Prebiotics

The human gut microbiota, an intricate ecosystem within the gastrointestinal tract, plays a pivotal role in health and disease. Prebiotics, non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of beneficial microorganisms, have emerged as a key modulator of this complex microbial community. This review article explores the evolution of the prebiotic concept, delineates various types of prebiotics, including fructans, galactooligosaccharides, xylooligosaccharides, chitooligosaccharides, lactulose, resistant starch, and polyphenols, and elucidates their impact on the gut microbiota composition. We delve into the mechanisms through which prebiotics exert their effects, particularly focusing on producing short-chain fatty acids and modulating the gut microbiota towards a health-promoting composition. The implications of prebiotics on human health are extensively reviewed, focusing on conditions such as obesity, inflammatory bowel disease, immune function, and mental health. The review further discusses the emerging concept of synbiotics-combinations of prebiotics and probiotics that synergistically enhance gut health-and highlights the market potential of prebiotics in response to a growing demand for functional foods. By consolidating current knowledge and identifying areas for future research, this review aims to enhance understanding of prebiotics' role in health and disease, underscoring their importance in maintaining a healthy gut microbiome and overall well-being.

The trillions of microbes that constitute the human gut microbiome play a crucial role in digestive health, immune response regulation, and psychological wellness. Maintaining gut microbiota is essential as metabolic diseases are associated with it. Functional food ingredients potentially improving gut health include prebiotics, probiotics, synbiotics, and postbiotics (PPSPs). While probiotics are living bacteria that provide health advantages when ingested sufficiently, prebiotics are non-digestible carbohydrates that support good gut bacteria. Synbiotics work together to improve immunity and intestinal health by combining probiotics and prebiotics. Postbiotics have also demonstrated numerous health advantages, such as bioactive molecules created during probiotic fermentation. According to a recent study, PPSPs can regulate the synthesis of metabolites, improve the integrity of the intestinal barrier, and change the gut microbiota composition to control metabolic illnesses. Additionally, the use of fecal microbiota transplantation (FMT) highlights the potential for restoring gut health through microbiota modulation, reinforcing the benefits of PPSPs in enhancing overall well-being. Research has shown that PPSPs provide several health benefits, such as improved immunological function, alleviation of symptoms associated with irritable bowel disease (IBD), decreased severity of allergies, and antibacterial and anti-inflammatory effects. Despite encouraging results, many unanswered questions remain about the scope of PPSPs' health advantages. Extensive research is required to fully realize the potential of these functional food components in enhancing human health and well-being. Effective therapeutic and prophylactic measures require further investigation into the roles of PPSPs, specifically their immune-system-modulating, cholesterol-lowering, antioxidant, and anti-inflammatory characteristics.

Background/Objectives: Polycystic ovary syndrome is a common endocrine disorder in women of reproductive age characterized by insulin resistance and hormonal imbalances. Recent research suggests that probiotics and synbiotics may improve these parameters by modulating the gut microbiota. This study systematically reviewed randomized clinical trials evaluating the impact of probiotic, prebiotic, and synbiotic supplementation on insulin resistance and hormonal parameters in women with PCOS. Methods: Exhaustive searches were conducted in PubMed, Cochrane CENTRAL, Scopus, Web of Science, and Embase, following PRISMA guidelines. Randomized trials assessing supplementation with probiotics, prebiotics, or synbiotics for at least 8 weeks in women diagnosed with PCOS according to the Rotterdam criteria were included. Data on participants, interventions, and outcomes related to insulin resistance and hormones were extracted. Results: Eleven studies from Iran involving overweight or obese women aged 15 to 48 were included. Probiotic and synbiotic supplementation showed significant improvements in insulin resistance (reductions in HOMA-IR, fasting glucose, and insulin), lipid profiles (decreased LDL and triglycerides; increased HDL), and hormonal balance (increased SHBG, decreased total testosterone). Synbiotics had more pronounced effects than probiotics or prebiotics alone. Adherence was high, and side effects were minimal. Conclusions: Despite promising results, limitations such as small sample sizes, homogeneous populations, and short intervention durations limit the generalization of the findings. Larger, longer, multicenter trials with diverse populations and standardized methodologies are needed to confirm the efficacy and safety of synbiotics in managing PCOS. Integrating these interventions could improve clinical management and quality of life for affected women, but additional evidence is required to support widespread use.

An unhealthy diet disrupts feeding behavior and the gut microbiota, but whether early-life dietary effects persist, or can be restored later in life, remains unclear. We investigated whether microbiota-targeted interventions (FOS + GOS or Bifidobacterium longum APC1472) could restore early-life high-fat/high-sugar (HFHS) diet-induced feeding alterations in adult female and male mice. HFHS exposure exclusively in early-life induced persistent, sex-specific feeding alterations in adult mice, despite normalized body weight. Early-life HFHS diet reduced hypothalamic cells expressing feeding-related markers (POMC, GHSR, PNOC, NOD2) in adult mice. Females were more vulnerable, with reduced LEPR+ cells and disrupted arginine/tryptophan metabolism, while males showed impaired peptidoglycan sensing and steroid metabolism. We show that microbiota interventions restore these effects via distinct mechanisms. FOS + GOS induced extensive microbiome compositional shifts and sex-specific restoration of gut-brain pathways, while B. longum APC1472 induced greater behavioral restoration with minimal microbiome compositional changes. These findings highlight sex-specific vulnerabilities and mechanism-dependent therapeutic potential of microbiota-based interventions after exposure to early-life unhealthy diets.