Effect of synbiotics on weight loss and metabolic health in adults with overweight and obesity: A randomized controlled trial

A comprehensive review of synbiotics: an emerging paradigm in health promotion and disease management

Synbiotics are complex preparations of prebiotics that can be selectively utilized by live microorganisms to improve host health. Synbiotics are divided into complementary synbiotics, which consist of probiotics and prebiotics with independent functions, and synergistic synbiotics, which consist of prebiotics that are selectively used by gut microorganisms. Complementary synbiotics used in human clinical trials include Lactobacillus spp. and Bifidobacterium spp. as probiotics, and fructooligosaccharides, galactooligosaccharides, and inulin as prebiotics. Over the past five years, synbiotics have been most commonly used in patients with metabolic disorders, including obesity, and immune and gastrointestinal disorders. Several studies have observed alterations in the microbial community; however, these changes did not lead to significant improvements in disease outcomes or biochemical and hematological markers. The same synbiotics have been applied to individuals with different gut environments. As a result, even with the same synbiotics, there are non-responders who do not respond to the applied synbiotics due to the different intestinal environment for each individual. Therefore, to obtain meaningful results, applying different synbiotics depending on the individual is necessary. Synergistic synbiotics are one solution to circumvent this problem, as they combine elements that can effectively improve health, even in non-responders. This review aims to explain the concept of synbiotics, highlight recent human clinical trials, and explore the current state of research on synergistic synbiotics.

An Update on Prebiotics and on Their Health Effects

Prebiotic compounds were originally defined as "a nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health"; however, a significant modulation of the definition was carried out in the consensus panel of The International Scientific Association for Probiotics and Prebiotics (ISAPP), and the last definition states that "prebiotics are substrates that are selectively utilized by host microorganisms conferring a health benefit". Health effects of prebiotics compounds attracted the interest of researchers, food companies and Regulatory Agencies, as inferred by the number of articles on Scopus for the keywords "prebiotic" and "health effects", that is ca. 2000, for the period January 2021-January 2024. Therefore, the aim of this paper is to contribute to the debate on these topics by offering an overview of existing knowledge and advances in this field. A literature search was performed for the period 2012-2023 and after the selection of the most relevant items, the attention was focused on seven conditions for which at least 8-10 different studies were found, namely colorectal cancer, neurological or psychiatric conditions, intestinal diseases, obesity, diabetes, metabolic syndrome, and immune system disorders. In addition, the analysis of the most recent articles through the software VosViewer version 1.6.20 pointed out the existence of five clusters or macro-categories, namely: (i) pathologies; (ii) metabolic condvitions; (iii) structure and use in food; (iv) immunomodulation; (v) effect on gut microbiota.