Polyunsaturated Fatty Acids as Prebiotics: Innovation or Confirmation?

The International Scientific Association for Probiotics and Prebiotics (ISAPP), in its last consensus statement about prebiotics, defined polyunsaturated fatty acids (PUFAs) as "candidate prebiotics" due to a lack of complete scientific evidence. Previous studies have demonstrated the ability of microbiota to metabolize PUFAs, although the role of the resulting metabolites in the host is less known. Recent partial evidence shows that these metabolites can have important health effects in the host, reinforcing the concept of the prebiotic action of PUFAs, despite the data being mostly related to omega-6 linoleic acid and to lactobacilli taxon. However, considering that the symbionts in our gut benefit from the nutritional molecules that we include in our diet, and that bacteria, like all living organisms, cannot benefit from a single nutritional molecule, the concept of the "correct prebiotic diet" should be the new frontier in the field of gut microbiota research

From pre-and probiotics to post-biotics: A narrative review

Background and aims: Gut microbiota (GM) is a complex ecosystem containing bacteria, viruses, fungi, and yeasts. It has several functions in the human body ranging from immunomodulation to metabolic. GM derangement is called dysbiosis and is involved in several host diseases. Pre-, probiotics, and symbiotics (PRE-PRO-SYMB) have been extensively developed and studied for GM re-modulation. Herein, we review the literature data regarding the new concept of postbiotics, starting from PRE-PRO-SYMB. Methods: We conducted a search on the main medical databases for original articles, reviews, meta-analyses, randomized clinical trials, and case series using the following keywords and acronyms and their associations: Gut microbiota, prebiotics, probiotics, symbiotic, and postbiotics. Results: Postbiotics account for PRO components and metabolic products able to beneficially affect host health and GM. The deeper the knowledge about them, the greater their possible uses: The prevention and treatment of atopic, respiratory tract, and inflammatory bowel diseases. Conclusions: Better knowledge about postbiotics can be useful for the prevention and treatment of several human body diseases, alone or as an add-on to PRE-PRO-SYMB

Irritable Bowel Syndrome (IBS) and Non-Celiac Gluten Sensitivity (NCGS): Where Is the Culprit Hiding? Nutritional Tips for Gastroenterologists.

At least 40% of all the gastroenterological outpatient visits are due to functional gastrointestinal disorders (FGIDs), among which irritable bowel syndrome (IBS) is the most common, accounting for a worldwide prevalence of about 12% [...]

Food Additives, Gut Microbiota, and Irritable Bowel Syndrome: A Hidden Track

The interactions between diet, gut microbiota, and irritable bowel syndrome (IBS) have many complex mechanisms that are not fully understood. Food additives are one component of the modern human diet that deserves attention from science and government policies. This review aims at identifying the current knowledge about the impact of food additives on gut microbiota and their potential role in the development of IBS. To date, few data on the effect of food additives on gut microbiota in IBS patients are available. However, exposure to food additives could induce the dysbiosis and dysregulation of gut homeostasis with an alteration of the gut barrier and activation of the immune response. These microbial changes could exacerbate the gut symptoms associated with IBS, such as visceral pain, low-grade inflammation, and changes in bowel habits. Some additives (polyols) are excluded in the low fermentable oligo-, di- and monosaccharide, and polyol (FODMAP), diets for IBS patients. Even if most studies have been performed in animals, and human studies are required, many artificial sweeteners, emulsifiers, and food colorants could represent a potential hidden driver of IBS, through gut microbiota alterations. Consequently, food additives should be preventively avoided in the diet as well as dietary supplements for patients with IBS

Impact of patients nutritional status on major surgery outcome

Abstract. – OBJECTIVE: Surgery is a major stress factor that activates several inflammatory and catabolic pathways in man. An appropriate nutritional status allows the body to react properly to this stressor and recover in a faster and more efficient manner. On the other hand, malnutrition is related to a worse surgery outcome and to a higher prevalence of comorbidities and mortality. The aims of this study were to evaluate the nutritional status of patients undergoing major surgery and investigate the potential correlation between malnutrition and surgical outcomes. PATIENTS AND METHODS: Mini Nutritional Assessment (MNA) and global clinical examination (including biochemical parameters and comorbidities existence) were undertaken in 50 consecutive patients undergoing major surgery. Patients’ clinical conditions were re-evaluated at 3 and 6 days after surgery, recording biochemical parameters and systemic and/or wound-related complications. RESULTS: A compromised nutritional status was present in more than half (54%) of patients (malnutrition in 10% and risk of malnutrition in 44% of patients, respectively). Females were slightly more at risk of malnutrition (48% vs. 41%, p=NS, females vs. males) and clearly malnourished (14% vs. 7%, p<0.05, females vs. males). Age was an independent risk factor for malnutrition and within the elders’ group (> 80 years old) 16.70% of patients was diagnosed with malnutrition and 58.3% was at risk of malnutrition. Systemic complications were registered in all patients both at 3 and 6 days after surgery. However, well-nourished and at-risk of malnutrition patients had earlier complications that only partially resolved within six days after the operation. Malnourished patients showed fewer complications at the 3rd post-surgery follow-up day but had a worse outcome six days after surgery. CONCLUSIONS: Older age and but not female sex are independent risk factors for malnutrition development in patients undergoing major surgery. More interestingly, more than half of patients with an impaired nutritional status presented a less appropriated stress response to surgery. These data suggest that nutritional status assessment may be important to recognize patients at potential risk of surgical complications and that early nutritional interventions must be promptly arranged

Imaging assessment of portal venous system: pictorial essay of normal anatomy, anatomic variants and congenital anomalies

The purpose of this pictorial essay is to describe anatomic variants and congenital anomalies of portal venous system and related liver parenchymal alterations. The imaging findings of some of these entities have been previously described in other articles, however, this work encompasses all congenital anomalies of portal venous system with attention to their features on various imaging modalities; in particular we illustrated with detailed pictures all the main portal vein variants, congenital extra- and intra-hepatic porto-systemic venous shunts and portal vein aneurysm. Variants of portal branches and intrahepatic portosystemic shunts are quite uncommon, however, when present, they should be recognized before performing surgery or interventional procedures. Congenital absence of the portal vein is an important finding as the complete loss of portal perfusion predisposes the liver to focal or diffuse hyperplastic or dysplastic changes. Portal vein aneurysm is a rare clinical entity that can affect intraand extra-hepatic portal branches; although usually asymptomatic, thrombosis can occur. Awareness of congenital variants of portal venous system among radiologists should allow a more confident diagnosis and permit an accurate planning of surgical procedures and percutaneous interventions; identification of portal system anomalies also suggest an accurate evaluation of associated hepatic parenchymal anomalies such as nodular regenerative hyperplasia, focal nodular hyperplasia (FNH), and adenomas with high risk of malignant transformatio

Food Components and Dietary Habits: Keys for a Healthy Gut Microbiota Composition.

The gut microbiota is a changing ecosystem, containing trillions of bacteria, continuously shaped by many factors, such as dietary habits, seasonality, lifestyle, stress, antibiotics use, or diseases. A healthy host-microorganisms balance must be respected in order to optimally maintain the intestinal barrier and immune system functions and, consequently, prevent disease development. In the past several decades, the adoption of modern dietary habits has become a growing health concern, as it is strongly associated with obesity and related metabolic diseases, promoting inflammation and both structural and behavioral changes in gut microbiota. In this context, novel dietary strategies are emerging to prevent diseases and maintain health. However, the consequences of these different diets on gut microbiota modulation are still largely unknown, and could potentially lead to alterations of gut microbiota, intestinal barrier, and the immune system. The present review aimed to focus on the impact of single food components (macronutrients and micronutrients), salt, food additives, and different dietary habits (i.e., vegan and vegetarian, gluten-free, ketogenic, high sugar, low FODMAP, Western-type, and Mediterranean diets) on gut microbiota composition in order to define the optimal diet for a healthy modulation of gut microbiota

The Role of Diet, Micronutrients and the Gut Microbiota in Age-Related Macular Degeneration: New Perspectives from the Gut\u207bRetina Axis.

Age-related macular degeneration (AMD) is a complex multifactorial disease and the primary cause of legal and irreversible blindness among individuals aged 6565 years in developed countries. Globally, it affects 30\u207b50 million individuals, with an estimated increase of approximately 200 million by 2020 and approximately 300 million by 2040. Currently, the neovascular form may be able to be treated with the use of anti-VEGF drugs, while no effective treatments are available for the dry form. Many studies, such as the randomized controlled trials (RCTs) Age-Related Eye Disease Study (AREDS) and AREDS 2, have shown a potential role of micronutrient supplementation in lowering the risk of progression of the early stages of AMD. Recently, low-grade inflammation, sustained by dysbiosis and a leaky gut, has been shown to contribute to the development of AMD. Given the ascertained influence of the gut microbiota in systemic low-grade inflammation and its potential modulation by macro- and micro-nutrients, a potential role of diet in AMD has been proposed. This review discusses the role of the gut microbiota in the development of AMD. Using PubMed, Web of Science and Scopus, we searched for recent scientific evidence discussing the impact of dietary habits (high-fat and high-glucose or -fructose diets), micronutrients (vitamins C, E, and D, zinc, beta-carotene, lutein and zeaxanthin) and omega-3 fatty acids on the modulation of the gut microbiota and their relationship with AMD risk and progression

What is the Healthy Gut Microbiota Composition? A Changing Ecosystem across Age, Environment, Diet, and Diseases.

Each individual is provided with a unique gut microbiota profile that plays many specific functions in host nutrient metabolism, maintenance of structural integrity of the gut mucosal barrier, immunomodulation, and protection against pathogens. Gut microbiota are composed of different bacteria species taxonomically classified by genus, family, order, and phyla. Each human's gut microbiota are shaped in early life as their composition depends on infant transitions (birth gestational date, type of delivery, methods of milk feeding, weaning period) and external factors such as antibiotic use. These personal and healthy core native microbiota remain relatively stable in adulthood but differ between individuals due to enterotypes, body mass index (BMI) level, exercise frequency, lifestyle, and cultural and dietary habits. Accordingly, there is not a unique optimal gut microbiota composition since it is different for each individual. However, a healthy host\u207bmicroorganism balance must be respected in order to optimally perform metabolic and immune functions and prevent disease development. This review will provide an overview of the studies that focus on gut microbiota balances in the same individual and between individuals and highlight the close mutualistic relationship between gut microbiota variations and diseases. Indeed, dysbiosis of gut microbiota is associated not only with intestinal disorders but also with numerous extra-intestinal diseases such as metabolic and neurological disorders. Understanding the cause or consequence of these gut microbiota balances in health and disease and how to maintain or restore a healthy gut microbiota composition should be useful in developing promising therapeutic interventions

Short-Chain Fatty-Acid-Producing Bacteria: Key Components of the Human Gut Microbiota

Short-chain fatty acids (SCFAs) play a key role in health and disease, as they regulate gut homeostasis and their deficiency is involved in the pathogenesis of several disorders, including inflammatory bowel diseases, colorectal cancer, and cardiometabolic disorders. SCFAs are metabolites of specific bacterial taxa of the human gut microbiota, and their production is influenced by specific foods or food supplements, mainly prebiotics, by the direct fostering of these taxa. This Review provides an overview of SCFAs' roles and functions, and of SCFA-producing bacteria, from their microbiological characteristics and taxonomy to the biochemical process that lead to the release of SCFAs. Moreover, we will describe the potential therapeutic approaches to boost the levels of SCFAs in the human gut and treat different related diseases