujourd'hui l'objet d'un regain d'intérêt de la part des médecins et des chercheurs, en raison de son potentiel effet thérapeutique dans d'autres pathologies comme certaines maladies neurodégénératives, le syndrome métabolique ou même le cancer. Le cancer étant l'un des grands défis de santé publique, les approches complémentaires pour améliorer l'efficacité des thérapies anticancéreuses standards font l'objet de nombreuses recherches. Cet article fait le point sur la place du régime cétogène comme thérapie complémentaire dans le cancer, les évidences scientifiques et les éventuels aspects pratiques d'une telle approche.

Physical activity in inflammatory bowel disease: benefits, challenges and perspectives.

PURPOSE OF THE REVIEW: Physical activity is gaining significative interest in the field of inflammatory bowel disease (IBD). In the light of the most recent publications, the present review aims to describe the level of physical activity in adult patients with IBD; describe the current body of evidence on the benefits of physical activity and discuss the challenges and perspectives related to physical activity in this population. RECENT FINDINGS: Recent studies showed that IBD patients tend to be less active than healthy people. There is growing evidence of a positive impact of physical activity on mortality, quality of life, fatigue, body composition, strength and physical performance. The direct benefits of physical activity on clinical remission and disease activity have recently been observed only in Crohn's disease. Limitations to physical activity related to the disease, such as gastrointestinal and psychological symptoms, need to be considered in this population. Finally, no guidelines are available and there is no evidence regarding the effects of combined physical activity and nutritional support. SUMMARY: Although physical activity seems beneficial and safe for IBD patients, future studies are needed to clearly define recommendations in this population.

Oral function and nutritional status in non-acute hospitalised elders.

INTRODUCTION: Malnutrition and risk of malnutrition continues to be a common finding in elders, yet its association with oral function in hospitalised patients remains unclear. MATERIAL AND METHODS: Patients aged 70 years or over who had been hospitalised for non-acute rehabilitation were recruited. Nutritional risk was screened using the Mini-Nutritional Assessment Short Form (MNA-SF) and Nutritional Risk Screening (NRS) scores. Malnutrition was assessed according to the Global Leadership Initiative on Malnutrition (GLIM) criteria. All participants underwent the oral hypofunction test battery, evaluating oral hygiene, oral dryness, occlusal force, tongue-lip motor function, tongue pressure, masticatory and swallowing function. Statistical analyses comprised Mann-Whitney or Kruskal-Wallis tests. Bivariate associations between categorical variables were tested using the Pearson chi-square test; for continuous variables, the Spearman correlation was calculated. A P-value < .05 was considered statistically significant. RESULTS: Sixty patients aged a mean 82.5 ± 7.0 years participated. Some 88.3% were diagnosed with oral hypofunction, and this was more common in older patients (P = .020). Analysing the 7 oral hypofunction tests as an interval variable (NiOF) revealed additional correlations with number of teeth (ρ = 0.477) as well as the nutritional risk, evaluated by the MNA-SF (ρ = -0.284) and NRS (ρ = 0.317) scores. NiOF scores were higher among denture wearers (P = .003). GLIM did not confirm the correlation with NiOF. Biomarkers such as serum albumin and CRP were not associated with the NiOF score. CONCLUSION: In this sample, the association between oral function and nutritional state is more obvious in nutritional risk scores than in the malnutrition diagnosis by GLIM.

[Vitamin deficiencies in the adult outpatient setting]. / Carences vitaminiques chez l'adulte en médecine ambulatoire.

Since their discovery more than a century ago to this day, vitamins went from misunderstood molecules with mysterious properties to fundamental components with undoubted clinical implications. Despite the scientific progresses in the understanding of their physiopathological role, vitamins raise to this day multiple interrogations in clinical practice. This article aims at answering questions that are frequently encountered in the outpatient setting regarding vitamin deficiencies: who to screen ? At what moment ? By which test ? How to interpret the results ? How to supplement ? By answering these questions, we hope to provide the general practitioners with a pragmatic tool to guide them in the management of issues related to vitamins.

Depuis leur découverte il y a plus d'un siècle à aujourd'hui, les vitamines sont passées de molécules méconnues et aux propriétés mystérieuses à des composants primordiaux et aux implications cliniques certaines. Malgré les progrès scientifiques dans la compréhension de leur rôle physiopathologique, les vitamines suscitent encore de nombreuses interrogations en pratique clinique. Cet article s'efforce de répondre aux questions fréquem ment rencontrées en médecine ambulatoire portant sur les carences vitaminiques: qui dépister ? À quel moment ? Par quel test ? Comment interpréter les résultats ? Comment supplémenter ? En répondant à ces questions, nous espérons fournir au médecin de premier recours un outil pragmatique pour l'orienter dans la prise en charge des problématiques vitaminiques.

Incidence, characteristics and clinical relevance of acute stroke in old patients hospitalized with COVID-19.

BACKGROUND: Stroke in the course of coronavirus disease (COVID-19) has been shown to be associated with more severe respiratory symptoms and higher mortality, but little knowledge in this regard exists on older populations. We aimed to investigate the incidence, characteristics, and prognosis of acute stroke in geriatric patients hospitalized with COVID-19. METHODS: A monocentric cross-sectional retrospective study of 265 older patients hospitalized with COVID-19 on acute geriatric wards. 11/265 presented a stroke episode during hospitalization. Mortality rates and two-group comparisons (stroke vs non-stroke patients) were calculated and significant variables added in logistic regression models to investigate stroke risk factors. RESULTS: Combined ischemic and hemorrhagic stroke incidence was 4.15%. 72.7% of events occurred during acute care. Strokes presented with altered state of consciousness and/or delirium in 81.8%, followed by a focal neurological deficit in 45.5%. Ischemic stroke was more frequently unilateral (88.8%) and localized in the middle cerebral artery territory (55.5%). Smoking and a history of previous stroke increased by more than seven (OR 7.44; 95% CI 1.75-31.64; p = 0.007) and five times (OR 5.19; 95% CI 1.50-17.92; p = 0.009), respectively, the risk of stroke. Each additional point in body mass index (BMI) reduced the risk of stroke by 14% (OR 0.86; 95% CI 0.74-0.98; p = 0.03). In-hospital mortality (32.1% vs. 27.3%; p > 0.999) and institutionalization at discharge (36.4% vs. 21.1%; p = 0.258) were similar between patients with and without stroke. CONCLUSION: Incident stroke complicating COVID-19 in old patients was associated with active smoking, previous history of stroke, and low BMI. Acute stroke did not influence early mortality or institutionalization rate at discharge.

Results from an Epidemiological Follow-Up Survey on Home Artificial Nutrition in Switzerland from 2010 to 2015.

BACKGROUND: Home artificial nutrition (HAN) is an established treatment for malnourished patients. Since July 2012, the costs for oral nutrition supplements (ONS) are covered by the compulsory health insurance providers in Switzerland if the patient has a medical indication based on the Swiss Society for Clinical Nutrition guidelines. Therefore, the purpose of our study was to analyse the development of HAN, including ONS, before and after July 2012. METHODS: We obtained the retrospective and anonymized data from the Swiss association for joint tasks of health insurers (SVK), who registered patients on HAN. Since not all health insurers are working with SVK, this retrospective study recorded nearly 65% of all new patients on HAN in Switzerland from January 1, 2010, to December 31, 2015. RESULTS: A total of 33,410 patients (49.1% men and 50.9% women) with a mean BMI of 21.3 ± 4.5 kg/m2 and mean age of 68.9 ± 17.8 years were recorded. The number of patient cases on ONS increased from 808 cases in 2010 to 18,538 cases in 2015, while patient cases on home enteral nutrition (HEN) and home parenteral nutrition (HPN) remained approximately the same. The relative distribution of type of HAN changed from 26.2% cases on ONS, 68.7% cases on HEN and 5.1% cases on HPN in 2010 to 86.1% cases on ONS, 12.8% cases on HEN, and 1.1% cases on HPN in 2015. Treatment duration decreased for ONS from 698 ± 637 days to 171 ± 274 days, for HEN from 416 ± 553 days to 262 ± 459 days, and for HPN from 96 ± 206 days to 72 ± 123 days. Mean costs per patient decreased for ONS from 1,330 CHF in 2010 to 606 CHF in 2015. Total costs for HAN increased from 16,895,373 CHF in 2010 to 32,868,361 CHF in 2015. CONCLUSION: Our epidemiological follow-up study showed an immense increase in number of patients on HAN in Switzerland after July 2012. Due to shorter therapy duration and reduced mean costs per patient, total costs were only doubled while the number of patients increased 7-fold.

Reliability and comparability of methods for assessing oral function: Chewing, tongue pressure and lip force.

BACKGROUND: Quantitative clinical assessment tests for oral function have become popular in patient assessment; however, their comparability remains unclear. OBJECTIVE: To assess the reliability and comparability of pairs of different instruments for measuring maximum tongue pressure (MTP), chewing function (CF) and maximum lip force (MLF), and to analyse the influence of subjects' characteristics on the applied instruments. METHODS: Each pair of instruments, as well as a single device measuring the maximum voluntary bite force (MBF), was assessed across 26 healthy volunteers. The respective pairs of devices were compared using Bland-Altman plots and linear regression analysis. Furthermore, the influence of age, occlusal support zones, number of functional occlusal units, MBF, MTP and MLF were investigated as predictors on CF using a generalised estimating equation model. RESULTS: Neither the two assessments of CF, nor of MLF were correlated to each other, but there was a significant correlation between the assessments of MTP. Hue-Check Gum was able to demonstrate a significantly higher CF in younger compared to older individuals (P = .004) and individuals with high numbers compared to low numbers of occlusal units (P < .001). Those differences could not be demonstrated with the Vivident chewing gum. CONCLUSION: The absolute values of MTP assessed by the two applied devices cannot directly be compared, although normalised values may be directly comparable. Moreover, our observations suggest that the Hue-Check Gum was able to discriminate the effects of age and the number of occlusal units on CF. Our observations suggest that the two gums cannot be used interchangeably.

[Microbiota specificities among the elderly Summary of the 5th symposium «â€ Feeding the Microbiota†¼]. / Caractéristiques du microbiote chez le sujet âgé - Synthèse du 5e symposium «â€ Feeding the Microbiota†¼.

The microbiota is a subject of particular interest and research. It is defined as all microorganisms present in tissues and on body surfaces. It sits at the interface with many systems, including the immune system, plays a role in the metabolism, immunity, or inflammation and is thought to be associated with some pathological mechanisms. Its composition and metabolic activity are influenced by diverse factors such as aging. This article summarizes the 5th symposium «â€…Feeding the Microbiota ¼ (Geneva University Hospitals, February 6, 2020), focused on microbiota and aging.

Le microbiote est le sujet de nombreuses recherches. Il est défini comme l'ensemble des microorganismes présents dans les tissus et sur les surfaces corporelles. Il est à l'interface avec de nombreux systèmes dont le système immunitaire, joue un rôle dans le métabolisme, l'immunité ou l'inflammation, et serait associé à certains mécanismes pathologiques. Sa composition et son activité métabolique sont influencées par différents facteurs comme l'âge. Cet article résume les thématiques abordées lors du 5e symposium «â€…Feeding the Microbiota ¼ (HUG, 6 février 2020), focalisé sur le microbiote et le vieillissement.

[Issues and challenges related to COVID-19 in acute geriatric care: lessons learned from the Geneva experience]. / Enjeux et défis du Covid-19 en gériatrie aiguë: leçons tirées de l'expérience genevoise.

The older patients have been the most affected by the SARS-CoV-2 pandemic. In addition, this infection has been responsible for high mortality rate in this population. In this article we wanted to describe the clinical findings we encountered in older people with COVID-19 and share some of the issues and challenges we faced during the COVID-19 pandemic.

Les personnes âgées ont été les plus touchées par la pandémie de SARS-CoV-2. De plus, cette infection a été responsable d'une mortalité élevée au sein de cette population. Dans cet article, nous avons souhaité décrire les particularités cliniques du Covid-19 que nous avons constatées chez les patients âgés et faire part de plusieurs enjeux et défis auxquels nous avons été confrontés au cours de la pandémie de Covid-19.

Impact of sarcopenia on 1-year mortality in older patients with cancer.

OBJECTIVES: sarcopenia is common especially in hospitalised older populations. The aim of this study was to assess the prevalence of sarcopenia, defined as low skeletal mass and muscle strength, and its impact on 1-year mortality in older patients with cancer. METHODS: skeletal muscle mass was estimated using bioelectric impedance analysis and related to height2 (SMI; Janssen et al. 2002). Grip strength was measured with the JAMAR dynamometer and the cut-offs suggested by the European Working Group on Sarcopenia in Older People (EWGSOP) were applied. One-year mortality was assessed by telephone follow-up and the local cancer death registry. RESULTS: of the 439 consecutively recruited cancer patients (60-95 years; 43.5% women), 119 (27.1%) had sarcopenia. Of the patients with sarcopenia, 62 (52.5%) died within 1 year after study entry compared to 108 (35.1%) patients who did not have sarcopenia (P = 0.001). In a stepwise, forward Cox proportional hazards analysis, sarcopenia (HR = 1.53; 95% CI: 1.034-2.250; P < 0.05), advanced disease (HR = 1.87; 95% CI: 1.228-2.847; P < 0.05), number of drugs/day (HR = 1.11; 95% CI: 1.057-1.170; P < 0.001), tumour diagnosis (overall P < 0.05) and Karnofsky index (HR = 0.98, 95% CI: 0.963-0.995; P < 0.05) associated with 1-year mortality risk. The factors sex, age, co-morbidities and involuntary 6-month weight loss ≥5% were insignificant. CONCLUSIONS: sarcopenia was present in 27.1% of older patients with cancer and was independently associated with 1-year mortality. The fact that sarcopenia was nearly as predictive for 1-year mortality as an advanced disease stage underlines the importance of preservation of muscle mass and function as a potential target of intervention in older patients with cancer.

[Vegetarian and vegan diets and their impact on health]. / Alimentations végétariennes et véganes†: quelles conséquences sur la santé†?

Vegetarian and vegan diets are increasing in the population, but the prevalence remains low (< 3 %). Vegetarians consume diary and eggs while vegans do not consume or use any animal derived products. Vegetarians have a low risk of deficiency except for iron deficiency with anemia in pre-menopausal women. Vegans should receive a mandatory vitamin B12 substitution because of an important risk of deficiency. Furthermore, vegans are at higher risk of iron and calcium deficiency with higher rates of osteoporotic fracture and iron deficiency anemia. Dietary advice is recommended, particularly for vegans, even though no clear recommendations can be found in the literature. These diets seem to be associated with a reduction in cardio-vascular risk factors, but this association remains to be confirmed.

La prévalence des végétariens et véganes dans la population générale augmente, mais reste faible (< 3 %). Au contraire des véganes qui ne consomment que des produits d'origine végétale, les végétariens consomment des produits laitiers et des œufs. Les végétariens présentent peu de risque de carence mis à part un risque d'anémie ferriprive chez les femmes préménopausées. Les véganes, quant à eux, doivent être substitués systématiquement en vitamine B12 en raison d'un risque élevé de carence. Ils sont aussi plus à risque de carence en calcium et en fer, avec des taux de fracture ostéoporotique et de carence martiale plus élevés. Un suivi diététique est conseillé, en particulier pour les véganes, malgré l'absence de recommandations claires de la littérature. Ces régimes semblent améliorer de nombreux facteurs de risque cardiovasculaire mais ces effets restent à confirmer.

Innovations in energy expenditure assessment.

PURPOSE OF REVIEW: Optimal nutritional therapy has been associated with better clinical outcomes and requires providing energy as closed as possible to measured energy expenditure. We reviewed the current innovations in energy expenditure assessment in humans, focusing on indirect calorimetry and other new alternative methods. RECENT FINDINGS: Although considered the reference method to measure energy expenditure, the use of indirect calorimetry is currently limited by the lack of an adequate device. However, recent technical developments may allow a broader use of indirect calorimetry for in-patients and out-patients. An ongoing international academic initiative to develop a new indirect calorimeter aimed to provide innovative and affordable technical solutions for many of the current limitations of indirect calorimetry. New alternative methods to indirect calorimetry, including CO2 measurements in mechanically ventilated patients, isotopic approaches and accelerometry-based fitness equipments, show promises but have been either poorly studied and/or are not accurate compared to indirect calorimetry. Therefore, to date, energy expenditure measured by indirect calorimetry remains the gold standard to guide nutritional therapy. SUMMARY: Some new innovative methods are demonstrating promises in energy expenditure assessment, but still need to be validated. There is an ongoing need for easy-to-use, accurate and affordable indirect calorimeter for daily use in in-patients and out-patients.

[Gut microbiota and kidney diseases : dangerous liaisons?] / Microbiote et maladies rénales : liaison dangereuse ?

Recent studies have found a relationship between the kidney and the intestinal microbiome, called the colo-renal axis. Mounting evidence suggests that patients suffering from chronic kidney disease (CKD) have an altered composition of gut microbiota. This leads to 1) the increased fermentation of intestinal proteins to uremic toxins such as p-cresyl sulphate and indoxyl sulphate, 2) an altered, more 'leaky' intestinal barrier, and 3) translocation of bacteria and toxins from the gut lumen to the circulation, inducing systemic inflammation. This may contribute to the increased morbidity and mortality in this population. Future studies are needed to confirm this hypothesis, and to assess whether manipulating the intestinal microbiota with pre-, pro-, or symbiotics may alter the development and course of CKD.

Des études récentes démontrent l'existence d'une relation entre le rein et le microbiote intestinal, parfois appelée « axe intestin-rein ¼. Les patients souffrant de maladie rénale chronique (MRC) ont une composition altérée du microbiote intestinal. Ces modifications conduisent à : 1) une augmentation de la fermentation de protéines intestinales en toxines urémiques comme par exemple le p-crésyl sulfate et l'indoxyl sulfate ; 2) une augmentation de la perméabilité de la barrière intestinale et 3) une translocation de bactéries et de toxines de la lumière intestinale vers la circulation sanguine, responsables d'une inflammation systémique. Ces mécanismes pourraient contribuer à l'augmentation de la morbi-mortalité dans cette population. Des études ultérieures sont nécessaires pour confirmer cette hypothèse, mais également pour évaluer si des modifications dans la composition du microbiote par des agents pré, pro ou symbiotiques pourraient avoir un effet bénéfique sur l'évolution de la MRC.

[Microbiota and malnutrition: an overview]. / Microbiote et dénutrition : état des lieux.

Currently, there is an increased interest in the role of gut microbiota in health issues. Evidence shows that an imbalance of gut microbiota or dysbiosis is involved in the mechanisms of weight changes. This review aims at summarizing the present knowledge between gut microbiota and malnutrition. Intestinal bacterial diversity and richness are altered in malnourished people compared to healthy people. The first studies on the modulation of the gut microbiota by probiotics, prebiotics, symbiotics, fecal transplantation and antibiotics for weight gain are encouraging. However, further studies are needed to develop and implement effective treatment for malnutrition.

L'analyse du microbiote intestinal suscite un intérêt grandissant. Il est maintenant établi qu'un déséquilibre du microbiote intestinal ou dysbiose est impliqué dans les mécanismes de variations pondérales. Cet article vise à faire l'état des lieux des connaissances actuelles entre microbiote intestinal et dénutrition. Les personnes dénutries ont une diversité et une abondance bactérienne intestinale altérées en comparaison des personnes en bonne santé. Les premières études concernant la modulation du microbiote intestinal par les probiotiques, les prébiotiques, les symbiotiques, la transplantation fécale et les antibiotiques dans un but de prise pondérale sont encourageantes. Cependant, de nombreuses études sont encore nécessaires avant toute implication thérapeutique.

Can calculation of energy expenditure based on CO2 measurements replace indirect calorimetry?

BACKGROUND: Methods to calculate energy expenditure (EE) based on CO2 measurements (EEVCO2) have been proposed as a surrogate to indirect calorimetry. This study aimed at evaluating whether EEVCO2 could be considered as an alternative to EE measured by indirect calorimetry. METHODS: Indirect calorimetry measurements conducted for clinical purposes on 278 mechanically ventilated ICU patients were retrospectively analyzed. EEVCO2 was calculated by a converted Weir's equation using CO2 consumption (VCO2) measured by indirect calorimetry and assumed respiratory quotients (RQ): 0.85 (EEVCO2_0.85) and food quotient (FQ; EEVCO2_FQ). Mean calculated EEVCO2 and measured EE were compared by paired t test. Accuracy of EEVCO2 was evaluated according to the clinically relevant standard of 5% accuracy rate to the measured EE, and the more general standard of 10% accuracy rate. The effects of the timing of measurement (before or after the 7th ICU day) and energy provision rates (<90 or ≥90% of EE) on 5% accuracy rates were also analyzed (chi-square tests). RESULTS: Mean biases for EEVCO2_0.85 and EEVCO2_FQ were -21 and -48 kcal/d (p = 0.04 and 0.00, respectively), and 10% accuracy rates were 77.7 and 77.3%, respectively. However, 5% accuracy rates were 46.0 and 46.4%, respectively. Accuracy rates were not affected by the timing of the measurement, or the energy provision rates at the time of measurements. CONCLUSIONS: Calculated EE based on CO2 measurement was not sufficiently accurate to consider the results as an alternative to measured EE by indirect calorimetry. Therefore, EE measured by indirect calorimetry remains as the gold standard to guide nutrition therapy.

Impact of Hypocaloric Hyperproteic Diet on Gut Microbiota in Overweight or Obese Patients with Nonalcoholic Fatty Liver Disease: A Pilot Study.

BACKGROUND: NAFLD is likely to become the most common cause of chronic liver disease. The first-line treatment includes weight loss. AIMS: To analyze the impact of a hypocaloric hyperproteic diet (HHD) on gut microbiota in NAFLD patients. METHODS: Fifteen overweight/obese patients with NAFLD were included. At baseline and after a 3-week HHD (Eurodiets(®), ~1000 kcal/day, ~125 g protein/day), we measured gut microbiota composition and function by shotgun metagenomics; body weight; body composition by bioelectrical impedance analysis; liver and visceral fat by magnetic resonance imaging; plasma C-reactive protein (CRP); and liver tests. Results between both time points, expressed as median (first and third quartile), were compared by Wilcoxon signed-rank tests. RESULTS: At baseline, age was 50 (47-55) years and body mass index 34.6 (32.4, 36.7) kg/m(2). HDD decreased body weight by 3.6 % (p < 0.001), percent liver fat by 65 % (p < 0.001), and CRP by 19 % (p = 0.014). HDD was associated with a decrease in Lachnospira (p = 0.019), an increase in Blautia (p = 0.026), Butyricicoccus (p = 0.024), and changes in several operational taxonomic units (OTUs) of Bacteroidales and Clostridiales. The reduced liver fat was negatively correlated with bacteria belonging to the Firmicutes and Bacteroidetes phyla (a Ruminococcaceae OTU, r = -0.83; Bacteroides, r = -0.73). The associated metabolic changes concerned mostly enzymes involved in amino acid and carbohydrate metabolism. CONCLUSIONS: In this pilot study, HHD changes gut microbiota composition and function in overweight/obese NAFLD patients, in parallel with decreased body weight, liver fat, and systemic inflammation. Future studies should aim to confirm these bacterial changes and understand their mode of action. TRAIL REGISTRATION: Under clinicaltrials.gov: NCT01477307.